Source: AGRICOLA database (1970-1996)

Ernst, E. and C. Stevinson (1999). New data on old herbal remedies. Perfusion . May 12(5): 192-194.

Herbal remedies are booming worldwide, This article briefly reviews our present knowledge regarding three of the most popular herbal drugs: echinacea, ginkgo biloba and hypericum. With all three, several open questions persist. It is concluded that herbal treatments can represent promising therapeutic options worthy of more research, particularly randomized clinical trials and systematic reviews.

Chung, H. S., A. Harris, et al. (1999). Ginkgo biloba extract increases ocular blood flow velocity. Journal Of Ocular Pharmacology And Therapeutics. Jun 15(3): 233-240.

We evaluated a possible therapeutic effect of Ginkgo biloba extract (GEE) on glaucoma patients that may benefit from improvements in ocular blood flow. A Phase I cross-over trial of GEE with placebo control in 11 healthy volunteers (8 women, 3 men: Age; 34 +/- 3 years, mean +/- SE) was performed. Patients were treated with either GEE 40 mg or placebo three times daily orally, for 2 days. Color Doppler imaging (Siemens Quantum 2000) was used to measure ocular blood flow before and after treatment. There was a two week washout period between GEE and placebo treatment.Ginkgo biloba extract significantly increased end diastolic velocity (EDV) in the ophthalmic artery (OA) (baseline vs GEE-treatment; 6.5 +/- 0.5 vs 7.7 +/- 0.5 cm/sec, 23% change, p=0.023), with no change seen in placebo (baseline vs GEE-treatment; 7.2 +/- 0.6 vs 7.1 +/- 0.5 cm/sec, 3 % change, p=0.892). No side effects related to GEE were found. Ginkgo biloba extract did not alter arterial blood pressure, heart rate, or IOP.Ginkgo biloba extract significantly increased EDV in the OA and deserves further investigation in ocular blood flow and neuroprotection for possible application to the treatment of glaucomatous optic neuropathy as well as other ischemic ocular diseases.

Ellnain, W. M. and G. Zgorka (1999). High-performance liquid chromatography and thin-layer chromatography of phenolic acids from Ginkgo biloba L-leaves collected within vegetative period. Journal Of Liquid Chromatography And Related Technologies 22(10): 1457-1471.

In this paper, thin-layer chromatography and highperformance liquid chromatography for the qualitative and quantitative analysis of phenolic acids in Ginkgo biloba L. leaves are described. The amounts of both free and bound phenolic acids were determined within the whole vegetative period. For this purpose, a special extraction procedure, comprising acid and alkaline hydrolyses, was used. The described method allowed us to identify and estimate the concentration levels of eight phenolic acids: protocatechuic, para-hydroxybenzoic, vanillic, caffeic, isovanillic, para-coumaric, ferulic, and sinapic.Depending on the part of the plant vegetation, significant differences in the content of the compounds examined were observed and discussed. The elaborated method could be used in studies on the seasonal distribution of phenolic acids in plant material.

Kimura, Y., S. Matsuo, et al. (1999). A new affinity chromatography using yeast invertase-sepharose 4B for purification of plant endo-beta-N-acetylglucosaminidases. Bioscience Biotechnology And Biochemistry. May 63(5): 948-950.

For the purification of plant endo-beta-N-acetylglucosaminidase, in this report, we introduce a new affinity chromatography using the reduced and carboxymethylated yeast invertase (cm-YI) as a ligand. Two plant endo-8-N-acetylglucosaminidases (endo-LE from tomato fruits (Kimura, Y., et al. Biochim. Biophys. Acta 1381, 27-36 (1998)) and endo-GB from Ginkgo biloba seeds (Kimura, Y,, et al, Biosci. Biotechnol, Biochem., 62, 253-261 (1998)) could completely bind to the high-mannose type N-glycans linked to the immobilized yeast invertase and the activities of both enzymes could be recovered by increasing the concentration of NaCl, By using this purification procedure with some other purification procedures, endo-LE could be purified 1,700-fold and endo-GB was purified to apparent homogeneity at 63 kDa as reported previously.

Janssens, D., J. Remacle, et al. (1999). Protection of mitochondrial respiration activity by bilobalide. Biochemical Pharmacology. Jul 58(1): 109-119.

Mitochondria alteration is an early event in ischemia-induced damage, and its prevention improves tissue survival upon reperfusion. Adenine translocase and complex I activities are rapidly affected by ischemia. Ginkgo biloba extract demonstrates anti-ischemic properties attributable to the terpenoid fraction, mainly due to the presence of bilobalide. The mechanism of the protection afforded by bilobalide is not yet known. In this work, the effects of bilobalide on mitochondrial respiration were investigated. Mitochondria isolated from rats treated with bilobalide (2 to 8 mg/kg) showed a dose-dependent increase in the respiratory control ratio, due to a lower oxygen consumption during state 4. Bilobalide also decreased the sensitivity of oxygen consumption to inhibition of complex I by Amytal or to inhibition of complex III by antimycin A or myxothiazol. There was no protection of complexes IV and V. It also increased the activity of complex I but not of adenine translocase. Similar effects were also obtained in vitro when control mitochondria were preincubated for 1 hr with 0.8 mu g/mL bilobalide. Treatment of the rats with 8 mg/kg bilobalide also prevented the ischemia-induced decrease in state 3 of the mitochondrial respiration and thus the decrease in RCR. The protective effect of bilobalide on cellular ATP content observed under ischemic conditions can be correlated with the above observations. By protecting complex I and III activities, bilobalide allows mitochondria to maintain their respiratory activity under ischemic conditions as long as some oxygen is present, thus delaying the onset of ischemia-induced damage. This mechanism provides a possible explanation for the anti ischemic properties of bilobalide and of Ginkgo biloba extract in therapeutic interventions. BIOCHEM PHARMACOL 58;1: 109-119, 1999. (C) 1999 Elsevier Science Inc.

Pryse, P. W. (1999). Do we have drugs for dementia? No. Archives Of Neurology. Jun 56(6): 735-737.

Tateyama, S., R. Wititsuwannakul, et al. (1999). Dolichols of rubber plant, ginkgo and pine. Phytochemistry . May 51(1): 11-15.

Using a two-plate thin-layer chromatography method, we analyzed polyisoprenoid alcohols (dolichols and polyprenols) of the rubber plant Hevea brasiliensis (angiosperm), and of ginkgo Ginkgo biloba and pine Pinus sylvestris (gymnosperms). Special attention was paid to the occurrence of dolichol in various tissues of different plants. Dolichols were found to occur in all of the tissues examined except for flowers of the rubber plant. The chain length distributions of dolichols in seeds,young roots, young shoots, young leaves and old leaves of the rubber plant were C-70-C-95, C-85-C-105, C-80-C-105, C-75-C-105 and C-65-C-90, respectively. In the case of ginkgo, the chain length distributions of dolichols in seeds, embryos, young and old leaves were C-70-C-90, C-70-C-85, C-70-C-90 and C-80-C-95, respectively. Pine seeds were found to contain dolichols with the chain length distribution of C-70-C-90. Two kinds of polyprenol families were detected in leaves of the rubber plant and ginkgo. The longer chain polyprenol family was also detected in seeds of the rubber plant, in seeds and embryos of ginkgo and in seeds of pine. The chain length distributions of the polyprenols were not necessarily the same as those of dolichols occurring in the same tissues. (C) 1999 Elsevier Science Ltd. All rights reserved.

Xu, J. P., Y. C. Rui, et al. (1999). Antagonistic effects of Ginkgo biloba extract on adhesion of monocytes and neutrophils to cultured cerebral microvascular endothelial cells. Acta Pharmacologica Sinica. May 20(5): 423-425.

AIM: To study the action of Ginkgo biloba extract (GbE) on tumor necrosis factor (TNF-alpha)-induced adhesion of monocytes (Mon) and neutrophils (Neu) to cultured cerebral microvascular endothelial cells. METHODS: TNF-alpha-induced endothelial adhesivity toward Mon and Neu was studied using bovine cerebral microvascular endothelial cells (BCMEC) in vitro. The number of Mon and Neu adhering to the BCMEC monolayers was determined by flow cytometry. RESULTS: Pretreatment of BCMEC with TNF-alpha increased Mon and Neu adhesion to BCMEC from 12.5% +/- 0.2% to 31.3% +/- 0.5% and from 13.8% +/- 0.4% to 32.1% +/- 0.5%, respectively. GbE (1-100 mg.L-1) inhibited the effect of TNF-alpha in a concentration-dependent manner. E-selectin mAb (1 mg.L-1) blocked Mon and Neu adhesion to BCMEC induced by TNF-alpha. CONCLUSION: The inhibition of GbE on Mon and Neu adhesion to BCMEC was mediated through the suppression of E-selection expression.

Gajewski, A. and S. A. Hensch (1999). Ginkgo biloba and memory for a maze. Psychological Reports. Apr 84(2): 481-484.

A number of sources suggest that the natural herb ginkgo biloba enhances mental sharpness by increasing blood now to the brain. A preliminary study was designed to examine whether memory for a maze would be enhanced in 5 mice who received a dietary supplement containing ginkgo biloba. The mice showed an improved memory for the maze as evidenced by a decrease in the number of errors in reaching the goal box when they received gingko biloba as a dietary supplement.

Carrier, D. J., B. T. A. van, et al. (1999). Distribution of ginkgolides and terpenoid biosynthetic activity in Gingko biloba (vol 48, pg 89, 1998). Phytochemistry . Apr 50(8).

Chang, J. (1999). Scientific evaluation of traditional Chinese medicine under DSHEA: A conundrum. Journal Of Alternative And Complementary Medicine. Apr 5(2): 181-189.

In the United States, traditional Chinese medicines (TCM) are currently sold as dietary supplements, as defined by The Dietary Supplement Health and Education Act (DSHEA). This legislation is unique to the United States and while "structure and function" claims are allowable under DSHEA, disease claims are not. The narrow definition, however, poses a challenge to designing appropriate clinical studies that can provide data for "structure and function" claim substantiation. The process of melding Chinese herbal medicines into the dietary supplement category is complex and there is a need to define a clinical trial paradigm carefully that addresses "structure and function claims" without sacrificing scientific rigor. It is frequently not recognized that TCM favors an amalgamation of several herbs to generate the putative clinical effect. Because of this historical multiherb approach, the reliance on retrospective data to support the potential health benefits of an herb extract has severe limitations. Notwithstanding the immense value of identifying the pharmacological activity of a TCM herb to a chemical suitable for pharmaceutical development, another approach to safe and efficacious herbal products is to develop a standardized herbal extract. This article highlights issues related to the latter approach and will discuss a research-based strategy that may be suitable for validating, in part, the putative health benefits of TCM.

Ranchon, I., J. M. Gorrand, et al. (1999). Functional protection of photoreceptors from light-induced damage by dimethylthiourea and Ginkgo biloba extract. Investigative Ophthalmology And Visual Science. May 40(6): 1191-1199.

PURPOSE. To investigate the functional protective effect of a synthetic (dimethylthiourea, DMTU) and a natural antioxidant (Ginkgo biloba extract, EGb 761) against light-induced retinal degeneration.METHODS. Wistar rats were exposed for 24 hours to 1700-lux light after treatment with DMTU or EGb 761. Electroretinograms were recorded before and on day (D)1, D3, D8, D15, D22, and D29 after light exposure. The b-wave amplitude was plotted against log L (ganzfeld luminance), providing the b-wave sensitivity curve. The Naka-Rushton function fitted to the sensitivity curve enabled derivation of the parameters B-max (saturated amplitude) and K (luminance-inducing B-max/2). In addition, rats from each group were killed for retinal morphometric analyses.RESULTS. In the untreated group, light exposure caused collapse of the b-wave sensitivity curves. B-max was reduced by 51% at DI without subsequent recovery. K increased temporarily, reverting to normal Values 8 days later. The outer nuclear layer thicknesses decreased markedly in the superior retina. In the treated groups, light exposure had a weaker effect on sensitivity curves. The values of B-max were not significantly different from those in the unexposed-untreated group, although K increased temporarily. Retinal morphometry was preserved.CONCLUSIONS. Dimethylthiourea and EGb 761 afford functional protection against Light-induced retinal damage.

Wolff, R. L., F. Pedrono, et al. (1999). The seed fatty acid composition and the distribution of Delta 5-olefinic acids in the triacylglycerols of some Taxares (Cephalotaxus and Podocarpus). Journal Of The American Oil Chemists Society. Apr 76(4): 469-473.

The fatty acid compositions of the seeds from four Cephalotaxus species or varieties (plum yews; Cephalotaxaceae) and two Podocarpus species (podocarps; Podocarpaceae) have been established. These compositions were compared with those previously published for some Taxaceae species (Taxus and Torreya). Cephalotaxaceae; Podocarpaceae, and Taxaceae belong to the Taxares suborder. Delta 5-Olefinic acids are present in the seed lipids from all species analyzed. In Cephalotaxus, Podocarpus, and Torreya, the prominent Delta 5-olefinic acid that occurs is the trienoic acid 5,11,14-20:3 (sciadonic) acid, comprising from 6.7 to 26.4% of total fatty acids. In these species, the Delta 5,11 structure is largely favored over the Delta 5,9 structure: the 5,9-18:2 (taxoleic) and 5,9,12-18:3 (pinolenic) acids are at the limit of detection, in contrast to Taxus and most Pinaceae species, where these two Delta 5-olefinic acids generally predominate. 14-Methylhexadecanoic acid, an habitual though minor component of Pinaceae and Ginkgo biloba seed lipids, could not be detected in Cephalotaxus species studied here and was tentatively identified in trace amounts only in one Podocarpus species. In addition to sciadonic acid, Cephalotaxus and Podocarpus seeds are characterized by unusually high amounts of 11,14-20:2 acid, in the range of 3.1-12.0%. This contrasts with most of the 170 species of conifers analyzed so far (from the families Pinaceae, Cupressaceae, Taxodiaceae, Taxaceae, and Sciadopityaceae, which belong to the Pinares suborder), where this acid is generally less than or equal to 2%. A close resemblance between Torreya grandis and three of the Cephalotaxus species analyzed might be indicative of some phyletic relationship between the families Cephalotaxaceae and Taxaceae. C-13 nuclear magnetic resonance spectroscopy of the seed oils from C. drupaceae and P. andinus has shown that Delta 5-olefinic acids are apparently excluded from the internal position of triacylglycerols, which is a characteristic common to all Coniferales species analyzed so far, and consequently of great antiquity.

Fitzl, G., R. Martin, et al. (1999). Protective effects of Ginkgo biloba extract EGb 761 on myocardium of experimentally diabetic rats - I: Ultrastructural and biochemical investigation on cardiomyocytes. Experimental And Toxicologic Pathology. May 51(3): 189-198.

Chronic diabetes in man and animal models develops cardiomyopathic alterations which cannot be absolutely avoided by insuline therapy. Since diabetic damage is part ly attributed to oxidative stress antioxidative treatment could be able to reduce the alterations. Aim of this study was to investigate the cardioprotective effects of EGb 761, Known as a radical scavenger, against diabetic alterations in rats.The diabetes was induced by i.p. injection of 60 mg/kg body weight streptozotocin. Duration of diabetes was 4 months, the protected group received 100 mg/kg body weight EGb 761 with the drinking water over 3 months.Electron and light microscopic morphometry of left-ventricular samples revealed typical diabetic alterations consisting in decrease of volume fraction of myofibrils, SR and t-tubules and diminishing of cardiomyocyte diameter, increase of interstitial volume, mitochondrial size and volume fraction, and of vacuoles and of lipid drops. EGb treat ment could gradually prevent the loss of myofibrils and reduction of myocyte diameter but has only little influence on interstitial and mitochondria volume. The diabetic-induced increase of lipid and vacuoles and the decrease of SR and t-tubules were not influenced.Biochemical parameters of oxidative stress: malondialdehyde (MDA) was only insignificantly altered by diabetes and EGb. The superoxide dismutase (SOD) activity was in creased by diabetes and more increased by EGb treatment. Creatine kinase (CK) activity was diminished by diabetes but slightly increased by EGb. The polymerase chain reaction (PCR) of i-NOS was not different between the diabetic and protected diabetic groups.

Welt, K., J. Weiss, et al. (1999). Protective effects of Ginkgo biloba extract EGb 761 on the myocardium of experimentally diabetic rats - II. Ultrastructural and immunohistochemical investigation on microvessels and interstitium. Experimental And Toxicologic Pathology. May 51(3): 213-222.

Interstitial and microvascular disorders are known as a characteristic part of the diabetic cardiomyopathy and to resist partly insulin therapy. Aim of this study was to demonstrate structure-protecting effects of Ginkgo Extract EGb 761 known as a natural radical scavenger in streptozotocin-diabetic rats on the microvascular compartment.Wistar rats (n = 5) were made diabetical by i.p. injection of 60 mg/kg body mass streptozotocin for 4 months. Rats of the protected group (n = 5) received daily 100 mg/kg body mass EGb 761 for 3 months, starting 1 month after induction of diabetes. 5 age-matched rats served as control.The volume fraction of interstitium was slightly but significantly increased only in the unprotected diabetic group. Diminishing of the capillary to the myocyte ratio was seen in the diabetic but not in the protected group.Immunostaining of collagen revealed a slight increase of type Ill, type IV, and type VI fibres in the interstitium, more expressed in the unprotected group. Ultrastuctural morphometry revealed significant thickening of endothelial and muscular basement membranes in diabetic animals, less expressed in the EGb- protected group. The capillary diameter was slightly increased in the diabetic and slightly decreased in the protected group. The number of plasmalemmal vesicles was tendentially more decreased, that of lysosomes more increased in the diabetic than in the protected group.It is concluded that EGb 761 can diminish partly interstitial fibrosis and reduce endothelial and muscular basement membrane thickening of the diabetic myocardium. It may contribute to prevent late diabetic complications.

Ernst, E. and M. H. Pittler (1999). Ginkgo biloba for dementia - A systematic review of double-blind, placebo-controlled trials. Clinical Drug Investigation. Apr 17(4): 301-308.

Objective: To systematically review the clinical evidence of Ginkgo biloba preparations as a symptomatic treatment for dementia.Methods: Computerised literature searches were performed to identify all double-blind, randomised, placebo-controlled trials assessing clinical end-points of Ginkgo biloba extract as a treatment for dementia. Databases included Medline, Embase, Biosis and the Cochrane Library. There were no restrictions regarding the language of publication. Data were extracted in a standardised, predefined fashion, independently by both authors.Results: Nine double-blind, randomised, placebo-controlled trials met the inclusion criteria and were reviewed. These studies are of varying methodological quality. They collectively suggest that Ginkgo biloba extract is more effective for dementia than placebo. However, a number of caveats pertain. Few, generally mild, adverse effects were reported.Conclusion: These findings are encouraging and warrant independent, large scale confirmatory and comparative trials.

Tommasi, F., C. Paciolla, et al. (1999). The ascorbate system in recalcitrant and orthodox seeds. Physiologia Plantarum. Feb 105(2): 193-198.

Recalcitrant seeds of Ginkgo biloba L,, Quercus cer I is L,, Aesculus hippocastanum L, and Cycas revoluta Thunb, are shed bgl the plant at a high moisture content, contain a large amount of ascorbic acid (ASA) and maintain high ascorbate (ASC) peroxidase (EC 1.11.1.11) activity. Three proteins showing ASC peroxidase activity are present in G, biloba seeds. Conversely, dry orthodox seeds (Vicia faba L,, Avena sativa L,, Pinus pinea L.) are completely devoid of ASA and ASC peroxidase. Experimentally induced rapid variations of the mater Iel el in both recalcitrant and orthodox seeds do not affect the ASC peroxidase; slow dehydration affects the ASC peroxidase activity moderately in recalcitrant seeds, but provokes a complete loss of germinability. Another peculiar difference between orthodox and recalcitrant seeds concerns the ascorbate recycling enzymes, ascorbate free radical (AFR) reductase (EC 1.6.5.4) and dehydroascorbate (DHA) reductase (EC 1.8.5.1), The DHA reduction capability is lo in recalcitrant seeds, but is high in the orthodox ones. In contrast, AFR reductase activity is high in recalcitrant seeds and low in the orthodox ones. Data reported here concerning the ASC system appear to contribute to better understanding the recalcitrance. The presence of three different proteins showing ASC peroxidase activity in the archaic seed-bearing plant G. biloba and its involvement in the spermatophyte evolution is discussed.

Ott, B. R. and N. J. Owens (1998). Complementary and alternative medicines for Alzheimer's disease. Journal Of Geriatric Psychiatry And Neurology. Win 11(4): 163-173.

The recent successes of large, multicenter clinical trials of acetylcholinesterase inhibitors for symptomatic treatment of Alzheimer's disease have spawned enthusiasm that this common and fatal neurologic disease is "treatable." A parallel explosion has occurred in the consumption of alternative medicines by the public seeking more effective, natural, or safer methods for treatment of dementia. Some of these medicines may, in fact, be biologically active in modulating the disease as well as producing side effects and interactions with accepted pharmaceuticals. This review brings to focus the scientific evidence presently available regarding such agents.

Kimura, Y., T. Harada, et al. (1999). Purification and some chemical properties of 30 kDa Ginkgo biloba glycoprotein, which reacts with antiserum against beta 1 -> 2 xylose-containing N-glycans. Bioscience Biotechnology And Biochemistry. Mar 63(3): 463-467.

From the seeds of Ginkgo biloba, a glycoprotein, which is a major component that reacts with an antiserum against beta 1-->2 xylose-containing N-glycans, has been purified and characterized, The N-terminal amino acid sequence of the purified glycoprotein was H-K-A-N-X-V-T-V-A-F-V-M-T-Q-H-L-L-F-G-Q-. The molecular mass was estimated to be 17 kDa and 16 kDa by SDS-PAGE under reducing conditions, however, the molecular mass of this glycoprotein in the native state was 30,762 by MALDI-TOF MS, suggesting that this glycoprotein consists of two subunits; one is glycosylated and the other is not. The structure of N-glycan linked to this glycoprotein (designated 30 kDa GBGP) was identified as Man(3)Fuc(1)Xyl(1)GlcNAc(2), which is the predominant N-glycan linked to the storage glycoproteins in the same seeds (Kimura, Y et al, (1998) Biosci. Biotechnol, Biochem, 62, 253-261). From the peptic digest of the carboxymethylated glycosylated subunit, one glycopeptide was purified by RP-HPLC and the amino acid sequence was identified as H-K-A-N-N(Man(3)Fuc(1)Xyl(1)GlcNAc(2))-V-T-Y-A-F, which corresponded to the N-terminal amino acid sequence.

Biber, A. and E. Koch (1999). Bioavailability of ginkgolides and bilobalide from extracts of Ginkgo biloba using GC/MS. Planta Medica. Mar 65(2): 192-193.

The bioavailability of ginkgolides A, B and bilobalide was studied in rats after single oral administration of 30, 55 and 100 mg/kg Ginkgo extract EGb 761(R). The plasma levels of the terpene lactones were measured by a specific GC/MS method. The pharmacokinetics of the mentioned substances were found to be dose-linear. For the lowest dose maximum concentrations were 68, 40 and 159 ng/ml and half-lives 1.7, 2.0 and 2.2 h for ginkgolide A, B and bilobalide, respectively, Clearance values ranged from 24.2 to 37.6 ml/min/kg.

Chen, C., T. T. Wei, et al. (1999). Different effects of the constituents of EGb761 on apoptosis in rat cerebellar granule cells induced by hydroxyl radicals. Biochemistry And Molecular Biology International. Mar 47(3): 397-405.

The present study was conducted to evaluate the different effects of the constituents of EGb761(Ginkgo biloba Extract) on apoptosis in cerebellar granule cells induced by hydroxyl radicals. The total flavonoid component of EGb761, two pure EGb761 components (rutin and quercetin), and a mixture of flavonoids and terpenes protected cerebellar granule cells from oxidative damage and apoptosis induced by hydroxyl radicals. ESR(electron spin resonance) results showed that the IC,, of the flavonoids for scavenging hydroxyl radicals was almost the same as that of EGb761, even though flavonoids make up only 24% of EGb761, implying that other constituents of EGb761 besides flavonoids can scavenge hydroxyl radicals. Total terpenes of EGb761 did not protect against apoptosis. Flavonoids and terpenes did not show a synergistic effect in this regard. Terpenes did not scavenge hydroxyl radicals directly, which might be related to their "cage-like" structures.

Wu, L. S. H., G. H. H. Hong, et al. (1999). Classification of the single oleosin isoform and characterization of seed oil bodies in gymnosperms. Plant And Cell Physiology. Mar 40(3): 326-334.

Oleosins are hydrophobic proteins abundantly present in the oil bodies of plant seeds. Two immunologically distinct oleosins are present in seed oil bodies of diverse angiosperms, and classified as high and low M-r isoforms according to their relative molecular masses in each species. Only one putative oleosin was found in seed oil bodies of three representative gymnosperm species, Pinus kouaiensis, Ginkgo biloba, and Cycas revoluta. The three gymnosperm oleosins were restricted to oil bodies, as detected on immune-assaying. Immunological cross-recognition using antibodies against the three putative gymnosperm oleosins and those against the two (high and low M-r) rice oleosin isoforms suggests that the single oleosin of pine or ginkgo is immunologically related to the low M-r isoform of angiosperms, while the single cycad oleosin is immunologically distinct from both low and high M-r isoforms of angiosperms. Oil bodies were found in embryos and megagametophytes of these three species, as observed on electron microscopy. Seed oil bodies purified from these three gymnosperms maintained their integrity via electronegative repulsion and steric hindrance on the surface of the organelles. The compositions of the three essential constituents (neutral lipid, phospholipid and protein) in seed oil bodies from these three species were determined and compared with those calculated from the oil body model proposed in angiosperms, The results suggested that seed oil bodies of gymnosperms and angiosperms possess similar surface properties and structural organization.

Pierre, S., I. Jamme, et al. (1999). Ginkgo biloba extract (EGb 761) protects Na,K-ATPase activity during cerebral ischemia in mice. Neuroreport . Jan 10(1): 47-51.

NEUROPROTECTIVE drugs such as Ginkgo biloba extract (EGb 761) could prevent the ischemia-induced impairment of the Na,K-ATPase activity. In this study, Na,K-ATPase activity and expression, contents in fatty acids and malondialdehyde, an index of lipoperoxidation, were compared in the ipsilateral (ischemic) and the contralateral (unlesioned) cortices after Ih of unilateral focal cortices cerebral ischemia in the mouse. EGb 761 (100 mg/kg) was administered daily to half of the animals for 10 days before ischemia. Ischemia significantly reduced Na,K-ATPase activity by about 40% and increased malondialdehyde content; EGb 761 pretreatment abolished these effects. The free radical scavenger properties of EGb 761 are a potential mechanism by which Na,K-ATPase injury and lipoperoxidation are prevented. (C) 1999 Lippincott Williams and Wilkins.

Kim, G. H., S. M. Kang, et al. (1999). Laboratory evaluation of selected anti-stain chemicals for control of fungal staining on Ginkgo sapwood. Forest Products Journal. Mar 49(3): 49-52.

The susceptibility of Ginkgo sapwood to fungal attack and the ability of selected anti-stain chemicals to control colonization of sapstain and mold fungi on green Ginkgo sapwood were evaluated. Ginkgo sapwood was very susceptible to fungal staining, suggesting that prompt application of anti-stain chemicals after sawing will be essential for preventing fungal colonization. The ability of eight chemicals to prevent fungal discoloration of Ginkgo sapwood was evaluated using a small-scale laboratory procedure. NexGen provided excellent protection against stain and mold. NP-1 Plus, PQ-8, and Busan 1030 provided good short-term protection (4 wk), but higher chemical loadings were required for long-term protection (6 wk.). Britewood Q, Britewood S, Britewood XL, and Nytek-GD provided little or no protection over the test period.

Lugasi, A., P. Horvahovich, et al. (1999). Additional information to the in vitro antioxidant activity of Ginkgo biloba L. Phytotherapy Research. Mar 13(2): 160-162.

The in vitro antioxidant and free radical scavenging activity of the ethanol extract from Ginkgo biloba L. was examined in different systems. The extract showed hydrogen-donating ability, reducing power, copper-binding property, free radical scavenging activity in a H2O2/. OH-luminol system and it could prevent the autoxidation of linoleic acid. All these properties are involved in the overall antioxidant activity of Ginkgo biloba which makes it suitable for the prevention of human disease in which free radicals play an important role. Copyright (C) 1999 John Wiley and Sons, Ltd.

Wolff, R. L., W. W. Christie, et al. (1999). Reinvestigation of the polymethylene-interrupted 18 : 2 and 20 : 2 acids of Ginkgo biloba seed lipids. Journal Of The American Oil Chemists Society. Feb 76(2): 273-276.

The fatty acid composition of Ginkgo biloba seed lipids was reinvestigated with particular emphasis on the polymethylene-interrupted octadecadienoic and eicosadienoic acids. Analysis of the picolinyl esters and 4,4-dimethyloxazoline derivatives by capillary gas-liquid chromatography on a highly polar cyanopropyl polysiloxane stationary phase coupled with mass spectrometry revealed the presence of three such acids, with the structures 5,9-18:2, 5,11-18:2, and 5,11-20:2. This indicated that in G. biloba seeds, cis-vaccenic (11-18:1) acid may be a substrate for the Delta 5-desaturase characteristic of gymnosperms. The 5,11-18:2 acid was not limited to G. biloba, as it may occur in a few other species. The 5,11-20:2 acid is a common component of the seed lipids from almost all gymnosperm species analyzed so far.

Cupp, M. J. (1999). Herbal remedies: Adverse effects and drug interactions. American Family Physician. Mar 59(5): 1239-1244.

A growing number of Americans are using herbal products for preventive and therapeutic purposes. The manufacturers of these products are not required to submit proof of safety and efficacy to the U.S. Food and Drug Administration before marketing. For this reason, the adverse effects and drug interactions associated with herbal remedies are largely unknown. Ginkgo biloba extract, advertised as improving cognitive functioning, has been reported to cause spontaneous bleeding, and it may interact with anticoagulants and antiplatelet agents. St. John's wort, promoted as a treatment for depression, may have monoamine oxidase-inhibiting effects or may cause increased levels of serotonin, dopamine and norepinephrine. Although St. John's wort probably does not interact with foods that contain tyramine, it should not be used with prescription antidepressants. Ephedrine-containing herbal products have been associated with adverse cardiovascular events, seizures and even death. Ginseng, widely used for its purported physical and mental effects, is generally well tolerated, but it has been implicated as a cause of decreased response to warfarin. Physicians must be alert for adverse effects and drug interactions associated with herbal remedies, and they should ask all patients about the use of these products.

Punkt, K., I. Psinia, et al. (1999). Effects on skeletal muscle fibres of diabetes and Ginkgo biloba extract treatment. Acta Histochemica. Feb 101(1): 53-69.

Combined cytophotometric and morphometric analysis of muscle fibre properties and myosin heavy chain electrophoresis were performed on extensor digitorum longus and soleus muscles from healthy rats and rats with streptozotocin-induced diabetes. Moreover, the protective effect of Ginkgo biloba extract, a potent oxygen radical scavenger, on diabetic muscles was investigated. Changes in fibre type-related enzyme activities, fibre type distribution, fibre cross areas and myosin isoforms were found. In muscles of diabetic rats, a metabolic shift was measured mainly in fibres with oxidative metabolism. Fast-oxidative glycolytic fibres showed a shift to more glycolytic metabolism and about a third transformed into fast-glycolytic fibres. Slow-oxidative fibres became more oxidative. Fibre atrophy was measured in diabetic muscles dependent on fibre type and muscle. Different fibre types atrophied to a different degree. Therefore, a decreased area percentage of slow fibres and an increased area percentage of fast fibres of the whole muscle cross section in both muscles were found. This is supported by reduced slow and increased fast myosin heavy chain isoforms. These alterations of diabetic muscle fibres could be due to less motion of diabetic rats and diabetic neuropathy. After treatment with Ginkgo biloba extract, enzyme activities were increased mainly in oxidative fibres of diabetic muscles, which was interpreted as protective effect. Generally, the soleus muscle with predominant oxidative metabolism was more vulnerable to diabetic alterations and Ginkgo biloba extract treatment than the extensor digitorum longus muscle with predominant glycolytic metabolism.

Chen, F., S. Yasuda, et al. (1999). Evidence for a novel biosynthetic pathway that regulates the ratio of syringyl to guaiacyl residues in lignin in the differentiating xylem of Magnolia kobus DC. Planta . Feb 207(4): 597-603.

The biosynthetic pathways to monolignols in Magnolia kobus were investigated by feeding stems with a deuterium-labeled precursor. Pentadeutero [gamma,gamma-H-2(2), (OCH3)-H-2] coniferyl alcohol was supplied to shoots of Magnolia kobus and the incorporation of the labeled precursor into lignin was traced by gas chromatography-mass spectrometry. In addition to the direct incorporation of the labeled precursor into guaiacyl units, we detected a significant amount of pentadeuterium-labeled syringyl units with two gamma-deuterium atoms. The relative level of trideuterium-labeled syringyl monomers (the result of conversion via the cinnamic acid pathway, in which two gamma-deuterium atoms are removed during enzymatic re-oxidation) was negligible. Our results provide conclusive evidence for a novel alternative pathway for generation of lignin subunits at the monolignol stage and they suggest that this new pathway might be important for regulation of the composition of lignin.

Maurer, K., R. Ihl, et al. (1998). Clinical efficacy of Ginkgo biloba special extract EGb 761 in dementia of the Alzheimer type. Phytomedicine . Dec 5(6): 417-424.

Among the psychiatric illnesses associated with old age primary degenerative dementia of the Alzheimer type (DAT) has gained increasing importance in recent years. Even though a curative treatment of the disease is currently impossible, various drugs can be used to slow down its progression. In the present study the influence of oral treatment with 240 mg/day of Ginkgo biloba special extract EGb 761 (Tebonin(R) forte, manufactured by Dr. Willmar Schwabe, Karlsruhe) on the clinical course of DAT was investigated in a double-blind, randomized, placebo-controlled parallel-group design in 20 outpatients. The duration of treatment was 3 months. The primary outcome variable was the sum score in the SKT-test for the determination of attention and memory. Other psychometric tests (trailmaking test, ADAS, CGI) and electrophysiological investigations (EEG topography) were evaluated descriptively. Although the active-treatment group, with a mean sum score of 19.67 points in the S.K.T., had a poorer baseline level than the placebo group (18.11 points), it experienced an improvement to 16.78 points under treatment with EGb 761 whereas the placebo group deteriorated to 18.89 points. The differences between the baseline and final values formed the basis for a statistical group comparison, which gave a result favourable to EGb 761, at a significance level of p < .013. In addition to this psychometric confirmation of efficacy, certain descriptive trends were found at the psychopathological (Clinical Global Impression) and dynamic functional (EEG findings) levels, which can be interpreted as evidence of effectiveness of Ginkgo biloba special extract EGb 761 in mild to moderate dementia and of local effects in the central nervous system. Inter-group differences in the ADAS cognitive and non-cognitive subscales did not reach statistical significance, probably because of the small sample size.

Brautigam, M. R. H., F. A. Blommaert, et al. (1998). Treatment of age-related memory complaints with Ginkgo biloba extract: a randomized double blind placebo-controlled study. Phytomedicine . Dec 5(6): 425-434.

A growing number of people is subject to age-related cognitive impairment due to the proportional increase of the ageing population. Therefore, there is a growing interest in cognition-enhancing substances. The efficacy of an alcohol/water extract of Ginkgo biloba in elderly individuals with memory- and/or concentration complaints was tested in a randomized, double-blind, placebo-controlled study by using both subjective and objective parameters.After a wash-out period of 4 weeks 241 non-institutionalised patients in the age range 55-86 years were randomly allocated to receive either Ginkgo biloba alcohol/water extract in a high dose (HD), a low dose (LD) or a placebo (PL) for 24 weeks. Patients were assessed using a psychometric testbattery in the following order: Expended Mental Control Test (EMCT) measuring attention and concentration, Benton Test of Visual Retention-Revised (measures short term visual memory), Rey Test part 1 (measures short term memory and learning curve), Beck Depressive Inventory (BDI) measuring the presence and severeness of a depression in order to exclude depressive patients and Rey Test part 2 (measures long term memory: recognition). Furthermore, subjective perception of memory and concentration was measured. 197 patients completed the study (mean MMSE score: 26.29).In the subjective test, the EMCT, the Rey 1 and Rey 2 no significant differences in improvement in time between the groups were observed. In the Benton test increases of 18%, 26% and 11% (expressed as percentage of baseline scores) were observed in the HD, LD and PL respectively (MANOVA; p = 0.0076). No substantial correlation was observed between subjective perception of the severeness of memory complaints and the objective test results. No differences in the number of (gastrointestinal) side effects were observed between placebo and verum groups.These results indicate that the use of Ginkgo extracts in elderly individuals with cognitive impairment might be promising. Further research using both subjective and objective measurements is recommended.

Schulz, H., M. Jobert, et al. (1998). The quantitative EEG as a screening instrument to identify sedative effects of single doses of plant extracts in comparison with diazepam. Phytomedicine . Dec 5(6): 449-458.

Two multiple crossover studies, each involving 12 adult female subjects, were performed to screen for acute sedative effects of eight different plant extracts (Valeriana off., Lavandula off., Passiflora incarnata, Kava-kava, Melissa off., Eschscholzia californica, Hypericum perforatum and Ginkgo biloba). Both studies were placebo-controlled, and a single dose of 10 mg diazepam was used as an active reference drug. All drugs were administered as a single dose. Prior to administration, as well as 2 h and 3 h after administration the EEG was recorded from two leads (F-z-C-z and O-z-T-6) under vigilance-controlled and resting conditions, for five minutes each. The extend of tiredness was rated by the subjects on a visual analogue scale. The EEG was digitized and stored for later analysis of the absolute and relative power of seven factorially defined frequency bands.Under diazepam the power in the theta frequency band decreased while it increased in the beta band. In contrast, some plant extracts showed an increase of power in the theta frequency band, but no increase in the beta frequency range. Valerian extract, which was administered in both studies, displayed an increase of power in the delta and theta band and a decrease in the beta band. Self-rated tiredness increased under diazepam and under some of the plant extracts but not with placebo. The results show that sedating effects of plant extracts can be identified by quantitative EEG analysis and by self-assessment instruments.

Kozubek, A. and J. H. P. Tyman (1999). Resorcinolic lipids, the natural non-isoprenoid phenolic amphiphiles and their biological activity. Chemical Reviews. Jan 99(1): 1-25.

Landsberg, G. (1999). Identification and medical management of cognitive dysfunction syndrome and other geriatric behavior problems. Veterinary Medicine. Feb: 2-19.

Winter, J. C. and D. Timineri (1999). The discriminative stimulus properties of EGb 761, an extract of Ginkgo biloba. Pharmacology Biochemistry And Behavior. Mar 62(3): 543-547.

Stimulus control was established in a group of nine rats using a dose of EGb 761 of 10 mg/kg, administered IF, 15 min before training. A two-lever operant task using a fixed-ratio 10 schedule of sweetened milk reinforcement was used. Based upon a criterion for the presence of stimulus control of five consecutive sessions during which 83% or more of all responses were on the appropriate lever, a mean of 24 sessions was required to reach criterion performance. Subsequently, it was observed that EGb 761-induced stimulus control is significantly antagonized by the selective S-HT1A antagonist WAY 100635, but is unaffected by the 5-HT2 antagonist pirenperone. Furthermore, EGb 761 generalized to the selective 5-HT1A agonist, 8-hydroxy-dipropylaminotetralin [8-OH-DPAT], and this generalization was blocked by WAY-100635. The present results indicate that EGb 761 is able to induce stimulus control when administered via the intraperitoneal route, and that its stimulus effects are mediated in part by activity at the 5-HT1A receptor. (C) 1999 Elsevier Science Inc.

Ondrizek, R. R., P. J. Chan, et al. (1999). Inhibition of human sperm motility by specific herbs used in alternative medicine. Journal Of Assisted Reproduction And Genetics. Feb 16(2): 87-91.

Purpose: Our purpose was to analyze sperm motility parameters in the presence of herbs.Methods: Washed sperm were incubated in either saw-palmetto (Serenoa repens, Permixon Sabal serrulatum), echinacea purpura, ginkgo biloba, St. John's wort (Hypericum perforatum), or control medium. Parameters were measured on a Hamilton-Thorn analyzed after 1, 4, 24, and 48 hr or 37 degrees C.Results: Sperm motility was inhibited at the high concentration (0.6 mg/mL) of Sr. John's wort. Curvilinear velocities and hear cross frequencies also decreassed, but not hyperactivation. High-concentration saw-palmetto, echinacea, or ginkgo inhibited motility at 24 and 48 hrConclusions: A potent inhibition of sperm motility was seen in St. John's wort unrelated to changes in pH. Furthermore, sperm viability was compromised in St. John's wort, suggesting a spermicidal effect. Metabolic changes were observed in saw-palmetto-treated sperm. High-concentration echinacea purpura interfered,vith sperm enzymes. Ginkgo did not have an antioxidant effect on sperm motility.

Sasaki, K., S. Hatta, et al. (1999). Effects of bilobalide on gamma-aminobutyric acid levels and glutamic acid decarboxylase in mouse brain. European Journal Of Pharmacology. Feb 367(2-3): 165-173.

We have previously demonstrated that bilobalide, a constituent of the Ginkgo biloba extract, possesses anticonvulsant activity, and suggested that the mechanism of its anticonvulsant action involves modulation of gamma-aminobutyric acid (GABA)-related neuronal transmission. This study examined the effects of bilobalide on the level of GABA and glutamate, the activity and the amount of glutamic acid decarboxylase (EC 4.1.1.15), and the function of GABA(A) receptors in the hippocampus, cerebral cortex and striatum of the mouse. GABA levels, glutamic acid decarboxylase activity, and the protein amount of 67 kDa glutamic acid decarboxylase in the hippocampus of mice treated with bilobalide (30 mg/kg, p.o., once a day for 4 days) were significantly higher than those in controls. However, there were no significant differences in glutamate levels or, the number and the dissociation constants of GABA(A) receptors in the hippocampus between control and bilobalide-treated mice. These results suggest that the anticonvulsant effect of bilobalide is due to elevation of GABA levels, possibly through potentiation of glutamic acid decarboxylase activity and enhancement of the protein amount of 67 kDa glutamic acid decarboxylase by bilobalide. (C) 1999 Elsevier Science B.V. All rights reserved.

Ahlemeyer, B., A. Mowes, et al. (1999). Inhibition of serum deprivation- and staurosporine-induced neuronal apoptosis by Ginkgo biloba extract and some of its constituents. European Journal Of Pharmacology. Feb 367(2-3): 423-430.

Previous studies have already demonstrated that some constituents of an extract of Ginkgo biloba (EGb), such as ginkgolide B and bilobalide, protect cultured neurons from hypoxia- and glutamate-induced damage. This prompted us to investigate whether they were also able to inhibit neuronal apoptosis. We induced apoptosis in cultured chick embryonic neurons as well as in mixed cultures of neurons and astrocytes from neonatal rat hippocampus by serum deprivation and staurosporine. The increase in the percentage of apoptotic chick neurons from 12% in controls to 30% after 24 h of serum deprivation was reduced to control level by EGb (10 mg/l), ginkgolide B (10 mu M), ginkgolide J (100 mu M) and bilobalide (1 mu M). After treatment with staurosporine (200 nM) for 24 h we observed 74% apoptotic chick neurons. This percentage of apoptotic neurons was reduced to 24%, 62% and 31% in the presence of EGb (100 mg/l), ginkgolide J (100 mu M) and ginkgolide B (10 mu M), respectively. Bilobalide (10 mu M) decreased apoptotic damage induced by staurosporine treatment for 12 h nearly to the control level. In mixed neuronal/glial cultures, the extract of EGb (100 mg/l) and bilobalide (100 mu M) rescued rat neurons from apoptosis caused by serum deprivation, whereas, bilobalide (100 mu M) and ginkgolide B (100 mu M) reduced staurosporine-induced apoptotic damage. Ginkgolide A revealed no anti-apoptotic effect in either serum-deprived or staurosporine-treated neurons. Our results suggest that EGb and some of its constituents possess anti-apoptotic capacity and that bilobalide is the most potent constituent. (C) 1999 Elsevier Science B.V. All rights reserved.

Maggini, F., R. Marrocco, et al. (1998). Lengths and nucleotide sequences of the internal spacers of nuclear ribosomal DNA in gymnosperms and pteridophytes. Plant Systematics And Evolution 213(3-4): 199-205.

The nucleotide sequences of the internal transcribed spacers (ITS1 and ITS2) of the nuclear ribosomal DNA were analyzed in species belonging to gymnosperms and pteridophytes. The lengths of the ITSs of sixteen species of gymnosperms and seven species of pteridophytes were estimated. The gymnosperms have ITS1 regions larger than those observed in the pteridophytes and angiosperms (ca. 610-3100 bp versus 159-360 bp). On the other hand, the ITS2 regions appear to be of a conserved length (182-370 bp). We have determined the complete nucleotide sequences of ITS regions from four gymnosperm species and five pteridophyte species by cloning the PCR products. Sequence analysis showed the presence of three short tandem arranged subrepeats of about 70 bp in the 1112 bp ITS1 of Ephedra fragilis. Pyrimidine rich (about 90%) DNA segments of 40-50 bp were observed in the ITS1 of Ginkgo biloba. A highly conserved 16 bp long sequence known to be present in the ITS1 of the angiosperm species has been also found in the ITS1 of Cycas revoluta, Taxus baccata and Ephedra fragilis.

Watson, D. G. and E. J. Oliveira (1999). Solid-phase extraction and gas chromatography mass spectrometry determination of kaempferol and quercetin in human urine after consumption of Ginkgo biloba tablets. Journal Of Chromatography B. Feb 723(1-2): 203-210.

A method was developed for the quantification of the flavonoids quercetin and kaempferol in human urine using a solid-phase extraction procedure followed by gas chromatography-mass spectrometry. Deuterated internal standards of the analytes were spiked into the samples prior to extraction. The limit of detection of the method was ca. 10 pg on column and precision of the method for quantification in a sample of urine was +/-9.40% for kaempferol and +/-7.34% for quercetin (n=6). The levels of quercetin and kaempferol found in urine samples were only a small fraction of the amount ingested. The treatment of urine samples with beta-glucuronidase markedly increased the levels of flavonoids detected, supporting the view that kaempferol and quercetin are eliminated in the urine as glucuronides. (C) 1999 Elsevier Science B.V. All rights reserved.

Kubo, J., J. R. Lee, et al. (1999). Anti-Helicobacter pylori agents from the cashew apple. Journal Of Agricultural And Food Chemistry. Feb 47(2): 533-537.

Anacardic acids and (E)-2-hexenal characterized from the cashew Anacardium occidentale L. (Anacardiaceae) apple have been found to exhibit antibacterial activity against the Gram-negative bacterium Helicobacter pylori, which is now considered to cause acute gastritis. The same antibacterial compounds have also been found to inhibit urease (EC 3.5.1.5).

Ondrizek, R. R., P. J. Chan, et al. (1999). An alternative medicine study of herbal effects on the penetration of zone-free hamster oocytes and the integrity of sperm deoxyribonucleic acid. Fertility And Sterility. Mar 71(3): 517-522.

Objective: To analyze the effects of certain herbs on sperm DNA and on the fertilization process.Design: Prospective comparative study.Setting: Clinical and academic research environment.Patient(s): Donor sperm specimens.Intervention(s): Zona-free hamster oocytes were incubated for 1 hour in saw palmetto (Serenoa repens), echinacea purpura, ginkgo biloba, St. John's wort (Hypericum perforatum), or control medium before sperm-oocyte interaction. The DNA of herb-treated sperm was analyzed with denaturing gradient gel electrophoresis.Main Outcome Measure(s): Oocyte penetration and integrity of the sperm BRCA1 exon 11 gene.Result(s): Pretreatment of oocytes with 0.6 mg/mL of St. John's wort resulted in zero penetration. A lower concentration (0.06 mg/mL) had no effect. High concentrations of echinacea and ginkgo also resulted in reduced oocyte penetration. Exposure of sperm to echinacea purpura and St. John's wort resulted in DNA denaturation. In contrast, saw palmetto and ginkgo had no effect. Sperm exposed to 0.6 mg/mL of St. John's wort showed mutation of the BRCA1 exon 11 gene.Conclusion(s): High concentrations of St. John's wort, echinacea, and ginkgo had adverse effects on oocytes. Saw palmetto had no effect. The data suggested that St. John's wort, ginkgo, and echinacea at high concentrations damage reproductive cells. St. John's wort was mutagenic to sperm cells. (Fertil Steril(R) 1999; 71:517-22. (C) 1999 by American Society for Reproductive Medicine.)

Heinze, G. and M. Ontiveros (1998). Phytopharmacology as an alternative treatment in psychiatry. Salud Mental. Dec 21(6): 33-42.

Phytomedicines for the treatment of different diseases have been used since a long time ago, but the discovery of synthetic dregs, like sulphas, peniciline and others antibiotics, disminshed the popularity of traditional medicine. In this work we explain why the interest on medical plant extracts surged again.We describe the pharmacodynamic and the pharmacokinetic aspects of three phytomedicines: Hypericum perforatum (Saint John's flower) for depression, Piper-methysticum (Kava-kava) for anxiety and Ginkgo biloba, for dementia.

Trovero, F., D. Brochet, et al. (1999). Ginkgo biloba extract EGb761 reduces the development of amphetamine-induced behavioral sensitization: effects on hippocampal type II corticosteroid receptors. Brain Research. Feb 818(1): 135-139.

Pretreatment of rats with the extract of Ginkgo biloba termed EGb761 reduced the behavioral sensitization induced by successive D-amphetamine administrations (0.5 mg/kg) as estimated by increasing values of locomotor activity. EGb761 pretreatment also prevented the reduced density of [H-3]dexamethasone binding sites in the dentate gyrus and the CA1 hippocampal regions of D-amphetamine treated animals. These observations suggest that EGb761, by reducing glucocorticoid levels, could modulate the activity of the neuronal systems involved in the expression of the behavioral sensitization. (C) 1999 Elsevier Science B.V. All rights reserved.

Khalsa, D. S. (1998). Integrated medicine and the prevention and reversal of memory loss. Alternative Therapies In Health And Medicine. Nov 4(6): 38-43.

This article, based on scientific research and clinical observations, suggests that memory lass is not an inevitable consequence of aging and that Alzheimer's disease can be prevented and reversed using an integrated medical approach. Three nai, associations with memory loss other than age, heredity, and genetics are described They include a high-fat diet, chronic unbalanced stress with ils attendant risk in the adrenal hormone cortisol, and the presence of cardiovascular disease. A 4-pillar integrative medical program on brain longevity is presented. The program includes a diet consisting of 15% fat and supplementation with brain-specific nutrients such as vitamin B complex, vitamin E, ubiquinone, ginkgo biloba, and phosphatidylserine. In addition, stress-relieving meditation, mind-body and cognitive exercise, antiaging drugs like L-deprenyl citrate, as well as hormones such as dehydroepiandrosterone and pregnenolone complete the program. Patient benefits such as greater wisdom and spiritual happiness are also explored.

Itil, T. M., E. Eralp, et al. (1998). The pharmacological effects of Ginkgo biloba, a plant extract, on the brain of dementia patients in comparison with tacrine. Psychopharmacology Bulletin 34(3): 391-397.

In 1994, a standardized dry extract of Ginkgo biloba leaves (SeGb), has been approved by German health authorities for the treatment of primary degenerative dementia and vascular dementia. More than 24 different brands of Ginkgo biloba extract are sold in the United States. Tac ri ne, a Iso known as tetrahydroaminoacrine (THA), and donepezil are currently the only drugs approved in the United States for the treatment of Alzheimer's disease. Previous studies demonstrated that SeGb and tacrine induce significant pharmacological effects on the brains of young, healthy human males, as determined by bioelectrical activity measurements obtained using the quantitative pharmaco-electroencephalogram (QPEEG(R)) method. The type of central nervous system (CNS) effects we have seen on computer-analyzed EEGs (CEEGs(R)) after administration of tacrine or EGb suggests both are "cognitive activators" which are, as a class of products, characterized by a (prepost) relative increase of 7.5 to 13 Hz ("alpha") and decrease of 1.3 to 7.5 Hz ("delta" end "theta") activity.To determine whether EGb or tacrine had noticeable pharmacological effects on elderly subjects diagnosed with possible or probable Alzheimer's, the present open, uncontrolled trial was conducted. Data from 18 subjects (11 males, 7 females) at an average age of 67.4 years with light to moderate dementia (Mini Mental mean score = 23.7, ranges: 15-29 [Geriatric Depression Scale mean scores = 3.7; range: 3.2-5.4]) were analyzed for this presentation, Each subject was randomly administered a single oral "Test-Dose(R)" of either 40 mg of tacrine or 240 mg of EGb2in two separate sessions within 3- to 7-day intervals. Before drug administration and at 1- and 3-hour intervals after drug administration, CEEGs were recorded for a minimum of 10 minutes. The CEEGs were analyzed using Period Analysis programs we developed for QPEEG.The results indicated that both EGb and, to a lesser degree, tacrine induced pharmacological effects, as established by QPEEG measurements, in the CNS similar to those previously established in healthy, young subjects. The type of CNS effects produced by EGb (as established by HZI's CEEG psychotropic drug database) in elderly dementia patients were similar to those induced by tacrine responders as well as those seen after the administration of other "cognitive activators" (pramiracetam, vinpocetine, BMY21502, suloctidil, and lisuride) and anti-dementia drugs approved in the United States or Europe (tacrine, donepezil, nimodipine, piracetam, and oxiracetam) from our database. The results also showed that 240 mg of EGb has typical cognitive activator CEEG profiles (responders) in more subjects (8 of 18) than 40 mg tacrine (3 of 18 subjects). Because of the small sample size, we could not test the hypothesis that subjects who showed cognitive activator-type pharmacological response to the first Test-Dose(R) of EGb or tacrine also exhibit more therapeutic effects (compared to nonresponders) when drugs are administered chronically.

Nakao, Y., S. Shiozaki, et al. (1999). Changes in carbohydrate and water content with ovule growth of Ginkgo biloba L. Journal Of Horticultural Science And Biotechnology. Jan 74(1): 60-63.

The carbohydrate and water contents of the ovule of Ginkgo biloba L. (ginkgo) were evaluated during its development. The ovule grew rapidly (stage I) after pollination in early May, temporarily stopped growing, in mid-July (stage II), and resumed growth slowly (stage III) from mid-August until maturation. The water content in the endosperm and outer integument were highest in June, and decreased thereafter, accompanied by ovule development. In the endosperm, the sugar content decreased rapidly during stage I, followed by a rapid increase in the starch content which is high level in early September. In the outer integument, the sugar content increased in early June, and remained nearly constant until early August. Then it transiently decreased in mid-August, when meso-integument hardening was completed, followed by a rapid increase. The starch content in the outer integument was low, but peaked in mid-August, when the sugar content was lowest. Although ginkgo nuts are usually harvested in October, we recommend early harvest in late August when starch accumulation in the endosperm, an important factor influencing the taste of ginkgo nuts, is at a high level.

Steinberg, M. (1999). Pharmacologic treatment of Alzheimer's disease: An update on approved, unapproved therapies. Formulary . Jan 34(1): 32-34.

This article reviews Various approved and nonapproved therapies for Alzheimer's disease (AD) and offers recommendations for their clinical use. The cholinesterase inhibitors tacrine and donepezil are the only FDA-approved drugs for AD. While both offer modest benefit in cognition and functioning, donepezil is the first-line agent because of its ease of dosing, better side effect profile, and lack of monitoring requirements. Several other cholinesterase inhibitors are in late-stage development. Clinicians may also consider other agents as supplements to cholinesterase inhibitors in appropriate patients. Vitamin E and selegiline may slow functional decline in AD patients, possibly via their antioxidant properties, and Ginkgo biloba extracts may have mild cognitive benefits. Nonsteroidal anti-inflammatory drugs and estrogen are being studied for their potential to halt, delay, or prevent AD progression.

Klepser, T. B. and M. E. Klepser (1999). Unsafe and potentially safe herbal therapies. American Journal Of Health System Pharmacy. Jan 56(2): 125-138.

Unsafe and potentially safe herbal therapies are discussed.The use of herbal therapies is on the rise in the United States, but most pharmacists are not adequately prepared educationally to meet patients' requests for information on herbal products. Pharmacists must also cope with an environment in which there is relatively little regulation of herbal therapies by FDA. Many herbs have been identified as unsafe, including borage, calamus, coltsfoot, comfrey, life root, sassafras, chaparral, germander, licorice, and ma huang. Potentially safe herbs include feverfew, garlic, ginkgo, Asian ginseng, saw palmetto, St. John's wort, and valerian. Clinical trials have been used to evaluate feverfew for migraine prevention and rheumatoid arthritis; garlic for hypertension, hyperlipidemia, and infections; ginkgo for circulatory disturbances and dementia; ginseng for fatigue and cancer prevention; and saw palmetto for benign prostatic hyperplasia. Also studied in formal trials have been St. John's wort for depression and valerian for insomnia. The clinical trial results are suggestive of efficacy of some herbal therapies for some conditions. German Commission E, a regulatory body that evaluates the safety and efficacy of herbs on the basis of clinical trials, cases, and other scientific literature, has established indications and dosage recommendations for many herbal therapies.Pharmacists have a responsibility to educate themselves about herbal therapies in order to help patients discern the facts from the fiction, avoid harm, and gain what benefits may be available.

Shadlen, M. F. and E. B. Larson (1999). What's new in Alzheimer's disease treatment? Reasons for optimism about future pharmacologic options. Postgraduate Medicine. Jan 105(1): 109-118.

There is reason for optimism about future treatment options for Alzheimer's disease, despite uncertainties about which subgroups of patients will respond to treatment, the magnitude of therapeutic effects, the duration of benefit, and the long-term outcomes from disease-modifying agents. Because Alzheimer's disease is a heterogeneous disorder, the range of treatment responses likely will remain variable. The decision to initiate treatment must be individualized to the therapeutic goals of the patient and his or her caregiver.Advances in the understanding of the pathogenesis of Alzheimer's disease have led to new treatment strategies. Augmentation of cholinergic function through the use of acetylcholinesterase inhibitors with favorable side-effect profiles (eg, donepezil, possibly metrifonate) can create the potential for improved memory and cognition. Anti-inflammatory drugs, estrogen, alpha-tocopherol, selegiline, and ginkgo biloba are the subject of ongoing clinical trials to determine their effectiveness in Alzheimer's disease. Future treatment strategies will likely include a combination of acetylcholinesterase inhibitors and disease-modifying agents. A greater understanding of the pathogenesis of Alzheimer's disease may lead to the development of new neuroprotective agents. The longterm human and social costs, as well as potential benefits, of prolonging the natural course of the disease can only become evident with study of these agents in years to come.(24)

Mosle, B., M. E. Collinson, et al. (1998). Factors influencing the preservation of plant cuticles: a comparison of morphology and chemical composition of modern and fossil examples. Organic Geochemistry 29(5-7): 1369-1380.

Samples of Recent Ginkgo biloba, two Cretaceous Ginkgo and two Cretaceous conifer cuticles from different enclosing lithologies but with similar thermal maturity of the fossils, have been analysed by scanning and transmission electron microscopy (SEM, TEM), Fourier transform-infrared spectroscopy (FT-IR), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Recent and Fossil Ginkgo cuticles under SEM reveal sheets, similar in appearance, varying in the abundance and texture of the cuticular papillae. TEM of the Recent Ginkgo shows an outer amorphous cuticle layer, a structured middle layer and an inner laminated layer of cell wall. The Cretaceous Ginkgo cuticles retain the amorphous layer and a modified structured layer. SEM of Cretaceous Abletites and Frenelopsis also shows preservation of cuticle sheets but each has distinctive morphology. These conifer cuticles are very thick (TEM), Frenelopsis cuticle has remarkable multilaminar ultrastructure whilst Abietites amorphous. G. biloba cuticle consists mainly of the natural polyester, cutin, as revealed by FT-IR and pyrolysis, indicated by an abundance of saturated, unsaturated and hydroxy fatty acids. IR spectra of fossil cuticles, like modern cuticles, show aliphatic C-H, hydroxyl and carbonyl functions. However, in fossils, the carbonyl ester is transformed to carboxylic acid or ketone groups. Pyrolysates of fossils show phenolic constituents like modern cuticles but loss of cutin fatty acid monomers and an increased prominence of an homologous series of n-alkene and n-alkane fragments up to n-C-30 Since most Recent cuticles, including those of conifers and Ginkgo biloba which we have studied, do not yield a non-saponifiable highly resistant residue it is proposed that organic preservation of fossil species investigated involves the diagenetic stabilisation of chemically-labile aliphatic cutin constituents along with incorporation of waxes. These general chemical modifications characterise all fossil Ginkgo and conifer cuticles, irrespective of their enclosing lithology, systematic affinity, external morphology or internal ultrastructural preservation. However there are also clear chemical differences between the fossil samples which may relate to their systematic affinity (ginkgos vs Abietites and Frenelopsis). (C) 1998 Elsevier Science Ltd. All rights reserved.

Balon, R. (1999). Ginkgo biloba for antidepressant-induced sexual dysfunction? Journal Of Sex And Marital Therapy. Jan Mar 25(1): 1-2.

Houghton, P. J. (1999). Roots of remedies: plants, people and pharmaceuticals. Chemistry And Industry. Jan 4(1): 15-19.

Tu, T. T. N., H. Bocherens, et al. (1999). Ecological distribution of Cenomanian terrestrial plants based on C-13/C-12 ratios. Palaeogeography Palaeoclimatology Palaeoecology. Jan 145(1-3): 79-93.

The Cenomanian lagoonal member of the 'Argiles du Baugeois' (Anjou, France) yielded a rich and exceptionally well-preserved fossil leaf flora. Stable carbon isotope ratios of fossil plants were measured in order to investigate the presence of a palaeoenvironmental signal. The small intraspecies variations of delta(13)C values observed for most of the fossil leaves suggested that the isotopic signal had not been significantly altered. Hence, an isotopic approach was used as an attempt to assist in reconstructing the ecological distribution of the flora. The C-13-enrichment of the fossil leaves suggested that the plants underwent water or salt stress. The occurrence of the conifer Frenelopsis suggested, at least locally, a saline environment such as a lagoon. According to their decreasing delta(13)C values, all the plants collected could have been distributed along a decreasing salinity transect from the lagoon to a flood plain. The predominant species, Eretmophyllum andegavense, a fossil ginkgo, exhibited a wide range of delta(13)C values. This could indicate that this taxon grew in a wide range of habitats with varying salinities. The origin of the organic matter appeared to be terrestrial with a major contribution from water-stressed plants such as Frenelopsis, as suggested by the similarity between delta(13)C values of the conifer and the sedimentary organic matter. delta(13)C values of the sediment indicated stable palaeoenvironmental conditions during the deposition of the 'Argiles du Baugeois' member. Hence, while detailed palaeovegetation reconstructions are generally limited to the few deposits which present in-situ palaeoflora, the contribution of isotope geochemistry could allow reconstructions for a wider range of fossil plant deposits. (C) 1999 Elsevier Science B.V. All rights reserved.

Inoue, H., S. Kamoda, et al. (1998). Ginkgolide production in relation to organogenesis in Ginkgo biloba. Journal Of Wood Science 44(5): 375-378.

The contents of diterpenoids, ginkgolides A, B, and C, in seeds, embryos, and plantlets of Ginkgo biloba were analyzed to clarify the relations between organogenesis and terpene contents in G. biloba. There is so far no published report on the contents and changes in such terpenes in seeds and very young plantlets of G. biloba. Ginkgolides were present in seeds and embryos. Plantlets cultured in both the dark and under illumination contained substantial amounts of ginkgolides, more abundant than in seeds and embryos. It is concluded that ginkgo yields ginkgolides in its early stage of development regardless of light.

Akiba, S., T. Kawauchi, et al. (1998). Inhibitory effect of the leaf extract of Ginkgo biloba L. on oxidative stress-induced platelet aggregation. Biochemistry And Molecular Biology International. Dec 46(6): 1243-1248.

The effect of the leaf extract of Ginkgo biloba L. on platelet aggregation induced by oxidative stress was studied. The extract caused a dose-dependent inhibition of platelet aggregation stimulated with tert-butyl hydroperoxide (t-BHP) and Fe2+. Similar inhibitory activity was observed when platelets were exposed to H2O2 and Fe2+. Synergistic aggregation induced by a combination of t-BHP and Fe2+ or H2O2 and Fe2+ in association with suboptimal concentration of collagen or U46619, was prevented by the extract. However, the extract failed to inhibit aggregation in response to collagen, thrombin or U46619. Ginkgolides A, B and C inhibited platelet-activating factor-induced aggregation, but not oxidant-induced aggregation. These data suggest that the suppressive effect of the extract is specific on platelet aggregation stimulated by oxidative stress, and that this effect is involved in the mechanism related to its protective effect upon cerebral or myocardial injuries.

Janssens, D., C. Michiels, et al. (1999). Increase in circulating endothelial cells in patients with primary chronic venous insufficiency: Protective effect of Ginkor Fort in a randomized double-blind, placebo-controlled clinical trial. Journal Of Cardiovascular Pharmacology. Jan 33(1): 7-11.

One possible mechanism that accounts for the alterations observed in varicose veins is the activation of endothelial cells by ischemia occurring in the leg veins during blood stasis and the cascade of reactions that follows. Because in vitro data suggest that endothelium alteration is a key event in the development of the pathology, it was important to confirm this hypothesis in patients. We used the number of circulating endothelial cells detached from the vascular wall as a criterion of the endothelium injury. We first compared the number of circulating endothelial cells (CECs) in patients with chronic venous insufficiency (CVI) with those of a control population. A twofold increase in the CEC count (1,001 +/- 127 CEC/ml of plasma compared with 514 +/- 82 CECs/ml) was observed in CVI patients, which indeed suggests an alteration of the endothelium in this disease. Second, the protective effect of a venotropic drug, Ginkgo biloba extract, troxerutine, and heptaminol (Ginkor Fort), was tested by a randomized double-blind, placebo-controlled clinical trial. In the active-treatment group, the mean values of the CEC count decreased by 14.5% after a 4-week treatment, whereas in the placebo group, the decrease was less (8.4%). The decrease from week 0 to the end of treatment was significantly higher in the active-treatment group than in the placebo group. These results confirm the important role of the endothelium alterations in the development of varicose veins and suggest a potential beneficial action of a venotropic drug on the venous wall.

Perry, E. K., A. T. Pickering, et al. (1998). Medicinal plants and Alzheimer's disease: Integrating ethnobotanical and contemporary scientific evidence. Journal Of Alternative And Complementary Medicine. Win 4(4): 419-428.

The use of complementary medicines such as plant extracts in dementia therapy, varies according to the different cultural traditions. In orthodox Western medicine, contrasting with that in China and the Far East for example, pharmacological properties of traditional cognitive or memory enhancing plants have not been widely investigated in the context of current models of Alzheimer's disease. An exception is Ginkgo biloba in which the ginkgolides have antioxidant, neuroprotective, and cholinergic activities relevant to Alzheimer's disease mechanisms. The therapeutic efficacy of Ginkgo biloba extracts in Alzheimer's disease in placebo-controlled clinical trials is reportedly similar to currently prescribed drugs such as tacrine or donepezil and, importantly, undesirable side effects of Ginkgo biloba are minimal. Old European reference books (eg, medical herbals) document a variety of other plants such as Salvia officinalis (sage) and Melissa officinalis (balm) with memory improving properties, and cholinergic activities have recently been identified in extracts of these plants. Precedents for modern discovery of clinically relevant pharmacological activities in plants with long-established medicinal use include, for example, the interaction of alkaloid opioids in Papaver somniferum (Opium poppy) with endogenous opiate receptors in the brain. With recent major advances in understanding the neurobiology of Alzheimer's disease, and as yet limited efficacy of so-called rationally designed therapies, it may be timely to re-explore historical archives for new directions in drug development. This article considers not only the value of an integrative traditional and modern scientific approach to developing new treatments for dementia, but also in the understanding of disease mechanisms. Long before the current biologically based hypothesis of cholinergic derangement in Alzheimer's disease emerged, plants now known to contain cholinergic antagonists were recorded for their amnesic and dementia-inducing properties.

Winther, K., C. Randlov, et al. (1998). Effects of Ginkgo biloba extract on cognitive function and blood pressure in elderly subjects. Current Therapeutic Research Clinical And Experimental. Dec 59(12): 881-888.

In this randomized, double-masked study, we assessed the effects of a Ginkgo biloba (GB-8) extract on elderly volunteers with age-related cognitive dysfunction. A total of 260 subjects were tested to obtain a homogeneous group of 60 elderly subjects with mild-to-moderate cognitive impairment, as defined by a clinical rating scale. The subjects were allocated to one of three groups and received either GB-8 40 mg or 80 mg or placebo three times daily for 3 months. Before therapy was started and after 1 and 3 months of treatment, standardized testing of attention, concentration, and memory was performed. The subjects completed self-assessments before and after 3 months of therapy, and arterial blood pressure was measured at the same intervals. Clinical ratings were done before and after 3 months of treatment. Six subjects withdrew from the study, whereas 54 subjects (31 women and 23 men; mean age, 74 years; age range, 61 to 88 years) completed the study. After randomization, the groups were similar with respect to age, social class, level of education, and demographic characteristics. Objective test results showed that attention, concentration, and short-term verbal memory improved significantly in subjects receiving the low-dose (standard) treatment. Similar improvements were seen in the results of the self-assessment test and the clinical rating. Diastolic blood pressure decreased significantly during low-dose treatment. Treatment with the GB-8 extract was found to improve objective measures of cerebral function in elderly subjects with mild-to-moderate cognitive impairment; the improvement appeared to be clinically relevant. The possible antihypertensive action of Ginkgo biloba extract is sufficient to warrant further investigation.

Viola, H., M. Marder, et al. (1998). Central nervous system effects of natural and synthetic flavonoids. Anales De La Asociacion Quimica Argentina. May Dec 86(3-6): 229-236.

Flavonoids are naturally occurring molecules present in the human diet. We demonstrate that some flavonoids possess central nervous system effects acting through the central benzodiazepine receptors. The pharmacological characterization of chrysin (5,7-dihydroxyflavone) and apigenin (5,7,4'-trihydroxyflavone), isolated from Passiflora coerulea and Matricaria recutita, respectively showed their anxiolytic, but not myorelaxant or amnesic effects. Cirsiliol (5,3',4'-trihydroxy-6,7-dimethoxyflavone), however isolated from Salvia guaranitica, had sedative-depressant properties. We were able to increase the biochemical and pharmacological potency of the natural flavonoids by means of the addition of halo and/or nitro groups to the flavone nucleus. Some flavonoids are partial agonists of the benzodiazepine receptors and may become new therapeutic drugs, devoid of the unwanted side effects of classical benzodiazepines.

Baudouin, C., P. J. Pisella, et al. (1999). Effects of EGb761 and superoxide dismutase in an experimental model of retinopathy generated by intravitreal production of superoxide anion radical. Graefes Archive For Clinical And Experimental Ophthalmology. Jan 237(1): 58-66.

Background: A study was carried out to investigate the effect of two antioxidants - Ginkgo biloba extract (EGb761) and superoxide dismutase (SOD)- in an experimental model of vitreoretinopathy obtained by direct production of oxygen free radicals in the vitreous cavity. Methods: Twenty-eight pigmented rabbits were used. Vitreoretinopathy was induced by intravitreal injection of 50 mu l of a mixture composed of 40 nmol of xanthine and 0.001 IU of xanthine oxidase. Rabbits were randomly distributed into four groups: Group 1 (n=8) did not receive any treatment and served as a positive control. Groups 2 (n=8) and 3 (n=8) received for 1 month EGb761 given orally at a dose of 100 mg/kg/day, respectively 1 day after and 1 week before induction of retinopathy. Group 4 (n=4) was treated by three intramuscular injections of 15 000 IU/kg of SOD, 24 h before induction and 24 and 48 h thereafter. Clinical evaluations and electroretinograms (ERG) were repeatedly performed until the animals were killed at day 28. Histological examinations and immunohistological procedures were performed to ascertain the origin and characteristics of the cellular proliferation and to compare vitreoretinal structures in the four groups. Results: Intravitreal injection of xanthine-xanthine oxidase produced a strong inflammatory response with vitreous infiltrates and epiretinal membrane formation, inconstantly associated with retinal detachment. ERG showed a decrease of the a-, b- and c-waves beginning within a few hours after injection. Histologic evaluation found an intravitreal and epiretinal infiltration by leukocytes and epithelial-derived cells, dense vitreoretinal membranes and retinal detachments with occasional neovascularization. In the treated groups (groups 2-4), all clinical, electric and histologic data were significantly improved compared to the control group. However, no difference could be found among the three treated groups. Conclusion: This study demonstrates the strong pathologic effects of free radical production on the retina and the close relationships between free radicals, inflammatory pathways and vitreoretinal proliferative disorders. It also confirms the pharmacological interest of prevention by antioxidants and free radical scavengers.

Mast, C. (1998). Ginkgo for treatment of tinnitus - Commentary. Forschende Komplementarmedizin. Oct 5(5): 251-252.

Rapin, J. R., M. Zaibi, et al. (1998). In vitro and in vivo effects of an extract of Ginkgo biloba (EGb 761), ginkgolide B, and bilobalide on apoptosis in primary cultures of rat hippocampal neurons. Drug Development Research. Sep 45(1): 23-29.

Primary cultures of rat hippocampal neurons were prepared and exposed to increasing concentrations of a peroxyl radical-generator, 2,2'-azobis 2 amidinopropane (AAPH). Addition of AAPH (20 or 50 mM) to the medium caused a decrease in cell viability and an increase in the number of apoptotic cells. Values for the number of nucleosomes were obtained using an ELISA technique. "Factor F," an indicator of enrichment in nucleosomes, was found to be directly proportional to the number of neuronal apoptoses. Addition of an extract of Ginkgo biloba (EGb 761; 5-20 mu g/ml) or ginkgolide B (one of its terpenoid constituents; 0.2 or 0.4 mu g/ml) to the culture medium in vitro led to increases in cell viability and decreases in the number of hippocampal cells undergoing AAPH-induced apoptosis, whereas addition of bilobalide (another terpenoid constituent of EGb 761; 0.1-1.0 mu g/ml) was ineffective. These in vitro results were corroborated and extended when these same substances were administered to rats in vivo. Oral administration of EGb 761 (50 mg/kg/day) for 8 days caused a significant increase in cell viability and a highly significant decrease in the numbers of both spontaneously occurring and AAPH-induced apoptoses. Similar protective effects were observed with ginkgolide B (2 mg/kg/day, p.o.), whereas bilobalide (2 mg/kg/day, p.o.) was ineffective. As AAPH enhances the production of peroxyl radicals, the protective actions of subacute in vivo treatments with EGb 761 and ginkgolide 8 appear to be associated with an anti-lipoperoxidative effect of these substances. Drug Dev. Res. 45:23-29, 1998. (C) 1998 Wiley-Liss, Inc.

Pitchumoni, S. S. and P. M. Doraiswamy (1998). Current status of antioxidant therapy for Alzheimer's disease. Journal Of The American Geriatrics Society. Dec 46(12): 1566-1572.

Accumulating evidence from preclinical and clinical studies supports the hypothesis that oxidative stress may be associated with the onset and progression of Alzheimer's Disease (AD). Antioxidant therapies are being promoted in the lay press to enhance mental functions and delay cognitive losses with aging. An increasing number of physicians are also recommending antioxidant therapies, such as high dose vitamin E, for subjects with AD and other neurodegenerative disorders. High dose vitamin E, ginkgo biloba, and selegiline are three putative antioxidants that have been tested in randomized multicenter trial conditions in the US. This paper summarizes the oxidative stress hypothesis of AD and reviews the strengths and limitations of published antioxidant studies in AD in relation to the role of such therapies in practice.

Hodisan, T., M. Culea, et al. (1998). Separation, identification and quantitative determination of free amino acids from plant extracts. Journal Of Pharmaceutical And Biomedical Analysis. Nov 18(3): 319-323.

This research presents the results obtained from the separation, identification and quantitative determination of free amino acids from Gingko biloba and Hedera helix leaf extracts, using three modem techniques: thin layer chromatography (TLC), high performance liquid chromatography (HPLC), and gas chromatography-mass spectrometry. The presence of the determined amino acids explains the utilisation of G. biloba and H. helix leaf extracts in cosmetic and pharmaceutical products. (C) 1998 Elsevier Science B.V. All rights reserved.

Rosler, M., W. Retz, et al. (1998). Free radicals in Alzheimer's dementia: currently available therapeutic strategies. Journal Of Neural Transmission 54: 211-219.

Substantial evidence now exists that oxidative stress may play an important role in the etiopathogenesis of DAT. The different sources of oxidative stress in DAT are suggesting several pharmacological opportunities for influencing the disease. It is possible to distinguish 2 major types of possible therapeutic agents according to their pharmacological. point of attack.1. Radical scavengers, agents directly interacting with free radicals. Candidates of this type are gingko biloba, vitamins A, C, E and estrogen.2. Antioxidants, which are able to prevent or decrease the production of free radicals by use of specific neuropharmacological properties. Candidates are selegiline, a MAO-B inhibitor well established in the therapy of Parkinson's disease, and tenilsetam, which is believed to be an AGE-inhibitor.Recent in vitro studies have demonstrated the efficacy of both types of therapeutic agents by preventing or delaying oxidative neural damage.Some clinical data exist regarding the antidementive properties particularly in terms of gingko biloba, selegiline and vitamin E. The efficacy studies about these compounds seem to indicate a promising future strategy in the therapy of DAT. But it is too early to draw definite conclusions since it is well kown that all of our candidate substances do not act specifically as radical scavengers or antioxidants.

Wolff, R. L., F. Pedrono, et al. (1998). The seed fatty acid composition and the distribution of Delta 5-olefinic acids in the triacylglycerols of some taxaceae (Taxus and Torreya). Journal Of The American Oil Chemists Society. Nov 75(11): 1637-1641.

The fatty acid compositions of the seeds from three Taxus (yew) species and one Torreya species belonging to the Taxaceae family [Taxus cuspidata (Japanese yew), T. chinensis (Chinese yew), T. baccata (English yew), and Torreya grandis (Chinese nutmeg yew)] have been established. These compositions were compared with those previously published for T. canadensis (Canadian yew) and Torreya nucifera. in Taxus species, as well as in Torreya species, Delta 5-olefinic acids are present in the seed lipids from all species analyzed. In Taxus, 5,9-18:2 (taxoleic) acid is the prominent Delta 5-olefinic acid. It represents between 9.5 and 16.2% of total fatty acids. Other Delta 5-olefinic acids that occur in low amounts are 5,9,12-18:3 (<3.5%), 5,11-20:2 (<0.3%), 5,11,14-20:3 (<2.2%), and 5,11,14,17-20:4 (<0.3%) acids. In Torreya species, the major Delta 5-olefinic acid is 5,11,14-20:3 (sciadonic) acid (between 6.7 and 11.2%). In contrast to Taxus species, the 5,9-18:2 and 5,9,12-18:3 acids are scarce in Torreya species: less than 0.1%. Also, the 9,12,15-18:3 acid content is significantly lower in Torreya than in Taxus. The prominence of taxoleic acid among Delta 5-olefinic acids in the seed lipids is a unique characteristic of the genus Taxus that isolates it from all other Coniferophytes analyzed so far. However, this feature is not shared by other Taxaceae species, such as Torreya, and with regard to their seed fatty acid compositions, the family Taxaceae appears particularly heterogeneous. Our observations favor the hypothesis that in Gymnosperm seeds, there might exist two Delta 5-desaturases, one specific for unsaturated acids with a Delta 9-ethylenic bond (active in Taxus but not in Torreya), and the other specific for unsaturated acids with a Delta 11-ethylenic bond (active in Torreya but not in Taxus). Our data also highlight the importance of the elongase(s) in the metabolism of fatty acids in Gymnosperm seeds. 14-Methylhexadecanoic acid, a habitual component of Pinaceae and Ginkgo biloba seed lipids, could not be detected in the Taxaceae studied here. C-13 nuclear magnetic resonance spectroscopy of the oils from both genera has confirmed that Delta 5-olefinic acids are apparently excluded from the internal position of triacylglycerols, which is a characteristic common to all Gymnosperm species analyzed so far, and consequently of great antiquity in their life history.

Wang, D. D., T. J. Girard, et al. (1998). Inhibitory activity of unsaturated fatty acids and anacardic acids toward soluble tissue factor-factor VIIa complex. Journal Of Natural Products. Nov 61(11): 1352-1355.

Five compounds, which inhibited the amidolytic activity of soluble tissue factor/activated factor VII complex (sTF/VIIa), were isolated from two traditional Chinese medicinal plants commonly used in the treatment of cardiovascular and cerebrovascular diseases; The active compounds were found to be linolenic, linoleic, and oleic acids from roots of Salvia miltiorrhiza; and two anacardic acids, 6-(8'Z-pentadecenyl)- and 6-(10'Z-heptadecenyl)-salicylic acids, from leaves of Ginkgo biloba. The IC50 values were in the range 30-80 mu mol/L. Palmitic acid, isolated from roots of Salvia miltiorrhiza, and 2-[(3',7',11',15'-tetramethyl)-2'E,6'E, 10'E,14'E-hexadecatetraenyl]-1,4-hydroquinone, isolated from the marine sponge Adocia viola, did not inhibit sTF/VIIa. Further expansion of the structure-activity relationship to include anacardic acids, 6-(8'Z,11'Z-heptadecadienyl)- and 6-(8'Z, 11'Z, 14'Z-heptadecatrienyl)-salicylic acids from leaves of Anacardium spondias, and other fatty acids demonstrated that at least one cis double bond was essential for inhibitory activity, and that fatty acids containing two or three cis double bonds were optimal. Evidence from preincubation studies implied that these fatty acids may exert their effect by binding to VIIa and consequently preventing binding of sTF to VIIa.

Saponara, R. and E. Bosisio (1998). Inhibition of cAMP-Phosphodiesterase by biflavones of Ginkgo biloba in rat adipose tissue. Journal Of Natural Products. Nov 61(11): 1386-1387.

This work compares the inhibition of cAMP-phosphodiesterase in rat adipose tissue by a mixture of Ginkgo biloba biflavones with the effect of individual dimeric flavonoids. The degree of enzyme inhibition by G. biloba biflavones was amentoflavone > bilobetin > sequoiaflavone > ginkgetin = isoginkgetin. Sciadopitysin was almost inactive.

Li, C. X., L. Li, et al. (1998). The protective effects of traditional Chinese medicine prescription, Han-Dan-Gan-Le, on CCl4-induced liver fibrosis in rats. American Journal Of Chinese Medicine 26(3-4): 325-332.

Han-Dan-Gan-Le, a Chinese medicine preparation composed of Salvia miltorrhiza, Radix paeoniae, Astragalus membranaceus, Stephania tetrandra, and dried leaves of Ginkgo biloba, has been used successfully to treat human liver fibrosis and cirrhosis for years. This study was designed to examine the mechanisms of the protection. Male Wistar rats were given CCl4 (1.2 ml/kg, 2 times/week), 20% fat diet, and 30% alcohol in drinking water (every other day) for 6 weeks. Han-Dan-Gan-Le (0.5 and 1.0 g/kg, p.o., daily for 6 weeks) was administered to rats simultaneously to examine the protective effects against CCl4-induced liver fibrosis. The experimentally-induced liver fibrosis and other morphological alterations were significantly ameliorated by Han-Dan-Gan-Le. Han-Dan-Gante treatments decreased CCl4-induced hepatic collagen accumulation by more than 50%, and significantly increased urinary excretion of hydroxyproline. The CCl4-induced lipid peroxidation in liver and serum was ameliorated as a result of Han-Dan-Gan-Le treatment, possibly by restoring the activity of superoxide dismutase activity in liver and erythrocytes, In conclusion, Han-Dan-Gan-Le is effective in protecting against liver fibrosis, The mechanisms of the protection appear to be due to its antioxidant properties and the modulation of hepatic collagen metabolism.

Jobst, K. A. (1998). Gingko for treatment of dementia. Forschende Komplementarmedizin. Apr 5(2): 93-95.

Schneider, B. (1998). Gingko for treatment of dementia. Forschende Komplementarmedizin. Apr 5(2): 95-96.

Cesarani, A., F. Meloni, et al. (1998). Ginkgo biloba (EGb 761) in the treatment of Equilibrium disorders. Advances In Therapy. Sep Oct 15(5): 291-304.

In an open, controlled study, 44 patients complaining of vertigo, dizziness, or both, caused by vascular vestibular disorders were randomly treated with extract of Ginkgo biloba (EGb 761) 80 mg twice daily or with betahistine dihydrochloride (BI) 16 mg twice daily for 3 months. A complete neuro-otologic and equilibrimetric examination was performed at baseline and after 3 months of treatment, with evaluation of clinical findings. In the first month of therapy, vertigo and dizziness improved in 64.7% of patients treated with BI and in 65% of those who received EGb 761. Compared to baseline, no statistically significant changes were observed in cranial scans for patients with a ''central'' cranial pattern. Likewise, no changes versus baseline were observed in both groups for the equilibrium score. The comprehensive test battery showed the following findings: EGb 761 induced a slight decrease of saccadic delay and considerably increased saccadic velocities; BI improved saccadic accuracy but did not modify delay; EGb 761 improved smooth pursuit gain at 0.4 Hz 40 degrees/s three times more than BI; both drugs asymmetrically reduced nystagmus maximum velocity at 40 degrees/s; both drugs asymmetrically improved the sinusoidal vestibule-ocular reflex; BI considerably reduced-whereas EGb 761 considerably improved-visuovestibular ocular reflex. No side effects were recorded during the trial except for transient mild headache and gastric upset in 2 patients receiving EGb 761 and transient cyanosis of nails and lips in 1 patient given BI. These results suggest that EGb 761 and BI operate at different equilibrium receptor sites and show that EGb 761 can considerably improve oculomotor and visuovestibular function.

Pietta, P., P. Simonetti, et al. (1998). Antioxidant activity of selected medicinal plants. Journal Of Agricultural And Food Chemistry. Nov 46(11): 4487-4490.

Commonly used medicinal plant extracts with standardized content of polyphenols were investigated for their total antioxidant activity(TAA). Green tea, oligomeric procyanidins (from grape seed and pine bark), bilberry, and ginkgo exhibited TAA in the range of 5.12-2.57 mM Trolox, thereby indicating a valuable antioxidant capacity. Witch hazel, propolis EPID, artichoke, and hawthorn afforded lower TAA (1.54-0.44 mM Trolox), whereas echinacea, ginseng, passionflower, sweet clover, and eleuthero were rather uneffective (TAA < 0.32 mM Trolox). Excipients normally used to prepare the extracts did not interfere with the assay, and a good correlation between the content of polyphenols and the TAA was assessed. The measured TAB was higher than those calculated from the content and antioxidant potential of specific components, as exemplified for green tea and ginkgo extracts. This may be attributed to the presence in these extracts of other substances with antioxidant capacity. On the other hand, some components (such as ginkgolides in ginkgo extract) insensitive to the TAA assay played an important antioxidant role in vivo. These results suggest that TAA determination is of interest for a comparative evaluation of in vitro antioxidant potential, but it needs to be combined with in vivo data for adequate assessment of the antioxidant capacity of medicinal plant extracts.

Oken, B. S., D. M. Storzbach, et al. (1998). The efficacy of Ginkgo biloba on cognitive function in Alzheimer disease. Archives Of Neurology. Nov 55(11): 1409-1415.

Objective: To determine the effect of treatment with Ginkgo biloba extract on objective measures of cognitive function in patients with Alzheimer disease (AD) based on formal review of the current literature.Methods: An attempt was made to identify all English and non-English-language articles in which G biloba extract was given to subjects with dementia or cognitive impairment. Inclusion criteria for the meta-analysis were (1) sufficiently characterized patients such that it was clearly stated there was a diagnosis of AD by either Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition, or National Institute of Neurological Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria, or there was enough clinical detail to determine this by our review; (2) clearly stated study exclusion criteria, ie, those studies that did not have stated exclusions for depression, other neurologic disease, and central nervous system-active medications were excluded; (3) use of standardized ginkgo extract in any stated dose; (4) randomized, placebo-controlled and double-blind study design; (5) at least 1 outcome measure was an objective assessment of cognitive function; and (6) sufficient statistical information to allow for meta-analysis.Results: Of more than 50 articles identified, the overwhelming majority did not meet inclusion criteria, primarily because of lack of clear diagnoses of dementia and AD. Only 4 studies met all inclusion criteria. In total there were 212 subjects in each of the placebo and ginkgo treatment groups. Overall there was a significant effect size of 0.40 (P<.0001). This modest effect size translated into a 3% difference in the Alzheimer Disease Assessment Scale-cognitive subtest.Conclusions: Based on a quantitative analysis of the literature there is a small but significant effect of 3- to 6-month treatment with 120 to 240 mg of G biloba extract an objective measures of cognitive function in ED. The drug has not had significant adverse effects in formal clinical trials but there are 2 case reports of bleeding complications. In AD, there are limited and inconsistent data that preclude determining if there are effects on noncognitive behavioral and functional measures as well as on clinician's global rating scales. Further research in the area will need to determine if there are functional improvements and to determine the best dosage. Additional research will be needed to define which ingredients in the ginkgo extract are producing its effect in individuals with AD.

Ohara, M., D. Kiefer, et al. (1998). A review of 12 commonly used medicinal herbs. Archives Of Family Medicine. Nov Dec 7(6): 523-536.

A large and increasing number of patients use medicinal herbs or seek the advice of their physician regarding their use. More than one third of Americans use herbs for health purposes, yet patients (and physicians) often lack accurate information about the safety and efficacy of herbal remedies. Burgeoning interest in medicinal herbs has increased scientific scrutiny of their therapeutic potential and safety, thereby providing physicians with data to help patients make wise decisions about their use. This article provides a review of the data on 12 of the most commonly used herbs in the United States. In addition, we provide practical information and guidelines for the judicious use of medicinal herbs.

Akisu, M., N. Kultursay, et al. (1998). Platelet-activating factor is an important mediator in hypoxic ischemic brain injury in the newborn rat. Biology Of The Neonate. Dec 74(6): 439-444.

Hypoxic-ischemic encephalopathy is still a very important cause of neonatal mortality and morbidity. Recently, platelet-activating factor (PAF) has been accused of being responsible for the neuronal damage in hypoxic-ischemic brain. We investigated tissue PAF concentrations in hypoxic-ischemic brain injury in immature rats. Endogenous PAF concentration in brain tissue showed a marked increase in hypoxic-ischemic pups (85.6 +/- 15.5 pg/mg protein) when compared to that of control (9.05 +/- 3.1 pg/mg protein). In addition, we examined the effects of flunarizine, a selective calcium channel blocker, and Ginkgo biloba extract (EGb 761) on endogenous PAF concentration in hypoxic-ischemic brain injury. Endogenous PAF concentrations in both flunarizine-pretreated (16.6 +/- 4.8 pg/mg protein) and EGb 761-pretreated (33.5 +/- 8.9 pg/mg protein) pups were significantly lower than the untreated group. These results indicate that PAF is an important mediator in immature rat model of cerebral hypoxic-ischemic injury. The suppressor effect of flunarizine and EGb 761 on PAF production may open new insight into the treatment of hypoxic-ischemic brain injury.

Knipschild, P. G., R. Hoerr, et al. (1998). Optimization of placebos for double-blind clinical trials - Experience with a phytopharmaceutical. Arzneimittel Forschung Drug Research. Oct 48(10): 1033-1036.

The maintenance of double-blind conditions in placebo-controlled trials depends on the quality of the placebo preparation. The placebo should match the active substance-containing preparation as closely as possible, but it must not contain any substances that might themselves be pharmacologically active. Active substances characterized by a particular colour taste, smell or other easily perceptible properties constitute a challenge to researchers. The way of developing a placebo that matches a phytopharmaceutical to a satisfactory extent is described and discussed.

Ellison, J. M. (1998). Antidepressant-induced sexual dysfunction: Review, classification, and suggestions for treatment. Harvard Review Of Psychiatry. Nov Dec 6(4): 177-189.

Sexual function, an important component of quality of life, is often affected by antidepressant treatment. Reports associate antidepressant medications with a wide range of sexual disorders of desire, arousal, and orgasm, and with the occurrence of sexual pain. Fewer sexual dysfunctions have been reported with bupropion, nefazodone, and mirtazapine than with the monoamine-oxidase inhibitors, tricyclic antidepressants, selective serotonin-reuptake inhibitors, and venlafaxine. Sexual dysfunctions may occur in more than half of patients treated with selective serotonin-reuptake inhibitors, but patients may not readily divulge sexual information unless a clinician is knowledgeable and proactive in assessment. Once an antidepressant-induced sexual dysfunction is detected and its nature is characterized, an appropriate treatment intervention can be chosen in order to alleviate the sexual disorder and enhance treatment compliance. This review classifies antidepressant-induced sexual dysfunctions, discusses assessment and differential diagnosis, and describes currently reported treatment approaches.

Yang, X. and Z. L. Li (1998). Callus formation in relation to changes of the membrane Ca2+ in the graft unions of Ginkgo biloba L. Chinese Science Bulletin. Oct 43(20): 1732-1736.

The relationship between the callus formation and intracellular Ca2+ at the early stage of development of graft unions in Ginkgo biloba L. was investigated. On the second day after grafting, part of the undamaged living cells at the graft interface of the stock and scion in the regions of the cortex and. pith began to dedifferentiate or divide. 8 d after grafting, a great number of callus cells were produced from the cortex and phloem, while callus bridges linking the stock with scion formed between the callus cells of the graft partners from the cortex. A membrane Ca2+ probe, chlortetracycline (CTC), was used to locate the intracellular Ca2+ distribution and it was found that the cortical and pith parenchyma cells were the first to show remarkably increased CTC-Ca2+ fluorescence, suggesting that the cortical and other parenchyma cells play a leading role at the early stage of development of graft unions by earlier dedifferentiation and more rapid production of callus cells.

Simonson, W. (1998). Promising agents for treating Alzheimer's disease. American Journal Of Health System Pharmacy. Nov 1(55): S11-S16.

Key issues related to the pharmacotherapy of Alzheimer's disease (AD) are discussed, and current and investigational agents are described.There are three key issues in the pharmacotherapy of AD. First, there is a need to eliminate or minimize drug-related adverse reactions. Second, concurrent diseases that either resemble AD or complicate its treatment must be addressed. The third issue is the need for pharmacotherapy not only to improve cognitive performance but to treat related symptoms. Current strategies for treating AD usually rely on increasing cholinergic function. To date, cholinesterase inhibitors (ChEIs) are the only agents that have been well studied and that have shown efficacy by improving cognitive deficits and, in some cases, psychiatric and behavioral components of AD. Tacrine is rarely used today; the only other FDA-approved ChEI is donepezil. Many other approaches are under clinical investigation, including selective muscarinic agonists, antioxidants, anti-inflammatory drugs, and estrogen replacement therapy. New drug discovery efforts focus on molecular events believed to be important in the pathogenesis of AD. Future pharmacotherapy will probably involve increased use of ChEIs in combination with drugs that have other mechanisms of action.Current treatment of AD primarily involves ChEI therapy, but other therapeutic options, particularly combination therapies, hold promise.

Miller, L. G. (1998). Herbal medicinals: Selected clinical considerations focusing on known or potential drug-herb interactions. Archives Of Internal Medicine. Nov 158(20): 2200-2211.

Herbal medicinals are being used by an increasing number of patients who typically do not advise their clinicians of concomitant use. Known or potential drug-herb interactions exist and should be screened for. If used beyond 8 weeks, Echinacea could cause hepatotoxicity and therefore should not be used with other known hepatoxic drugs, such as anabolic steroids, amiodarone, methotrexate, and ketoconazole. However, Echinacea lacks the 1,2 saturated necrine ring associated with hepatoxicity of pyrrolizidine alkaloids. Nonsteroidal anti-inflammatory drugs may negate the usefulness of feverfew in the treatment of migraine headaches. Feverfew, garlic, Ginkgo, ginger, and ginseng may alter bleeding time and should not be used concomitantly with warfarin sodium. Additionally, ginseng may cause headache, tremulousness, and manic episodes in patients treated with phenelzine sulfate. Ginseng should also not be used with estrogens or corticosteroids because of possible additive effects. Since the mechanism of action of St John wort is uncertain, concomitant use with monoamine oxidase inhibitors and selective serotonin reuptake inhibitors is ill advised. Valerian should not be used concomitantly with barbiturates because excessive sedation may occur. Kyushin, licorice, plantain, uzara root, hawthorn, and ginseng may interfere with either digoxin pharmacodynamically or with digoxin monitoring. Evening primrose oil and borage should not be used with anticonvulsants because they may lower the seizure threshold. Shankapulshpi, an Ayurvedic preparation, may decrease phenytoin levels as well as diminish drug efficacy. Kava when used with alprazolam has resulted in coma. Immunostimulants (eg, Echinacea and zinc) should not be given with immunosuppressants (eg, corticosteroids and cyclosporine). Tannic acids present in some herbs (eg, St John wort and saw palmetto) may inhibit the absorption of iron. Kelp as a source of iodine may interfere with thyroid replacement therapies. Licorice can offset the pharmacological effect of spironolactone. Numerous herbs (eg, karela and ginseng) may affect blood glucose levels and should not be used in patients with diabetes mellitus.

Mashour, N. H., G. I. Lin, et al. (1998). Herbal medicine for the treatment of cardiovascular disease: Clinical considerations. Archives Of Internal Medicine. Nov 158(20): 2225-2234.

Herbs have been used as medical treatments since the beginning of civilization and some derivatives (eg, aspirin, reserpine, and digitalis) have become mainstays of human pharmacotherapy. For cardiovascular diseases, herbal treatments have been used in patients with congestive heart failure, systolic hypertension, angina pectoris, atherosclerosis, cerebral insufficiency, venous insufficiency, and arrhythmia. However, many herbal remedies used today have not undergone careful scientific assessment, and some have the potential to cause serious toxic effects and major drug-to-drug interactions. With the high prevalence of herbal use in the United States today, clinicians must inquire about such health practices for cardiac disease and be informed about the potential for benefit and harm. Continuing research is necessary to elucidate the pharmacological activities of the many herbal remedies now being used to treat cardiovascular diseases.

Ezzo, J., B. M. Berman, et al. (1998). Complementary medicine and the Cochrane Collaboration. Jama Journal Of The American Medical Association. Nov 280(18): 1628-1630.

Wong, A. H. C., M. Smith, et al. (1998). Herbal remedies in psychiatric practice. Archives Of General Psychiatry. Nov 55(11): 1033-1044.

Patients' use of alternative and complementary health services has created a need for physicians to become informed about the current literature regarding these treatments. Herbal remedies may be encountered in psychiatric practice when they are used to treat psychiatric symptoms; produce changes in mood, thinking, or behavior as a side effect; or interact with psychiatric medications. English-language articles and translated abstracts or articles (where available) found on MEDLINE and sources from the alternative/complementary health field were reviewed. Each herb was assessed for its safety, side effects, drug interactions, and efficacy in treating target symptoms or diagnoses, A synopsis of the information available for each herb is presented. In many cases the quantity and quality of data were insufficient to make definitive conclusions about efficacy or safety. However, there was good evidence for the efficacy of St John's wort for the treatment of depression and for ginkgo in the treatment of memory impairment caused by dementia. More research is required for most of the herbs reviewed, but the information published to date is still of clinical interest in diagnosing, counseling, and treating patients who may be taking botanical remedies.

Zink, T. and J. Chaffin (1998). Herbal 'health' products: What family physicians need to know. American Family Physician. Oct 58(5): 1133-1140.

Patients who self-medicate with herbs for preventive and therapeutic purposes may assume that these products are safe because they are ''natural,'' but some products cause adverse effects or have the potential to interact with prescription medications. The United States lacks a regulatory system for herbal products. Although only limited research on herbs has been published, St John's wort shows promise as a treatment for depression. Ginkgo biloba extract is possibly effective for cerebrovascular insufficiency and dementia. Feverfew is used extensively in Canada for migraine prophylaxis but needs more rigorous study. Ephedrine has been regulated by many states because its misuse has been associated with several deaths. Echinacea is being tried as an agent for immune stimulation, and garlic is under study for cholesterol-lowering properties, but both require more study. Physicians should educate themselves and their patients about the efficacy and adverse interactions of herbal agents and the limitations of our present knowledge of them.

DeLaGarza, V. W. (1998). New drugs for Alzheimer's disease. American Family Physician. Oct 58(5): 1175-1182.

Alzheimer's disease is characterized by degeneration of various structures in the brain, with development of amyloid plaques and neurofibrillary tangles. Deficiencies of acetylcholine and other neurotransmitters also occur. Pharmacologic treatment of the disease generally seeks to correct the histopathology, the biochemical derangements or their effects. The only drugs labeled to date for the treatment of cognitive symptoms in patients with Alzheimer's disease are two cholinesterase inhibitors that prevent the breakdown of acetylcholine in the synapse. Both medications are associated with modest improvements in cognitive function. However, all benefit is lost when these drugs are discontinued; the disease then progresses to the level seen in placebo-treated patients. Tacrine, the first cholinesterase inhibitor to be so labeled, must be taken four times daily and is associated with hepatic toxicity. Donepezil is taken once daily. Side effects of the cholinesterase inhibitors include nausea, vomiting and diarrhea, which tend to subside after the titration period. Other drugs that have shown some promise in the treatment of Alzheimer's disease are vitamin E, estrogen, selegiline and a mixture of ergoloid mesylates. Anti-inflammatory drugs and nicotine are also being studied for their effects as neuroprotectors or neurotransmitter enhancers. The caregivers of patients with Alzheimer's disease may see little effect from these or other investigational agents, but nursing home placement may be delayed.

Roy, S., H. Kobuchi, et al. (1998). Ginkgo biloba extract (EGb 761): antioxidant properties and regulation of gene expression. Ginkgo Biloba Extract Egb 7: 1-17.

EGb 761 has proven beneficial in pathologies related to cerebral and circulatory disorders. Such effects of EGb, 761 extract have been substantiated with placebo-controlled, double-blind clinical trials. Mechanisms underlying the beneficial effects of EGb 761 are only partially understood. One of the main mechanisms seems to be related to the antioxidant properties of EGb 761, which appear to be due to the synergistic action of its major constituents, such as flavonoids, terpenoids and the organic acids. EGb 761 directly scavenges hydroxyl, superoxide, peroxyl and nitric oxide radicals in vitro. EGb 761 also protects against free radical-mediated damage in biological model systems, including ischemia-reperfusion injury of organs and oxidative modification of low-density lipoprotein. EGb 761 inhibits nitric oxide production in macrophages by inhibiting nitric oxide synthase (NOS) activity and regulating inducible-NOS gene expression. EGb 761 down-regulates agonist-induced cell adhesion molecule expression and lymphocyte-endothelial cell adhesion. Exposure of human endothelial cells to EGb 761 resulted in modulation of several mRNA transcripts identified by differential display of mRNA. Such regulatory effects of EGb 761 on nitric oxide metabolism, cell adhesion processes and gene expression may be implicated in its beneficial effect in brain and circulatory disorders.

Perianin, A., S. Rais, et al. (1998). Ginkgolide B (BN 52021) and transductional activities of human polymorphonuclear leukocytes. Ginkgo Biloba Extract Egb 7: 19-31.

Ginkgolide B (GKB, BN 52021), a bioactive component of EGb 761 (a standardized extract of Ginkgo biloba leaves), has been extensively studied as an antagonist of platelet-activating factor (PAF). Although EGb, 761 possesses free radical-scavenger activity due to its flavonoid content, GKB is a potent antioxidant and has pleiotrophic beneficial effects. To gain insight into the mechanism of action of GKB, we explored its potential effects on 2 transductional events, ie, the phospholipase D (PLD) activity of human polymorphonuclear leukocytes (PMN) and protein phosphorylation, and respiratory burst, ie, the production of superoxide anion. PLD cleaves phosphatidylcholine (PC) and generates choline and phosphatidic acid (PA); the latter is then dephosphorylated into diglycerides (DG) by PA-phosphohydrolase (PPH). PLD activity was assessed by 2 methods, one based on radiolabeling PC pools with 1-O-[H-3]octade-cyl-sn-glycero-3-phosphocholine and the other on a chemiluminescence assay for choline,Treatment of radiolabeled PMN with GKB (0.12-7.1 mu M) for 10 min induced a concentration-dependent increase in [H-3]PA formation that was maximal in the presence of 1.2 mu M (approximately +50% of control values); higher drug concentrations were less effective. Elevated [H-3]PA levels were not due to inhibition of PPH, as GKB did not alter the formation of tritiated DG and PA induced by the chemottractant f-Met-Leu-Phe (fMLP). By contrast, PAF-induced PLD activity was efficiently prevented by GKB (IC50 of approximately 1 mu M), which is consistent with its 'anti-PAF' effect. Further evidence of PLD activation by GKB was that the choline content increased in parallel with [H-3]PA levels.GKB (1.2-12 mu M) also stimulated phosphorylation of several proteins (molecular masses of 38, 47, 55 and 67 kDa) in a PMN cytosolic fraction in the presence of [P-32-gamma]ATP. In contrast, when protein phosphorylation was stimulated by protein kinase C (PKC), high GKB concentrations (7.2 and 12.5 mu M) were inhibitory. Stimulation of the PMN respiratory burst by the bacterial peptide fMLP, phorbol myristate acetate or zymosan particles under optimal conditions was not altered by GKB (0.12-7.1 mu M). In contrast, GKB potentiated the respiratory burst induced by the calcium ionophore A23187, whereas that induced by PAF (IC50 of 1 mu M) was inhibited. These data provide evidence that GKB stimulates PLD activity and protein phosphorylation, and suggest that it may have the potential to enhance cellular activities.

Gozin, A., L. DaCosta, et al. (1998). Oxygen radicals activate neutrophil adhesion to and tyrosine phosphorylation in endothelial cells: effect of the antioxidant Ginkgo biloba extract (EGb 761). Ginkgo Biloba Extract Egb 7: 33-43.

Reactive oxygen species (ROS) play an important role in the initiation, duration and breakdown of inflammation, during which polymorphonuclear neutrophils (PMN) are recruited in tissues acid activated. Among inflammatory diseases, ischemia-reperfusion syndrome is an example of an excess of oxygen free radicals produced by PMN NADPH oxidase or by other oxidases, such as xanthine oxidase, which could then be responsible for the important PMN infiltration into tissues.In this study, we looked for the role of ROS in the adhesion of neutrophils to endothelial cells and for the intracellular mechanism involved. Human umbilical cord vein endothelial cells (HUVEC) in culture were subjected to the action of H2O2 and O-2(-), produced by the oxidation of hypoxanthine (HX, 2 x 10(-4) M) by xanthine oxidase (XO, 4.5 mU/ml), and the adhesion of resting PMN was measured by the amount of myeloperoxidase. Adhesion was increased when HUVEC were stimulated for 15 min (from 10 to 22%) and was inhibited by 100 and 200 mu g/ml of Ginkgo biloba extract (EGb, 761), suggesting an involvement of ROS in this increased adhesion.The tyrosine kinase inhibitors genistein (30 mu M), herbimycin A (0.9 mu.M) and erbstatin (26 nM) inhibited this adhesion, suggesting a role for tyrosine kinases in this function. Tyrosine phosphorylation of 2 main bands of 120 and 70 kDa was increased by ROS and inhibited by EGb 761. These bands have been identified as focal adhesion kinase (p125(FAK)), paxillin (PAX) and p130cas, which are cytoskeletal proteins involved in focal adhesion,In conclusion, ROS are involved in an increase of PMN-HUVEC adhesion and tyrosine kinase activation, which leads to paxillin and p130cas phosphorylation. These results support the idea that a correlation may exist between tyrosine phosphorylation and PMN adhesion induced by ROS, but this remains to be confirmed. The production of ROS by PMN could thus be involved in the recruitment of neutrophils into inflamed tissues by increasing their adherence to the vascular endothelium, EGb 761 is able to inhibit the phosphorylation, which seems to be involved early in the mechanism of PMN-HUVEC adhesion. These results confirm the anti-inflammatory properties of EGb 761.

Maixent, J. M., S. Pierre, et al. (1998). Protective effects of Ginkgo biloba extract (EGb 761) on the alterations of Na/K-ATPase isoenzyme activities during cerebral ischemia in mouse. Ginkgo Biloba Extract Egb 7: 45-55.

We investigated the effect of cerebral ischemia and the protection provided by pretreatment with EGb 761 on Na/K-ATPase activity and its isoforms in the mouse. Infarct size, fatty-acid and malondialdehyde contents were evaluated in parallel. Focal ischemia reduced the Na/K-ATPase activity by 43 and 62%, 1 and 6 h postocclusion, respectively. These deleterious effects of ischemia on Na/K-ATPase were prevented by EGb 761 pretreatment. Membrane integrity, as assessed by detergent treatment of isolated membranes, was altered by ischemia, since impermeable vesicles were undetectable. Membrane integrity was intact in preparations from animals pretreated with EGb 761. The activities of isoenzymes, as determined by ouabain in dose-response curves, were all affected by ischemia and preserved by EGb 761. The degree of protection afforded by EGb 761 pretreatment paralleled that of the reduction of enhanced lipid peroxidation of cerebral tissue, as estimated from malondialdehyde production. Because these effects occurred without major changes of overall fatty-acid composition and membrane protein expression of alpha and beta Na/K-ATPase isoforms, and with negligible reduction of the necrotic area, the present results suggest that the decreased intrinsic activity of Na/K-ATPase following hours of cerebral ischemia occurred through mechanisms affecting the membrane microenvironment and enzyme turnover of the 3 active Na/K-ATPase isoenzymes. Through its anti-ischemic effect, EGb 761 might play a crucial role in this neuroprotection.

LeiningerMuller, B., C. Jolivalt, et al. (1998). Oxidation of human apolipoprotein E: isoform susceptibility and protection with Ginkgo biloba extract (EGb 761). Ginkgo Biloba Extract Egb 7: 57-68.

Apolipoprotein E (ApoE) is a polymorphic protein whose specific isoform, ApoE4, has been widely associated with Alzheimer's disease (AD). ApoE may be Linked with this disease by its isoform-specific interaction with lipids or proteins of amyloid plaques. On the other hand, oxidative stress has been proposed to be linked to the development of AD. We recently detected myeloperoxidase (MPO), a heme protein known to be implicated in inflammation, in the human brain. in the presence of H2O2 and Cl-, MPO produces hypochlorite that oxidizes proteins.Using the MPO enzymatic system, we now report that the oxidation of the 3 recombinant ApoE isoforms is differential, with ApoE4 being more susceptible than ApoE3, which is itself more susceptible than ApoE2. To study whether the association of oxidized ApoE with lipids could be modified, we prepared well-defined ApoE-phospholipid complexes. The more the isoform was susceptible to oxidation, the more its ability to interact with phospholipids was reduced. The effects of the Ginkgo biloba extract (EGb 761) at concentrations ranging from 100 to 600 mu g/ml, on the oxidation of each ApoE isoform were investigated. We observed 40% relative protection with EGb 761. Moreover, the more the isoform was susceptible to oxidation, the lower the concentration of EGb 761 that was necessary to protect the protein against oxidation. Taken together, these results could explain the strong association of the epsilon 4 allele with AD. The structural alteration of the more oxidizable ApoE4 could lead to inefficient lipid recycling in the brain, a phenomenon implicated in the development of AD that EGb 761 might be able to prevent.

Ramassamy, C., P. Krzywkowski, et al. (1998). Apolipoprotein E, oxidative stress and Ginkgo biloba extract (EGb 761) in Alzheimer's disease. Ginkgo Biloba Extract Egb 7: 69-83.

Apolipoprotein E (ApoE) is a glycoprotein implicated in cholesterol homeostasis and in lipid turnover. Inheritance of the epsilon 4 allele of ApoE has been demonstrated to be a major risk factor for late and sporadic Alzheimer's disease (AD). Age-related oxidative challenges may also be an important factor in AD. Preliminary results suggest a relationship between the ApoE genotype and oxidative stress in AD, but firm evidence is still lacking.The first part of our study consisted of examining the ApoE genotype in AD brain (hippocampus, frontal cortex) as a function of the oxidation of (phospho)lipids. We have demonstrated that the level of oxidation of lipids is associated with inheritance of the epsilon 4 allele. Oxidative stress is a long-lasting process that increases with aging. We tested the efficacy of the Ginkgo biloba extract (EGb 761), a compound that might delay this process. EGb 761 is a drug with a wide variety of pharmacological activities and it is well known for its antioxidant properties, derived from its ability to scavenge different types of free radicals.We previously demonstrated that EGb 761 can protect primary hippocampal neurons in culture under oxidative stress conditions. These results prompted us to study the effect of EGb 761 on the in vitro stimulated oxidation of phospholipids in hippocampi and frontal cortices from AD patients with different ApoE genotypes. In vitro oxidation was induced by high concentrations of hydrogen peroxide and FeSO4 (0.1 mM). The presence of EGb 761 (25-50 mu g/ml) completely prevented the induction of (phospho)lipid oxidation in controls and the tissues of AD patients with the epsilon 3/epsilon 3 or epsilon 3/epsilon 4 genotype. The protective effect of EGb 761 was less potent in AD patients with the epsilon 4/epsilon 4 genotype.To further study the relationship between EGb 761 and the neurobiology of ApoE, we investigated the effect of EGb 761 on the synthesis and secretion of ApoE by astrocytes in culture. Our results showed that 3 h of treatment with EGb 761 markedly potentiated ApoE secretion by astrocytes. The ApoE secretion induced by EGb 761 is not associated with increases in lactate dehydrogenase.These results demonstrate that AD subjects with the epsilon 4 allele exhibit more aberrant lipid homeostasis and that treatment with a pharmacological concentration of EGb 761 reversed these disturbances in the tissues of AD subjects. This study represents the first pharmacogenetic analysis of the efficacy of EGb 761 in a neurodegenerative disease. The neurobiochemical properties of EGb 761 associated with its clinical benefits (ie, its ability to improve memory and certain other cognitive functions in elderly patients) are consistent with the notion that EGb 761 is a good candidate for the treatment of some age-related disorders such as AD.

Bastianetto, S., C. Ramassamy, et al. (1998). Ginkgo biloba extract (EGb 761) prevents cell death induced by oxidative stress in hippocampal neuronal cell cultures. Ginkgo Biloba Extract Egb 7: 85-99.

Previous studies reported that Ginkgo biloba extract (EGb 761, Tanakan(R), IPSEN Laboratories, France) is a free-radical scavenger that possesses neuroprotective effects in models of oxidative stress. Certain brain regions are particularly susceptible to free-radical damage, such as the hippocampus, an area that is especially affected in Alzheimer's disease (AD). These data, together with the fact that oxygen-activated free radicals may be a component in the pathogenesis of AD and aged-related diseases, led us to investigate whether EGb 761 could protect hippocampal neurons against toxicity induced by hydrogen peroxide (H2O2) or sodium nitroprusside (SNP), 2 generators of reactive oxygen species. Exposure of rat primary mixed or enriched neuronal hippocampal cell cultures to H2O2 Or SNP (which generates nitric oxide, NO) resulted in concentration-dependent decreases in cell survival, as estimated by 2 colorimetric assays. Cotreatment of mixed or enriched neuronal cell cultures with EGb 761 (10-100 mu g/ml) protected concentration-dependently against toxicity induced by either H2O2 (50-150 mu M) or SNP (50-1000 mu M). Maximal protection was observed in the range of 50-100 mu g/ml whereas lower concentrations of EGb 761 did not affect H2O2- or SNP-induced toxicity. These data indicate that EGb 761 is able to protect in vitro hippocampal neurons against oxidative stress and suggest its therapeutic usefulness in treating age-related central nervous system diseases. These results also raise the possibility that treatment efficacy may be predicted on the basis of its in vitro antioxidant capacities.

Pardon, M. C., J. M. Launay, et al. (1998). Effects of long-term treatment with Ginkgo biloba extract (EGb 761) on in vivo regulation of cerebral monoamine oxidase activity in chronically stressed senescent mice. Ginkgo Biloba Extract Egb 7: 101-108.

Studies conducted over the past 10 years have produced evidence that EGb 761, a fully standardized extract of Ginkgo biloba leaves, when tested in rodents, can reduce certain biological and behavioral effects of stress. A number of clinical effects of EGb 761 on the central nervous system have formed the basis for a hypothesis suggesting that the flavonoid substances contained in the leaves of Ginkgo biloba may inhibit monoamine oxidase (MAO), which would provide an explanatory basis for the anti-stress effect of the substance. The aim of the present experimental study, conducted in senescent female B6D2F1 mice, was to investigate the long-term effects of EGb 761 upon in vivo cerebral MAO-A and MAO-B activities. To do so, we studied stressed mice and unstressed controls using a multiple chronic ultra-mild stress procedure for which it has been proven that EGb 761 can reduce the behavioral impact.The results showed that the age-related increases of these enzyme activities in stressed and treated mice appeared to be reversed for both MAO-A and MAO-B: after 8 weeks of stress, the activities of these stressed and treated mice did not differ significantly from the performance of unstressed and untreated younger mice. A more likely hypothesis is that EGb 761 may have a down-regulating effect on cerebral MAO activity, rather than an inhibitory effect. A possible explanatory hypothesis for this regulatory effect could be based on the well-known antioxidant properties of EGb 761.

Rabin, O., A. D. Purdon, et al. (1998). Ginkgo biloba extract (EGb 761) may reduce neuronal death following transient cerebral ischemia by accelerating reincorporation of released arachidonic acid into brain lysophospholipids. Ginkgo Biloba Extract Egb 7: 109-120.

Ginkgo biloba extract (EGb 761) has been reported to reduce neuronal death in the hippocampus of gerbils subjected to 5 min of forebrain ischemia. One possibility is that EGb 761 acts by reducing the concentrations of unesterified fatty acids, including arachidonic acid (AA), which are released from brain phospholipids during transient ischemia and are thought to contribute to cell death. To test this hypothesis, awake gerbils that had or had not been treated with EGb 761 (150 mg/kg per os daily for 2 wk) were subjected to 5 min of bilateral occlusion of the common carotid arteries. Rates of reacylation of released AA and palmitic acid (PAM) into lysophospholipids were quantified during the following 5 min by an in vivo method that involves intravenous infusion of a radiolabeled fatty acid, followed by measurement of: 1) plasma radioactivity to time of death, 2) regional hippocampal and hindbrain radioactivity at the time of death using quantitative autoradiography, and 3) specific activity of the acyl-coenzyme A (CoA) pools (precursors for reacylation) compared with plasma specific activity (ratio defined as dilution factor;1). In untreated animals, recovery from transient ischemia was associated with a 2.6-fold increase in the rate of reincorporation of AA but no significant change in the rate of reincorporation of PAM into brain phospholipids, EGb 761 treatment significantly accelerated reincorporation of AA to 3.7 times the control mean, but had no effect on the rate of reincorporation of PAM. Thus, the reported reduction by EGb 761 of neuronal death following transient ischemia may reflect its ability to reduce neuronal exposure to high and prolonged toxic concentrations of released unesterified AA. Possible targets are the enzymes that control AA reincorporation.

Chandrasekaran, K., L. I. Liu, et al. (1998). Stimulation of mitochondrial gene expression by bilobalide, a component of Ginkgo biloba extract (EGb 761). Ginkgo Biloba Extract Egb 7: 121-128.

A leaf extract of Ginkgo biloba (EGb 761) is used as therapy for cerebrovascular diseases. The molecular mechanism by which EGb 761 mediates its protective effect is unknown. We hypothesized that EGb 761 may act by up-regulating gene expression of oxidative phosphorylation enzymes within mitochondria. In this study, we evaluated the effects of ginkgolide B and bilobalide, components of EGb 761, on gene expression of mitochondrial DNA (mtDNA)encoded cytochrome oxidase subunit III (COX III) in a neuronal culture. Rat pheochromacytoma cells (PC12) were differentiated with nerve growth factor (50 ng/ml) for 10 days, and ginkgolide B (from 0.2 mu g/ml to 10 mu g/ml) or bilobalide (from 0.2 mu g/ml to 10 mu g/ml) was added to the culture medium for 6 h. Total RNA was isolated and the levels of COX III mRNA (normalized to beta-actin mRNA) were measured by Northern blot analysis. Ginkgolide B caused no significant change in COX III-mRNA levels. In contrast, 5 or 10 mu g/ml of bilobalide increased COX III-mRNA levels by approximately 2. Measurement of total mtDNA levels by Southern blot and dot-blot analyses showed no significant changes. These results suggest that bilobalide either upregulates mtDNA transcription or reduces the turnover of mtDNA-encoded mRNA.

Yao, Z. X., N. Boujrad, et al. (1998). Antioxidant properties of ginkgolides: protection of testicular Leydig-cell cytochrome P-450(scc) activity and androgen formation. Ginkgo Biloba Extract Egb 7: 129-138.

Leydig cells in culture are susceptible to O-2-mediated free-radical damage resulting in decreased steroidogenic responsiveness of the cells to the gonadotropins, luteinizing hormone (LH) and human chorionic gonadotropin (hCG). The standardized extract of Ginkgo biloba leaves, EGb 761, is known to have free-radical scavenging and/or antioxidant properties. The latter property was recently shown to be due to the terpene constituents, ginkgolides. Treatment of purified adult rat Leydig cells for 72 h with ginkgolides resulted in the maintenance, compared to control, of the hCG-stimulated androgen formation. Bilobalide had no effect. To examine the mechanism of action of ginkgolides, we used the substrates 22R-hydroxycholesterol and pregnenolone with or without steroidogenic enzyme inhibitors. The results obtained indicate that treatment of the cells with ginkgolides does not affect the sidechain cleaving cytochrome P-450, the enzyme responsible for the cleavage of cholesterol to pregnenolone, mRNA or protein expression but rather directly protects the enzyme activity reduced by the culture conditions. Since P-450 enzyme inactivation is an O-2-mediated event, it can be concluded that ginkgolides have antioxidant properties that can be used to protect the hormone-stimulated androgen formation from O-2-mediated damage.

Sluse, F. E., G. H. Du, et al. (1998). Protective effects of Ginkgo biloba extract (EGb 761) on functional impairments of mitochondria induced by anoxia-reoxygenation in situ and in vitro. Ginkgo Biloba Extract Egb 7: 139-148.

A decrease of the oxygen supply disrupts cellular energetics. Some critical events occurring during anoxia-reoxygenation form the borderline between cell recovery and necrosis. Since mitochondrial generation of oxygen radicals during anoxia-reoxygenation represents an important cause of cell damage, the study of permanent oxidative phosphorylation dysfunctions is of great interest.Because of its antiradical properties, the protective effects of EGb 761 on mitochondrial function has been tested in 2 different experimental models: 1) in situ, during cold and warm ischemia of rabbit kidneys, with animals or organs receiving an acute administration of EGb 761 during the experiments; and 2) in vitro, during short-term anoxia of isolated liver mitochondria followed by reoxygenation with the EGb, 761 extract in the incubation medium. Respiratory parameters were evaluated in isolated mitochondria in both models by in vitro measurements of oxygen consumption rates.In situ protective effects of EGb 761 (50 mg/kg) were observed during an acute treatment. EGb 761 protected oxidoreductase activities against damage induced in vivo during warm ischemia and this protection was still visible after 48 h of ex vivo cold ischemia. This treatment provided permanent protection of mitochondria against permanent damage induced by ischemia in vivo.In vitro anoxia (1-10 min) followed by reoxygenation (within 4 +/- 1 min) of well-coupled liver mitochondria induced several types of damage at the level of oxidative phosphorylation, for example, decreases of ADP phosphorylation versus oxygen consumption and respiration rate, and a marked increase in superoxide anion production by the mitochondria. The presence of EGb 761 in the incubation medium, at a concentration that did not modify mitochondrial functions before anoxia (50-100 mu g/ml), improved oxidative phosphorylation and prevented the production of superoxide anion after reoxygenation.It may be concluded that an acute administration of EGb 761 in vivo as well as its presence in vitro is beneficial in reducing mitochondrial energy-production disorders induced by anoxia-reoxygenation.

Sastre, J., J. G. delaAsuncion, et al. (1998). Mitochondrial DNA, aging and Ginkgo biloba extract (EGb 761). Ginkgo Biloba Extract Egb 7: 149-157.

Twenty years ago, Miquel and Fleming suggested that mitochondria may play a key role in cellular aging, since mitochondria, and especially mitochondrial DNA (mtDNA), are major targets of free-radical attack. At present, a great deal of experimental evidence shows an age-associated accumulation of mitochondrial deficits due to oxidative damage. Thus, oxidative lesions to mtDNA accumulate with age in human and rodent tissues. Furthermore, levels of oxidative damage to mtDNA are several times higher than those to nuclear DNA,Recently, we studied the effect of the Ginkgo biloba extract EGb 761 on age-associated indices of oxidative damage in liver and brain mitochondria from rats. Treatment with EGb, 761 protects against oxidative damage to mtDNA, oxidation of mitochondrial glutathione and also the age-related increase in peroxide generation by mitochondria. Hence, the antioxidant action of EGb 761 is able to prevent the oxidative stress that occurs in mitochondria upon aging.

Perichon, R., M. T. DroyLefaix, et al. (1998). Effect of Ginkgo biloba extract (EGb 761) on muscarinic cholinergic signal transduction in rat brain synaptosomes during aging. Ginkgo Biloba Extract Egb 7: 159-171.

During aging and in aging-related diseases, changes occur in signal-transduction activity of membrane-associated muscarinic cholinergic receptors (mAChR) and membrane-lipid composition. It has been hypothesized that the changes in membrane-lipid composition are responsible for some of the changes in signal-transduction activity. Additionally, there are well-established age-related decreases in the synthesis and oxidation of polyunsaturated fatty acids. These findings suggest a metabolic defect as the cause for changes in membrane-lipid composition occurring during aging.In peroxisomal diseases, deficiencies in docosahexaenoic acid (DHA) and plasmalogens and an excess of very-long-chain fatty acids (VLCFA) have been associated with neurological defects. DHA and plasmalogens have been proven to be involved in cholinergic signal transduction. Additionally, the presence of carbon-carbon double bonds in DHA and plasmalogens makes these components very sensitive to oxidative stress. Interestingly, both are processed in the peroxisome, which produces large amounts of the pro-oxidant hydrogen peroxide. Since the peroxisomal marker catalase is known to be decreased in old animals, DHA (which is less efficiently synthesized in aged animals) and plasmalogens are more likely to be altered by reactive oxygen species.The present study was designed to test the in vitro and in vivo effects of short- and long-term Ginkgo biloba extract (EGb 761) treatments on rat brain synaptosomal mAChR signal-transduction activity in young and old animals. The analysis also included measurement of synaptosomal membrane lipoperoxidability and width, as well as estimation of liver peroxisomal activities. In vitro results indicate that old brain synaptosomes are more sensitive to lipoperoxidation than young ones. EGb 761 effectively protects synaptosomes against free radicals in both young and old synaptosomes. In vivo results indicate that, in old (20-month-old) rats fed a diet supplemented with EGb 761 (50 mg/kg daily intake) for 6 weeks, membrane width tended to increase (P = 0.07) and signal-transduction activity increased significantly in association with the muscarinic cholinergic receptor (P = 0.044), despite no improvement against free radicals.

Tadano, T., O. Nakagawasai, et al. (1998). Effects of Ginkgo biloba extract on impairment of learning induced by cerebral ischemia in mice. American Journal Of Chinese Medicine 26(2): 127-132.

The effect of Ginkgo biloba extract (GbE) on cerebral ischemia induced by 10-min bilateral occlusion of the carotid arteries in mice was studied. Severe impairment of memory was apparent when the passive avoidance test was carried out 48 hr after bilaterally induced ischemia. When GbE at doses of 50 and 100 mg/kg was given p.o. 1 hr before the 10-min occlusion, there was a significant improvement in memory. The i.p. injection of ifenprodil (30 mg/kg) also showed improvement on learning tasks. The p.o. administration of flavonoid, a fraction isolated from GbE, showed high step-through latency on scopolamine-induced amnesia. All these findings indicate that GbE is beneficial for clinical use in amnesia accompanied with cerebral vascular disease.

Doraiswamy, P. M. and D. C. Steffens (1998). Combination therapy for early Alzheimer's disease: What are we waiting for? Journal Of The American Geriatrics Society. Oct 46(10): 1322-1324.

The practical pharmacological approaches currently available to palliate the cognitive and functional losses in early Alzheimer's disease (AD) include cholinesterase inhibitors (ChEI), antioxidants (e.g., vitamin E), anti-inflammatory agents, estrogen, seligiline, vasoactive agents, and ginkgo biloba. Reviewing available data on these therapies and using models from medical illnesses such as cancer and hypertension, we highlight the urgent need for evaluating combination therapies in early AD.

Canturk, N. Z., N. Z. Utkan, et al. (1998). The effects of prostaglandin E-2 indomethacin and Ginkgo biloba extract on resistance to experimental sepsis. Indian Journal Of Medical Research. Sep 108: 88-92.

We investigated the effect of 16,16-dimethyl prostaglandin E-2 indomethacin and Ginkgo biloba extract on the survival in two experimental sepsis models in rats due to administration of 1 x 10(7) cfn and 1 x 10(9) cfu Escherichia coli. Animals in each model were then randomly divided (10/group) into four groups, administered saline, indomethacin, G. biloba extract and prostaglandin E-2 respectively. When compared, there was no significant difference in the survival period between the two sepsis models (P>0.05). The best survival rate was observed in the PGE(2)-administered animals in the first major model(P<0.05). Indomethacin appeared not to decrease the mortality rates. There was no significant difference in PGE(2) levels between two sepsis models (P>0.05). Our results suggest that elevated prostaglandin E-2 levels following major trauma are not responsible for the postinjury increased susceptibility to infectious complications. Our observations should also discourage aggressive use of cyclo-oxygenase inhibitors for protection against infectious complications after major trauma.

Paasche, G., D. Huster, et al. (1998). The glutathione content of retinal Muller (glial) cells: The effects of aging and of application of free-radical scavengers. Ophthalmic Research. Nov Dec 30(6): 351-360.

The dependence of intracellular glutathione (GSH), an important radical scavenger, on aging with or without externally applied Ginkgo biloba extract EGb 761, another established radical scavenger, was studied in guinea pig Muller (retinal glial) cells by using the fluorescent dye monochlorobimane. The GSH content of freshly dissociated cells from untreated aged animals was significantly lower than that of young controls; most of this reduction was prevented by application of EGb 761. Culturing the cells in amino-acid-free Ringer's solution for 7 h caused a loss of up to 50% of the initial GSH content. When the culture medium contained 100 mu M glutamate and 100 mu M cystine, ongoing GSH synthesis counteracted the loss of GSH. The rates of net GSH synthesis were equal for the two groups of aged animals but significantly higher for cells from young controls. It is concluded that externally applied radical scavengers may enhance the protective glutathione 'reserve' of Muller cells in cases of neuronal degeneration.

Skogh, M. (1998). Extracts of Ginkgo biloba and bleeding or haemorrhage. Lancet . Oct 352(9134): 1145-1146.

Vale, S. (1998). Extracts of Ginkgo biloba and bleeding or haemorrhage - Reply. Lancet . Oct 352(9134): 1146-1146.

Gilani, A. U. H. (1998). Novel developments from natural products in cardiovascular research. Phytotherapy Research 12(1): S66-S69.

The prevalence of cardiovascular diseases has been the main cause of mortality in the history of mankind and consequently, most breakthrough discoveries from natural products have been in the area of cardiovascular research. Digitalis, reserpine, ajmaline, quinidine, ergotamine, atropine and lovastatin are a few examples of important discoveries from plants. More recently, some standardized plant extracts, such as Ginkgo biloba, Ginseng, Hawthorn and Garlic have also been introduced into the clinical medicine. In addition, forskolin, himbacine, reserpine and cocaine are considered useful pharmacological tools for further understanding of disease and design of new drugs. (C) 1998 John Wiley and Sons, Ltd.

Mascolo, N., F. Borrelli, et al. (1998). Natural products and cardiovascular disturbances. Phytotherapy Research 12(1): S121-S123.

Digitalis and other plants containing cardioactive glycosides are infrequently used today for congestive heart failure. Hawthorn has positive inotropic effects and accelerates the heart rate but its use is restricted to the prevention of angina. Ginkgo is employed in chronic cerebral ischaemia and intermittent claudication white horse-chestnut is effective in chronic venous insufficiency. These vegetable drugs are useful in themselves and also in association with more effective therapeutic agents. (C) 1998 John Whey and Sons, Ltd.

Flint, A. J. and R. VanReekum (1998). The pharmacologic treatment of Alzheimer's disease: A guide for the general psychiatrist. Canadian Journal Of Psychiatry Revue Canadienne De Psychiatrie. Sep 43(7): 689-697.

Objective: To review the drug treatment of Alzheimer's disease (AD) and to provide guidelines for the physician on how to integrate these treatments into the overall management of this disorder.Method: A qualitative review of randomized, double-blind, placebo-controlled trials of medications used to treat cognitive deficits, disease progression, agitation, psychosis, or depression in AD. A computerized search of Medline was used to identify, relevant literature published during the period 1968-1998. Key words used in the search were 'randomized controlled trials, with 'dementia' and with 'Alzheimer's disease'.Results: Agents that are currently available in Canada to treat the cognitive deficits of AD include donepezil, ginkgo biloba, selegiline, and ergoloid mesylates. Donepezil and ginkgo biloba are associated with a statistically significant but clinically modest improvement in cognitive function in a substantial minority of patients with mild to moderate AD. Selegiline may have a mild beneficial effect on cognitive function in some patients with AD, but the data are inconclusive. Ergoloid mesylates have questionable efficacy in AD and can only be recommended as a last line of treatment. The results of a single trial suggest that vitamin E or selegiline (both have antioxidant properties) may slow the progression of AD. Antipsychotic medications can result in clinically significant improvement in agitation and psychosis. Carbamazepine also appears to be an effective treatment for agitation in AD, and there is preliminary evidence that the selective serotonin reuptake inhibitor citalopram reduces irritability in this disorder. There is no evidence that other nonneuroleptic medications are more efficacious than placebo in treating agitation in AD. Limited data indicate that depression in dementia responds to antidepressant medication.Conclusion: These data indicate that selected medications can be used to treat cognitive deficits, disease progression, agitation, psychosis, and depression in AD. However, there is considerable heterogeneity in patients' responses to these medications. Pharmacotherapy needs to be considered as a component of a package of care that also includes psychosocial and environmental interventions and support of the caregiver.

Joseph, J. A., B. ShukittHale, et al. (1998). Long-term dietary strawberry, spinach, or vitamin E supplementation retards the onset of age-related neuronal signal-transduction and cognitive behavioral deficits. Journal Of Neuroscience. Oct 18(19): 8047-8055.

Recent research has indicated that increased vulnerability to oxidative stress may be the major factor involved in CNS functional declines in aging and age-related neurodegenerative diseases, and that antioxidants, e.g., vitamin E, may ameliorate or prevent these declines. Present studies examined whether long-term feeding of Fischer 344 rats, beginning when the rats were 6 months of age and continuing for 8 months, with diets supplemented with a fruit or vegetable extract identified as being high in antioxidant activity, could prevent the age-related induction of receptor-mediated signal transduction deficits that might have a behavioral component. Thus, the following parameters were examined: (1) oxotremorine-enhanced striatal dopamine release (OX-K+-ERDA), (2) cerebellar beta receptor augmentation of GABA responding, (3) striatal synaptosomal Ca-45(2+) clearance, (4) carbachol-stimulated GTPase activity, and (5) Morris water maze performance. The rats were given control diets or those supplemented with strawberry extracts (SE), 9.5 gm/kg dried aqueous extract (DAE), spinach (SPN 6.4 gm/kg DAE), or vitamin E (500 IU/kg). Results indicated that SPN-fed rats demonstrated the greatest retardation of age-effects on all parameters except GTPase activity, on which SE had the greatest effect, whereas SE and vitamin E showed significant but equal protection against these age-induced deficits on the other parameters. For example, OX-K+-ERDA enhancement was four times greater in the SPN group than in controls. Thus, phytochemicals present in antioxidant-rich foods such as spinach may be beneficial in retarding functional age-related CNS and cognitive behavioral deficits and, perhaps, may have some benefit in neurodegenerative disease.

Buer, C. S., K. T. Gahagan, et al. (1998). Insertion of microscopic objects through plant cell walls using laser microsurgery. Biotechnology And Bioengineering. Nov 60(3): 348-355.

A detailed protocol is presented for precisely inserting microscopic objects into the periplasmic region of plant callus cells using laser microsurgery. Ginkgo biloba and Agrobacterium rhizogenes were used as the model system for developing the optical tweezers and scalpel techniques using a single laser. We achieved better than 95% survival after plasmolyzing G. biloba cells, ablating a 2-4-mu m hole through the cell wall using a pulsed UV laser beam, trapping and translating bacteria into the periplasmic region using a pulsed infrared laser beam, and then deplasmolyzing the cells. Insertion of bacteria is also described. A thermal model for temperature changes of trapped bacteria is included. Comparisons with other methods, such as a reverse-pressure gradient technique, are discussed and additional experiments on plants using laser microsurgery are suggested. (C) 1998 John Wiley and Sons, Inc.

Joseph, J. A., N. Denisova, et al. (1998). Age-related neurodegeneration and oxidative stress: Putative nutritional intervention. Neurologic Clinics. Aug 16(3).

This review describes age-related changes that occur in neuronal function and cites evidence to show that these alterations may be the result of increased sensitivity to oxidative stress (OS). Evidence is presented to show that the abilities to mitigate the OS effects and to repair the damage from OS show decline as a function of age. Results from age- and OS-sensitive tests are given; these results indicate that one of the major sites of action of OS is the membranes, especially if compromised by high amounts of sphingomyelin, and one of the major effects of OS is to further alter the calcium disregulation in aging. It is suggested that attempts to increase antioxidant protection through diets comprised of fruits and vegetables identified as being high in total antioxidant activity might prevent or reverse the deleterious OS effects on neuronal aging.

Nakao, Y., A. Tateishi, et al. (1998). Seed set of Ginkgo biloba L. as related to pollination and its optimum pollination time. Journal Of The Japanese Society For Horticultural Science. Sep 67(5): 753-758.

Ovule set and growth were investigated on ginkgo as related to open- and hand-pollination as well as the critical pollination period.1. The ginkgo pollen placed on an agar medium under 25 degrees C took 3 days to germinate. Over 73% of the pollen stored for less than 7 days after anthesis at room temperature germinated but pollen stored much longer at room temperature did not.2. All ovules which were covered with paper bags during anthesis to be free from pollen contamination abscised for 41 days after leafing.3. When non-viable, heat-treated pollen were used for hand-pollination, the ovules began to drop 28 days after leafing; the percentage ovule set decreased from 19 to 47 days after leafing. Thereafter, for 82 days after leafing, fewer ovules dropped; the final seed set was 7%. These female reproductive organs set parthenocarpically because no embryo formed. The seeds and nuts resulting from hand-pollination were larger than those obtained from open-pollination.4. Of seeds that set by hand-pollination 16 and 19 days after leafing, 59% and 94%, respectively, remained at harvest and their sizes were significantly larger than those obtained from open-pollination. None of the ovules pollinated 23 days after leafing persisted until harvest.

Rabin, O., K. Drieu, et al. (1998). Effects of EGb 761 on fatty acid reincorporation during reperfusion following ischemia in the brain of the awake gerbil. Molecular And Chemical Neuropathology. May 34(1): 79-101.

Transient cerebral ischemia (5 min) releases unesterified fatty acids from membrane phospholipids, increasing brain concentrations of fatty acids for up to 1 h following reperfusion. To understand the reported anti-ischemic effect of Ginkgo biloba extract (EGb 761), we monitored its effect on brain fatty acid reincorporation in a gerbil-stroke model. Both common carotid arteries in awake gerbils were occluded for 5 min, followed by 5 min of reperfusion. Animals were infused intravenously with labeled arachidonic (AA) or palmitic acid (Pam), and rates of incorporation of unlabeled fatty acid from the brain acyl-CoA pool were calculated by the model of Robinson et al. (1992), using quantitative autoradiography and biochemical analysis of brain acyl-CoA. Animals were treated for 14 d with 50 or 150 mg/kg/d EGb 761 or vehicle. Ischemia-reperfusion had no effect on the rate of unlabeled Pam incorporation into brain phospholipids from palmitoyl-CoA; this rate also was unaffected by EGb 761. In contrast, ischemia-reperfusion increased the rate of incorporation of unlabeled AA from brain arachidonoyl-CoA by a factor of 2.3-3.3 compared with the control rate; this factor was further augmented to 3.6-5.0 by pretreatment with EGb 761. There is selective reincorporation of AA compared with Pam into brain phospholipids following ischemia. EGb 761 further accelerates AA reincorporation, potentially reducing neurotoxic effects of prolonged exposure of brain to high concentrations of AA and its metabolites.

Boveris, A. D. and S. Puntarulo (1998). Free-radical scavenging actions of natural antioxidants. Nutrition Research. Sep 18(9): 1545-1557.

A dose-dependent inhibitory effect of wheat, alfalfa and ginkgo biloba (EGb) extracts on TEARS production was measured. The half-inhibition concentration (IC50) of the tested antioxidants were 2.7+/-0.2, 1.3+/-0.1, and 0.20+/-0.02 mg/ml for wheat, alfalfa and EGb extracts, respectively. Lipid radicals combined with the spin trap POBN resulted in adducts that gave a characteristic EPR spectrum. The IC50 of the tested antioxidants on lipid radical content, were 12.4+/-0.2, 7.7+/-0.3, and 1.20+/-0.06 mg/ml:for wheat, alfalfa and EGb extracts, respectively. Rat liver microsomes in the presence of DMPO, NADPH and iron-citrate generate an EPR spectra with characteristics of the DMPO-OH spin adduct. The basic system, without the addition of any scavenger showed an area of 3.5 AU/mg protein. The areas in the presence of 1.5 mg/ml EGb, 4 mg/ml wheat or alfalfa, were of 1.7+/-0.2, 3.4 +/-0.3, and 3.6+/-0.2 AU/mg protein, respectively. O-2(-) generation rate by the microsomes exposed to EGb extract was decreased by 40%, as compared to the rate measured in microsomes incubated in the absence of the extract. However, the supplementation of rat liver microsomes with either wheat or alfalfa extracts did not affect microsomal generation of O-2(-). Iron reduction rate was not affected by the addition of any of the tested extracts. The data presented here showed that EGb extracts were able to limit lipid peroxidation and scavenge lipid radicals in rat liver microsomes more efficiently than alfalfa and wheat bran extracts. Moreover, wheat and alfalfa extracts were not able to inhibit O-2(-) and . OH generation by biological membranes, suggesting that their potentiality to be successfully used in human health in the treatment of diseases involving free radical and oxidative damage are not as promising as that for the use of EGb extracts. (C) 1998 Elsevier Science Inc.

Li, A. L., Y. D. Shi, et al. (1998). Hemorheology and walking of peripheral arterial occlusive diseases patients during treatment with Ginkgo biloba extract. Acta Pharmacologica Sinica. Sep 19(5): 417-421.

AIM: To study the effects of Ginkgo biloba extract 761 (GbE)(5) from the points of view of hemorheology for patients of peripheral arterial occlusive diseases (PAOD). METHODS: The treatment with GbE (240 mg . d(-1), po) and the pain-free walking distance (PFWD) were carried out for 24 PAOD patients (12 nondiabetic, ND and 12 diabetic, D) over 48 wk. The parameters erythrocyte stiffness (ES) and relaxation time (RT), the blood plasma viscosity (eta) the plasma fibrinogen concentration (C-f) and the blood sedimentation rate (BSR), the PFWD, and maximal walking distance (MWD) were determined at 6 wk before treatment ( - 6), at the beginning of the treatment (0), and after 6, 11, 16, and 48 wk of treatment. RESULTS: At wk - 6, ES and RT of both the ND- and D-group were not significantly different from a healthy control group. At wk 0, stiffness and RT were significantly higher than healthy control, and the mean PFWD was only 111 m. The eta value was significantly elevated and C-f and BSR were enhanced. Throughout 11 wk of treatment ES, RT, eta, and C-f decreased gradually and PFWD improved. Between 16 and 48 wk, ES, and RT were no longer significantly different from the controls, whereas eta and C-f decreased gradually but remained higher than normal, BSR decreased, and the PFWD improved by a factor of 3.8 times (D) and 3.3 times (ND). CONCLUSION: GbE gives therapeutic effects in PAOD patients.

Friedman, W. E. and J. S. Carmichael (1998). Heterochrony and developmental innovation: Evolution of female gametophyte ontogeny in Gnetum, a highly apomorphic seed plant. Evolution . Aug 52(4): 1016-1030.

Seed plant female gametophytes are focal points for the evolutionary modification of development. From a structural perspective, the most divergent female gametophytes among all seed plants are found in Gnetum, a clade within Gnetales. Coenocytic organization at sexual maturity, absence of defined egg cells (free nuclei are fertilized), lack of centripetal cellularization, and postfertilization development of embryo-nourishing tissues are features of the female gametophytes of Gnetum unparalleled among seed plants. Although the female gametophyte of Gnetum retains the three basic phases of somatic development common to female gametophytes of plesiomorphic seed plants (free nuclear development, cellularization, cellular growth), the timing of fertilization has been accelerated relative to the rate of somatic development. As a consequence, the female gametophyte of Gnetum matures sexually (is fertilized) at a juvenile (compared with the ancestral somatic ontogeny) and free nuclear stage of somatic development, thereby precluding differentiation of egg cells. Unlike progenetic animals, where truncation of somatic ontogeny evolves in tandem with acceleration in the timing of sexual maturation, the female gametophyte of Gnetum completes the entire ancestral somatic ontogeny after precocious sexual maturation. This results in the evolution of postfertilization development of embryo-nourishing female gametophyte tissues, a phenomenon unique among seed plants. Nonheterochronic developmental innovations have also played important roles in the evolution of the female gametophyte of Gnetum. Centripetal cellularization, which is always associated with the phase change from coenocytic to cellular organization among plesiomorphic seed plant female gametophytes, is lacking in Gnetum. Instead, during early phases of development, apomorphic free nuclear organization is coupled with a highly anomalous pattern of cellularization. Stage-specific innovations during early development in the female gametophyte of Gnetum do not affect plesiomorphic aspects of later phases of development. Thus, a complex array of heterochronic and nonheterochronic developmental innovations have played critical roles in the ontogenetic evolution of the highly apomorphic female gametophyte of Gnetum.

Beerling, D. J., J. C. McElwain, et al. (1998). Stomatal responses of the 'living fossil' Ginkgo biloba L. to changes in atmospheric CO2 concentrations. Journal Of Experimental Botany. Sep 49(326): 1603-1607.

Leaf stomatal density and index of Ginkgo biloba L. were both significantly (P < 0.05) reduced after 3 years growth at elevated CO2 (560 ppm), with values comparable to those of cuticles prepared from Triassic and Jurassic fossil Ginkgo leaves thought to have developed in the high CO2 'greenhouse world' of the Mesozoic. A reciprocal transfer experiment indicated that reductions in stomatal density and index irreversibly reduced stomatal conductance, particularly at low leaf-to-air vapour pressure deficits and low internal leaf CO2 concentrations (C-i). These effects probably contributed to the high water-use efficiency of Ginkgo spp. in the Mesozoic relative to those of the present, as determined from carbon isotope measurements of extant and fossil cuticles.

Skinner, J. S. and M. P. Timko (1998). Loblolly pine (Pinus taeda L) contains multiple expressed genes encoding light-dependent NADPH:protochlorophyllide oxidoreductase (POR). Plant And Cell Physiology. Aug 39(8): 795-806.

NADPH:protochlorophyllide oxidoreductase (POR) catalyzes the light-dependent reduction of protochlorophyllide (Pchlide) to chlorophyllide (Chlide), a key regulatory step in chlorophyll biosynthesis, In most angiosperms, FOR is encoded by a small nuclear gene family, containing at least two differentially-expressed genes designated pol A and porB. We have demonstrated that the PORs of loblolly pine (Pinus taeda L.), a gymnosperm, are encoded by a large multigene family, composed of two distinct subfamilies encoding porA and porB genes similar to those previously described in angiosperms. DNA gel blot analysis of genomic DNA showed that the two por subfamilies of loblolly pine have duplicated at different rates, with the porA subfamily containing two members, and the porB subfamily containing at least 11 potential members. DNA sequence analysis and gel blot hybridization studies also showed that a subset of the por genes present in the loblolly pine genome are pseudogenes. Based on the results of 5'-and 3'-RACE analysis, it appears that multiple porA and porB genes are expressed in loblolly pine cotyledons and stems during development. Using gene specific probes, no difference was observed in the steady-state levels of the different porA and porB transcripts in cotyledons of dark-grown seedlings before and following illumination. However, the steady state levels of the porA and porB transcripts were found to increase at different rates in the stems of dark-grown seedlings following illumination. The phylogenetic relationship between the por gene family members in P. taeda and other pine species and the potential significance of the two por subfamilies to the evolution of por gene function are discussed.

Grasel, I. and C. Reuter (1998). Analysis of 6-hydroxykynurenic acid in Ginkgo biloba and Ginkgo preparations. Planta Medica. Aug 64(6): 566-570.

Methods for rapid quantitative analysis of 6-hydroxykynurenic acid (6-HKA) by high-performance liquid chromatography (HPLC) and high-performance thin layer chromatography (HPTLC) have been developed. Sample preparation involves solid phase extraction with an ion exchange resin. These methods are used for the determination of the 6-HKA content in various Ginkgo biloba leaf samples, in herbal tea preparations and in a representative number of solid, liquid and homeopathic Ginkgo preparations available in Germany. A simple and effective isolation method for 6-HKA is described.

Lee, S. L., W. W. Wang, et al. (1998). Superoxide scavenging effect of Ginkgo biloba extract on serotonin-induced mitogenesis. Biochemical Pharmacology. Aug 56(4): 527-533.

We have reported previously that serotonin (5-HT) stimulates the mitogenesis oi bovine pulmonary artery smooth muscle cells (SMCs) through active transport of 5-HT and cellular signaling that includes elevation of superoxide (O-2(.-)) and enhancement of protein tyrosine phosphorylation. Ginkgo biloba extract 501 (EGb 501), which has been demonstrated to act as an antioxidant, was found to block both the elevated O-2(.-) and the proliferative and hypertrophic influences of 5-HT on SMCs, but not to directly inhibit the associated activation of NAD(P)H oxidase or the stimulation of phosphorylation of GTPase-activating protein (GAP). A similar effect of Ginkgo biloba extract 501 occurred on Chinese hamster lung fibroblasts (CCL-39), where 5-HT receptor, as opposed to transporter, action has been associated with mitogenesis. We conclude from these studies that Ginkgo biloba extract 501 quenches O-2(.-) formation by 5-HT, thereby blocking its mitogenic effect. Stimulation of protein tyrosine phosphorylation of GAP by 5-HT appears to precede the elevation of O-2(.-). BIOCHEM PHARMACOL 56;4:527-533, 1998. (C) 1998 Elsevier Science Inc.

Hably, L. and Z. Kvacek (1998). Pliocene mesophytic forests surrounding crater lakes in western Hungary. Review Of Palaeobotany And Palynology. Jun 101(1-4): 257-269.

Two new palaeobotanical sites, Gerce and Pula from western Hungary, found in volcanic craters are characterized in terms of floristic composition, vegetation, and palaeoclimate. Radiometric dating of adjacent volcanic bodies indicates the age of the fossiliferous deposits near the Lower/Upper Pliocene boundary. Deciduous broad-leaved, woody plants prevail in both localities (Quercus, Ulmus, Zelkova, Acer, Salicaceae) and are associated with some rare exotic elements (Ginkgo, Torreya, Engelhardia, Eucommia, Sassafras) and Buxus. The climatic conditions inferred from the reconstructed vegetation indicate a Cf-type of climate with a mean annual temperature of 10-13 degrees C and some dry periods during the year. (C) 1998 Elsevier Science B.V. All rights reserved.

Lee, J. S., Y. S. Cho, et al. (1998). Phospholipase C gamma 1 inhibitory principles from the sarcotestas of Ginkgo biloba. Journal Of Natural Products. Jul 61(7): 867-871.

Ten phenolic compounds were isolated from the CHCl3 extract of Ginkgo biloba sarcotestas (Ginkgoaceae) as a new class of phosphatidylinositol-specific phospholipase C gamma 1 (PI-PLC gamma 1) inhibitors. The substances without the long chain were ineffective. On the other hand, the activities of these compounds were dramatically decreased by acetylation of aromatic hydroxyl groups of cardanol, phenolic acid, and bilobol and by methylation of the aromatic carboxyl group of phenolic acid. The unsaturated long chain as well as the aromatic hydroxyl and carboxyl groups might play a key role for the PI-PLC gamma 1 inhibitory activity. These compounds also inhibited the growth of a number of human cancer cell lines, but were less cytotoxic against a human normal colon cell line.

Buck, T. (1998). Goethe's poem `Ginkgo biloba'. Etudes Germaniques. Apr Jun 53(2): 277-290.

Kim, Y. C., S. R. Kim, et al. (1998). Ginsenosides Rb-1 and Rg(3) protect cultured rat cortical cells from glutamate-induced neurodegeneration. Journal Of Neuroscience Research. Aug 53(4): 426-432.

Certain natural products and Asian herbal remedies have been used in Asia to attenuate neurodegenerative diseases, including senile dementia, We have examined derivatives of several natural products for potential neuroprotective activity in an in vitro test system, In the present study, we assayed a number of compounds that were isolated from Panax ginseng C.A. Meyer (Araliaceae) for an ability to protect rat cortical cell cultures from the deleterious effects of the neurotoxicant, glutamate, We found that ginsenosides Rb-1 and Rg(3) significantly attenuated glutamate-induced neurotoxicity, Brief exposure of cultures to excess glutamate caused extensive neuronal death, Glutamate-induced neuronal cell damage was reduced significantly by pretreatment with Rb-1 and Rg(3). Ginsenosides Rb-1 and Rg(3) inhibited the overproduction of nitric oxide, which routinely follows glutamate neurotoxicity, and preserved the level of superoxide dismutase in glutamate-treated cells, Furthermore, in cultures treated with glutamate, these ginsenosides inhibited the formation of malondialdehyde, a compound that is produced during lipid peroxidation, and diminished the influx of calcium. These results show that ginsenosides Rb-1 and Rg(3) exerted significant neuroprotective effects on cultured cortical cells, Therefore, these compounds may be efficacious in protecting neurons from oxidative damage that is produced by exposure to excess glutamate. (C) 1998 Wiley-Liss,Inc.

Kim, Y. S., M. K. Pyo, et al. (1998). Antiplatelet and antithrombotic effects of a combination of ticlopidine and Ginkgo biloba ext (EGb761). Thrombosis Research. Jul 91(1): 33-38.

The antiplatelet and antithrombotic effects of the oral combination treatment of ticlopidine and Ginkgo biloba extract (EGb 761) were studied in normal and thrombosis-induced rats. The ex vivo inhibitory effect on ADP-induced platelet aggregation of a small dose of ticlopidine (50 mg/kg/day) in combination with EGb 761 (40 mg/kg/day) was comparable to a larger dose of only ticlopidine (200 mg/kg/day). Bleeding time was also prolonged by 150%. Thrombus weight was also consistently decreased by a combination of ticlopidine and EGb 761 in an arterio-venous shunt model at two doses of ticlopidine (50 mg/kg) plus EGb 761 (20 mg/kg) and ticlopidine (50 mg/kg) plus EGb 761 (40 mg/kg). A combinatory treatment in acute thrombosis model in mice also showed a higher recovery than a single treatment. (C) 1998 Elsevier Science Ltd.

AlZuhair, H., A. A. A. ElFattah, et al. (1998). The effect of meclofenoxate with ginkgo biloba extract or zinc on lipid peroxide, some free radical scavengers and the cardiovascular system of aged rats. Pharmacological Research. Jul 38(1): 65-72.

Aged rats are highly prone to many physiological changes such as blood pressure and heart rate. These changes could be due to modification in membrane phospholipid composition of their blood vessels. Lipid peroxide in vivo has been identified as a basic deteriorative reaction in cellular mechanisms of aging in human. The effect of a nootropic drug, meclofenoxate (MF) or its combination with extract of ginkgo biloba (EGb-761) or zinc (Zn) on malondialdehyde (MDA) product as an index of endogenous lipid peroxidation; phospholipid; glutathione (GSH) and protein thiols (PrSHs) contents as well as superoxide dismutase (SOD) activity in blood, brain, heart and liver of 24-month-old male rats was investigated. Aged rats were treated with MF once daily at oral doses of 100 mg kg-(1) body wt. alone or with either EGb at a dose of 150 mg kg(-1) body wt. or Zn at 10.5 mg kg(-1) body wt, for 4 weeks. This study showed that aging caused a higher increment in MDA level of brain and heart than liver and plasma accompanied with reduction in brain and heart phospholipid contents as well as alteration of the antioxidant systems as compared to 4-month-old rats. Treatment of aged rats with MF alone or combined with either EGb or Zn caused improvement in the measured free radical scavengers especially in brain and heart tissues. Our results also showed that both EGb and Zn induced a significant potential effect of MF action on blood pressure and heart rate. The results were explained in the light of the antioxidant properties of EGb and Zn. Thus it is concluded that EGb and Zn have a beneficial role with MF in diminishing cumulative oxidative changes in aging. (C) 1998 The Italian Pharmacological Society.

Medina, J. H., H. Viola, et al. (1998). Neuroactive flavonoids: new ligands for the Benzodiazepine receptors. Phytomedicine . May 5(3): 235-243.

Flavonoids isolated from plants used as tranquilizers in folkloric medicine have a selective affinity, for central benzodiazepine receptors (BDZ-Rs) and some of them possess a pharmacological profile compatible with a partial agonist action. Synthetic derivatives of the common flavone nucleus, give rise to high affinity ligands when electronegative groups are introduced in carbons 6 and/or 3'. Representative compounds such as 6,3'-dinitroflavone and, 6-bromo-3'-nitroflavone exhibit a high affinity for the BDZ-Rs (Ki = 1.5 to 30 nM) and have anxiolytic effects not associated with myorelaxant, sedative or amnesic actions.These compounds or similar ones, could lead to improved therapeutic drugs in the treatment of anxiety.

Chen, J. X., W. Z. Chen, et al. (1998). Protective effects of Ginkgo biloba extract against lysophosphatidylcholine-induced vascular endothelial cell damage. Acta Pharmacologica Sinica. Jul 19(4): 359-363.

AIM: To study the protective effects of Ginkgo biloba extract (GbE) against endothelial cell damage induced by lysophosphatidylcholine (LPC). METHODS: The vasorelaxation response to acetylcholine (ACh) were investigated in the isolated rabbit thoracic aorta. Lipid peroxidation products were determined by measuring thiobarbituric acid reactive substance. RESULTS: GbE attenuated the inhibition of vasorelaxation response to ACh and prevented the LPC-induced increase of malondialdehyde (MDA) content both in thoracic aortae. GbE prevented the leakage of LDH and the increase of MDA content in cultured endothelial cells in a concentration-dependent manner. GbE also markedly increased epoprostenol level in cultured endothelial cells treated with LPC. CONCLUSION: GbE protected endothelial cells against LPC-induced damage due to reduction in lipid peroxidation and facilitation of synthesis and/or release of epoprostenol.

Vale, S. (1998). Subarachnoid haemorrhage associated with Ginkgo biloba. Lancet . Jul 352(9121): 36-36.

Shen, J. G., J. Wang, et al. (1998). Effects of EGb 761 on nitric oxide and oxygen free radicals, myocardial damage and arrhythmia in ischemia-reperfusion injury in vivo. Biochimica Et Biophysica Acta Molecular Basis Of Disease. Apr 28(3): 228-236.

The cardioprotective effects of EGb 761 on the release of nitric oxide (NO), the concentration of serum thiobarbituric acid reaction substance (TBARS), the activity of creatine kinase (CK) and the incidence of ventricular arrhythmias were investigated in myocardial ischemia-reperfusion injury in vivo. Using sodium nitrite (NaNO2) as standard source of nitric oxide (NO), we compared the correlation coefficients of the three measuring methods used currently in the determination of NOFe2+ (DETC)(2) complex with that of the measuring method suggested in this study. The result showed that measuring the whole height of three splitting signals is the best linear correlation to the concentration of NO comparing with other methods in this system. Using this method, we observed the effects of EGb 761 on NOFe2+(DETC), complex in myocardial ischemia-reperfusion injury in vivo. The hearts of the Wistar rats were subjected to 30 min of ischemia and 10 min of reperfusion in vivo. Different doses of EGb 761 (25, 50, 100, 200 mg/kg i.p.), superoxide dismutase (SOD, 10(4) U/kg). L-arginine (50 mg/kg i.p.) and nitric oxide synthase (NOS) inhibitor N-G-nitro-L-arginine (NNA, 50 mg/kg i.p.) were administered to the ischemia-reperfusion rats. EGb 761 under the dose of 100 mg/kg increased the signal intensity of NOFe2+ (DETC)(2) complex, while EGb 761 at 200 mg/kg showed an effect of decreasing the signal intensity of NOFe2+ (DETC), complex. EGb 761 inhibited the formation of TEARS, the release of CK, and mitigated the incidence of ventricular arrhythmias in a dose dependent way. Both L-arginine and SOD increased the signal intensity of NOFe2+ (DETC)(2) complex and inhibited the formation of TEARS, the leakage of CK and the incidence of ventricular arrythmia. NNA not only had no protective effects on myocardial injury, but also increased the incidence of reperfusion-induced arrhythima, In conclusion, EGb 761 has cardiovascular protective effects by means of adjusting the level of NO and inhibiting oxygen free radicals induced lipid peroxidation in myocardial ischemia-reperfusion injury in vivo. (C) 1998 Elsevier Science B.V. All rights reserved.

Chung, K. H., D. E. Buetow, et al. (1998). Isolation and characterization of a type I gene encoding a light-harvesting chlorophyll a/b-binding protein of photosystem II in peach. Journal Of The American Society For Horticultural Science. Jul 123(4): 493-499.

A nuclear gene, Lhcb1Pp1 encoding a light-harvesting chlorophyll a/b-binding protein of photosystem II has been isolated from peach [Prunus persica (L,) Batsch, 'Stark Earliglo'] leaf genomic DNA, cloned, and sequenced. This gene encodes a precursor polypeptide of 267 amino acids with a transit peptide of 34 and a type I mature protein of 233 amino acids. The amino acid sequence of the mature polypeptide is 89% to 94% and 80% to 94% similar to those encoded by type I Lhcb genes of annual and other woody plants, respectively. In contrast, the amino acid sequence of the peach transit peptide is less conserved being 47 % to 69 % similar to those of annual plants and only 17% to 22% similar to those of other woody plants. The peach gene was used as a probe for Lhcb gene expression. Lhcb mRNA is detected in leaves of field-grown trees during June to October. Lhcb mRNA is detected at a high level in leaves of peach shoots grown in tissue culture in the light, but only at a trace level in leaves grown in the dark. Some Lhcb genes appear to be light-modulated in stems. Lhcb1*Pp1contains four potential polyadenylation sites, S1 nuclease analysis detected transcripts of the sizes expected from each of the four polyadenylation sites. All four are found in leaves of light-grown shoots and of field-grown trees throughout the growing season. In contrast, only three are detected in stems of light-grown shoots.

Matthews, M. K. (1998). Association of Ginkgo biloba with intracerebral hemorrhage. Neurology . Jun 50(6): 1933-1933.

Lewis, S. L. and J. Rowin (1998). Association of Ginkgo biloba with intracerebral hemorrhage - Reply. Neurology . Jun 50(6): 1933-1934.

Bekerecioglu, M., M. Tercan, et al. (1998). The effect of Gingko biloba extract (Egb 761) as a free radical scavenger on the survival of skin flaps in rats - A comparative study. Scandinavian Journal Of Plastic And Reconstructive Surgery And Hand Surgery. Jun 32(2): 135-139.

Free radicals may have a role in pedicle flap necrosis. We undertook this study to compare the effect of various antioxidants and scavengers of free radicals such as vitamin E, vitamin C, deferoxamine, and Gingko biloba extract (Egb 761) on McFarlane caudal-based dorsal rat flaps. Fifty rats were divided into five groups of 10 animals each. One group served as a control (saline) group. The remaining four groups were given vitamin C 340 mg/kg, deferoxamine 150 mg/kg, Egb 761 100 mg/kg, and vitamin E 20 mg/kg. The necrosed area of flap was significantly reduced in the deferoxamine (p < 0.001), Egb 761 (p < 0.001), and vitamin C (p < 0.05) groups compared with the control group. Vitamin E had no effect on distal flap necrosis (p = 0.20).

Madoka, Y., S. Yasuda, et al. (1998). Formation and regulation of secondary metabolites in cell cultures of woody plants II. Effect of gallocatechin related substances added to medium on browning of ginkgo callus. Mokuzai Gakkaishi 44(2): 71-76.

Effects of gallocatechin and catechin, added to medium, on browning of calluses derived from ginkgo (Ginkgo biloba L.) leaves were studied.Browning of calluses was stimulated by adding gallocatechin to the medium and then changed much of the phenolic compounds in the culture cells. From these results it became apparent that (1) these changes were induced by the formation of gallocatechin and (2) the transformation of these components in cells were associated with the browning of the calluses. On the other hand, it has not been found to have a powerful effect of the browning induction accorded to catechin and proanthocyanidins. In particular, catechin seemed to have depression rather than stimulation on the browning of calluses.From results of this research and that reported in a previous paper, we made estimates of the mechanism of browning in ginkgo calluses.

SchneiderPoetsch, H. A. W., U. Kolukisaoglu, et al. (1998). Non-angiosperm phytochromes and the evolution of vascular plants. Physiologia Plantarum. Apr 102(4): 612-622.

The phytochromes, a class of plant light-sensing pigments, are a gene family with a long, complex evolutionary history. Angiosperms each have five or more phytochromes (designated A to E in Arabidopsis) with distinct functions as light receptors and only moderate sequence identities for different types within a species. The long-term challenge taken up here is to trace the origin and function of the various motifs within the angiosperm phytochromes through gymnosperm phytochromes (types N, O and P) and lower plant phytochromes, sometimes reaching even to bacterial progenitor molecules, Particularly intriguing are the findings of homology of a C-terminal region of phytochromes with bacterial transmitter modules and of a large N-terminal region with a protein encoded by a gene from the cyanobacterum Synechocystis. Phylogenetic analysis helps to answer general questions such as the times of divergence of mono-and dicotyledons, of groups of gymnosperms or of ferns. Phytochrome sequences suggest (1) that mono-and dicotyledons became separated 150-200 million years earlier than indicated by the fossil record and 12 that Ginkgo and Cycas have been separated unexpectedly late from the lineage giving rise to the Pinidae. (3) The status of Psilotum as a close relative of the primeval vascular plants is not supported. Phytochrome gene sequences additionally reveal that (4) moss and fern phytochromes have erratically acquired C-termini which, though kinase-like, are different from the common ones and that (5) introns have been lost, gained or shifted in position from algae to angiosperms. Phytochromes promise to be a rich source of phylogenetic information into the future as more sequences and functional data emerge, not least from studies of lower plants.

Carrier, D. J., T. A. vanBeek, et al. (1998). Distribution of ginkgolides and terpenoid biosynthetic activity in Ginkgo biloba. Phytochemistry . May 48(1): 89-92.

The terpene trilactone content (bilobalide and ginkgolides) of extracts prepared from leaves of terminal buds, rosettes and side branches, from stem and root bark, and from root and root meristems of three-year-old Ginkgo biloba plants was determined. The aerial parts were relatively rich in bilobalide while ginkgolides were the major constituents of the underground parts. The formation of farnesyl and geranylgeranyl pyrophosphate was monitored by incubating cell-free extracts prepared from the corresponding plant parts with [1-C-14]isopentenyl pyrophosphate. Extracts prepared from leaves of the terminal buds displayed terpenoid biosynthetic activity, suggesting that terpene trilactone synthesis might occur inactively growing tissues. (C) 1998 Elsevier Science Ltd. All rights reserved.

Marcilhac, A., N. Dakine, et al. (1998). Effect of chronic administration of ginkgo biloba extract or ginkgolide on the hypothalamic-pituitary-adrenal axis in the rat. Life Sciences. May 62(25): 2329-2340.

The hypersecretion of glucocorticoids during exposure to various stressors may induce or worsen pathological states in predisposed subjects. Therefore it is of interest to evaluate drugs able to reduce glucocorticoid secretion. It has recently been shown that chronic administration of a Ginkgo biloba extract (EGb 761) inhibits stress-induced corticosterone hypersecretion through a reduction in the number of adrenal peripheral benzodiazepine receptors. The present study was designed to analyze the effect of EGb 761 and one of its components, Ginkgolide B on the biosynthesis and secretion of CRH and AVP, the hypothalamic neurohormones that regulate the pituitary-adrenal axis. Chronic administration of EGb 761 (50 or 100 mg/kg p.o. daily for 14 days) reduced basal corticosterone secretion and the subsequent increase in CPH and AVP gene expression. Under the same conditions, surgically-induced increase in CPH secretion was attenuated while the activation of CRH gene expression, ACTH and corticosterone secretion following insulin-induced hypoglycemia remained unchanged. Chronic i.p. injection of Ginkgolide B reduced basal corticosterone secretion without alteration in the subsequent CRH and AVP increase. However, the stimulation of CPH gene expression by insulin-induced hypoglycemia was attenuated by Ginkgolide B. These data confirm that the administration of EGb 761 and Ginkgolide B reduces corticosterone secretion. In addition, these substances act also at the hypothalamic level and are able to reduce CPH expression and secretion. However the latter effect appears to be complex and may depend upon both the nature of stress and substance (Ginkgolide B or other compounds of EGb 761).

RodriguezNunez, J. A. (1998). The contemporary art trade in Spain - Some incomplete and hasty points. Cuadernos Hispanoamericanos. Feb 572: 21-27.

Peters, H., M. Kieser, et al. (1998). Demonstration of the efficacy of ginkgo biloba special extract EGb 761(R) on intermittent claudication - A placebo-controlled, double-blind multicenter trial. Vasa Journal Of Vascular Diseases. May 27(2): 106-110.

Background: A multicentric, randomized, placebo-controlled double-blind study on ginkgo biloba special extract EGb 761 (Tebonin(R) forte) in patients suffering from peripheral occlusive arterial disease (POAD) in Fontaine stage II b was carried out in order to prove its clinical efficacy in this indication according to guidelines of European Community authorities and the German Angiological Society and to confirm the results of former clinical studies with EGb 761.Patients and methods: In total, 111 patients with angiographically proven POAD in Fontaine stage II b and intermittent claudication (pain-free walking distance < 150 m on the treadmill) were recruited in 5 centers and treated with either EGb 761 or placebo at a daily dose of 3 times 1 film-coated tablet over a duration of 24 weeks following a 2-week placebo run-in period. The primary response variable was the difference of the pain-free walking distance between the start of the treatment and after 8, 16 and 24 weeks as measured on the treadmill (walking speed 3 km/h and slope of 12%) under standardized conditions.Results: At the start of the treatment period, the mean pain-free walking distances were very similar with 108.5 m in the EGb 761 group and 105.2 m in the placebo group. At the end of the treatment period these values increased to 153.2 m and 126.6 m, respectively. The group differences were statistically significant at all three control visits with p = 0.017, p = 0.007, and p = 0.016. The differences for the maximum walking distance and the relative increases of the pain-free walking distance and the maximum distance were also significantly higher in the EGb 761 group with p-values < 0.05 each. In both groups Doppler indices remained nearly unchanged during therapy. The subjective assessment of the patients demonstrated an amelioration of complaints in both groups. Tolerability was very good with no adverse events under EGb 761 and one case of heartburn and gastric pain in the placebo group.Conclusions: It can be concluded from the results of this study that treatment with EGb 761 in POAD patients with Fontaine stage II b is very safe and causes a significant and therapeutically relevant prolongation of the patients' walking distance.

Stefanovic, S., M. Jager, et al. (1998). Phylogenetic relationships of conifers inferred from partial 28S rRNA gene sequences. American Journal Of Botany. May 85(5): 688-697.

The conifers, which traditionally comprise seven families, are the largest and most diverse group of living gymnosperms. Efforts to systematize this diversity without a cladistic phylogenetic framework have often resulted in the segregation of certain genera and/or families from the conifers. In order to understand better the relationships between the families, we performed cladistic analyses using a new data set obtained from 28S rRNA gene sequences. These analyses strongly support the monophyly of conifers including Taxaceae. Within the conifers, the Pinaceae are the first to diverge, being the sister group of the rest of conifers. A recently discovered Australian genus Wollemia is confirmed to be a natural member of the Araucariaceae. The Taxaceae are nested within the conifer clade, being the most closely related to the Cephalotaxaceae, The Taxodiaceae and Cupressaceae together form a monophyletic group. Sciadopitys should be considered as constituting a separate family. These relationships are consistent with previous cladistic analyses of morphological and molecular (18S rRNA, rbcL) data. Furthermore, the well-supported clade linking the Araucariaceae and Podocarpaceae, which has not been previously reported, suggests that the common ancestor of these families, both having the greatest diversity in the Southern Hemisphere, inhabited Gondwanaland.

Lu, M. Z., A. E. Szmidt, et al. (1998). RNA editing in gymnosperms and its impact on the evolution of the mitochondrial coxI gene. Plant Molecular Biology. May 37(2): 225-234.

Sequence analysis of the mitochondrial coxI gene in eight gymnosperm species revealed a high rate of nonsynonymous nucleotide substitutions with a strong (98%) predominance of C-T substitutions. Further analysis of the corresponding coxI cDNA sequences showed that all the non-synonymous C-T changes in the coxI genomic DNA sequences were eliminated by RNA editing resulting in nearly identical mRNA (amino acid) sequences among the species. Pronounced variation in the number and location of edited sites was found among species. Most species had a relatively large number of edited sites (from 25 to 34). However, no RNA editing of the coxI sequence was found in Gingko biloba or Larix sibirica. The sequence composition of the investigated coxI fragment suggests that the coxI gene in G. biloba and L. sibirica originated from edited mitochondrial coxI transcripts by reverse transcription followed by insertion into the nuclear genome or back into the mitochondrial genome. Our results also demonstrate that where there are a large number of edited sites, RNA editing can accelerate the divergence of nucleotide sequences among species.

Yang, F. Q., J. Quan, et al. (1998). Multidimensional counter-current chromatographic system and its application. Journal Of Chromatography A. Apr 803(1-2): 298-301.

A multidimensional counter-current chromatographic system was set up for the first time with two sets of high-speed counter-current chromatography instruments. This system was successfully applied to the preparative separation of isorhamnetin, kaempferol and quercetin from crude flavone aglycones of Ginkgo biloba L. and Hippophae rhamnoides L. with a two-phase solvent system composed of chloroform-methanol-water (4:3:2, v/v/v). (C) 1998 Elsevier Science B.V.

Ellison, J. M. and P. DeLuca (1998). Fluoxetine-induced genital anesthesia relieved by Ginkgo biloba extract. Journal Of Clinical Psychiatry. Apr 59(4): 199-200.

Cohen, A. J. and B. Bartlik (1998). Ginkgo biloba for antidepressant-induced sexual dysfunction. Journal Of Sex And Marital Therapy. Apr Jun 24(2): 139-143.

In an open trial ginkgo biloba, an extract derived from the leaf of the Chinese ginkgo tree and noted for its cerebral enhancing effects, was found to be 84% effective in treating antidepressant-induced sexual dysfunction predominately caused by selective serotonin reuptake inhibitors (SSRIs, N = 63). Women (n = 33) were more responsive to the sexually enhancing effects of ginkgo biloba than men (N 30), with relative success rates of 91% versus 76%. Ginkgo biloba generally had a positive effect on all 4 phases of the sexual response cycle: desire, excitement (erection and lubrication), orgasm, and resolution (afterglow). This study originated from the observation that a geriatric patient on ginkgo biloba for memory enhancement noted improved erections. Patients exhibited sexual dysfunction secondary to a variety of antidepressant medications including selective serotonin reuptake inhibitor (SSRIs), serotonin and nonrepinephrine reuptake inhibitor (SNRIs) monoamine oxidase inhibitor (MAOIs), and tricyclics. Dosages of ginkgo biloba extract ranged from 60 mg qd to 120 mg bid (average = 209 mg/d). The common side effects were gastrointestinal disturbances, headache, and general central nervous system activation. The article includes a discussion of presumed pharmacologic mechanisms, including effects on platelet activating factor, prostaglandins, peripheral vasodilatation, and central serotonin and norepinephrine receptor factor modulation.

Shi, H. L. and E. Niki (1998). Stoichiometric and kinetic studies on Ginkgo biloba extract and related antioxidants. Lipids . Apr 33(4): 365-370.

Owing to increasing evidence showing the importance oi lipid peroxidation in oxidative stress in vivo, the role and evaluation of antioxidants have received much attention. Ginkgo biloba extract (CBE), well-known as an efficient drug against diseases induced by free radicals, has been suggested to exert its effect by antioxidant action. A method was established to determine the activity of GEE as a hydrogen donor by stoichiometric and kinetic studies, and GEE was compared with several other antioxidants such as alpha-tocopherol, propyl gallate, and two kinds of flavonoids which are found in CBE, quercetin, and kaempferol. It was found that there were 6.62 x 10(19) active hydrogens in 1 g of GBE. Stoichiometric studies showed that one molecule of alpha-tocopherol reacted with one molecule of galvinoxyl radical. For quercetin, kaempferol and propyl gallate, the experimental stoichiometric numbers were 4.0, 1.9, and 3.1, respectively. The rates of reaction oi antioxidants with galvinoxyl in ethanol were determined spectrophotometrically, using a stopped-flow technique. The second-order rate constant, k(2), obtained at 25 degrees C was 0.13 (g/L)(-1)s(-1) for GEE and 5.9 x 10(3), 2.1 x 10(3), 1.2 x 10(4), and 2.4 x 10(3) M(-1)s(-1) for quercetin, kaempferol, propyl gallate, and alpha-tocopherol, respectively. The second-order rate constant, k(2)', On the molar basis of active hydroxyl groups in the tested substances obtained at 25 degrees C decreased in the order of propyl gallate > alpha-tocopherol > quercetin > CBE approximate to kaempferol. This is the first study on GEE as an antioxidant which reports both stoichiometric and kinetic results.

Chen, P., X. L. Su, et al. (1998). Analysis of Ginkgolides and bilobalides in Ginkgo biloba L. extract for its production process control by high performance liquid chromatography. Journal Of Chromatographic Science. Apr 36(4): 197-200.

Colak, O., A. Sahin, et al. (1998). The effect of Ginkgo biloba on the activity of catalase and lipid peroxidation in experimental strangulation lieus. International Journal Of Clinical And Laboratory Research. Apr 28(1): 69-71.

This study was designed to assess the therapeutic effect of Ginkgo biloba extract (EGb 761) in experimental strangulation ileus. Rats were divided into control (n = 7), placebo (n = 11), and EGb-treated (n = 11) groups. No surgical procedure was carried out on the control group. Strangulation ileus was produced in the placebo and EGb groups for 2.5 h. At the end of this period, 100 mg/kg EGb in 1 ml of saline was injected intraperitoneally to the EGb-treated group. In the placebo group, animals received an equivalent amount of saline intraperitoneally; 24 h later, repeat laparotomies were performed to take blood and intestinal tissue samples. The EGb treatment decreased tissue malondialdehyde levels and increased catalase activities compared with the placebo group (P < 0.05 for both). Serum creatine kinase and phosphorus levels were also determined in all groups. In the placebo group these were significantly higher than in the control group (P < 0.01 and P < 0.05, respectively). In the EGb group these were not different from controls and the increase in creatine kinase activity in the EGb group was not as high as in the placebo group (P < 0.05). Our results suggest that EGb could be preventive against the effects of strangulation ileus in a rat model.

Czier, Z. (1998). Ginkgo foliage from the Jurassic of the Carpathian Basin. Palaeontology . Mar 2: 349-381.

Mesophytic Ginkgo foliage from the Carpathian Basin (Romania and Hungary) is revised using a new statistical method for identification. The genera Ginkgoites and Baiera are suppressed in favour of Ginkgo. New combinations G. marginata and G. skottsbergii are studied for the first time using scanning electron microscopy. G. baieraeformis banaticus subsp. nov. is an Indo-European member of the Dictyophyllum-Clathropteris Flora. G. marginata banatica subsp. nov. is characteristic of the Clathropteris meniscioides Biozone (Hettangian-Sinemurian) of the European Province. G. polymorpha is of western origin, later spreading out into Siberia. G. skottsbergii europeica subsp. nov. possibly belongs to the Dictyophyllum-Clathropteris Flora that originated in the Late Triassic in eastern South-east Asia, spread to Europe in the Early Jurassic and to South America in the Mid Jurassic, where it persisted until the Early Cretaceous.

Son, Y. and H. W. Kim (1998). Above-ground biomass and nutrient distribution in a 15-year-old ginkgo (Ginkgo biloba) plantation in central Korea. Bioresource Technology. Feb 63(2): 173-177.

Above-ground tree biomass and distribution of nutrients between tree components and within the major components of the ecosystem were determined for a 15-year-old ginkgo (Ginkgo biloba L.) plantation in central Korea. Total ecosystem biomass (excluding roots) was 160.6 Mg ha(-1), of which 79% was soil organic matter 6% was forest floor and 15% was living, above-ground biomass. Total above-ground tree biomass was 23.8 Mg ha(-1), of which 10% was foliage. Concentrations of N, P and Mg were greatest in foliage, while concentrations of Ca and K were greater in branch or stembark than foliage. Total ecosystem nutrient contents were (kg ha(-1)) 5544 for N, 1384 for Ca, 554 for K, 480 for P and 145 for Mg, respectively The forest floor had the largest accumulation of N, P, K, Ca, and Mg in live and dead above-ground components. The greatest proportion of total ecosystem nutrient capital was contained in the mineral soil. Of the total contents of N and P, more than 90% were contained in the upper 20 cm mineral soil. Foliage-only harvesting of ginkgo trees commonly practiced in Korea might degrade site-quality, proper plans for nutrition-management should be considered if foliages were to be harvested regularly. (C) 1998 Elsevier Science Ltd. All rights reserved.

Kirste, T., B. Hauns, et al. (1998). Complete remission in patients with pancreatic cancer: A rare but sometimes achievable event. Onkologie . Feb 21(1): 64-66.

Background: Treatment of nonresectable pancreatic cancer is often controversial, and best supportive care is considered a sufficient control group for investigational drug trials. Individual cases with remarkable responses call this caution regarding therapy into question. Case Report: We report 2 patients with histologically proven nonresectable primary or recurrent pancreatic cancer. The initial CT scan showed well demarcated pancreatic tumors in head and tail of the pancreas, respectively. Both patients achieved complete remission after 6 cycles of chemotherapy. Patient I (61 years, male), was treated with gemcitabine 1,000 mg/m(2) on days 1, 8, and 15 starting the next cycle on day 29. Patient II (76 years, male) was included into a phase II trial with 5-fluorouracil (500 mg/m(2) i.v. days 2-6) plus Ginkgo biloba extract (GBE-761-ONC, 350 mg total dose i.v. days 1-6) starting the next cycle on day 21. Both regimens were generally well tolerated and showed no major side effects. Both patients were controlled by CT scan. Patient I showed a complete remission (CR) after 6 cylces. Remission was confirmed at the end of treatment and 2, 4, 6, and 8 months after starting the treatment. No evidence of disease was found in the CT scan, although CA 19-9 began to rise 2 months after stop of treatment with gemcitabine. The patient remains well and without measurable disease 14 months after initial diagnosis of the metastatic pancreatic carcinoma. Patient II was first diagnosed 2 years before his first visit in our center. Initially, the patient underwent complete surgical resection and a local recurrence occurred 1 month before the chemotherapy was started. CR was achieved 6 weeks after the treatment initiation and confirmed after 2, 6, and 8 months. The recurrence was diagnosed gastroscopically without evidence of disease in CT scans 2 months after the 9th cycle of chemotherapy. The patient died 13 months after the initial diagnosis of local recurrence and 12 months after treatment initiation. Conclusion: This case report underlines the possibility to offer a palliative therapy to patients with nonresectable pancreatic carcinoma. Such results raises questions to the use of placebo within clinical trials.

Satyan, K. S., A. K. Jaiswal, et al. (1998). Anxiolytic activity of ginkgolic acid conjugates from Indian Ginkgo biloba. Psychopharmacology . Mar 136(2): 148-152.

Ginkgolic acid conjugates (GAC) (6-alkylsalicylates, namely n-tridecyl-, n-pentadecyl-, n-heptadecyl-, n-pentadecenyl- and n-heptadecenylsalicylates) isolated from the leaves of Indian Ginkgo biloba Linn., (IGb) were tested for their putative role in anxiety in rats. Elevated plus maze, open-field behaviour, novelty-induced feeding latency and social interaction were the rodent behavioural models used in this study. GAC (0.3 and 0.6 mg/kg, each, PO) on single acute administration, showed dose-related changes in the behaviour. GAC (0.6 mg/kg) and DZ augmented open arm entries, the open arm/closed arm entries ratio and increased time spent in the open arm on the elevated plus maze. In the open field, GAC (0.6 mg/kg) and DZ significantly increased ambulation and reduced the immobility time. EGb 761 showed a similar profile. GAC (0.6 mg/kg) and DZ significantly attenuated the increased latency to feed in novel environment. By contrast, EGb 761 and Ginkocer further augmented feeding latency. None of the drugs tested showed any significant effect in the social interaction test. GAC showed consistent and significant anxiolytic activity in all the variables investigated. By contrast, EGb 761 and Ginkocer, which are devoid of GAC, did not evoke significant activity. However, increased rearing and decreased immobility time only in open field behaviour shown by EGb 761 may be due to some antianxiety activity of a lesser degree. Our observations suggest that GAC may be the active constituents of Ginkgo biloba responsible for the anxiolytic activity.

Mourier, M. (1998). Les `Fruits du Gingko' (French), by K. Miyazawa, H. Morita. Quinzaine Litteraire. Jan 16(731): 6-7.

Kimura, Y., S. Matsuo, et al. (1998). Enzymatic properties of a Ginkgo biloba endo-beta-N-acetylglucosaminidase and N-glycan structures of storage glycoproteins in the seeds. Bioscience Biotechnology And Biochemistry. Feb 62(2): 253-261.

An endo-beta-N-acetylglucosaminidase has been purified to homogeneity from mature seeds of Ginkgo biloba. The molecular mass of the endo-beta-N-acetylglucosaminidase, named Endo-GB, was estimated to be around 63 kDa by SDS-PAGE and around 62 kDa by Hiprep S-200 chromatography, respectively. The substrate specificity has been explored with regard to the pyridylaminated N-glycans. Several high mannose-type sugar chains bearing alpha-1,2-mannosyl residue(s), Man(9-6)GlcNAc(2)-PA, were the most favored substrates followed by Man(5)GlcNAc(2)-PA and a typical hybrid-type structure (GlcNAc,Man,Glc NAc2-PA) which does not bear an alpha-1,2-mannosyl residue, On the contrary, endo-GB could hardly hydrolyze the common core pentasaccharide of N-glycan (Man(3)GlcNAc(2)-PA) and the xylose-containing sugar chains (Man(4-3)Xyl(1)Glc NAc2-PA, Man(3)Fuc(1)Xyl(1)GlcNAc(2)-PA) being widely distributed in plant glycoproteins. Furthermore, we analyzed the structures of N-glycans conjugated to storage glycoproteins in the mature Ginkgo seeds to see the occurrence of endogenous substrates for Endo-GB. The structural analysis showed, however, only xylose-containing type N-glycans (Man(3)Fuc(1)Xyl(1)GlcNAc(2) (95%) and Man(3)Xyl(1) GlcNAc(2) (5%)), which can not be substrate for Endo-GB, predominantly occur in the storage glycoproteins.

Nardi, M. C., E. Giacomelli, et al. (1998). Ginkgo biloba expresses calreticulin, the major calcium-binding reticuloplasmin in eukaryotic cells. Botanica Acta. Feb 111(1): 66-70.

Calreticulin, the main Ca2+ binding protein in the endoplasmic reticulum of eukaryotic cells, was characterized in Ginkgo biloba L. pollen and seeds. Electrophoretic analysis of the partly purified extracts showed the presence of two protein bands of 57 and 50 kDa apparent molecular masses, which strongly cross-reacted with antibodies against plant calreticulins. Amino acid sequence comparison with other plant and animal calreticulins revealed a much higher similarity of the N-terminus of Ginkgo calreticulins with the homologue from angiosperms rather than with that from mammals. The finding of calreticulin in Ginkgo is indicative of the conservation also in gymnosperms of Ca2+ homeostatic mechanisms, which seem to rely on the same molecular components as all eukaryotic cells.

Franks, P. J., I. R. Cowan, et al. (1998). A study of stomatal mechanics using the cell pressure probe. Plant Cell And Environment. Jan 21(1): 94-100.

The relationship between stomatal aperture (a) and guard cell pressure (P-g) was measured directly in four different species (Vicia faba, Tradescantia virginiana, Ginkgo biloba and Nephrolepis exaltata) using a special cell pressure probe technique, The effect of epidermal turgor (P-ep) on this relationship was also measured in T. virginiana. The relationship was sigmoidal for V. faba and T. virginiana, but entirely convex for G, biloba and N. exaltata, Epidermal turgor,vas found to have a pronounced closing effect on stomata of T. virginiana. Maximum aperture with full epidermal turgor (0.92 MPa) was about half that with zero epidermal turgor, Also, with full epidermal turgor stomata of I: virginiana did not begin to open until P-g was more than 1.25 MPa. These characteristics were used to develop an expression for a as a function of P-g and P-ep. Results for the different species are compared and discussed in terms of possible advantages and limitations of water economy.

Vann, A. (1998). The herbal medicine boom: Understanding what patients are taking. Cleveland Clinic Journal Of Medicine. Mar 65(3).

Soholm, B. (1998). Clinical improvement of memory and other cognitive functions by Ginkgo biloba: Review of relevant literature. Advances In Therapy. Jan Feb 15(1): 54-65.

Ginkgo biloba is a plant extract used to alleviate symptoms associated with cognitive deficits, eg, decreased memory performance, lack of concentration, decreased alertness, tinnitus, and dizziness. Pharmacologic studies have shown that the therapeutic effect of ginkgo is based on several active constituents with vasoactive and free radical-scavenging properties. The use of ginkgo extract in either dementias of the Alzheimer or multi-infarct type or in the case of cerebral insufficiency, a symptom complex related to age-dependent impairment of cerebral circulation, is based mainly on positive results from good-quality placebo-controlled studies that enrolled approximately 1200 patients with criteria established by international Classification of Diseases (4th and 10th revisions, ICD-9 and ICD-10) or the 3rd revision of the Diagnostic and Statistical Manual (DSM III-R) (uncomplicated dementia). Effect on cognitive symptoms was within the range of a 25% reduction. Memory, concentration, and alertness were the first symptoms to be relieved, with tinnitus and dizziness improving somewhat later. A minimum of 4 to 6 weeks were needed before a pronounced effect could be expected. The pharmacologic advantage of ginkgo seems to be a very tolerable side-effect profile, with a side-effect frequency at the placebo level.

Wang, J., C. Yang, et al. (1998). Fine structure and assembly in vitro of nuclear lamina in plant cells. Science In China Series C Life Sciences. Feb 41(1): 71-79.

The fine structure of the nuclear lamina (NL) in sperm cells of Ginkgo biloba was visualised using high resolution low-voltage scanning electron microscopy (LVSEM). It was shown that the nuclear lamina was composed of 10 nm filaments which formed a fine network. Lamins were purified from cultured carrot suspension cells and assembled in vitro. Long 8-12 nm diameter filaments were seen and sometimes subfilaments could be distinguished. Western blot of filament preparations showed that these contained the 66 and 84 ku lamins. These data demonstrate that plant lamins are capable of assembling into filaments in vitro.

Castelli, D., L. Colin, et al. (1998). Pretreatment of skin with a Ginkgo biloba extract/sodium carboxymethyl-beta-1,3-glucan formulation appears to inhibit the elicitation of allergic contact dermatitis in man. Contact Dermatitis. Mar 38(3): 123-126.

The clinical efficiency of mitigating contact dermatitis with a Ginkgo biloba extract and carboxymethyl-beta-1,3-glucan formulation was investigated in a double-blind versus placebo study using 22 subjects (Caucasian women aged 22-55 years) with allergic contact dermatitis from various substances in the European standard series. The formulation was applied to intact skin 2X a day for 2 weeks (''in use'' application) prior to a single application of a selected contact allergen under a Finn Chamber for 24 h. Readings were carried out in a blind study by a dermatologist 2 and 3 days after patch removal. Representative photographs were taken of treated, placebo and untreated test areas. 68.2% of the panelists showed significantly reduced skin reactivity (p=0.037*) on the treated site 2 days after patch removal, versus untreated and/or placebo sites. This finding indicates that the Ginkgo biloba/carboxymethyl-beta-1,3-glucan formulation can mitigate against allergic contact dermatitis. (C) Munksgaard, 1998.

Arnould, T., C. Michiels, et al. (1998). Effect of Ginkor Fort on hypoxia-induced neutrophil adherence to human saphenous vein endothelium. Journal Of Cardiovascular Pharmacology. Mar 31(3): 456-463.

This study was performed to evaluate the effects of Ginkor Fort, a venotropic drug composed of Ginkgo biloba extract, troxerutine, and heptaminol, on neutrophil adherence to the endothelium of saphenous veins. When saphenous veins were incubated 2 h in hypoxic conditions, they showed a five- to sixfold increase in neutrophil adherence to the endothelium. Ginkor Fort at 0.3 mg/ml was able to inhibit this increase by 69%. These results were confirmed by observations in scanning electron microscopy. Ginkor Fort also inhibited the subsequent activation of these neutrophils, as evidenced by the inhibition of superoxide anion release. The biochemical mechanism of this inhibition of neutrophil adherence was studied on endothelial cells in culture. We observed that Ginkor Fort was able to inhibit the different steps of the activation of endothelial cells by hypoxia: the activation of phospholipase A(2) and the decrease in adenosine triphosphate (ATP) content. By preventing the first step of the activation cascade, the decrease in ATP content, Ginkor Fort blocks the subsequent increase in neutrophil adherence as well as neutrophil activation. The biochemical mechanism evidenced in this work might explain the beneficial effect of this drug in the treatment of patients with chronic venous insufficiency.

Wesnes, K. A., R. A. Faleni, et al. (1997). The cognitive, subjective, and physical effects of a Ginkgo biloba Panax ginseng combination in healthy volunteers with neurasthenic complaints. Psychopharmacology Bulletin 33(4): 677-683.

We evaluated the effects of a Ginkgo biloba/ginseng combination on cognitive function in this 90-day, double-blind, placebo-controlled, parallel-group study. Sixty-four healthy volunteers (aged 40 to 65 years), selected on the basis of fulfilling the ICD-10 F48.0 criteria for neurasthenia, were assigned randomly to four equal dosing groups, receiving 80, 160, or 320 mg of the combination b.i.d. or placebo. Assessments were performed on the day before dosing, and again at Days 1, 30, and 90 at 1 hour after the morning dose and 1 hour after the afternoon dose. The assessments included the Cognitive Drug Research (CDR) computerized assessment system, the Vienna Determination Unit, cycle ergometry, and various questionnaires. The treatments were well tolerated by all volunteers. On Day 90 at 1 hour post morning dosing, dose-related improvements were seen on the CDR tests, the 320 mg dose being significantly superior to placebo. These effects, however, were reversed 1 hour after the afternoon dose, possibly suggesting that a longer inter-dosing interval would be preferable. The 80-mg dose produced a significant benefit on the ergometry assessment of heart rate at maximum load. There were also several supporting changes from other assessments, including an advantage of 320 mg over placebo on the global score from the Symptom Checklist-90-revised (SCL-90-R) at Day 90.

Heinze, G. (1997). Pharmacologic development during the last decades. Salud Mental. Dec 20(4): 34-38.

Pharmacotherapy in psychiatry has reached a high level of advancement in the introduction of new molecules with more specific actions on determined neurotransmitters of the Central Nervous System. New psyche drug action mechanisms are suggested taking into consideration neuronal plasticity and their induced changes by intracellular regulatory proteins, by means of the phosphorilation process. This is a work on the ''addiction'' model of drug abuse, as a phenomenon of therapeutic change in the treatment of affective illnesses and schizophrenia.Genetic therapy is another path for the development of new drugs by means of molecular information. It will lead us to correct dysfunction's by means of the manipulation of the individual genoma.Recapture of inhibition, as an explanation for the therapeutic effect of antidepressants, has not been able to increase its therapeutic effectivity in depressive dysfunction's since the introduction of imipramine, there fore, phytopharmacology has arisen new interest in clinicians for filling the gaps left by actual drugs.Herboreal medicine manages at this moment three substances (Gingko-Biloba, Flor de San Juan and Kava-kava) which must be studied with the same methodology used for the well known psychodrugs.

Itoh, K., K. Shiraishi, et al. (1998). Production of ginkgolides by callus cultures of icho (Ginkgo biloba) leaves. Mokuzai Gakkaishi 44(1): 1-8.

Calli were induced from leaves of young trees of icho, Ginkgo biloba L., on Murashige and Skoog medium, supplemented with 2,4-dichlorophenoxyacetic acid and kinetin, and subcultured on the same medium. High-performance liquid chromatographic analyses of the extractives of calli revealed that they produced Ginkgolides A and B that are known as antagonists to the platelet-activating factor. The contents of Ginkgolides A and B in the calli were 0.0049% and 0.0180%, respectively, of the dry weight when the calli were incubated at 25 degrees C in light. On the other hand, the contents of Ginkgolides A and B in the calli incubated at 25 degrees C in the dark were 0.0017% and 0.0094%, respectively, of dry weight. The calli cultures of the leaves of icho in the dark and light produced from 23 to 67% and from 57 to 110% of Ginkgolides A and B, respectively, of those of the leaves of the intact plants.The contents of Ginkgolides A and B in the calli were increased 1.2 and 5.9 times in maximum values, respectively, to those of the leaves of the intact plants when the chito-oligosaccharides functioning as elicitors were added to the calli. When geranylgeraniol as a biogenetic precursor of ginkgolides was added to the calli, the contents of Ginkgolides A and B in the calli were inceased 1.2 and 3.0 times, respectively, in maximum values, of those of the leaves of the intact plants.

Yang, F. Q., T. Y. Zhang, et al. (1998). Preparative separation and purification of kaempferol, isorhamnetin, and quercetin by high-speed countercurrent chromatography. Journal Of Liquid Chromatography And Related Technologies 21(1-2): 209-216.

High-speed countercurrent chromatography was used for the preparative separation and purification of kaempferol, isorhamnetin, and quercetin from leaf extracts of Ginkgo biloba L. and the commercial quercetin standard with a two-phase solvent system composed of chloroform-methanol-water (4:3:2, v/v/v).HPLC analyses of the CCC fractions revealed that all three main flavone aglycones were over 99% pure. Their chemical structures were identified by mass spectrometric analysis.

GarciaGutierrez, A., F. Dubois, et al. (1998). Two different modes of early development and nitrogen assimilation in gymnosperm seedlings. Plant Journal. Jan 13(2): 187-199.

Light-independent chloroplast development and expression of genes encoding chloroplast proteins occur in many but not all species of gymnosperms. Early development in maritime pine (Pines pinaster) seedlings was strongly light-independent, whereas Ginkgo biloba seedlings exhibited a typical angiosperm-like morphogenesis with differentiated patterns in light and dark. In pine, chloroplast polypeptides were undetectable in the seed embryo and accumulated in cotyledons of both light-and dark-grown plants in good correlation with light-independent chlorophyll synthesis. In contrast, chlorophyll and chloroplast proteins were only detected in light-grown ginkgo. Pine cytosolic glutamine synthetase (GS) and ferredoxin glutamate synthase (Fd-GOGAT) were present at low levels in the seeds and accumulated at comparable amounts in light-and dark-grown seedlings. Fd-GOGAT was also barely detectable in the seeds of ginkgo and only accumulated in green plants with mature chloroplasts. In G. biloba seeds and etiolated plants only cytosolic GS was identified, while in light-grown seedlings this molecular form was present at low abundance and choroplastic GS was the predominant isoenzyme. The above results have been confirmed by immunolocalization of GS protein in pine and ginkgo plantlets. In pine, GS was present in the peripheral cytoplasm of mesophyll cells and also in the phloem region of the vascular bundle. Immunocytochemical analysis showed that the labelling of mesophyll and phloem cells was only cytoplasmic. In developing ginkgo, GS antigens were present in the chloroplasts of mesophyll parenchyma cells of leaflets and green cotyledons. In contrast, a weak labelling of GS was observed in the parenchyma and phloem cells of non-green cotyledons enclosed in the seed coat. Taking all this into account, our data indicate the existence of two different modes of GS and GOGAT regulation in gymnosperms in close correlation with the differential response of plants to light. Furthermore, the results suggest that glutamine and glutamate biosynthesis is confined to the chloroplast of mesophyll cells in species with light-dependent chloroplast, development whereas compartmentation would be required in species with light-independent plastid development.

Neinhuis, C. and W. Barthlott (1998). Seasonal changes of leaf surface contamination in beech, oak, and ginkgo in relation to leaf micromorphology and wettability. New Phytologist. Jan 138(1): 91-98.

The leaf surfaces of beech, oak and ginkgo have been investigated with respect to contamination with particles during one growing season. Based on the observation that particles are removed from water-repellent leaves by rain (Lotus effect) the three species were selected because they differ in leaf surface micromorphology and wettability. Leaves of beech are smooth, lacked wax crystals and were +/-wettable. Those of ginkgo were rough because their cells were convex and were densely covered by wax crystals, resulting in permanent water repellency. Leaves of oak were covered by waxes and were water repellent when young, but, a few weeks after leaf expansion had ceased the waxes were rapidly eroded. These differences in wettability resulted in different amounts of contamination. Ginkgo collected a very small number of particles during the whole vegetation period. In beech the contamination was significantly higher, but fairly constant, whereas oak leaves accumulated particles with age.

Watson, D. G. and A. R. Pitt (1998). Analysis of flavonoids in tablets and urine by gas chromatography mass spectrometry and liquid chromatography mass spectrometry. Rapid Communications In Mass Spectrometry 12(4): 153-156.

A method was developed for the analysis and characterization of quercetin and kaempferol in urine following ingestion of Ginkgo biloba tablets. The method utilized gas chromatography/negative ion chemical ionization mass spectrometry of the trimethysilyl derivatives of the flavonoids. Limits of detection for these compounds using this method were ca, 20 pg on column. Liquid chromatography with electrospray mass spectrometry in the negative ion mode was utilized to characterize the complex mixture of glycosides present in the G. biloba tablets, the limit of detection with this technique was ca. 10 ng on column. (C) 1998 John Wiley and Sons, Ltd.

Schulz, V., W. D. Hubner, et al. (1997). Clinical trials with phyto-psychopharmacological agents. Phytomedicine . Dec 4(4): 379-387.

Phyto-psychopharmacological agents are extracts of plants with stimulating or calming effects on the central nervous system. Phyto-psycho-pharmacological agents are among the most commonly prescribed herbal medicines in Germany. The efficacy and harmlessness of some of the preparations have been established by high quality clinical trials. Between 1975 and 1992, a total of 34 clinical studies involving some 2326 patients were published on the effects of Ginkgo special extract EGb 761 and LI 1370; to date, 28 clinical trials in 2120 patients have been undertaken with alcoholic extracts of St. John's Wort. The therapeutic efficacy of kava and valerian extracts has been investigated in six and four controlled studies, respectively. In general, a high placebo effect is likely, which is why it is essential to include control groups in these studies. A considerable advantage over synthetic psychopharmacological agents is the low incidence of side effects, which in safety assessment studies is below 3%. The sharp increase in quality standards for clinical trials has meant that only a few preparations have undergone large scale testing programs in accordance with international guidelines. For other phyto-psychopharmacological agents, there is the danger that no further clinical trials will be undertaken due to the excessively high standards now demanded.

Hasenohrl, R. U., B. Topic, et al. (1998). Dissociation between anxiolytic and hypomnestic effects for combined extracts of Zingiber officinale and ginkgo biloba, as opposed to diazepam. Pharmacology Biochemistry And Behavior. Feb 59(2): 527-535.

Previous work has shown that Zingicomb(R) (ZC), a combination preparation of zingiber officinale and ginkgo biloba, exerts anxiolytic-like effects in the elevated plus-maze (EPM), possibly related to 5-HT antagonistic properties of its components. The first experiment of this study was performed to gauge the specificity of the anxiolytic action of ZC with respect to the mixture ratio of the single components in the combination preparation. Two different combinations of zingiber officinale and ginkgo biloba extracts (ratio of components: 1:1 or 1:2.5) were compared with the standard ratio adjusted for ZC (2.5:1). Each combination was administered intragastrically (IG) in five doses (0.01 to 10 mg/kg) before the rats were tested on the EPM. Zingicomb at 1 mg/kg elevated the time spent on the open arms, scanning of the open arms and excursions into the ends of the open arms, whereas the two other combinations (1:1 and 1:2.5) did not influence rats' behavior on the EPM in the entire dose range tested. With regard to the memory-disrupting effects of anxiolytics, particularly of diazepam (DZP), a second experiment was performed to compare the effects of ZC (0.5, 1, 10 mg/kg, IG) and DZP (1 or 5 mg/kg, TP) on the performance of rats in two different learning tasks. Rats were treated with DZP or ZC prior to the learning trial of a one-trial step-through inhibitory avoidance task. Retention testing 24 h later showed impaired retention for rats injected with DZP at 5 mg/kg but not for animals that had received ZC prior to training. In a further experiment, rats were treated once daily with DZP or ZC prior to the training trials in a water maze. Injections of DZP at 5 mg/kg impaired place and cue learning, whereas the treatment with ZC did not influence the navigation performance in the maze. The present results indicate that the anxiolytic-like effects of ZC are specific in that only the mixture ratio of zingiber officinale and ginkgo biloba adjusted for the phytopharmacon was active in the EPM. Furthermore, ZC did not interfere negatively with the performance on an inhibitory avoidance and a water maze task, as opposed to DZP. This finding is interesting with regard to other studies that have revealed a similar dissociation between anxiolytic and memory-disrupting effects for chemically defined 5-HT antagonists, especially for those acting at 5-HT3 receptors. (C) 1998 Elsevier Science Inc.

CohenSalmon, C., P. Venault, et al. (1997). Effects of Ginkgo biloba extract (EGb 761) on learning and possible actions on aging. Journal Of Physiology Paris. Dec 91(6): 291-300.

A study of the effect of Ginkgo biloba extract (EGb 761) has shown enhancing effects on training in adult and aged Swiss mice. An analysis of inbred mice has confirmed this sensitivity to EGb 761, but depending on the strains, with different effects at different ages. The most interesting results are related to improvements in performances observed with aged mice of the DBA/2J strain. The results obtained with inbred strains in the study of the mossy fibers of the hippocampus make it possible to suggest a link between the improvements in training and the histological structure of the hippocampus. This possibility, which can be confirmed by further studies, is presented here.

Saller, R., J. Reichling, et al. (1998). Phytotherapy - treatment or side effect? Deutsche Medizinische Wochenschrift. Jan 123(3): 58-62.

Winter, J. C. (1998). The effects of an extract of Ginkgo biloba, EGb 761, on cognitive behavior and longevity in the rat. Physiology And Behavior. Feb 63(3): 425-433.

Extracts of the leaves of the Ginkgo biloba tree are widely used throughout the world for their purportedly beneficial effects on brain function. In the present investigation, a standardized extract, EGb 761, was self-administered orally by male Fischer 344 rats that were then tested in an eight-arm radial maze. The tasks employed were a) continuous learning and b) delayed nonmatching to position. Chronic postsession administration of EGb 761 at a dose of 50 mg/kg had no effect on continuous learning but the same dose given presession resulted in a trend toward fewer sessions to reach criterion performance as well as fewer errors. In addition, it was observed that rats chronically treated with EGb 761 lived significantly longer than vehicle-treated subjects. In a delayed nonmatching to position task using a 30-min delay in 20-month-old rats. EGb 761 administered presession produced a dose-related decrease in total, retroactive, and proactive errors; a repeated-measures design was used, with subjects serving as their own controls. Following the dose-response determination, the group, now 26 months of age, was divided in two with half receiving EGb 761 at a dose of 200 mg/kg presession and the other half vehicle (sweetened condensed milk). A statistically significant positive effect of treatment with EGb-761 was observed. The present data are consistent with the beneficial effects on cognitive performance which have been widely reported in human subjects. In addition, the data suggest that the methods employed, i.e., continuous learning and delayed nonmatching to position tasks in aged rats, are capable of detecting drugs of possible value in the treatment of human cognitive impairment. Finally, the present results encourage a search for the pharmacologically active principles of EGb 761 and for their mechanisms of action. (C) 1998 Elsevier Science Inc.

Niederl, S., T. Kirsch, et al. (1998). Co-permeability of H-3-labeled water and C-14-labeled organic acids across isolated plant cuticles - Investigating cuticular paths of diffusion and predicting cuticular transpiration. Plant Physiology. Jan 116(1): 117-123.

Penetration of H-3-labeled water ((H2O)-H-3) and the C-14-labeled organic acids benzoic acid ([C-14]BA), salicylic acid ([C-14]SA), and 2,4-dichlorophenoxyacetic acid ([C-14]2,4-D) were measured simultaneously in isolated cuticular membranes of Prunus laurocerasus L., Ginkgo biloba L., and Juglans regia L. For each of the three pairs of compounds ((H2O)-H-3/[C-14]BA, (H2O)-H-3/[C-14]SA, and (H2O)-H-3/[C-14]2,4-D) rates of cuticular water penetration were highly correlated with the rates of penetration of the organic acids. Therefore, water and organic acids penetrated the cuticles by the same routes. With the combination (H2O)-H-3/[C-14]BA, co-permeability was measured with isolated cuticles of nine other plant species. Permeances of (H2O)-H-3 of all 12 investigated species were highly correlated with the permeances of [C-14]BA (r(2) = 0.95). Thus, cuticular transpiration can be predicted from BA permeance. The application of this experimental method, together with the established prediction equation, offers the opportunity to answer several important questions about cuticular transport physiology in future investigations.

FughBerman, A. (1997). Clinical trials of herbs. Primary Care. Dec 24(4).

Consumers, clinicians, and corporations are taking an interest in botanical medicine. Although large gaps remain in research, many clinical trials of herbs exist. This article reviews these trials.

Li, C. L. and Y. Y. Wong (1997). The bioavailability of ginkgolides in Ginkgo biloba extracts. Planta Medica. Dec 63(6): 563-565.

A new Ginkgo biloba leaf extract, BioGinkgo 27/7, was prepared using a method that enriches ginkgolide B. The bioavailability of ginkgolides in these extracts was assessed in rabbits in comparison with a commercially available standardized 24/6 extract. it was found that, after a single dose, a higher concentration of ginkgolides was maintained for a longer period of time with these extracts than was found with commercial extract prepared by existing methods.

Maurer, K., R. Ihl, et al. (1997). Clinical efficacy of Ginkgo biloba special extract EGb 761 in dementia of the Alzheimer type. Journal Of Psychiatric Research. Nov Dec 31(6): 645-655.

Among the psychiatric illnesses associated with old age primary degenerative dementia of the Alzheimer type (DAT) has gained increasing importance in recent years. Even though a curative treatment of the disease is currently impossible, various drugs can be used to slow down its progression. In the present study the influence of oral treatment with 240 mg/day of Ginkgo biloba special extract EGb 761 (Tebonin(R) forte, manufactured by Dr Willmar Schwabe, Karlsruhe) on the clinical course of DAT was investigated in a double-blind, randomized, placebo-controlled parallel-group design in 20 outpatients. The duration of treatment was 3 months. The primary outcome variable was the sum score in the SKT-test for the determination of attention and memory. Other psychometric tests (trailmaking test, ADAS, CGI) and electrophysiological investigations (EEG topography) were evaluated descriptively. Although the active-treatment group, with a mean sum score of 19.67 points in the, S.K.T., had a poorer baseline level than the placebo group (18.11 points). it experienced an improvement to 16.78 points under treatment with EGb 761. whereas the placebo group deteriorated to 18.89 points. The differences between the baseline and final values formed the basis for a statistical group comparison, which gave a result favourable to EGb 761, at a significance level of p<.013. In addition to this psychometric confirmation of efficacy, certain descriptive trends were found at the psychopathological (Clinical Global Impression) and dynamic functional (EEG findings) levels, which can be interpreted as evidence of effectiveness of Ginkgo biloba special extract EGb 761 in mild to moderate dementia and of local effects in the central nervous system. Inter-group differences in the ADAS cognitive and non-cognitive subscales did not reach statistical significance, probably because of the small sample size. (C) 1997 Elsevier Science Ltd. All rights reserved.

Rasetti, M. F., D. Caruso, et al. (1997). Extracts of Ginkgo biloba L leaves and Vaccinium myrtillus L fruits prevent photo induced oxidation of low density lipoprotein cholesterol. Phytomedicine . Feb 3(4): 335-338.

Oxidation of low density lipoproteins (LDL) favours cholesterol loading in macrophages and formation of ''foam cells'', typical of the early atheroma lesions. LDL cholesterol oxidation generates oxysterols, extremely cytotoxic molecular species with diverse biological activities. Vegetable polyphenols are dietary components of pharmacological interest for their anti-oxidant properties. Ginkgo biloba L. (Gingkoaceae) leaves and Vaccinium myrtillus L. (Ericaceae) fruits are known for their beneficial effects in the treatment of various diseases involving free radicals and oxidative damage to biological lipids. In this study we investigated the effect of Ginkgo biloba L. and Vaccinium myrtillus L. extracts on the formation of cholesterol oxides during the photo induced oxidation of human LDL. The results demonstrate a concentration dependent inhibition of oxysterol formation in the presence of both extracts. Protection against oxidation was confirmed by the partial restoration of the normal electrophoretic mobility of LDL, which has been influenced by the UV irradiation. These effects extend knowledge of the therapeutic action of Ginkgo biloba L. and Vaccinium myrtillus L. as agents in anti-atherosclerotic regimens.

Husstedt, I. W., K. H. Grotemeyer, et al. (1997). Progression of distal symmetric polyneuropathy during diabetes mellitus: Clinical, neurophysiological, haemorheological changes and self-rating scales of patients. European Neurology 37(2): 90-94.

The complex interrelationships between progression of distal symmetric polyneuropathy (DSP) induced by diabetes mellitus and haemorheological alterations in correlation with the patients' self-rating scales about the progression of DSP were investigated. The study included 42 patients suffering from diabetes mellitus for 15 +/- 10 years. Clinical, neurophysiological and haemorheological follow-ups (platelet reactivity, erythrocyte aggregation, viscosity) were performed initially (A) and repeated 42 +/- 10 months later (B), At point B, clinical signs of DSP were found in 90.2% in the lower extremities, and 41.5% of the patients exhibited for the first time new symptoms and signs of DSP in the upper extremities, Besides conventional neurophysiological investigations (conduction velocity, amplitude) in the sural nerve, paired stimulation (LPSS) was applied, In peroneal nerve, conduction velocity, distal latency and F wave were estimated. These results confirmed the clinical progression of DSP (LPSS; p < 0.05). Platelet reactivity was statistically improved (p < 0.05) at point B predominantly as an effect of treatment (acetylsalicylic acid, Ginkgo biloba), whereas erythrocyte aggregation was increased at point B with and without treatment (p < 0.05). Blood glucose levels were abnormal at both points, Analogue self-rating scales showed that only 27% of the patients realized their progression of DSP. In conclusion, the results prove the clinical and neurophysiological progression of DSP and highlight that haemorheological changes may play a part in the conjectural pathogenesis of DSP. As patients to not realize the dramatic progression of DSP, information of the patients about the correlation between hyperglycaemia and progressive DSP should be reinforced.

Chermat, R., D. Brochet, et al. (1997). Interactions of Ginkgo biloba extract (EGb 761), diazepam and ethyl beta-carboline-3-carboxylate on social behavior of the rat. Pharmacology Biochemistry And Behavior. Feb 56(2): 333-339.

The social interaction test was used to examine the effects of an extract of Ginkgo biloba (EGb 761) and its possible interactions with diazepam and ethyl beta-carboline-3-carboxylate (beta-CCE). Pairs of naive (unfamiliar) male Wistar AF rats subjected to the same treatment were placed in a novel test arena that was brightly illuminated, and the duration (in s) of social contact was observed over a 10 min period. Single injections of EGb 761 (8-16 mg/kg, IF), given 30 min prior to testing, or repeated oral administration of the extract (48 or 96 mg/kg/day) for s days, significantly decreased social contact under conditions that did not influence locomotor activity. Injection of diazepam (1 mg/kg, LP), 30 min before testing, significantly increased social contact. Injection of diazepam to animals that had received repeated oral treatment with EGb 761 (96 mg/kg/day) increased social interaction to an extent greater than observed with diazepam alone. Injection of beta-CCE (2-16 mg/kg, IF), 15 min before testing, significantly decreased social contact. When the animals were treated with EGb 761 (48 or 96 mg/kg/day, p.o. for 8 days) and beta-CCE (4 mg/kg), both of which decreased social interaction when administered alone, the resulting level of social contact was similar to that of control animals. Interactions with certain sites of central GABA(A)/benzodiazepine/Cl- channel receptor complexes could be involved in mediating these effects of EGb 761, diazepam and beta-CCE. Copyright (C) 1997 Elsevier Science Inc.

Markova, T. A. and K. Z. Gamburg (1997). Stereoconfiguration of endogenous N-malonyltryptophan in plants. Plant Science. Feb 122(2): 119-124.

N-malonyltryptophan (MTry) isolated from soybean and ginkgo cell cultures, etiolated tomato, wheat and rye seedlings, turgescent and wilted tomato green leaves and from apple fruits was separated on 'Chiralplates'. In all cases the spots corresponding to M-L-Try were observed. Some amount of M-D-Try was also found in wheat and rye seedlings. Try released from endogenous MTry of soybean cell culture, wilted tomato leaves and apple fruits by alkaline hydrolysis corresponded to L-Try on Chiralplates and was deaminated by L-amino acid oxidase. The treatment of soybean cells and tomato leaves with D-Try resulted in the appearance of M-D-Try which became the predominant Try conjugate. It was postulated that malonylation was a significant part of endogenous L-Try metabolism in plants whereas M-D-Try was in most cases the result of exogenous D-Try malonylation. (C) 1997 Elsevier Science Ireland Ltd.

Mo, K., C. O. Lora, et al. (1997). Biodegradation of methyl t-butyl ether by pure bacterial cultures. Applied Microbiology And Biotechnology. Jan 47(1): 69-72.

Three pure bacterial cultures degrading methyl t-butyl ether (MTBE) were isolated from activated sludge and fruit of the Gingko tree. They have been classified as belonging to the genuses Methylobacterium, Rhodococcus, and Arthrobacter. These cultures degraded 60 ppm MTBE in 1-2 weeks of incubation at 23-25 degrees C. The growth of the isolates on MTBE as sole carbon source is very slow compared with growth on nutrient-rich medium. Uniformly-labeled [C-14]MTBE was used to determine (CO2)-C-14 evolution. Within 7 days of incubation, about 8% of the initial radioactivity was evolved as (CO2)-C-14. These strains also grow on t-butanol, butyl formate, isopropanol, acetone and pyruvate as carbon sources. The presence of these compounds in combination with MTBE decreased the degradation of MTBE. The cultures pregrown on pyruvate resulted in a reduction in (CO2)-C-14 evolution from [C-14]MTBE. The availability of pure cultures will allow the determination of the pathway intermediates and the rate-limiting steps in the degradation of MTBE.

Papadopoulos, V., H. Amri, et al. (1997). Peripheral benzodiazepine receptor in cholesterol transport and steroidogenesis. Steroids . Jan 62(1): 21-28.

Steroidogenesis begins with the metabolism of cholesterol to pregnenolone by the inner mitochondrial membrane cytochrome P450 side-chain cleavage (P450scc) enzyme. The rate of steroid formation, however, depends on the rate of cholesterol transport from intracellular stores to the inner mitochondrial membrane and loading of P450scc with cholesterol. In previous in vitro studies, we demonstrated that a key element in the regulation of cholesterol transport is the mitochondrial peripheral-type benzodiazepine receptor (PBR). We also showed that the polypeptide diazepam binding inhibitor (DBI), an endogenous PER ligand, stimulates cholesterol transport and promotes loading of cholesterol to P450scc in vitro, and that its presence is vital for hCG-induced steroido-genesis by Leydig cells. Based on these data and the observations that ii the mitochondrial PER binding and topography are regulated by hormones; ii) the 18-kDa PER protein is functionally coupled to the mitochondrial contact sire voltage-dependent anion channel protein; iii) the 18-kDa PER protein is a channel for cholesterol, as shown by molecular modeling and in vitro reconstitution studies; iv) targeted disruption of the PER gene in steroidogenic cells dramatically reduces the ability of the cells to transport cholesterol in the mitochondria and produce steroids: v) endocrine disruptors, with known anisteroidogenic effect, inhibit PER ligand binding; and vi) in vivo reduction of adrenal PER expression results in reduced circulating glucocorticoid levels, we conclude that PER is an indispensable element of the steroidogenic machinery. (C) 1997 by Elsevier Science Inc.

Rosch, P. J. (1997). Editorial: Stress and memory loss: Some speculations and solutions. Stress Medicine. Jan 13(1): 1-6.

Emerit, I., M. Quastel, et al. (1997). Clastogenic factors in the plasma of children exposed at Chernobyl. Mutation Research Fundamental And Molecular Mechanisms Of Mutagenesis. Jan 373(1): 47-54.

Clastogenic factors (CFs), as they were described previously in accidentally or therapeutically irradiated persons, in A-bomb survivors and in liquidators of the Chernobyl nuclear power plant, were also detected in the plasma of Chernobyl-exposed children. A high percentage of plasma ultrafiltrates from 170 children, immigrated to Israel in 1990, exerted clastogenic effects in test cultures set up with blood from healthy donors. The differences were highly significant in comparison to children immigrated from 'clean' cities of the former Soviet Union or children born in Israel. The percentage of CF-positive children and the mean values of the adjusted clastogenic scores (ACS) were higher for those coming from Gomel and Mozyr, which are high exposure sites (IAEA measurements), compared to those coming from Kiev. There was no correlation between residual 137-Caesium body burden and presence of CFs. However, both measurements were not done at the same time (in 1990 and 1992-1994, respectively). Also no relationship could be revealed between enlargement of the thyroid gland and CF-positivity. CFs are not only observed after irradiation, but in a variety of chronic inflammatory diseases with autoimmune reactions. They were also described in the congenital breakage syndromes, which are hereditary diseases with the highest cancer incidence in humans. Whether the clastogenic effects continuously produced by circulating CFs represent a risk factor for malignant late effects deserves further study and follow-up. Since CF formation and CF action are mediated by superoxide radicals, prophylactic treatment with antioxidants may be suggested for Chernobyl-exposed children, whose plasma induces a strongly positive CF-test.

Carlquist, S. (1996). Wood, bark, and stem anatomy of gnetales: A summary. INTERNATIONAL JOURNAL OF PLANT SCIENCES 157(6): Suppl.

Data from a series of eight papers, representing a survey of Gnetales at the species level, are summarized in order to develop concepts on the relationship between the anatomical data and ecology, phylogeny, and systematics. Most of the characters and character states newly reported have phylogenetic and ecological correlations far Gnetales as a whole rather than systematic significance within the genera. Wood features are sensitively related to habit, although strategies in lianoid species of Ephedra differ from those in lianoid Gnetum species. Data also bear close relationships to organography. Vessel details are given special attention because workers have questioned whether vessels originated in Gnetales independently of those in angiosperms, and thus whether or not vessel origin in the two groups is a synapomorphy. The evidence cited here favors origin of vessels in Gnetales independent of vessel origins in angiosperms. Hitherto unappreciated contrasts between vessels of Gnetales and those of angiosperms are detailed: the torus-margo structure of pits in Gnetales (both Ephedra and Gnetum), and the aspiration ability of gnetalean pits represent modes of conduction and promotion of conductive safety different from those in angiosperms, and the shape difference (circular vs. scalariform), cited in data matrices of cladograms, is secondary to the different functional syndromes. The intercalation of circular bordered pits into helical secondary wall thickenings of primary xylem tracheary elements of Ephedra and Gnetum (a feature found also in conifers and Ginkgo but not in angiosperms) is given new functional interpretations. Ephedra and Gnetum contain both tracheids and fiber-tracheids that co-occur in a mode different from that in angiosperms which contain both cell types together Ray structure like that of Gnetales occurs widely within seed plants and likely offers little conclusive information about relationships. Wood data on Gnetales are compatible with the hypothesis that a vesselless group of gymnosperms, such as Pentoxylales or Bennettitales. is the closest sister group of angiosperms. Formation of successive cambia in Gnetum differs from that in Welwitschia: the latter has phellem but no other bark. Because Welwitschia has only phellem, there are more numerous bark features in common between Ephedra and Gnetum than one might have expected. The three genera appear monophyletic on the basis of wood and bark. Infrageneric anatomical features of systematic importance are few, although the arboreal Gnetum gnemon differs from the lianoid Gnetum species in significant ways.

Chaw, S. M., A. Zharkikh, et al. (1997). Molecular phylogeny of extant gymnosperms and seed plant evolution: Analysis of nuclear 18S rRNA sequences. Molecular Biology And Evolution. Jan 14(1): 56-68.

To study the evolutionary relationships among the four living gymnosperm orders and the interfamilial relationships in each order, a set of 65 nuclear 18S rRNA sequences from ferns, gymnosperms, and angiosperms was analyzed using the neighbor-joining and maximum-parsimony methods. With Selaginella as the outgroup, the analysis strong ly indicates that the seed plants form a monophyletic group with the ferns as a sister group. Within the seed plants the angiosperms are clearly a monophyletic group. Although the bootstrap support for the monophyly of the gymnosperm clade is moderate, the monophyly is further supported by its lack of angiosperm-specific indels. Within the gymnosperms there appear to be three monophyletic clades: Cycadales-Ginkgoales, Gnetales, and Coniferales. The cycad-ginkgo clade is the earliest gymnosperm lineage. Given the strong support for the sister group relationship between Gnetales and Coniferales, it is unlikely that Gnetales is a sister group of the angiosperms, contrary to the view of many plant taxonomists. Within Coniferales, Pinaceae is monophyletic and basal to the remaining conifer families, among which there are three monophyletic clades: Phyllocladaceae-Podocarpaceae, Araucariaceae, and Sciadopityaceae-Taxaceae-Cephalotaxaceae Within the latter clade, Sciadopityaceae may be an outgroup to the other four families. Among the angiosperms, no significant cluster at the level of subclass was found, but there was evidence that Nymphaeaceae branched off first. Within the remaining angiosperms, the monocots included in this study are nested and form a monophyletic group. This study attests to the utility of nuclear 18S rRNA sequences in addressing relationships among living gymnosperms. Considerable variation in substitution rates was observed among the ferns and seed plants.

Bonga, J. M. (1996). Frozen storage stimulates the formation of embryo-like structures and elongating shoots in explants from mature Larix decidua and L x eurolepsis trees. Plant Cell Tissue And Organ Culture. Aug 46(2): 91-101.

Branches were collected from a Larix decidua and a L. x eurolepis tree, both 36 years old, in mid-winter. These branches were placed in freezers at -5 degrees C, -10 degrees C, and -18 degrees C. Primordial shoot explants were excised after 2 to 9 months of frozen storage. The material remained viable at all three temperatures for at least 9 months. The frozen storage stimulated formation of embryo-like structures that were capable of forming shoots with elongated stems.

Wang, J., C. Yang, et al. (1996). Nuclear lamina in plant cells. Science In China Series C Life Sciences. Oct 39(5): 449-457.

By using selective extraction and diethylene glycol disterate (DGD) embedment and embedment-free electron microscopy, the nuclear lamina was demonstrated in carrot and Ginkgo male generative cells. Western blotting revealed that the nuclear lamina was composed of A-type and B-type lamins which contained at least 66-ku and 84-ku or 66-ku and 86-ku polypeptides, respectively. These lamin proteins were localized at the nuclear periphery as shown by immunogold-labelling. In situ hybridization for light microscope and electron microscope showed that plant cells have the homologous sequences of animal lamin cDNA. The sorting site of lamin mRNA is mainly distributed in the cytoplasm near the nuclear envelope. The data have verified that there indeed exists nuclear lamina in plant cells.

Ha, S. W., C. J. Yi, et al. (1996). Enhancement of radiation effect by Ginkgo biloba extract in C3H mouse fibrosarcoma. Radiotherapy And Oncology. Nov 41(2): 163-167.

Background and purpose: Ginkgo biloba leaf extract (GEE) is known to increase peripheral blood circulation. The hypothesis that GEE may be able to enhance radiosensitivity of tumor by improving tumor blood flow and thus decreasing hypoxic fraction was tested.Materials and methods: Fibrosarcoma (FSaII) growing in C3H mouse leg muscle was used as a tumor model. GEE was given i.p. 1 h before irradiation with or without priming dose given 1 day earlier. Effect on tumor and normal tissue radiation reaction was investigated.Results: Tumor growth delay by radiation was more elongated after two doses (1-day interval) of GEE than after a single dose. Radiation dose for 3-day tumor growth delay was decreased from 12.45 (10.97-13.93) Gy to 6.06 (3.89-8.22) Gy by two doses of GEE [enhancement ratio=2.06 (1.32-2.79)]. Hypoxic cell fraction was 10.6% (6.3-18.2%) for control, 7.2% (3.8-14.0%) after a single dose (P=0.18) and 2.7% (1.5-5.0%) after two doses (P <0.001). Radiation effect on normal tissue, estimated by acute skin reaction and jejunal crypt assay, was not affected by GEE.Conclusion: Ginkgo biloba extract enhances radiation effect on tumor without increasing acute normal tissue radiation damage in this model system probably by increasing tumor blood flow and further investigation for this possible radiosensitizer is needed.

Dawe, R. A., J. S. Kerr, et al. (1996). Ginkgo Biloba extract: Validation of a test battery. Human Psychopharmacology Clinical And Experimental. Nov Dec 11(6): 523-524.

Ferreira, M. G. and M. C. Fonteles (1996). Different classes of PAF-antagonists block norepinephrine-induced vascular escape and tachyphylaxis in the isolated rabbit kidney. Research Communications In Molecular Pathology And Pharmacology. Nov 94(2): 147-155.

In order to study the role of platelet activating factor (PAF) on norepinephrine induced vascular escape and tachyphylaxis, compounds from different pharmacological families sharing PAF-antagonistic activity, were infused in the isolated rabbit kidney perfused with Krebs-Henseleit solution. A natural compound derived from Ginkgo biloba (BN 52020, 1.1 x 10(-6) M), a triazolobenzodiazepine substance (WEB 2170, 1.1 x 10(-6)M) and a dihydropyridine derivative lacking cardiovascular effects (PCA 4248, 2.7 x 10(-6)M), were analysed. The vascular reactivity to three cycles of norepinephrine (1.3 x 10(-6)M), infused in the kidneys treated with each of the PAF- antagonists, were evaluated for vascular escape and tachyphylaxis. The results demonstrated a significant reduction of both regulatory phenomena. A fall in renal vascular escape promoted by PAF antagonists, from a control level of 50.32 +/- 4.61 to 27.64 +/- 8. 01 % (p< 0.05), suggests a role for PAF-acether in the vascular adjustment of the mammalian kidney.

Arenz, A., M. Klein, et al. (1996). Occurrence of neurotoxic 4'-O-methylpyridoxine in Ginkgo biloba leaves, Ginkgo medications and Japanese Ginkgo food. Planta Medica. Dec 62(6): 548-551.

4'-O-Methylpyridoxine (ginkgotoxin) is a neurotoxic antivitamin B-6 which occurs in Ginkgo biloba L. seeds. Contrary to a previous report by Wada et al. (15), the toxin was also detected in Ginkgo biloba leaves. The leaves are a source of extracts (e.g. EGb761) employed in the preparation of Ginkgo medications. Consequently the toxin ws also present in Ginkgo medications and is even detectable in homoeopathic preparations. The toxin occurs also in boiled Japanese Ginkgo food. However, the amount of the toxin is likely to-be too low to exert a detrimental effect after administration of the medication or ingestion of food.

Moscatelli, A., G. Cai, et al. (1996). Dynein-related polypeptides in pollen and pollen tubes. Sexual Plant Reproduction. Nov 9(6): 312-317.

Microtubules in pollen tubes are evident within the vegetative and generative cell cytoplasm. This observation led to the formulation of several hypotheses regarding the role of microtubules in cytoplasmic movement and the migration of the vegetative nucleus/generative cell along the pollen tube. The study of microtubular motor proteins in pollen tubes followed the discovery and characterization of an immunoreactive homolog of mammalian kinesin in tobacco pollen tubes, Recent identification of dynein-related polypeptides in pollen tubes of Nicotiana tabacum and pollen of Ginkgo biloba is a significant step in the definition of the role of microtubule function within pollen and pollen tubes.

Noda, Y., K. Anzai, et al. (1997). Hydroxyl and superoxide anion radical scavenging activities of natural source antioxidants using the computerized JES-FR30 ESR spectrometer system. Biochemistry And Molecular Biology International. Jun 42(1): 35-44.

Free radical scavenging activities of water-soluble extracts from some natural sources, health foods, and antioxidant substances were measured using the JES-FR30 JEOL spectrometer. The objective was to develop a standardized method whereby comparison could be made between the radical scavenging activities of complex mixtures.Scavenging of hydroxyl radical was determined using DMPO. Activity was calibrated using a standard material, L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2(4,8,12-trimethyltridecyl)-2H-1-benzopyran-6yl-hydrogen phosphate] potassium salt (EPC-K-1), an analog of vitamin C and vitamin E which is water soluble and stable at room temperature. The order of greatest hydroxyl radical scavenging activity was green tea extract, pine bark extract (Pycnogenol), Ginkgo Biloba extract (EGb 761), a flavonoid blend of several fruit and vegetable extracts (GNLD), and Bio-Normalizer (Sun-O Corp). Activity was determined after treatment of samples with ascorbic acid oxidase. This treatment revealed the presence of ascorbate in some natural extracts and commercial preparations. The pine bark extract was the most heat resistant and had ascorbate-like activity in the preparations.Scavenging of superoxide anion was determined using the spin trap, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), and analyzed by comparison with a standard curve made with superoxide dismutase. Comparison of the water solubilized components of natural source antioxidants showed that filtrates fractionated using centrifuge type Millipore filter tubes (M.W.<100,000; M.W.<10,000) also had almost the same SOD-like activity. Samples were also treated with ascorbate oxidase or by heating (100 degrees C for 10 min). The order of activity, from greatest to least, was Ginkgo biloba extract EGb 761, pycnogenol, beta-catechin, tea and BioNormalizer.

Imai, T., N. Terashima, et al. (1997). Determination of the distribution and reaction of polysaccharides in wood cell walls by the isotope tracer technique .6. Selective radio-labeling of mannan in ginkgo (Ginkgo biloba). Mokuzai Gakkaishi 43(4): 342-348.

D-Mannose-[2-H-3] and GDP (guanosine diphosphate)-D-mannose-[mannose-1-H-3] were administered to the shoots of ginkgo (Ginkgo biloba L.) to label mannan selectively in the cell walls. To suppress the incorporation of radioactivity into the lignin and cellulose, the precursors were administered in the presence of the inhibitor of phenylalanine ammonia-lyase (PAL): namely, L-alpha-aminooxy-beta-phenylpropionic acid (AOPP) and the inhibitor of glucan synthesis: namely, 2-deoxy-D-glucose (2-DG) and 2.6-dichlorobenzonitrile (2.6-DCB). When D-mannose-[2-H-3] was administered in the absence of the inhibitors, great radioactivities were found in the mannose and glucose obtained by sulfuric acid hydrolysis of the newly-formed xylem, and also in the vanillin obtained by nitrobenzene oxidation. These results indicate that the radioactivity was incorporated not only into mannan but also into cellulose and lignin. When D-mannose-[2-H-3] was administered in the presence of both AOPP and 2-DG, the radioactivities of vanillin and glucose were decreased but that of mannose was not decreased. These results indicate that the incorporations of radioactivities into lignin and cellulose were suppressed by the inhibitors, but the incorporation into mannan was not interfered with. The treatment with 2,6-DCB lessened the incorporations of radioactivity into vanillin, xylose, mannose, and glucose of the newly formed xylem considerably which indicated that 2,6-DCB disturbed the metabolic activities of the plant fatally. Consequently, the selective radiolabeling of mannan in ginkgo was achieved by the administration of D-mannose-[2-H-3], in the presence of both AOPP and 2-DG, to a growing stem. In the case of GDP-D-mannose-[mannose-1-H-3], the radioactivity incorporated into the newly-formed xylem was very little, and the selectivity in labeling and the effects of the inhibitors were not clear.

Odawara, M., A. Tamaoka, et al. (1997). Ginkgo biloba. Neurology . Mar 48(3): 789-789.

Lewis, S. L. and J. Rowin (1997). Ginkgo biloba - Reply. Neurology . Mar 48(3): 789-790.

Pietta, P. G., C. Gardana, et al. (1997). Identification of Ginkgo biloba flavonol metabolites after oral administration to humans. Journal Of Chromatography B. May 693(1): 249-255.

An extract of Ginkgo biloba leaves (EGb) was given to healthy volunteers. Urine samples were collected for 3 days, and blood samples were withdrawn every 30 min for 5 h. The samples were purified through SPE C-18 cartridges and analyzed by reversed-phase LC-diode array detection for the presence of EGb metabolites. Only urine samples contained detectable amounts of substituted benzoic acids, i.e., 4-hydroxybenzoic acid conjugate, 4-hydroxyhippuric acid, 3-methoxy-4-hydroxyhippuric acid, 3,4-dihydroxybenzoic acid, 4-hydroxybenzoic acid, hippuric acid and 3-methoxy-4-hydroxybenzoic acid (vanillic acid). In contrast to rats no phenylacetic acid or phenylpropionic acid derivatives were found in urine, thus indicating that in humans a more extensive metabolism takes place. As for rats the metabolites found in human urines accounted for less than 30% of the flavonoids given. The same procedure was applied to blood samples, and no metabolites could be detected.

Sasaki, K., K. Wada, et al. (1997). Bilobalide, a constituent of Ginkgo biloba L, potentiates drug-metabolizing enzyme activities in mice: Possible mechanism for anticonvulsant activity against 4-O-methylpyridoxine-induced convulsions. Research Communications In Molecular Pathology And Pharmacology. Apr 96(1): 45-56.

Anticonvulsant effects of bilobalide, one of the constituents of Ginkgo biloba L., on the convulsions induced by 4-O-methylpyridoxine (MPN) were investigated in mice. Bilobalide reduced the duration and incidence of MPN-induced convulsions depending on its dose and the period of treatment. In addition, the anticonvulsant effect was manifested more than 24 hours after treatment and the effect lasted for 7 days after its withdrawal. In mice treated with bilobalide (30 mg/kg, p.o., once a day for 4 days), hepatic 7-methoxycoumarin O-demethylase activity was potentiated, and the disappearance of MPN in blood after MPN injection was faster than in controls. From these results, it is assumed that the anticonvulsant effect of bilobalide against convulsions induced by MPN partly involves modulation of hepatic drug-metabolizing enzyme activity, which leads to accelerated elimination of MPN.

Hoffman, S. W. and D. G. Stein (1997). Extract of Ginkgo biloba (EGb 761) improves behavioral performance and reduces histopathology after cortical contusion in the rat. Restorative Neurology And Neuroscience. Apr 11(1-2): 1-12.

Male rats received bilateral frontal cortex contusions and were injected with 100 mg/kg of EGb 761 or an equal volume of vehicle beginning 5 min after injury and then with 1 injection/day for 7 days. The rats were tested for spontaneous motor behavior on days 1, 5, 10, and 15 postinjury and then for 10 days of spatial navigation performance in the Morris Water Maze (MWM), beginning on the day 8 after the contusion. Brain tissue was removed for examination on the 18th day after injury. Contused rats given EGb 761 performed more like intact rats on measures of spontaneous motor activity while vehicle-treated counterparts remained more active than either shams or ECb 761-treated animals by the conclusion of testing. Contusion-only rats were worse than shams on spatial performance, while those given EGb 761 were less impaired. Histological analyses indicated that EGb 761 failed to prevent loss of tissue at the primary site of impact. However, the extract reduced retrograde degeneration of neurons, gliosis in the thalamus, and ex vacuo hydrocephalus. EGb 761 treatment also decreased the loss of ChAT-positive neurons in the dorsomedial caudate-putamen and in the nucleus basalis magnocellularis (NBM). The results of this study indicate that EGb 761 could be a possible treatment for traumatic brain injury. (C) 1997 Elsevier Science Ireland Ltd.

Ghosal, S., R. Sundaram, et al. (1997). The chemistry and action of 6-alkylsalicylates of Indian Ginkgo biloba. Indian Journal Of Chemistry Section B Organic Chemistry Including Medicinal Chemistry. Mar 36(3): 257-263.

Five 6-alkyl (n-tridecyl-, n-pentadecyl-, n-heptadecyl-, n-pentadecenyl- and n-heptadecenyl-) salicylates 1a-e, in free and conjugated testers, phospholipids) forms, constituting one of the largest classes of bioactive metabolites have been isolated from the leaves and fruits of ten Ginkgo biloba trees of different ages (3-80 years) and indigenous occurrence. These compounds have been characterized by comprehensive chromatographic-spectroscopic analyses (HPTLC, HPLC, GC-MS, H-1 NMR), chemical transformation, and by direct comparison of some of them with authentic markers. Selective anti-oxidative (lipoxygenase modulatory), free radical captodative ((OH)-O-0, (SO3-)-S-0), and anti-allergic and anti-inflammatory screening of the total IGb extract and of 1a-e have been conducted. Our findings suggest a significant contribution of the 6-alkylsalicylates towards the elixir effect of Ginkgo, contrary to an earlier apprehension that ginkgolic acids (equivalent to 6-alkylsalicylates) might cause allergic manifestations in recipients and, therefore, that they should be removed from Ginkgo formulations.

Ho, A. M. and K. V. Cashman (1997). Temperature constraints on the Ginkgo flow of the Columbia River Basalt Group. Geology . May 25(5): 403-406.

This study provides the first quantitative estimate of heat loss for a Columbia River Basalt Group flow. A glass composition-based geothermometer was experimentally calibrated for a composition representative of the 500-km-long Ginkgo flow of the Columbia River Basalt Group to measure temperature change during transport. Melting experiments were conducted on a bulk sample at 1 atm between 1200 and 1050 degrees C. Natural glass was sampled from the margin of a feeder dike near Kahlotus, Washington, and from pillow basalt at distances of 120 km (Vantage, Washington), 350 km (Molalla, Oregon), and 370 km (Portland, Oregon). Ginkgo basalt was also sampled at its distal end at Yaquina Head, Oregon (500 km). Comparison of the glass MgO content, K2O in plagioclase, and measured crystallinities in the experimental charges and natural samples tightly constrains the minimum flow temperature to 1085 +/- 5 degrees C. Glass and plagioclase compositions indicate an upper temperature of 1095 +/- 5 degrees C; thus the maximum temperature decrease along the flow axis of the Ginkgo is 20 degrees C, suggesting cooling rates of 0.02-0.04 degrees C/km. These cooling rates, substantially lower than rates observed in active and historic flows, are inconsistent with turbulent flow models. Calculated melt temperatures and viscosities of 240-750 Pa.s allow emplacement either as a fast laminar flow under an insulating crust or as a slower, inflated flow.

Klein, J., S. S. Chatterjee, et al. (1997). Phospholipid breakdown and choline release under hypoxic conditions: Inhibition by bilobalide, a constituent of Ginkgo biloba. Brain Research. May 755(2): 347-350.

A marked increase of choline release from rat hippocampal slices was observed when the slices were superfused with oxygen-free buffer, indicating hypoxia-induced hydrolysis of choline-containing phospholipids. This increase of choline release was suppressed by bilohalide, an ingredient of Ginkgo biloba, but not by a mixture of ginkgolides. The EC50 value for bilobalide was 0.38 mu M. In ex vivo experiments, bilobalide also inhibited hypoxia-induced choline release when given p.o. in doses of 2-20 mg/kg 1 h prior to slice preparation. The half-maximum effect was observed with 6 mg/kg bilobalide. A similar effect was noted after p.o. administration of 200 mg/kg EGb 761, a ginkgo extract containing approximately 3% of bilobalide. We conclude that ginkgo extracts can suppress hypoxia-induced membrane breakdown in the brain, and that bilobalide is the active constituent for this effect.

Deveci, M., I. Dibirdik, et al. (1997). Alpha-tocopherol and ginkgo biloba treatment protects lipid peroxidation during ischemic period in rat groin island skin flaps. European Journal Of Plastic Surgery. May 20(3): 141-144.

Oxygen-derived free radicals have been implicated in the causation of cellular injury during low-flow ischemia and during reperfusion of previously completely ischemic tissue; they are also believed to be the causative factor in the no-reflow phenomena. Modulation of these free radical substances has been suggested as a means of decreasing the amount of tissue loss due to ischemia and subsequent reperfusion. Pretreatment of tissues with a variety of agents has been reported to minimize the production of oxygen radicals and augment tissue survival after an ischemic insult. Further evidence of free radical involvement in skin flap necrosis in a rat groin island skin flap model is presented. In addition, the effects of two different free radical scavengers, alpha tocopherol (20 mg/kg intraperitoneally once daily for a week) and ginkgo biloba (5 mg/kg orally twice a day for a week) have been investigated and compared. Since malonyldialdehyde (MDA) is the end product of lipoperoxidation which occurs in cellular membranes in an ischemic period - dependent manner, MDA levels in tissue homogenates were measured 60, 90, and 120 min after an ischemic insult. MDA levels significantly increased in a time-dependent manner during the ischemic period in the control group. Results from the determination of tissue MDA levels at biopsy sites of radical scavenger treated groups compared with the placebo group showed that the ginkgo biloba-treated rat samples had significantly lower MDA levels than control samples only at the 120 min ischemic period (p<0.01). However, protection of lipoperoxidation in alpha tocopherol-treated rat samples was detected after both the 90 and 12 min ischemic periods (p<0.01), and the magnitude of these decreased MDA levels in alpha tocopherol-treated samples was found to be greater than it was after ginkgo biloba treatment. Decreasing free radicals during reperfusion by using these agents, preferably alpha tocopherol, may be beneficial in modulating the no-reflow phenomenon and subsequent reperfusion injury, and may help to improve tissue salvage.

Ahn, Y. J., M. Kwon, et al. (1997). Potent insecticidal activity of Ginkgo biloba derived trilactone terpenes against Nilaparvata lugens. Phytochemicals For Pest Control 658: 90-105.

Methanol extracts from 119 samples of 52 domestic plant species, 84 samples of 49 Indian plant species and 31 samples of 21 African plant species were tested for their insecticidal activities against the brown planthopper (BPH), Nilaparvata lugens Stal, using spray or topical application method. A foliar extract of Ginkgo biloba L. (Ginkgoaceae) revealed the most potent insecticidal activity against BPH. The active constituents were isolated by chromatographic techniques and characterized by spectral analysis as ginkgolides A, B and C, and bilobalide. Bilobalide not only revealed much more potent insecticidal activity against susceptible BPH than the commonly used carbamate insecticides carbofuran and fenobucarb, but was also highly effective against three strains of BPH resistant to diazinon, carbofuran, and fenobucarb, respectively. However, this compound was nontoxic to the tobacco cutworm, housefly, house mosquito, german cockroach, and two-spotted spider mite. At a dose of 0.01 mu g/female, topically-applied bilobalide caused signs of toxicity such as tremors and paralysis, and the insects died within 30 min of treatment. This compound was relatively nontoxic to mice (LD50 >1,000 mg/kg) and was not mutagenic, when tested against five strains of Salmonella typhimurium. Additionally, G. biloba-derived materials were not phytotoxic to rice plant seedlings at 2,000 ppm. As active ingredients of a naturally occurring insecticide, G. biloba-derived materials could be useful as a new control agent for BPH.

Kanowski, S., W. M. Herrmann, et al. (1997). Proof of efficacy of the Ginkgo biloba special extract EGb 761 in outpatients suffering from mild to moderate primary degenerative dementia of the Alzheimer type or multi-infarct dementia (Reprinted from Pharmacopsychiat, vol 29, pg 47-56, 1996). Phytomedicine . Mar 4(1): 3-13.

The efficacy of the Ginkgo biloba special extract EGb 761 in outpatients with presenile and senile primary degenerative dementia of the Alzheimer type (DAT) and multi-infarct dementia (MID) according to DSM III-R was investigated in a prospective, randomized, double-blind, placebo-controlled, multi-center study After a 4-week run-in period, 216 patients were included in the randomized 24-week treatment period. These received either a daily oral dose of 240 mg EGb 761 or placebo. In accordance with the recommended multi-dimensional evaluation approach, three primary variables were chosen: the Clinical Global Impressions (CGI Item 2) for psychopathological assessment, the Syndrom-Kurztest (SKT)(1) for the assessment of the patient's attention and memory, and the Nurnberger Alters-Beobachtungsskala (NAB)(2) for behavioral assessment of activities of daily life. Clinical efficacy was assessed by means of a responder analysis, with therapy response being defined as response in at least two of the three primary variables. The data from the 156 patients who completed the study in accordance with the study protocol were taken into account in the confirmatory analysis of valid cases. The frequency of therapy responders in the two treatment groups differed significantly in favor of EGb 761, with p<0.005 in Fisher's Exact Test. The intent-to-treat analysis of 205 patients led to similar efficacy results. Thus, the clinical efficacy of the ginkgo biloba special extract EGb 761 in dementia of the Alzheimer type and multi-infarct dementia was confirmed. The investigational drug was found to be well tolerated.

Rapin, J. R., R. G. Yoa, et al. (1997). Effects of repeated treatments with an extract of Ginkgo biloba (EGb 761) and bilobalide on liver and muscle glycogen contents in the non-insulin-dependent diabetic rat. Drug Development Research. Jan 40(1): 68-74.

The effects of repeated (15-day) oral treatments with an extract of Ginkgo biloba (EGb 761; 50 mg/kg/day) or with its terpenoid constituent, bilobalide (2 mg/kg/day), were assessed in normal rats and in rats that had been previously injected with streptozotocin (50 mg/kg, i.p. in saline solution), a dose which provided a model of non-insulin-dependent diabetes mellitus (NIDDM). In this model of diabetes, blood glucose is significantly increased while the circulating insulin level remains unchanged. Glucose penetrates cells because of decreased glycogen turnover, a metabolic abnormality that can be revealed by using an oral glucose tolerance test (OGTT). In control rats, hyperglycemia was accompanied by increased glycogen synthesis, as evidenced by increased concentrations of this storage substance in liver and skeletal muscle. Repeated treatment with EGb 761 or bilobalide increased the glycogen contents of both liver and muscle. This effect of bilobalide was additive to that of hyperglycemia in muscle. In diabetic rats, hyperglycemia did not modify glycogen synthesis, indicating impaired glucose utilization. Repeated treatment with EGb 761 or bilobalide partially prevented this impairment and led to increased in glycogen content in both liver and muscle under control conditions an during OGTT with 2 g/kg glucose. The moleculasr mechanism underlying these actions of EGb 761 could be related to an antioxidant effect (i.e., suppression of free radical formation) or to free radical-scavenging, since EGb 761 is known to have such effects and since free radicals have been implicated in the cytotoxic activity of streptozotocin. However, the increase in glucose uptake induced by bilobalide may have been related to increased glycogen synthesis. (C) 1997 Wiley-Liss, Inc.

Medina, J. H., H. Viola, et al. (1997). Overview - Flavonoids: A new family of benzodiazepine receptor ligands. Neurochemical Research. Apr 22(4): 419-425.

Benzodiazepines (BDZs) are the most widely prescribed class of psychoactive drugs in current therapeutic use, despite the important unwanted side-effects that they produce such as sedation, myorelaxation, ataxia, amnesia, ethanol and barbiturate potentiation and tolerance. Searching for safer BDZ-receptor (BDZ-R) ligands we have recently demonstrated the existence of a new family of ligands which have a flavonoid structure. First isolated from plants used as tranquilizers in folkloric medicine, some natural flavonoids have shown to possess a selective and relatively mild affinity for BDZ-Rs and a pharmacological profile compatible with a partial agonistic action. In a logical extension of this discovery various synthetic derivatives of those compounds, such as 6,3'-dinitroflavone were found to have a very potent anxiolytic effect not associated with myorelaxant, amnestic or sedative actions. This dinitro compound, in particular, exhibits a high affinity for the BDZ-Rs (Ki = 12-30 nM). Due to their selective pharmacological profile and low intrinsic efficacy at the BDZ-Rs, flavonoid derivatives, such as those described, could represent an improved therapeutic tool in the treatment of anxiety. In addition, several flavone derivatives may provide important leads for the development of potent and selective BDZ-Rs ligands.

Pietri, S., J. R. Seguin, et al. (1997). Ginkgo biloba extract (EGb 761) pretreatment limits free radical-induced oxidative stress in patients undergoing coronary bypass surgery. Cardiovascular Drugs And Therapy. Apr 11(2): 121-131.

A growing body of evidence supports the trigger role of free radicals in the delayed functional and metabolic myocardial recovery following cardiopulmonary bypass (CPB) in humans, thus opening the field to specific therapies. This clinical study was designed to evaluate, in 15 patients undergoing aortic valve replacement, whether the extent of CPB- and reperfusion-induced Lipid peroxidation, ascorbate depletion, tissue necrosis, and cardiac dysfunction is reduced by orally administered EGb 761, a Ginkgo biloba extract with potent in vitro antiradical properties. Patients received either EGb 761 (Tanakan, 320 mg/day, n = 8) or a matching placebo (n = 7) for 5 days before surgical intervention. Plasma samples were obtained from the peripheral circulation and the coronary sinus at crucial stages of the operation (i.e., before incision, during ischemia, and within the first 30 minutes post-unclamping), and up to 8 days postoperatively. Upon aortic unclamping, EGb 761 inhibited the transcardiac release of thiobarbituric acid-reactive species (p < 0.05), as assessed by high-performance liquid chromatography, and attenuated the early (5-10 minute) decrease in dimethylsulfoxide/ascorbyl free radical levels, an electron spin resonance index of the plasma ascorbate pool (p < 0.05). EGb 761 also significantly reduced the more delayed leakage of myoglobin (p = 0.007) and had an almost significant effect on ventricular myosin leakage (p = 0.053, 6 days postoperatively). The clinical outcome of recovery of treated patients was improved, but not significantly, compared with untreated patients. Our results demonstrate the usefulness of adjuvant EGb 761 therapy in limiting oxidative stress in cardiovascular surgery and suggest the possible role of highly bioavailable terpene constituents of the drug.

Pietri, S., E. Maurelli, et al. (1997). Cardioprotective and anti-oxidant effects of the terpenoid constituents of Ginkgo biloba extract (EGb 761). Journal Of Molecular And Cellular Cardiology. Feb 29(2): 733-742.

Hemodynamic and electron spin resonance analyses were used to assess the in vivo and in vitro cardioprotective and antioxidant effects of therapeutically relevant doses of Ginkgo biloba extract (EGb 761) and its terpenoid constituents (ginkgolides A and B, bilobalide) in the rat. Significant anti-ischemic effects, indicating improved myocardial functional recovery, were observed after repeated (15-day) oral treatments with both EGb 761 (60 mg/kg/day) and ginkgolide A (4 mg/kg/day), as compared to placebo. In vitro pre- and post-ischemic perfusion of hearts in the presence of the ginkgolides A and B (both at 0.05 mu g/ml) or bilobalide (0.15 mu g/ml), but not Ebb 761 (5 mu g/ml), significantly improved all hemodynamic parameters. Post-ischemic levels of the 5,5-dimethyl-1-pyrroline N-oxide (DMPO)/hydroxyl radical spin-adduct (DMPG-OH) in coronary effluents were Significantly decreased after in vivo oral treatments or after in vitro perfusion with EGb 761 or the terpenes, the most effective compound being ginkgolide A. As the presence of the terpenes did not influence the formation of the superoxide/DMPO adduct or DMPG-OH in acellular tests with superoxide and hydroxyl radical generators, their cardioprotective effects appear to involve an inhibition of free radical formation rather than direct free radical scavenging. (C) 1997 Academic Press Limited.

Schmid, W. (1997). Ginkgo thrives. Nature . Apr 386(6627): 755-755.

Gilbert, G. J. (1997). Ginkgo biloba. Neurology . Apr 48(4): 1137-1137.

Lewis, S. L. and J. Rowin (1997). Ginkgo biloba - Reply. Neurology . Apr 48(4): 1137-1137.

Rosenblatt, M. and J. Mindel (1997). Spontaneous hyphema associated with ingestion of Ginkgo biloba extract. New England Journal Of Medicine. Apr 336(15): 1108-1108.

Singh, A. K., S. S. Suri, et al. (1997). Somatic embryogenesis from immature zygotic embryos of Commiphora wightii, a woody medicinal plant. Gartenbauwissenschaft . Jan Feb 62(1): 44-47.

Immature zygotic embryos (2-3 mm) of Commipbora wightii produced somatic embryos when grown on B5 medium containing low concentrations (< 2.5 mu M) of 2,4,5-T, IBA, IAA, or NAA, but not using 2,4-D. Among the various auxins used, IBA and 2,4,5-T were more effective for the induction of somatic embryogenesis. Although the presence of kinetin in the medium was not essential for somatic embryogenesis, its presence at lower concentrations (< 0.5 mu M) stimulated somatic embryogenesis. Somatic embryos produced from the cotyledonary region of the explants on B5 medium supplemented with 2,4,5-T and kinetin were white and of various shapes, while embryos produced on the medium supplemented with IBA and kinetin were green and well developed from the beginning. Formation of secondary somatic embryos was observed on the medium devoid of plant growth regulators. Maximum plantlet development (62 %) was observed on B5 medium supplemented with 0.46 mu M IBA and 1.15 mu M kinetin.

Yu, K. N., S. Y. Mao, et al. (1997). A study of radioactivities in six types of fish consumed in Hong Kong. Applied Radiation And Isotopes. Apr 48(4): 515-519.

The contents of natural and artificial radionuclides in two types of fresh water fish and four types of marine fish commonly consumed by the Hong Kong population have been measured using HPGe gamma-ray spectrometry. The two types of fresh water fish are grey mullet (mugil cephalus) and grass carp (ctenopharyngodon idellus). The four types of marine fish are white pomfret (pampus argenteus), red bullseye (priacanthus macracanthus), golden thread (nemipterus) and ginkgo (gymnocranius griseus). All measurements of U and Th chain radionuclides in the samples have yielded values below MDA except for positive detection of Ra-228 (assuming Ra-228 to be in equilibrium with Ac-228) in grey mullet and bullseye perch. The K-40 and Cs-137 radionuclides were detectable in all samples, with values of 0.01-0.2 and 41.23-111.47 Bq/kg fresh respectively. The different levels of radioactivity in different species of fish is suggested to be due to differences in metabolism and feeding patterns. The radionuclide Co-60, the only other artificial radionuclide to be investigated herein, recorded values below MDA for most of the samples; observable values ranged from 0.01 to 0.04 Bq/kg fresh. Committed effective doses due to ingestion of radionuclides from fish have been estimated to be 1.2 (male) and 6.4 (female) mu Sv/yr for natural radionuclides; 0.027 (male) and 0.026 (female) mu Sv/yr for artificial radionuclides. (C) 1997 Elsevier Science Ltd.

Kobuchi, H., M. T. DroyLefaix, et al. (1997). Ginkgo biloba extract (EGb 761): Inhibitory effect on nitric oxide production in the macrophage cell line RAW 264.7. Biochemical Pharmacology. Mar 53(6): 897-903.

The present study was conducted to evaluate the effect of Ginkgo blloba extract (EGb 761) on the synthesis of nitric oxide (NO) induced by lipopolysaccharide (LPS) plus interferon-gamma (IFN ?I) in the mouse macrophage cell line RAW 264.7. EGb 761 inhibited nitrite and nitrate production, taken as an index for NO, in a concentration-dependent fashion. The IC50 for inhibition of nitrite production by activated macrophages was about 100 mu g/mL EGb 761, The inducible NO synthase (iNOS) enzyme activity of cytosolic preparations from activated RAW 264.7 cells was inhibited by treatment with EGb 761. In addition, reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that the expression of iNOS mRNA in activated macrophages was suppressed by high concentrations of EGb 761. However, NF-KB DNA binding activity induced by activation with LPS/IFN-gamma was not inhibited by EGb 761. These findings indicate that not only does EGb 761 directly act as an NO scavenger but also, that it inhibits NO production in LPS/IFN-gamma-activated macrophages by concomitant inhibiyion of induction of iNOS mRNA and the enzyme activity of iNOS. Thus, EGb 761 may act as a potent inhibitor oi NO production under tissue-damaging inflammatory conditions. (C) 1997 Elsevier Science Inc.

Kristofikova, Z. and J. Klaschka (1997). In vitro effect of Ginkgo biloba extract (EGb 761) on the activity of presynaptic cholinergic nerve terminals in rat hippocampus. Dementia And Geriatric Cognitive Disorders. Jan Feb 8(1): 43-48.

The effects of Ginkgo biloba extract (EGb) applied in vitro to hippocampal synaptosomes from young Wistar rats on the specific binding of [H-3]hemicholinium-3 ([H-3]HCh-3), high-affinity choline uptake (HACU) and activity of Na+,K+-ATPase were examined. EGb at a concentration of 100 mu g/ml markedly elevated the specific binding of [H-3]HCh-3 (to 306%) and moderately elevated HACU values (to 115%). Scatchard analysis revealed an increase in the B-max for [H-3]HCh-3 binding, Lineweaver-Burk analysis an increase in the V-max for choline uptake. No marked changes in the activity of the sodium pump were discovered. EGb was not able to influence the specific 'second messenger' effect of arachidonic acid.

Arot, L. O. M. and L. A. D. Williams (1997). A flavonol glycoside from Embelia schimperi leaves. Phytochemistry . Apr 44(7): 1397-1398.

A new flavonol glycoside, quercetin 3-galactosyl (1 --> 2) rhamnoside, has been isolated from the leaves of Embelia schimperi. The known compounds quercetin 3-rutinoside, quercetin 3-rhamnoside, quercetin 3-galactoside, myricetin and quercetin were also identified from this plant. Copyright (C) 1997 Elsevier Science Ltd.

Steins, A., D. Zuder, et al. (1997). Healing of an ulcer caused by ischemia under treatment with Ginkgo biloba EGb 761. European Journal Of Dermatology. Mar 7(2): 109-111.

We report on a 75-year-old man with peripheral, arterial occlusive disease in Fontaine stage IV. Treatment with Ginkgo biloba EGb 761 brought about the healing of an ulcer caused by ischemia. This pretibial ulcer had been triggered by a minor trauma and 3 years later still showed no signs of healing, despite intensive conservative (PgE(1), Lipo PgE(1)) and operative (Mashcraft) therapy. Because of the patient's cardiac condition, we decided not to implant a y or femeral-popliteal bypass and instead started drug therapy with Ginkgo biloba EGb 761. After 2 weeks, the ulcer had already decreased significantly in size and had healed completely after 4 months.

Szabo, M. E., M. T. DroyLefaix, et al. (1997). Direct measurement of free radicals in ischemic/reperfused diabetic rat retina. Clinical Neuroscience 4(5): 240-245.

Electron paramagnetic resonance (EPR) spectroscopy was used to directly measure free radical generation in ischemic/reperfused diabetic rat retina. Tissue was frozen at 77 degrees K after 90 min ischemia, and 90 min ischemia followed by 1 min, 3 min, 5 min, and 24 hours reperfusion, respectively. After 90 min of ischemia followed by 1 min, 3 min, 5 min, and 24 hours of reperfusion (n = 10 in each group), free radical signal intensity was increased from its diabetic nonischemic control value of 12 +/- 3 arbitrary units to 58 +/- 6 (P < 0.05), 62 +/- 7 (P < 0.05), 32 +/- 5 (P < 0.05), and 14 +/- 4 arbitrary units, respectively. The peak intensity of free radical production was observed after 90 min ischemia followed by 3 min of reperfusion;therefore, this time point was selected to study the retinal free radical production in superoxide dismutase (conjugated with polyethylene glycol, PEG-SOD) and EGb 761 (Ginkgo biloba extract)-treated groups. With 7,500, 15,000, and 30, 000 U/liter of SOD, and 25, 50, and 100 mg/kg of EGb 761, a dose-dependent reduction in oxygen free radical production was detected, respectively, which may be responsible for the attenuation of abnormal postischemic function in ischemic and reperfused diabetic retina. (C) 1997 Wiley-Liss, Inc.

Laurain, D., J. TremouillauxGuiller, et al. (1997). Production of ginkgolide and bilobalide in transformed and gametophyte derived cell cultures of Ginkgo biloba. Phytochemistry . Sep 46(1): 127-130.

Ginkgolide and bilobalide were detected by HPLC analysis in cell cultures established from various G. biloba explants. These secondary metabolites of pharmacological interest were found to occur in concentrations of 0.065 and 0.087% (dry weight) in two cell suspensions. One was derived from a female prothallus and the other one from putatively transformed embryos, by transfection via Agrobacterium rhizogenes agropine type strain CFBP 2409 (A4). (C) 1997 Elsevier Science Ltd. All rights reserved.

Chant, H. J. and J. Thompson (1997). Case history: Ginkgo biloba in end stage peripheral arterial disease. Perfusion . Jul 10(7): 240-240.

The use of ginkgo biloba in conditions of poor blood flow is widespread although experience in end stage arterial disease is limited. In this paper we describe a situation in which ginkgo biloba appears to have ameliorated seemingly irreversible tissue loss and avoided an amputation.

Yoon, S. Y., W. J. Choi, et al. (1997). Selective adsorption of flavonoid compounds from the leaf extract of Ginkgo biloba L. Biotechnology Techniques. Aug 11(8): 553-556.

A simple purification method has been developed in which flavonoid compounds are selectively adsorbed onto a polycarboxyl ester resin (XAD-7) from methanol extract of ginkgo leaves. When 1.0 g dried gingko leaves was extracted with 100 ml of methanol, about 98% of total flavonoid compounds was recovered by selective adsorption. The pH did not affect the adsorption of flavonoids but at high pH the chemical structure of flavonoids was changed and the adsorption decreased to almost zero. As the solution polarity played a key role in the selective adsorption, the amount of water added to the methanol extract was critical for the recovery and loading of flavonoids. Using standard flavonoids, kaempferol and quercetin, the optimal water content was 80% and the recovery was 80% with 10g of resin dosage/l.

Brailowsky, S. and T. Montiel (1997). Motor function in young and aged hemiplegic rats: Effects of a ginkgo biloba extract. Neurobiology Of Aging. Mar Apr 18(2): 219-227.

We have previously shown beneficial effects of a Ginkgo biloba extract (EGb761-IPSEN) in accelerating functional recovery from hemiplegia induced by unilateral motor cortex ablation. Here, we report the behavioral and histological effects of various dose regimes of EGb761. In young rats (3 months), 10 mg/kg/day for 7 days produced an improvement in meter performance, relative to untreated controls, on the last day of treatment. Applying a priming (P)-maintenance (M) dose regime (P-7 = 7 days, M-21 = 21 days), a P-7 of 50 (all doses expressed in mg/kg/day) and a M-21 of IO promoted recovery from the second day after surgery. However, in aged rats (26-28 months old) this treatment ameliorated motor performance only after the 10th day of treatment. A P-7 of 100 or 200 and a M-21 of 50 or 100 produced an acceleration of behavioral recovery in aged animals. Improvement was evident by the fifth day of treatment and was maintained after the treatment regimen. These two groups also demonstrated reduced glial fibrillary acid protein (GFAP) immunostaining and ex vacuo hydrocephalus. Thus, the confirmed efficacy of EGb in hemiplegic rats can be enhanced by an appropriate posology. (C) 1997 Elsevier Science Inc.

Murata, M., J. Irie, et al. (1997). Inhibition of lipid synthesis of bacteria, yeast and animal cells by anacardic acids, glycerol-3-phosphate dehydrogenase inhibitors from Ginkgo. Food Science And Technology Lebensmittel Wissenschaft And Technologie 30(5): 458-463.

The effects of anacardic acids (Anal, glycerol-3-phosphate dehydrogenase (GPDH) inhibitors from ginkgo on growth and lipid synthesis of Bacillus subtilis, Lipomyces starkeyi and 3T3-L1 cells were examined. Ana inhibited growth of B. subtilis, and the inhibition was reversed by phosphatidic acid or monoacylglycerol. Ana-a (100 mu g/mL) inhibited lipid accumulation in L. starkeyi but not growth, when it was added after 40 h of incubation. Ana did not inhibit the adipose conversion of 3T3-L1 cells, as their inhibitory activity against GPDH of the cells was weak.

Zhang, H., G. Q. Liu, et al. (1997). Purification and characterization of tubulin from ginkgo pollen. Sexual Plant Reproduction. Jun 10(3): 136-141.

Tubulin was purified by a combination of acetone powder preparation, DEAE Sephadex A-50 chromatography, Sephacryl S-300 gel filtration, and Mono Q anion exchange chromatography from the pollen of ginkgo (Ginkgo biloba L.), a typical gymnosperm. The average yield of tubulin is 2 mg per 100 g of pollen grain. The purified tubulin is electrophoretically homogeneous. It seems to be composed of two subunits on SDS-PACE and is resolved as two major spots on two-dimensional electrophoresis, preliminarily indicating that there are no obvious tubulin isotypes in ginkgo pollen. The apparent molecular weights of the two subunits are about 54 kDa and 52 kDa respectively, estimated from the SDS-PAGE. It was also demonstrated that tubulin from ginkgo pollen is immunochemically related to animal brain tubulin, and the purified tubulin was polymerized to microtubular aggregates in the presence of taxol and GTP in vitro.

vanBeek, T. A. and G. P. Lelyveld (1997). Preparative isolation and separation procedure for ginkgolides A, B, C, and J and bilobalide. Journal Of Natural Products. Jul 60(7): 735-738.

A simple preparative method for the isolation and purification of ginkgolides A, B, C, and J and bilobalide (ginkgo terpene trilactones) was developed. As starting material, a commercially available leaf extract from Ginkgo biloba containing greater than or equal to 6% ginkgo terpene trilactones was used. After a partition step with EtOAc, the enriched intermediate extract was separated into the individual terpenes by medium-pressure liquid chromatography on silica impregnated with 6.5% NaOAc with a gradient from petroleum ether-EtOAc to EtOAc-MeOH. After recrystallization from H2O-MeOH, all five terpenes could be isolated in high purity. After a selective extraction with H2O, leaves could also be used as a starting material.

Egger, E., T. ZellwegerZahner, et al. (1997). Language bias in randomised controlled trials published in English and German. Lancet . Aug 350(9074): 326-329.

Background Some randomised controlled trials (RCTs) done in German-speaking Europe are published in international English-language journals and others in national German-language journals. We assessed whether authors are more likely to report trials with statistically significant results in English than in German.Methods We studied pairs of RCT reports, matched for first author and time of publication, with one report published in German and the other in English. Pairs were identified from reports fround in a manual search of five leading German-language journals and from reports published by the same authors in English found on Medline. Quality of methods and reporting were assessed with two different scales by two investigators who were unaware of authors' identities, affiliations, and other characteristics of trial reports. Main study endpoints were selected by two investigators who were unaware of trial results. Our main outcome was the number of pairs of studies in which the levels of significance (shown by p values) were discordant.Findings 62 eligible pairs of reports were identified but 19 (31%) were excluded because they were duplicate publications. A further three pairs (5%) were excluded because no p values were given. The remaining 40 pairs were analysed. Design characteristics and quality features were similar for reports in both languages. Only 35% of German-language articles, compared with 62% of English-language articles, reported significant (p<0.05) differences in the main endpoint between study and control groups (p=0.002 by McNemar's test). Logistic regression showed that the only characteristic that predicted publication in an English-language journal was a significant result. The odds ratio for publication of trials with significant results in English was 3.75 (95% CI 1.25-11.3).Interpretation Authors were more likely to publish RCTs in an English-language journal if the results were statistically significant. English language bias may, therefore, be introduced in reviews and meta-analyses if they include only trials reported in English. The effort of the Cochrane Collaboration to identify as many controlled trials as possible, through the manual search of many medical journals published in different languages will help to reduce such bias.

Celikoz, B., A. Aydin, et al. (1997). The effects of Gingko biloba extract and deferoxamine on flap viability. European Journal Of Plastic Surgery. Jul 20(4): 197-201.

It has been claimed that pretreatment of tissues with a variety of agents can minimize the production of oxygen radicals and improve tissue survival after an ischemic insult. In this study, the effects of two different free radical scavengers, ginkgo biloba extract-EGb 761, and deferoxamine, were compared in a rat groin island skin flap model. The rates of skin flap necrosis were determined and biochemical enzymes including malonyldialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) levels were measured. The biopsy specimens were evaluated electron microscopically. The rates of skin flap necrosis in the treated groups were found to be lower than those in control groups (p<0.001). The biopsy specimens from radical scavenger treated groups showed that the ginkgo biloba and deferoxamine treated rat samples had significantly lower MDA; SOD, GSH-Px levels on the 2nd, 6th, 10th experiment days when compared with the results of control groups (p<0.001). However, in magnitude this marked decrease in MDA, SOD, and GSH-Px levels which was detected after 2nd, 6th and 10th days in ginkgo biloba treated group were found to be lower than in deferoxamine treated ones (p<0.05). The electron microscopic investigation also showed that the ginkgo biloba treated rat biopsy specimens had more normal tissue ultrastructures than the deferoxamine treated rat samples.

Mosle, B., P. Finch, et al. (1997). Comparison of modern and fossil plant cuticles by selective chemical extraction monitored by flash pyrolysis gas chromatography mass spectrometry and electron microscopy. Journal Of Analytical And Applied Pyrolysis. May 1: 585-597.

In order to investigate the preservation processes influencing the occurrence of plant cuticles (and hence leaves etc.) in the fossil record we have undertaken a comparative study of modern and fossil Ginkgo cuticles by chemical and microscopical methods. Cuticles are stripped or released from modern leaf tissue with hydrogen peroxide in aqueous acetic acid. The polysaccharide component and lignin can be selectively removed by acetyl bromide in acetic acid, and the cutin (polyester) by saponification. These treatments reveal the presence of a non-saponifiable residue of a resistant biomacromolecule with a characteristic dominantly aliphatic pyrolysis pattern as demonstrated and named cutan in the prototypical Agave americana cuticle. However, the same chemical treatments of recent Ginkgo biloba, the untreated cuticle of which shows an aliphatic signature upon pyrolysis, results in complete solubilisation of the sample with no resistant residue. The pyrolysis patterns can be clearly related to electron microscopic observations of the cuticles at different stages of chemical treatment. In particular the initial presence and extent of extracuticular cellular material, and its subsequent removal by the acetylation treatment can be visualised and explained. The saponifiable cutin polyester has a structural function even when associated with a resistant biomacromolecule in the Agave americana cuticle because electron microscopy shows that the resistant residue consists only of cuticle fragments. Fossil cuticles of Ginkgo huttonii were examined by Py-GC-MS and electron microscopy. These consist of extensive cuticle sheets on which SEM reveals gross morphology closely comparable to that in the modern cuticle whilst TEM shows that extra cuticular cellular material is lacking but that the outermost amorphous cuticle zone is preserved. An aliphatic pattern of alkene/alkane doublets has been identified in all of the samples. In addition, phenolic compounds have been found in the modern and fossil Ginkgo cuticle. The presence of a series of alkene/alkane doublets and some phenolic compounds in the fossil sample, combined with preservation of outer cuticle morphology and ultrastructure suggests that a less resistant, saponifiable polymer like that in modern Ginkgo cuticle is one possible source of the morphologically-preserved organic matter in the fossil. A highly resistant macromolecule is not responsible for the preservation of fossil Ginkgo cuticles. (C) 1997 Elsevier Science B.V.

Camper, N. D., P. S. Coker, et al. (1997). In vitro culture of Ginkgo. In Vitro Cellular And Developmental Biology Plant. Apr Jun 33(2): 125-127.

Ginkgo biloba L. is an important landscape tree, is resistant to insect, fungi and other pests, and produces a number of chemicals that have pharmaceutical properties (termed ginkgolides). Studies were initiated to establish an in vitro culture protocol for Ginkgo. Explants (intact embryos, embryos with cotyledons removed, and cotyledon tissue) were removed from disinfested seeds and cultured on Murashige and Skoog minimal organics medium with various combinations of either 2,4-dichlorophenoxyacetic acid (2,4-D) or naphthaleneacetic acid (NAA) and either kinetin or benzyladenine (BA). Cultures were incubated in the light and morphological development was recorded. Both embryo and cotyledon explants produced callus (cotyledon tissue produced the most callus). Ginkgolides A and B were detected in callus tissue extracts. Intact embryo cultures initiated on media with 2,4-D plus NAA for 5 wk produced shoots and roots when transferred to media with 4.5 mu M 2,4-D alone for an additional 5 wk. Plants were transferred from the 2,4-D media to pots and maintained in the greenhouse.

vanReekum, R., S. E. Black, et al. (1997). Cognition-enhancing drugs in dementia: A guide to the near future. Canadian Journal Of Psychiatry Revue Canadienne De Psychiatrie. Jun 42(1): S35-S50.

Objectives: To facilitate access to the available literature and to assist clinicians with the decision to recommend the use of medications for the enhancement of cognition in dementia.Method: A qualitative review of published research. Methodological issues confronting research in this area are described. An organizational scheme for the medication types, based on pathophysiologic processes relevant to Alzheimer's disease (AD), is reviewed. The paper makes extensive use of tables to present the minimal data necessary for the reader to appraise critically all of the original publications found. The paper further presents in summary form the opinions of previous reviews on each of the medications.Results: We identified 45 medications in the published research in which humans with dementia were assessed as having a change in cognition. immediate use of tacrine is supported by the evidence, but the degree of benefit is modest, and side effects are problematic.Conclusion: A number of medications warrant further investigation. Tacrine can be offered to patients with careful education regarding the limited efficacy and potential side effects. Newer perhaps safer, anticholinesterase inhibitors are now becoming available. Referral to a research study examining other medications is suggested as are some ''common sense'' strategies.

Stucker, O., C. Pons, et al. (1997). Effect of Ginkgo biloba extract (EGb 761) on the vasospastic response of mouse cutaneous arterioles to platelet activation. International Journal Of Microcirculation Clinical And Experimental. Mar Apr 17(2): 61-66.

The effect of intravenously administered Ginkbo biloba extract (EGb 761) on the vasospastic response to platelet activation has been assessed using a cutaneous flap preparation in anaesthetized mice. Arterioles of the axillary artery were observed by intravital microscopy, and platelets were activated by topical application of ADP under two steady state conditions: normothermia (37 degrees C) and hypothermia (24 degrees C). Responses of the cutaneous arterioles to stimulation by topical application of a thromboxane agonist (U46619) were also compared in animals treated intravenously with EGb 761 or with a thromboxane synthesis inhibitor (U63557). ADP induced a 34% constriction of the arterioles in control animals. However, no arteriolar constriction occurred in response to ADP in platelet-depleted animals (collagen-induced thrombocytopenia) or in animals treated with EGb 761 (60 mg/kg, i.v.). Exposure of the arterioles to hypothermia (24 degrees C) for 10 min induced constriction of 7-12% in all experimental groups of animals. Under these hypothermic conditions, either EGb 761 or thrombocytopenia abolished ADP-induced arteriolar constriction which was substituted by arteriolar dilation, indicating that EGb 761 can inhibit tile vasospasm that is produced by platelet activation. As topically applied U46619 (10(-5) M) induced arterioles constriction (about 22%) that was abolished by intravenous treatment with EGb 761, the extract appears to act directly rather than as a thromboxane synthase inhibitor. Collectively, these findings indicate that platelet factors can play a significant role in cutaneous vasospasm, and that EGb 761, via an action on the thromboxane pathway, could be useful in treating Raynaud's phenomenon and other vascular disorders which involve increased thromboxane production.

Kirsch, T., F. Kaffarnik, et al. (1997). Cuticular permeability of the three tree species Prunus laurocerasus L, Ginkgo biloba L and Juglans regia L: Comparative investigation of the transport properties of intact leaves, isolated cuticles and reconstituted cuticular waxes. Journal Of Experimental Botany. May 48(310): 1035-1045.

Cuticular transport properties of intact leaves, isolated cuticular membranes and reconstituted cuticular waxes of the three tree species Prunus laurocerasus L., Ginkgo biloba L. and Juglans regia L. were measured using six different C-14-labelled compounds, benzoic acid, salicylic acid, 2,4-dichlorophenoxy acid, metribuzin, 4-nitrophenol, and atrazine. For the same compound and the same species, the permeance of the intact leaf and the isolated cuticle was equal. This provides strong evidence demonstrating that transport properties of cuticles are not altered during isolation. Additionally, diffusion coefficients of the C-14-labelled compounds in isolated and subsequently reconstituted cuticular wax of the three tree species were measured. Permeances of intact leaves and isolated cuticles could be predicted from diffusion coefficients, wax/water partition coefficients and the thickness of the transport-limiting wax layer with a mean deviation of about 1.7. This provides evidence that transport properties of recrystallized cuticular waxes do indeed reflect barrier properties of isolated cuticular membranes and intact leaves with in situ waxes. Thus, it can be concluded that the investigation of cuticular permeability using the three independent experimental systems of different complexity give comparable results. Finally, it was observed that permeances and diffusion coefficients measured with P. laurocerasus were always significantly lower than those measured with G. biloba and J. regia, This is interpreted as an ecological adaptation of the respective species. The evergreen species P. laurocerasus must be more adapted to environmental stress such as drought and frost injury compared to the two deciduous species G. biloba and J. regia.

Zhu, L., J. Wu, et al. (1997). Antagonistic effects of extract from leaves of Ginkgo biloba on glutamate neurotoxicity. Acta Pharmacologica Sinica. Jul 18(4).

AIM: To determine whether the extract of leaves of Ginkgo biloba L (EGb) and several active constituents of EGb have protective effects against glutamate (Glu)-induced neuronal damage. METHODS: Microscopy and image analysis of nucleus areas in the arcuate nuclei (AN) of mice were made. The neuronal viability in primary cultures from mouse cerebral cortex was assessed using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] staining and the intracellular free calcium concentration ([Ca2+](i)) of single neuron was measured using Fura-2. RESULTS: EGb (2.5 mg.L-1) and its constituent ginkgolide B (Gin B, 2 mg.L-1) protected the neuronal viability against Glu-induced injury, and prevented the Glu-induced elevation in [Ca2+](i). EGb (3 - 10 mg.kg(-1)) attenuated the decrease of nucleus areas in arcuate nuclei induced by Glu (1 g.kg(-1), sc). CONCLUSION: EGb and Gin B prevent neurons from Glu neurotoxicity through reduction of the rise in [Ca2+](i).

Satyan, K. S., A. K. Jaiswal, et al. (1997). Effect of ginkgolic acid conjugates on the brain monoamines and metabolites in rodents. Biogenic Amines 13(2): 143-151.

The effect of acute administration of Ginkgo biloba leaf extract of Indian origin (IGb) mainly constituting ginkgolic acid conjugates (1a-e). (and their equivalents) have been evaluated on the concentrations of catecholamines, serotonin and their major metabolites in five different regions of the rodent brain namely, hypothalamus, hippocampus, striatum, ponsmedulla and frontal cortex. IGb extract in the doses 50 and 100 mg/kg., p.o (equivalent to 0.3 and 0.6 mg/kg ginkgolic acid conjugates) significantly decreased the levels of serotonin (5HT) and its metabolite 5-hydroxyindole acetic acid (5HIAA) in all the regions of the brain assayed except the pens medulla. The treatments also augmented the levels of norepinephrine (NE) and its metabolite methylhydroxyphenyl glycol (MHPG), dose dependently in various regions of the brain. Concomitantly, the levels of dopamine (DA) and its metabolite dihydroxyphenyl acetic acid (DOPAC) were augmented significantly in the striatum. However, the turnover rate of the monoamines was not influenced by the drug treatment except that of 5HIAA/5HT in frontal cortex. .The neurochemical effects of the ginkgolic acid conjugates can explain some of the behavioural actions induced by them, namely, anxiolytic, antidepressant and cognition facilitatory effects.

Holt, B. F. and G. W. Rothwell (1997). Is Ginkgo biloba (Ginkgoaceae) really an oviparous plant? American Journal Of Botany. Jun 84(6): 870-872.

Germination of Ginkgo biloba seeds with intact and removed sarcotesta was compared to test the role of the seed coat in germination biology. The presence of an intact sarcotesta significantly reduced total germination percentage when compared to seeds with the sarcotesta removed. Some seeds were also cold stratified. This treatment was not necessary for germination, but it did improve total germination percentage. The seeds were collected during the period of natural abscission. Contrary to the accepted literature, we found that Ginkgo seeds contain well-developed embryos at the time of dispersal. These data demonstrate that the seed coat contributes to winter dormancy of G. biloba, and that the phenology of this species is less primitive than popularly believed.

Jastreboff, P. J., S. T. Zhou, et al. (1997). Attenuation of salicylate-induced tinnitus by Ginkgo biloba extract in rats. Audiology And Neuro Otology. Jul Aug 2(4): 197-212.

The effects of an extract from Ginkgo biloba, EGb 761, on tinnitus were tested using an animal model of tinnitus. Daily oral administration of EGb 761 in doses from 10 to 100 mg/kg/day began 2 weeks before behavioral procedures and continued until the end of the experiment. Tinnitus was induced by daily administration of 321 mg/kg sodium salicylate s.c. (corresponding to 275 mg/kg/day of salicylate acid) in fourteen groups of pigmented rats, 6 animals/group. The results from salicylate- and EGb-761-treated animals were compared to control groups receiving either salicylate, saline, or EGb 761 only in doses of 100 mg/kg. Administration of EGb 761 resulted in a statistically significant decrease of the behavioral manifestation of tinnitus for doses of 25, 50 and 100 mg/kg/day.

Sastre, J., A. Millan, et al. (1998). A Ginkgo biloba extract (EGb 761) prevents mitochondrial aging by protecting against oxidative stress. Free Radical Biology And Medicine. Jan 24(2): 298-304.

The effect of aging on indices of oxidative damage in rat mitochondria and the protective effect of the Ginkgo biloba extract EGb 761 was investigated. Mitochondrial DNA from brain and liver of old rats exhibited oxidative damage that is significantly higher than that from young rats. Mitochondrial glutathione is also more oxidized In old than in young rats, Peroxide formation in mitochondria from old animals was higher than in those from young ones, According to morphological parameters (size and complexity), there are two populations of mitochondria. One is composed of large, highly complex mitochondria, and the other population is smaller and less complex. Brain and liver from old animals had a higher proportion of the large. highly complex mitochondria than from young animals, Treatment with the Ginkgo biloba extract EGb 761 partially prevented these morphological changes as well as the indices of oxidative damage observed in brain and Liver mitochondria from old animals. (C) 1998 Elsevier Science Inc.

Fukuda, T., Y. Madoka, et al. (1997). Formation and regulation of secondary metabolites in cell cultures of woody plants .1. Accumulation of catechin related substances and browning phenomenon in ginkgo callus. Mokuzai Gakkaishi 43(10): 819-823.

Calluses were taken from the leaves of two-year-old branches of Ginkgo biloba L. placed on modified Murashige and Skoog (MS) medium, and subcultured on the same medium. Monomeric flavanol, that is, gallocatechin, catechin, proanthocyanidins, and lignin were accumulated in the calluses. Accumulation of gallocatechin was in a larger amount than that of catechin. They increased in the early stage of browning, then decreased as the culture period proceeded, and finally they were not detectable in the last stage of the culture period.It had become apparent that the accumulation of gallocatechin is closely correlated with the browning phenomenon of the calluses.

Ihl, R. and C. Kretschmar (1997). Evaluation of nootropica in the practice. Nervenarzt . Nov 68(11): 853-861.

Treatment with ''nootropic drugs'' of patients suffering from dementia is often described as arbitrary. To define the potential usefulness of nootropic drugs, effects and side effects, economic aspects in comparison to other treatment approaches were studied. A summary of literature published concerning these criteria underlines the efficacy of nootropics in improving the symptoms at the beginning and in postponing the progress of the disease. The majority of substances does not lead to severe side effects. There are not enough studies comparing the effects of the substances or on prophylactic effects. Delayed admission to care units leads to a positive cost effect of nootropics. Thus, also for economic reasons it seems advisable to treat patients with nootropics. Better effects are gained when nootropic treatment is combined with training and changing of the structure of the environment. A proposal fora rational treatment with nootropics is derived from the data.

Kim, S. J., M. H. Lim, et al. (1997). Effects of flavonoids of Ginkgo biloba on proliferation of human skin fibroblast. Skin Pharmacology. Jul Aug 10(4): 200-205.

Ginkgo biloba studies have focused on the anti-inflammatory effects of the major components, ginkgolide and bilobalide, whereas little is known about their effect on fibroblasts. This study demonstrated the enhancing effects of Ginkgo L. extracts, especially the flavonoid fractions: quercetin, kaempferol, sciadopitysin, ginkgetin, isoginkgetin, on the proliferation of normal human skin fibroblast in vitro measured by MTT (3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyl-tetrazolium bromide) assay and direct hemocytometer cell count. Furthermore, increased production of collagen and extracellular fibronectin were documented by radioisotope (2,3-H-3-proline) incorporated collagen assay, procollagen type I C-peptide assay and by immunoturbidimetric assay. These proliferative effects suggest another useful pharmacologic application of Ginkgo L. extracts in addition to their well-known anti-inflammatory effect.

Scholtyssek, H., W. Damerau, et al. (1997). Antioxidative activity of ginkgolides against superoxide in an aprotic environment. Chemico Biological Interactions. Oct 106(3): 183-190.

The terpene lactones ginkgolide A, ginkgolide B, ginkgolide C, ginkgolide J and bilobalide, which are components of a standardized extract (EGb 761) from leaves of Ginkgo biloba, as well as ginkgolide M from roots of G. biloba were studied regarding their reaction against superoxide (O-2(-)) and hydroperoxyl radicals (HO2) in dimethyl sulfoxide as an aprotic solvent. It was found that the ginkgolides B, C, J, M as well as bilobalide react with superoxide and its protonated form as demonstrated by EPR and UV/VIS spectroscopy. The initial reaction rate with these oxygen-derived radicals is in the order of 100 M-1/s and below. Ginkgolide A does not react with superoxide under these conditions. From these findings it can be suggested that the superoxide scavenging effect of the ginkgolides B, C, J, M and bilobalide contributes to the antioxidant properties of G. biloba. (C) 1997 Elsevier Science Ireland Ltd.

Chen, X., S. Salwinski, et al. (1997). Extracts of Ginkgo biloba and ginsenosides exert cerebral vasorelaxation via a nitric oxide pathway. Clinical And Experimental Pharmacology And Physiology. Dec 24(12): 958-959.

1. Extracts from the leaves of Ginkgo biloba (EGb) and ginsenosides (GS) have been reported to be effective at increasing vascular relaxation. In the present study, the actions of EGb and GS on the vascular functions of procine basilar arteries were investigated in vitro using tissue bath techniques.2. Both EGb and GS relaxed the basilar artery in a concentration-dependent and partly endothelium-dependent manner. However, EGb appeared to be more potent than GS. Relaxation induced by transmural nerve stimulation (TNS) was significantly enhanced by EGb (7.5, 15 and 30 mu g/mL) and GS (20, 40 and 80 mu g/mL) in both endothelium-intact and -denuded basilar arteries. Enhanced TNS-induced relaxations were abolished by 0.3 mmol/L N-L-arginine.3. The present study demonstrates that nitric oxide plays a primary role in TNS-induced relaxation as well as in EGb- and GS-enhanced relaxation within the cerebral vasculature. In addition, our data support the potential of these compounds as therapeutic strategies in cerebral ischaemia and other related vascular dysfunctions.

Muller, J. L. and K. A. Clauson (1997). Pharmaceutical considerations of common herbal medicine. American Journal Of Managed Care. Nov 3(11): 1753-1770.

The popularity of alternative medicine in the United States has increased dramatically in the last 5-6 years. US sales of herbal medications exceed $1.5 billion and are increasing by approximately 25% annually. Herbal products have been used extensively in other countries for many years; now, US consumers are seeking alternative therapies due to the dissatisfaction with modern medicine. There are more than 250,000 flowered plants in the world; however only 1,800 herbal products are commercially available in the United States. This article will discuss the indications, dosing, side effects, drug interactions, and dosage forms of the following selected products: cranberry, echinacea, feverfew, garlic, ginger, ginkgo biloba, ginseng, milk thistle, St. John's wort, and saw palmetto.

Kose, K., P. Dogan, et al. (1997). In vitro antioxidant effect of Ginkgo biloba extract (EGb 761) on lipoperoxidation induced by hydrogen peroxide in erythrocytes of Behcet's patients. Japanese Journal Of Pharmacology. Nov 75(3): 253-258.

Excessive superoxide radical production and an impaired antioxidant mechanism in both the neutrophils and plasma of patients with Behcet's disease (BD) have been reported. To provide clinical support for the earlier data, erythrocyte membrane integrity was investigated by measuring malondialdehyde (MDA, a marker of lipid peroxidation) levels in the erythrocytes of BD patients. In addition, the antioxidant effect of Ginkgo biloba extract (EGb 761) at 25 and 250 mu g/ml concentrations on lipoperoxidation induced by hydrogen peroxide (H2O2) in erythrocyte obtained from BD patients was examined in in vitro conditions. When compared to healthy controls, basal erythrocyte MDA levels were found to be higher in BD patients. In the in vitro study, there was also a significant increase in H2O2-induced MDA production in the medium containing no EGb 761 in the patient group, whereas significant decreases in MDA levels were observed in the mediums containing EGb 761 both in the patient and control groups. The decrease in MDA production was found to be related to EGb 761 concentration. These data indicate that an oxidative damage is present in erythrocytes obtained from Behcet's patients, and EGb 761, which may strengthen the antioxidant defense system, may contribute to the treatment of BD.

Amri, H., K. Drieu, et al. (1997). Ex vivo regulation of adrenal cortical cell steroid and protein synthesis, in response to adrenocorticotropic hormone stimulation, by the Ginkgo biloba extract EGb 761 and isolated ginkgolide B. Endocrinology . Dec 138(12): 5415-5426.

We previously demonstrated that repeated treatment of rats with the standardized extract of Ginkgo biloba leaves, EGb 761, and its bioactive component ginkgolide B (GKB), specifically reduces the ligand binding, and protein and messenger RNA expression of the adrenal mitochondrial peripheral benzodiazepine receptor (PER), a key element in the regulation of cholesterol transport, resulting in decreased circulating corticosterone levels. Adrenocortical cells were isolated from rats treated with EGb 761 or GKB and cultured for 2 and 12 days. The effect of ACTH on normal and metabolically labeled cells was examined. Corticosterone levels were measured by RIA, and protein synthesis was analyzed by two-dimensional gel electrophoresis. Ex vivo treatment with EGb 761 and GKB resulted, respectively, in 50% and 80% reductions of ACTH-stimulated corticosterone production by adrenocortical cells cultured for 2 days compared with that by cells isolated from saline-treated rats. Two-dimensional gel electrophoresis analysis revealed that in cells from both control and drug-treated animals, ACTH induced the synthesis, at the same level, of a 29-kDa and pi 6.4-6.7 protein identified as the adrenal steroidogenic acute regulatory protein (StAR). In addition, treatment with EGb 761 and GKB specifically altered the synthesis of seven proteins, including inhibition of synthesis of a 17-kDa, identified as PER. After 12 days in culture, ACTH-stimulated adrenocortical cell steroid synthesis was maintained, and it was identical among the cells isolated from animals treated with GKB or saline. Under the same conditions, the expression of PER was recovered, whereas no effect of ACTH on the 29-kDa and 6.4-6.7 pi protein (StAR) or other protein synthesis could be seen. A comparative analysis of the effects of GKB and EGb 761 on adrenocortical steroidogenesis and protein synthesis identified, in addition to the 17-kDa PER, target proteins of 32 kDa (pi 6.7) and 40 kDa (pi 5.7-6.0) as potential mediators of the effect of EGb 761 and GKB on ACTH-stimulated glucocorticoid synthesis. In conclusion, these results 1) validate and extend our previous in vivo findings on the effect of EGb 761 and GKB on ACTH-stimulated adrenocortical steroidogenesis, 2) demonstrate the specificity and reversibility of EGb 761 and GKB treatment, 3) question the role of the 29-kDa, 6.4-6.7 pi protein (mature StAR) as the sole mediator of ACTH-stimulated steroid production, and 4) demonstrate the obligatory role of PER in hormone-regulated steroidogenesis.

Cartayrade, A., E. Neau, et al. (1997). Ginkgolide and bilobalide biosynthesis in Ginkgo biloba .1. Sites of synthesis, translocation and accumulation of ginkgolides and bilobalide. Plant Physiology And Biochemistry. Nov 35(11): 859-868.

Ginkgo biloba trees contain specific terpene compounds, ginkgolides (diterpene) and bilobalide (pentanorditerpene). Ginkgolide A (GA) and ginkgolide B (GB) are the main molecular forms of ginkgolides. These compounds are present in young seedlings and accumulate within roots and leaves, but not in stems. In vitro experiments showed a correlation between accumulation of terpenes and rhizogenesis. Ginkgolides and bilobalide could easily be formed from (CO2)-C-14 when the photosynthesis conditions were optimized. Ginkgolide A was first labelled, as early as 8 h after application of (CO2)-C-14. The ginkgolide labelling reached a maximum at day 3 followed by a steady state around day 10. Bilobalide labelling, occurred later and showed a maximum at day 6. The chronology of ginkgolide labelling indicated a possible in situ bioconversion of ginkgolides from GA to GC, by successive additions of hydroxyl group. With both (CO2)-C-14 and (U-C-14) glucose, the labelled terpenes were first detected in roots, and subsequently in stems and leaves. These complementary experiments indicate that all the enzymic steps leading to the Ginkgo diterpene end products take place in the roots but not in the leaves. Ginkgo roots are, at the same time, a site of biosynthesis and accumulation of ginkgolides and bilobalide, whereas leaves seem to act only as a sink. The balance of C-14-labelled terpenes in the whole plant during the chase period (27 days) indicates that terpenes seem to be translocated from the roots to the leaves in a source-sink manner. However, the possible involvement of modified terpene molecules in the transport process as well as the localization of the translocation pathway are not known.

Neau, E., A. Cartayrade, et al. (1997). Ginkgolide and bilobalide biosynthesis in Ginkgo biloba .2. Identification of a possible intermediate compound by using inhibitors of cytochrome P-450-dependent oxygenases. Plant Physiology And Biochemistry. Nov 35(11): 869-879.

The presence of diterpene hydrocarbons as biosynthetic intermediates in the formation of ginkgolides and bilobalide has been investigated in Ginkgo biloba seedlings. Diterpene hydrocarbons are present only in roots, as trace amounts (1-3 mu g g(-1) FW). Dehydroabietane is the main hydrocarbon compound. Two inhibitors of cytochrome P-450-dependent oxygenases, tetcyclacis and clotrimazole, were supplied to the seedlings via the roots in order to deregulate the terpene pathway. As a consequence of the treatment with inhibitors, the ginkgolide and bilobalide content was lowered, both in roots and leaves. A treatment with 10 mM tetcyclacis was more effective than a 100 mM clotrimazole treatment and resulted in a strong increase (up to 41 times) of diterpene hydrocarbons in roots. This increase concerned primarily dehydroabietane. (CO2)-C-14 feeding experiments, following 10 mu M tetcyclacis treatment, showed that only dehydroabietane was highly labelled. The absence of labelling in both ginkgolides and bilobalide indicates that the oxygenation reactions leading to the end-products are fully inhibited. All together, these results support the existence of a precursor-product relationship between dehydroabietane and ginkgolides plus bilobalides. The biosynthesis of oxygenated terpenes in G. biloba proceeds via a hydrocarbon intermediate.

Akama, K., A. Nass, et al. (1997). Characterization of nuclear tRNA(Tyr) introns: their evolution from red algae to higher plants. Febs Letters. Nov 417(2): 213-218.

We have previously isolated numerous intron-containing nuclear tRNA(Tyr) genes derived from either monocatyledonous (Triticum) or dicotyledonous (Arabidopsis, Nicotiana) plants by screening the corresponding genomic phage libraries with a synthetic tRNA(Tyr)-specific oligonucleotide, Here we have characterized additional tRNA(Tyr) genes from phylogenetically divergent plant species representing red algae (Champia),brown algae (Cystophyllum), green algae (Ulva), stonewort (Chara), liverwort (Marchantia), moss (Polytrichum), fern (Rumohra) and gymnosperms (Ginkgo) using amplification of the coding sequences from the corresponding genomic DNAs by polymerase chain reaction (PCR), All novel tRNA(Tyr) genes contain intervening sequences of variable sequence and length ranging in size from 11 to 21 bp, However, two features are conserved in all plant pre-tRNA(Tyr) introns: they possess a uridine and less frequently an adenosine at the 5' boundary and can adopt similar intron secondary structures in which an extended anticodon helix of 4-5 bp is formed by base-pairing between nucleotides of the intron and the anticodon loop, In order to elucidate the potential role of the highly conserved uridine at the first intron position, we have replaced it by all other nucleosides in an Arabidopsis pre-tRNA(Tyr) and have studied in wheat germ extract its effect on splicing and on conversion of U to Psi in the G Psi A anticodon, Furthermore, we discuss the putative acquisition of tRNA(Tyr) introns at an early step of evolution after the separation of Archaea and Eucarya. (C) 1997 Federation of European Biochemical Societies.

Lin, S. Y. and H. P. Chang (1997). Induction of superoxide dismutase and catalase activity in different rat tissues and protection from UVB irradiation after topical application of Ginkgo biloba extracts. Methods And Findings In Experimental And Clinical Pharmacology. Jul Aug 19(6): 367-371.

Ginkgo biloba extract (GBE) prepared from the leaves of Ginkgo biloba with 50% diluted alcohol was found to locally induce superoxide dismutase (SOD) and catalase (CAT) enzyme activity in epidermis after topical application, and also to systemically increase the activity of both enzymes in the liver, heart and kidney of Sprague Dawley rats. Skin pretreated with 50% diluted alcohol-extracted liquid formulation was protected from exacerbation of UVB damage. Changes in the lipid structure of the the skin of rats determined by ATR/FT-IR spectroscopy demonstrated penetration of active components from GBE dosage formulations.

DroyLefaix, M. T. (1997). Effect of the antioxidant action of ginkgo biloba extract (EGb 761) on aging and oxidative stress. Age . Jul 20(3): 141-149.

Aging is responsible for oxidative damage to DNA, protein, lipid, and other macromolecules linked to tissue alterations, The resultant damage contributes significantly to degenerative diseases, to include those of the brain, sensorial tissues, and cardiovascular system. To protect cellular components from oxyradical attack, especially lipoperoxidation, a substantial interest in the use of antioxidants has evolved, A free radical scavenger, Ginkgo biloba extract (EGb 761) may be effective in fighting the oxidative stress related to aging. Many data support the efficacy of EGb 761 in biological model systems. In aging processes, EGb 761 may ameliorate the mitochondria respiratory chain function by quenching the superoxide anion, and the hydroxyl and peroxyl radicals. It protects the brain by facilitating the uptake of neurotransmitters and by reducing ischemia-reperfusion episodes and level of apoptosis, Moreover, in sensorial tissues, EGb 761 reduces apoptosis in the olfactive bulb and in the retinal pigmented epithelium of the eye, and protects against the lipoperoxidation alteration of the retina that results in a decrease of the electroretinogram response, In the cardiovascular system, by a direct effect on oxidative low density lipoproteins, EGb 761 may decrease atherosclerosis evolution, and is shown to accelerate cardiac mechanical recovery after ischemia-reperfusion. In conclusion, the antioxidant effects of EGb 761 noted in many experimental data, may explain the therapeutic efficacy observed in clinical trials of the elderly. These beneficial properties seem in part to come from the activity of EGb 761 constituents, such as flavonoids and terpens.

Bradbury, J. (1997). Gingko biloba extract might slow progression of dementia. Lancet . Oct 350(9086): 1229-1229.

Jaggy, H. and E. Koch (1997). Chemistry and biology of alkylphenols from Ginkgo biloba L. Pharmazie . Oct 52(10): 735-738.

Ginkgolic acid acid related alkylphenols constitute major components of the lipid fraction of the fruit pods of Ginkgo biloba L. In addition, this class of substances is present in Ginkgo leaves which are widely used to prepare extracts for the treatment of peripheral or cerebral circulatory disorders, as well as vascular and Alzheimer type dementia. The present paper reviews the literature on chemical and biological aspects of alkylphenols from Ginkgo with special reference to their allergic and other undesired properties. As these compounds are present in crude leaf extracts, their completest possible removal has therefore to be guaranteed for therapeutically used extracts by the production process. Technically this does not imply any problem and most preparations available on the market fulfil the requirements of the Monograph of the Commission E of the former Federal German Health Authority (Bundesgesundheitsamt, BGA) requesting a maximal concentration of 5 ppm ginkgolic acids.

Packer, L., C. Saliou, et al. (1998). Ginkgo biloba extract EGb 761: Biological actions, antioxidant activity, and regulation of nitric oxide synthase. Flavonoids In Health And Disease 7: 303-341.

LeBars, P. L., M. M. Katz, et al. (1997). A placebo-controlled, double-blind, randomized trial of an extract of Ginkgo biloba for dementia. Jama Journal Of The American Medical Association. Oct 278(16): 1327-1332.

Context.-EGb 761 is a particular extract of Ginkgo biloba used in Europe to alleviate symptoms associated with numerous cognitive disorders, Its use in dementias is based on positive results from only a few controlled clinical trials, most of which did not include standard assessments of cognition and behavior.Objective.-To assess the efficacy and safety of EGb in Alzheimer disease and multi-infarct dementia.Design.-A 52-week, randomized double-blind, placebo-controlled, parallel-group, multicenter study.Patients.-Mildly to severely demented outpatients with Alzheimer disease or multi-infarct dementia, without other significant medical conditions.Intervention.-Patients assigned randomly to treatment with EGb (120 mg/d) or placebo, Safety, compliance, and drug dispensation were monitored every 3 months with complete outcome evaluation at 12, 26, and 52 weeks.Primary Outcome Measures.-Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog), Geriatric Evaluation by Relative's Rating Instrument (GERRI), and Clinical Global Impression of Change (CGIC).Results.-From 309 patients included in an intent-to-treat analysis, 202 provided evaluable data for the 52-week end point analysis, In the intent-to-treat analysis, the EGb group had an ADAS-Cog score 1.4 points better than the placebo group (P=.04) and a GERRI score 0.14 points better than the placebo group (P=.004). The same patterns were observed with the evaluable data set in which 27% of patients treated with EGb achieved at least a 4-point improvement on the ADAS-Cog, compared with 14% taking placebo (P=.005); on the GERRI, 37% were considered improved with EGb, compared with 23% taking placebo (P=.003). No difference was seen in the CGIC, Regarding the safety profile of EGb, no significant differences compared with placebo were observed in the number of patients reporting adverse events or in the incidence and severity of these events.Conclusions.-EGb was safe and appears capable of stabilizing and, in a substantial number of cases, improving the cognitive performance and the social functioning of demented patients for 6 months to 1 year. Although modest, the changes induced by EGb were objectively measured by the ADAS-Cog and were of sufficient magnitude to be recognized by the caregivers in the GERRI.

Jarvis, A. P. and D. Morgan (1997). Isolation of plant products by supercritical-fluid extraction. Phytochemical Analysis. Sep Oct 8(5): 217-222.

Supercritical fluid extraction (SFE) of plant materials began with industry and moved to the laboratory, along with supercritical-fluid chromatography, as high pressure systems became available. SFE has been applied to several groups of non-polar compounds, including essential oils, other flavour and fragrance compounds, medicinal compounds, lipids, carotenes and alkaloids. Each of these groups are reviewed in turn, together with the conditions used for their extraction. Information comparing the efficiency of SFE with solvent extraction or steam distillation would be valuable but is not always available. (C) 1997 by John Wiley and Sons, Ltd.

Israel, D. and E. Q. Youngkin (1997). Herbal therapies for perimenopausal and menopausal complaints. Pharmacotherapy . Sep Oct 17(5): 970-984.

Consumer use of alternative medicines in the United States is growing rapidly. Included in this phenomenon are herbal therapies instead of or as adjuncts with traditional medicine for perimenopausal and menopausal complaints. Of significant concern is the safety of these herbs. Since many women are using herbal therapies, clinicians must be knowledgeable about their use, quality, and safety. There are currently no government standards on the quality of herbal products in the United States, and some products are either unsafe or little is known scientifically about them. Selected herbal therapies touted in the lay press for common perimenopausal and menopausal complaints are examined, with advice on their use and safety based on scientific sources.

Punkt, K., V. Adams, et al. (1997). The correlation of cytophotometrically and biochemically measured enzyme activities: Changes in the myocardium of diabetic and hypoxic diabetic rats, with and without Ginkgo biloba extract treatment. Acta Histochemica. Aug 99(3): 291-299.

Changes of enzyme activities in the myocardium of rats from 6 different experimental groups (normal rats, diabetic rats, hypoxic diabetic rats, each with and without Ginkgo biloba extract treatment) were measured by using both cytophotometric and biochemical methods. The activity of succinate dehydrogenase, a marker of oxidative capacity, and of menadione-dependent glycerol-3-phosphate dehydrogenase and total lactate dehydrogenase, both markers of glycolytic capacity were measured to characterize changes of the metabolic profile in myocardium. A strong correlation between cytophotometric and biochemical data were found by linear regression analysis, justifying the use of cytophotometrical enzyme activity measurements in cells of organized tissue, where biochemistry cannot provide topographical information. The comparison of the results obtained from; the different groups revealed the following: Enzyme activities in the myocardium of rats with streptozotocin-induced diabetes were significantly increased by 10-30% as compared to the normal myocardium. This effect was interpreted as a metabolic compensation of the diabetic heart with reduced performance. When diabetic rats were exposed to acute hypoxia of 20 min duration, enzyme activities decreased under the normal level; to 56% of the succinate dehydrogenase activity, to 87% of glycerol-3-phosphate dehydrogenase activity and to 69% of lactate dehydrogenase activity. Treatment of rats with the oxygen radical scavenger Ginkgo biloba extract (EGb 761) over 3 months resulted primarily in an increase by 10% of oxidative capacity and in a decrease by 30% of glycolytic capacity. Under diabetic conditions a shift to more glycolytic metabolism was observed by increasing the glycolytic activity by 39% and remaining the oxidative activity.

Christen, Y. (1997). Adaptive effects of Ginkgo biloba extract (EGb 761) - Foreword. Adaptive Effects Of Ginkgo Biloba Extract Egb 6: R9-R10.

Auguet, M. and F. Clostre (1997). Ginkgo biloba extract (EGb 761) and vasomotor adaptation. Adaptive Effects Of Ginkgo Biloba Extract Egb 6: 1-7.

Much experimental evidence indicates that EGb 761 acts as a vasoregulator affecting all of the vascular tree. The first studies using EGb 761 indeed showed both sympathetic-dependent vasocontractile properties and a vasodilating effect mediated by inhibition of phosphodiesterases. The increasing knowledge in the vascular field has enabled us to specify the mechanisms of the EGb 761 effects: 1) the increase of the sympathetic influence in inhibiting the catecholamine degradation by catechol-O-methyltransferase, 2) the inhibitory effect on vascular platelet-activating factor (PAF) receptors, and 3) the release of a vasodilator factor, such as endothelium-derived relaxing factor identified as nitric oxide (EDRF/NO), by direct action on endothelial cells. Recently, many studies have focused on the role of NO in vascular pathophysiology.The present study was undertaken to investigate the interaction between EGb 761 and EDRF/NO once it is released. The study was performed using rat aortic rings mounted between L-shaped wires to record isometric tension, in Krebs-Heinseleit solution, at 37 degrees C, gassed with 95% O-2/5% CO2. The results indicate that the bioactivity of EDRF/NO released by the endothelial cells is sensitive to the antioxidant property of nordihydroguaiaretic acid (NDGA) and gossypol, but is less sensitive to the action of trolox. In addition,the bioactivity of EDRF/NO is affected by pyrogallol, a generator of superoxide anions. EGb 761 has a weak effect on the bioactivity of EDRF/NO but inhibits the effects of pyrogallol. Thus EGb 761 may protect EDRF/NO from superoxide anions. This effect may participate in the cardiovascular actions of EGb 761.Thus, the initial vasomotor tone of the artery or the arteriolar vessel is an essential prerequisite in determining the influence of one peculiar mechanism of action of EGb 761. Indeed, EGb 761 increases the release of EDRF/NO and prostacyclin from endothelium leading to inhibition of arteriolar spasm. EGb 761 may also restore arteriolar tone in a vascular area that is dilated by hypoxia and acidosis. This arterial regulation by EGb 761 cannot be dissociated from its effects on the capillary network, the venous tone and the main circulating cells: platelets, leukocytes and erythrocytes. At the capillary level, EGb 761 increases the vascular wall resistance and decreases vascular permeability, thus reducing tissular edema. In conclusion, the vasoregulatory effects of EGb 761, which implicate all of the vascular tree - arteries, veins and capillaries - are adjusted to the different vasomotor disturbances of an ischemic area.

Stucker, O., C. Pons, et al. (1997). Effects of Ginkgo biloba extract (EGb 761) on vascular regulation. Adaptive Effects Of Ginkgo Biloba Extract Egb 6: 9-19.

The effects of an extract of Ginkgo biloba (EGb 761) and its components on vascular regulation have been investigated in many studies to understand its mode of action. The importance of the vascular wall, through its endothelium and secreted substances, is now well established in phenomena such as hemostasis (platelet aggregation), inflammation (leukocyte adherence), local blood flow, etc. The effects of EGb 761 on these processes were determined.Platelets from rats treated with EGb 761 showed a doubled time lapse to in vitro aggregation after collagen induction and a decreased aggregation percentage after arachidonic acid induction. In vivo, in anesthetized rats, EGb 761 significantly decreased platelet thrombus formation in a flowing artery whose endothelium was damaged by an electrical current. The terpenic constituents of the extract seemed to be mainly responsible for this effect. Leukocyte adherence to rat cremaster venules can be induced by activated complement. No leukocyte adherence occurred when heat-inactivated complement was used or when rats had been treated with ginkgolide B, one of the terpenic constituents of EGb 761. Using intravital microscopy to quantify capillary perfusion, we demonstrated that treating rats with EGb 761 increased mean red blood cell velocity and decreased the number of low perfused capillaries. Investigating the way in which EGb 761 may act, other experiments showed that EGb 761 treatment was able to inhibit serum-induced vasoconstriction in rat cremaster. Several vasoconstricting serum components were tested, but only EGb 761, and particularly ginkgolide B, abolished the arteriolar constriction induced by U46619, a thromboxane analogue.Because thromboxane is implicated in many clinical disorders, this effect of EGb 761 seemed interesting to investigate in models of pathology such as Raynaud's phenomenon, where cellular stresses and thromboxane production increases are involved. A model of cutaneous flap preparation in anesthetized mice under normothermic or hypothermic conditions and adenosine disphosphate (ADP)-activated platelets was used. In normothermia, ADP induced constriction of cutaneous arterioles in the control group but not in the EGb 761-treated group. When arterioles were exposed to cold (24 degrees C), constriction occurred in all groups. When ADP was combined with hypothermia, EGb 761 or thrombopenia abolished arteriolar constriction, confirming that EGb 761 was able to antagonize platelet activation-induced vasospasm. Comparison of inhibitions of U46619-induced arteriolar constriction suggested that EGb 761 is not a thromboxane synthase inhibitor.Collectively, these findings seem to implicate the prostaglandin pathway to explain the EGb 761 effect on vascular regulation.

Emerit, I., A. AlaouiYoussefi, et al. (1997). Ginkgo biloba extract (EGb 761) and adaptation to radiation. Adaptive Effects Of Ginkgo Biloba Extract Egb 6: 21-29.

Clastogenic factors (CF) were first described in the blood of persons irradiated accidentally or for therapeutic reasons. They persisted in the plasma of A-bomb survivors for over 30 years. Work in our laboratory has shown that they also occur under other circumstances, which are characterized by oxidative stress, and that CF-induced chromosome damage is regularly prevented by superoxide dismutase (SOD). Recently we reported that CF are present in the plasma of Chernobyl accident-recovery workers (often referred to as 'liquidators'), and that these biological markers of oxidative stress can be influenced successfully by appropriate antioxidant treatment. Because SOD would have to be injected, we evaluated the anti-clastogenic effect of the Ginkgo biloba extract (EGb 761), whose superoxide-scavenging properties had been ascertained previously.EGb 761 was tested in cell cultures exposed to radiation-induced CF and compared to SOD. After confirmation of the protective effect of EGb 761 in vitro, 30 Armenian liquidators were treated with Tanakan(R) (trade name for EGb 761) at the usual dose of 3 x 40 mg/day for 2 months. The liquidators had received radiation doses varying between 1 and 200 cGy during their work at the Chernobyl reactor in 1986 and 1987. The clastogenic activity in the liquidators' plasma was 10 times higher than in reference plasma (8.1 +/- 2.3 additional aberrations in the test culture system compared to 0.8 +/- 1.0). Treatment reduced this activity to near normal values (2.0 +/- 0.6, P < 0.001). The beneficial effects of the treatment persisted in the majority of these persons for up to 1 year after the end of treatment. In about one-third of the workers, the CF test became positive again, showing that the process which produces clastogenic factors is not halted indefinitely. Whether the interval during which the radiation-induced oxidative stress factors were not detectable despite interruption of the treatment can be explained by a process of adaptation remains hypothetical at present. Given the limited number of subjects studied, no effort was made to evaluate clinical improvement in these workers. A double-blind clinical trial on a larger number of participants has now been initiated.

Roncin, J. P., F. Schwartz, et al. (1997). Ginkgo biloba extract (EGb 761) and mountain sickness adaptation. Adaptive Effects Of Ginkgo Biloba Extract Egb 6: 31-45.

Forty-four subjects were recruited to participate in a study of the preventive effect of EGb 761 on acute mountain sickness (AMS) and vasomotor changes of the extremities during a Himalayan expedition. After giving their written informed consent, the subjects were randomized into 2 groups. One group received 160 mg of EGb 761 per day in 2 divided doses and the other group received placebo. Assessment was based on the course of the environmental symptoms questionnaire (ESQ) score and the cold gradient measured by photoplethysmography. The prophylactic efficacy of treatment with EGb 761 was clearly demonstrated in this study. In terms of factor 1 (AMS-cerebral), no subject in the EGb 761 group developed AMS versus 40.9% of subjects in the placebo group; this difference was highly significant (P less than or equal to 1.4 x 10(-3)). In terms of factor 2 (AMS-respiratory), 3 subjects (13.6%) in the EGb 761 group developed AMS versus 18 (81.8%) in the placebo group; this difference was also highly significant (P = 1.2 x 10(-5)). Due to its multiple pharmacological actions, EGb 761 provides a complete response to the prevention of mountain sickness. It also very markedly decreased vasomotor disorders of the extremities, as demonstrated by plethysmography (P < 10(-8)) and a specific questionnaire (P < 10(-9)).

Darlington, C. L., P. F. Smith, et al. (1997). Effects of Ginkgo biloba extract (EGb 761) on recovery from peripheral vestibular deafferentation (vestibular compensation). Adaptive Effects Of Ginkgo Biloba Extract Egb 6: 47-58.

Vestibular compensation, the functional recovery that occurs following damage to the peripheral vestibular system, is used as a model of lesion-induced plasticity in the central nervous system. Although a number of drugs have been demonstrated to affect the expression of symptoms following vestibular deafferentation, few drugs have been demonstrated to increase the rate of vestibular compensation and, therefore, act on the mechanism of vestibular compensation. EGb 761 is one of the few drugs that has been consistently demonstrated to increase the rate of vestibular compensation. Recent studies have attempted to determine which of the components of EGb 761 may be the most effective in enhancing vestibular compensation; however, results to date are inconclusive. There is some evidence to suggest that different components of EGb 761 may act upon different aspects of the vestibular compensation process, suggesting that administration of the complete EGb 761 compound should be more effective in enhancing overall recovery than administration of individual components.

Janssens, D., C. Michiels, et al. (1997). Ginkgo biloba extract, a metabolic regulator of hypoxia-induced ATP decrease in endothelial cells. Adaptive Effects Of Ginkgo Biloba Extract Egb 6: 59-71.

Severe hypoxia is a pathological situation that can, through its ability to activate endothelial cells, initiate a complex cascade of events that will result in severe disturbances of blood vessel functions. When venous human endothelial cells are exposed to hypoxic conditions, they become activated and release high amounts of proinflammatory molecules, like platelet-activating factor (PAF) and prostaglandins. The adhesion of human polymorphonuclear neutrophils to human umbilical vein endothelial cells (HUVEC) is also markedly increased during hypoxia incubation. These two processes are related to a calcium-dependent activation of endothelial cells due to a decrease of the ATP content. These disturbances could be the origin of some vascular diseases.The results obtained in this study show that Ginkgo biloba extract (EGb 761) effectively protects the endothelial cells against the hypoxia-induced activation. The protection is observed at very low EGb 761 concentrations, similar to 0.5 mu g/ml. It results from the preservation of the high-energy phosphate pool of the cells and thus prevents the subsequent activation cascade, as observed by its protection of phospholipase A, activation. The EGb 761 protection against hypoxia is attributable to terpenes, with bilobalide being the most effective.The mechanism by which EGb 761 and bilobalide preserve the ATP content of hypoxia-incubated HUVEC was investigated. We first checked a possible effect on glycolysis. During hypoxia, glycolysis is activated, as evidenced by an increase of glucose transport, and enhanced lactate production. Bilobalide increases glucose transport within HUVEC under normoxic conditions, but neither bilobalide nor EGB 761 affects glucose transport under hypoxic conditions, suggesting that they do not act as activators of glycolysis. This hypothesis was confirmed by studies on lactate production. The results of these studies indicate that glycolysis slows down between the 60th and 120th minute of hypoxia, whereas EGb 761 and bilobalide delay the onset of glycolysis activation. In another experimental model, both compounds were shown to increase the respiratory control ratio of mitochondria isolated from the liver of orally treated rats. Since ischemia is known to uncouple mitochondria, the protection of ATP content and the delay of glycolysis activation observed during hypoxia in the presence of EGb 761 or bilobalide are best explained by their protection of the mitochondrial activity and, therefore, their ability to produce ATP even under hypoxic conditions.

Lamproglou, I., G. Boisserie, et al. (1997). Cognitive dysfunction induced by cranial irradiation: effect of Ginkgo biloba extract (EGb 761) in 4-month-old male rats. Adaptive Effects Of Ginkgo Biloba Extract Egb 6: 73-87.

This study attempted to define the action of Ginkgo biloba extract (EGb 761) on an experimental model of radiation-induced cognitive deficit. Sixty 4-month-old male Wistar rats were exposed to total cranial irradiation (CRT) (30 Gy/10 fractions/12 d) while 60 others were exposed to sham irradiation. They were treated starting from the week prior to CRT or sham, for 4 consecutive weeks, with EGb 761 at doses of 50 or 100 mg/kg or an equivalent volume of water (groups of 20 animals). A behavioral study based upon two negative reinforcement conditioning tests (one-and two-way avoidance) was performed before treatment and 24 days after it was stopped.Treatment with EGb 761 at doses of 50 and 100 mg/kg protected irradiated rats against a memory deficit found 1 month after CRT in the control;group (62% vs 76% and 79% avoidance; P = 0.04 and 0.005, respectively) during the follow-up session of the one-way avoidance test. Administration of 100 mg/kg of EGb 761 significantly facilitated learning of a second test (two-way avoidance test) started 1 month after CRT. EGb 761 at the dose of 100 mg/kg enabled sham irradiated rats to overcome (significant increase in percentage avoidance) the difficulty of learning two-way avoidance; this difficulty resulted from confusion and psychological disturbance induced by the change of situation in which they were placed.Improved retention of the first test indicated a protective effect of EGb 761 regarding irradiation. In the second learning test, the 'anti-stress' effect of EGb 761 could have accounted for the better performance of treated animals.

Pardon, M. C., E. Lepicard, et al. (1997). Chronic mild stress-induced dysregulation of decision-making in mice: regulatory effect of long-term treatment with Ginkgo biloba extract (EGb 761). Adaptive Effects Of Ginkgo Biloba Extract Egb 6: 89-98.

The chronic mild stress procedure produces neurobehavioral dysregulations, such as sleep disorders, diminished sexual activity, disturbances of circadian rhythms and, mainly, loss of responsiveness to reward. As all of these features are known to be markers of human depressive disorder, chronic unpredictable mild stress is considered to be a realistic animal model of depression. Because 'indecision' has recently been included among the latest criteria of depression, and given the well-known effects of Ginkgo biloba extract (EGb 761) on some behavioral and biochemical consequences of acute stress, the present study set out to test the effects of a chronic mild stress procedure on a 'decision-making' task in mice, comparing animals undergoing long-term EGb 761 treatment and untreated mice. The data provide strong support for the pharmacological effect of the substance on regulatory properties and the behavioral modifications caused by the chronic stress regimen. These results are discussed in comparison with the serotoninergic regulatory effects of EGb 761 susceptible to act on decision-making mechanisms.

Fillion, G., M. P. Fillion, et al. (1997). Serotoninergic system and Ginkgo biloba extracts. Adaptive Effects Of Ginkgo Biloba Extract Egb 6: 99-116.

Serotoninergic neurotransmission is known as a neuromodulatory system which is involved in the elaboration of an adapted response of the central nervous system to external stimuli. Accordingly, the 5-hydroxytryptamine (5-HT) system is structured in an appropriate manner being very centralized and present in almost all brain areas via a very high number of terminals able to release 5-HT. The autoreceptors 5-HT1B, present on these terminals, precisely control the release of the amine through a negative-feedback loop. Moreover, a novel endogenous peptide, 5-HT-moduline, regulates the efficacy of 5-HT1B receptors and thus participates in the control of 5-HT activity. Somatodendritic autoreceptors (5-HT1A) also participate in this control via their regulatory activity on the electrical activity of the 5-HT neurons. EGb 761 prevents the desentization of 5-HT1A receptors observed 24 h (not immediately) after an acute stress. More interestingly, the chronic treatment of rats with EGb 761 prevents the rapid desensitization of 5-HT1B receptors induced by an acute stress. These results suggest that Ginkgo biloba extracts may interact with the mechanisms controlling the serotoninergic activity and particularly those related to stressful situations. Therefore, Ginkgo biloba extracts may play a role in the modulation of the mechanisms involved in the adaptation of the organism to various sensory stimuli.

Amri, H., K. Drieu, et al. (1997). Regulation of peripheral benzodiazepine receptor, glucocorticoid synthesis and neuroprotection by the Ginkgo biloba extract (EGb 761) and isolated ginkgolide B. Adaptive Effects Of Ginkgo Biloba Extract Egb 6: 117-127.

Glucocorticoids have both beneficial and pathogenic effects. Glucocorticoid excess has broad pathogenic potential, including neurotoxicity and neuroendangerment. Ginkgo biloba leaf extracts have been used in traditional medicine for several hundred years. A standardized extract of Ginkgo biloba leaves (EGb 761) has been shown to have beneficial effects on senility-related cerebral deterioration, including cognitive deficits, dementias and mood changes, and to exert an 'anti-stress' effect in rodent models. Here we demonstrate that EGb 761 and its bioactive component, ginkgolide B, specifically reduce the expression of the adrenocortical mitochondrial peripheral-type benzodiazepine receptor, a key element in the regulation of cholesterol transport, the rate-determining step in steroid biosynthesis, resulting in decreased corticosteroid synthesis. These results suggest that the anti-stress and neuroprotective effects of EGb 761 are due to its effect on glucocorticoid biosynthesis.

Rapin, J. R., P. Provost, et al. (1997). Ginkgo biloba extract (EGb 761) anti-stress effects on hippocampal glucocorticoid receptors: comparison with diazepam. Adaptive Effects Of Ginkgo Biloba Extract Egb 6: 129-138.

The subacute treatment with prednisolone (50 mg/kg ip for 15 d) of Sprague-Dawley rats (150-170 g) induced a down-regulation of hippocampal glucocorticoid type II receptors studied by the binding of [H-3]dexamethasone. This treatment also lowered learning behavior. In a conditioning avoidance-response test (pole-climbing test), the learning ability was not modified but the kinetics of acquisition were significantly lower. In a discriminative test (Skinner box), the reaction time was decreased, with an increase in the number of errors after prednisolone treatment. In this model, diazepam, an anxiolytic drug (10 mg/kg po for 21 d), further decreased the binding of hippocampal glucocorticoid receptors and diminished learning ability both in avoidance and discriminative tests. In contrast, EGb 761 (a Ginkgo biloba leaf extract that has been shown to have anti-stress properties; 50 mg/kg/day po for 21 d) eliminated the effects of prednisolone on glucocorticoid receptor number and normalized the learning parameters. These data showed that corticoids altered cognitive performances in good correlation with the number of glucocorticoid receptors and that this deleterious effect can be suppressed by 'anti-stress' but not by anxiolytic drugs.

Marchand, A., D. Bonnot, et al. (1997). From pharmacology to clinic: how adaptive responses could lead to therapeutic applications of Ginkgo biloba extract (EGb 761). Adaptive Effects Of Ginkgo Biloba Extract Egb 6: 139-147.

Adaptation is a broad concept of great importance for the human life span. Pharmacologically, due to its various protective, curative and modulating properties, Ginkgo biloba extract (EGb 761) shows clinical adaptation. There is clinical evidence of the effect of EGb 761 on the entire Vascular system. Through its vasoregulatory action, EGb 761 can lead to adaptation to a situation, decreasing a Vascular spasm or restoring a vasomotor paralysis. By this regulation, EGb 761 shows beneficial improvements in mountain sickness, characterized by vascular reactivity to cold exposure especially at high altitude. Through its anti-lipoperoxidant properties, EGb 761 can reduce the effects of gamma-ray irradiation that gave rise to a clastogenic factor, as demonstrated in Chernobyl salvage workers. Through its several molecular mechanisms, EGb 761 exerts a stress-alleviating effect. By its modulatory effects on glucocorticoids and serotoninergic systems, EGb 761 can interfere with the dysregulation at the origin of central nervous system disorders. Several clinical reports show that EGb 761 can facilitate human behavioral adaptation under stressful conditions, characterized by improvements in memory disorders and mental fluidity and attenuation of behavior disturbances. EGb 761 can also enhance the rate of information processing in the brains of elderly patients, facilitating the maintenance of quality of life.

Wolff, R. L., W. W. Christie, et al. (1997). The unusual occurrence of 14-methylhexadecanoic acid in pinaceae seed oils among plants. Lipids . Sep 32(9): 971-973.

14-Methylhexadecanoic (14-MHD) acid has been identified in a sample of pine seed oil (Pinus contorta) by gas-liquid chromatography-mass spectrometry of its picolinyl ester derivative. Its identification (through its equivalent chain length) and its distribution in four conifer families have been checked. It occurred only in Pinaceae, where it was found in 72 species belonging to the genera Pinus, Abies, Cedrus, Tsuga, Pseudotsuga, Larix, and Picea, in the range 0.02-1.15%. 14-MHD acid could not be detected in the lipids of Taxaceae (Taxus baccata), Cupressaceae (Juniperus communis), or Taxodiaceae (Sciadopytis verticillata), even after a 10-fold concentration of the saturated acid fraction isolated by argentation thin-layer chromatography. It is concluded that Pinaceae along with Ginkgo biloba seed lipids, are major exceptions in the plant kingdom with regard to 14-MHD acid, which otherwise occurs almost exclusively in lipids of animals and microorganisms. The biosynthesis and metabolic role of 14-MHD acid, which otherwise also occur in wood and leaf lipids, remain unknown.

Kwon, M., Y. J. Ahn, et al. (1996). Potent insecticidal activity of extracts from Ginkgo biloba leaves against Nilaparvata lugens (Homoptera: Delphacidae). Applied Entomology And Zoology. Feb 31(1): 162-166.

Irie, J., M. Murata, et al. (1996). Glycerol-3-phosphate dehydrogenase inhibitors, anacardic acids, from Ginkgo biloba. Bioscience Biotechnology And Biochemistry. Feb 60(2): 240-243.

Four inhibitors of glycerol-3-phosphate dehydrogenase were isolated from Ginkgo biloba and identified as anacardic acids (6-tridecylsalicylic acid, 6-[(8Z)-pentadecenyl] salicylic acid, 6-[(9Z,12Z)-heptadecadienyl]salicylic acid, and 6-[(8Z)-heptadecenyl]salicylic acid) by instrumental analyses. Their 50% inhibitory concentrations against the enzyme were 1-3 mu g/ml under the standard assay conditions. Anacardic acid inhibited the enzyme non-competitively. The sarcotesta contained most of anacardic acids, and nuts a little.

Fitzl, G., K. Welt, et al. (1996). Myocardium-protective effects of Ginkgo biloba extract (EGb 761) in old rats against acute isobaric hypoxia. An electron microscopic morphometric study .1. Protection of cardiomyocytes. Experimental And Toxicologic Pathology. Jan 48(1): 33-39.

Ginkgo biloba extract EGb 761 was used in hypoxia experiments with old rats to investigate its ultrastructure-preserving effects on the myocardium. Hypoxia was performed by means of a hypoxia chamber combined with a commercial narcosis apparatus. N2O/O-2-mixture was applied with O-2 at 5 vol.% for 20 minutes under normobaric conditions.Ultrastructural-morphometric analysis revealed that EGb 761-pretreatment was able to diminish hypoxic damage at mitochondrial cristae and matrix and also distension of the sarcoplasmic reticulum during acute hypoxic stress. Whereas formation of vacuoles was depressed below the level of controls, the accumulation of lipid drops was not prevented. The preservation of mitochondrial cristae was confirmed by independent secondary morphometric parameter; and by cytophotometrically measured activities of mitochondrial enzymes.

Welt, K., G. Fitzl, et al. (1996). Myocardium-protective effects of Ginkgo biloba extract (EGb 761) in old rats against acute isobaric hypoxia. An electron microscopic morphometric study .2. Protection of microvascular endothelium. Experimental And Toxicologic Pathology. Jan 48(1): 81-86.

Aim of this electron microscopic morphometric study was to demonstrate ultrastructure protective properties of Ginkgo biloba extract EGb 761 on myocardial micrcovessels of old rats during acute hypoxic stress. Hypoxia of 2.0 minutes duration with N2O/O-2 mixture (5 vol% O-2) was performed using a hypoxia chamber combined with a commercial narcosis apparatus. EGb 761-pretreatment diminished significantly the percentage of endothelial cells exhibiting; edema, luminal blebs and of capillaries surrounded by pericapillary debris. Hypoxia-related decrease in plasmalemmal, vesicle frequency was prevented by EGb 761, formation of vacuoles non significantly diminished against the hypoxic group. Volume density of mitochondrial cristae was significantly less diminished, the volume fraction of degenerated areas less increased in the EGb 761-protected group. The results give some evidence that EGb 761 protects endothelial cell ultrastructure of myocardial microvasculature against hypoxic alterations, probably by its radical scavenging properties.

Didier, A., M. T. DroyLefaix, et al. (1996). Effects of Ginkgo biloba extract (EGb 761) on cochlear vasculature in the guinea pig: Morphometric measurements and laser Doppler flowmetry. European Archives Of Oto Rhino Laryngology. Jan 253(1-2): 25-30.

Ginkgo biloba extract (EGb 761) was administered orally for 4 or 6 weeks to healthy adult guinea pigs. Animals were then decapitated under deep ketamine anesthesia. Post-mortem morphometric measurements of cochlear vessels in the spiral lamina revealed a vasodilating effect of the extract in four of ten animals following 6 weeks of treatment. In vivo testing of the effect of 4 or 6 weeks of treatment with EGb 761 was monitored with laser Doppler flowmetry of the cochlear blood flow under pathological conditions. Results demonstrated that EGb 761 partly counteracted sodium salicylate-induced decreases in cochlear blood flow (CBF) and enhanced CBF increases induced by hypoxia. These findings indicate that EGb 761 may help to improve oxygenation in cochleas with compromised blood flow.

Khalil, A., A. Fortun, et al. (1996). Antioxidant effect of EGb(761) towards superoxide free radical action on LDL. Journal De Chimie Physique Et De Physico Chimie Biologique. Jan 93(1): 143-150.

Aqueous solutions of human low-density lipoproteins (LDL) (3 g/l) buffered at pH 7 (sodium phosphate 10(-2) M, sodium formate 10(-1) M) saturated with O-2 have been irradiated between O and 500 Gy (dose rate 2.4 x 10(-2) Gy/s) in the presence of increasing concentrations of Ginkgo biloba extract (EGb(761)) (0, 15, 30, 50 and 100 mu g/ml). The protective effect of EGb(761) after the O-2 free radical action on LDL, was monitored by several lipid peroxidation markers: 1/ decrease of endogenous vitamin E and beta carotene, 2/ formation of thiobarbituric acid-reactive substances (TEARS), 3/ formation of conjugated dienes and 4/ appearance of differential fluorescence.LDL peroxidation is markedly decreased in the presence of EGb(761), this effect being EGb(761) concentration dependent.

Hasenohrl, R. U., C. Nichau, et al. (1996). Anxiolytic-like effect of combined extracts of zingiber officinale and ginkgo biloba in the elevated plus-maze. Pharmacology Biochemistry And Behavior. Feb 53(2): 271-275.

The effects of the known anxiolytic compound diazepam (DZ) on the behavior of rats in the elevated plus-maze were compared with those of zingicomb (ZC) (registered trademark of Mattern et Partner), a combination preparation of standardized extracts of ginkgo biloba and zingiber officinale. DZ was administered intraperitoneally (IF) in a reference dosage of 1 mg/kg 30 min before the rats were tested on the elevated plus-maze for 5 min. The treatment with DZ elevated the time spent on the open arms and excursions into the end of the open arms, increased scanning over the edge of an open arm, and decreased risk-assessment from an enclosed arm. ZC was administered intragastrically (IG) in four doses ranging between 0.5 and 100 mg/kg 60 min prior to plus-maze testing. The treatment with 0.5 mg/kg ZC elevated the time spent on the open arms and excursions into the end of the open arms; at the high dosage of 100 mg/kg, ZC led to fewer excursions to and less scanning of the open arms, injection of 1 or 10 mg/kg ZC had no significant effect on the behavior in the maze. These data provide evidence that ZC has anxiolytic effects in the elevated plus-maze comparable to those of DZ, but that in high dosage the phytopharmacon may also have anxiogenic properties. The anxiolytic-like effects of ZC are discussed with regard to the known antiserotonergic action of ginger and ginkgo biloba.

Gsell, W., N. Reichert, et al. (1995). Interaction of neuroprotective substances with human brain superoxide dismutase. An in vitro study. Journal Of Neural Transmission Supplement 45: 271-279.

Human brain total superoxide dismutase activity (SOD) was assayed in the presence of increasing concentrations of neuroprotectives. Superoxide-dependent nitrobluetetrazolium (NET) reduction served as control for direct radical interaction of these substances. High concentrations of the dopamimetic substances L-DOPA slightly and the monoamine oxidase B inhibitor selegiline more effectively inhibit SOD activity. The MAO-B inhibitor RO 16-6491 (N-(2-aminoethyl)-4-chlorobenzamide hydrochloride) has no effect on SOD enzyme activity. Reduced glutathione stimulates SOD activity. Moreover it exhibits slight activity in scavenging radicals in vitro. Oxidized glutathione and vitamin E are unable to do so. Ascorbic acid mimics the activity of reduced glutathione, but directly interacts with NET reduction. Thioctic acid shows no effect on SOD activity but stimulates superoxide-dependent NET reduction. The Ginkgo biloba extract EGb 761 is highly active in inhibiting superoxide-dependent NET reduction as well as SOD activity.

Hoyer, S. (1995). Chance and limitation of therapy of age-associated brain dysfunction. Zeitschrift Fur Gerontologie Und Geriatrie. Nov Dec 28(6): 457-462.

Pharmacological treatment of patients suffering from sporadic late-onset dementia of Alzheimer type (DAT) is controversely discussed, omitting the fact that this age-related most frequently occurring DAT form is based on a heterogenous pathogenesis, but forms a rather uniform clinical phenotype. Furthermore, sporadic late-onset DAT is influenced in two different ways, 1) by the aging process, and 2) by the disease process itself. In this context, changes in brain glucose/energy metabolism, maintenance of calcium homeostasis, and membrane stability are discussed. It is concluded that some nootropic drugs such as dihydroergotoxille,Ginkgo biloba, nicergoline, nimodipine, piracetam, and pyritinol-HCI, registered in FRG, exert a positive effect on the clinical phenotype in approximately 30% of treated cases being in an incipient state of the disease. This effect has not been proven for advanced states.There is clear evidence that Ginkgo biloba acts on membrane lability, nimodipine on the maintenance of calcium homeostasis, and both piracetam and pyritinol-HCI on glucose/energy metabolism. These diverse effects on different underlying pathogenetic abnormalities can be assumed to be the reason why only subgroups of patients respond to the treatment with nootropic drugs.

Rong, Y. G., Z. H. Geng, et al. (1996). Ginkgo biloba attenuates oxidative stress in macrophages and endothelial cells. Free Radical Biology And Medicine 20(1): 121-127.

The action of Ginkgo biloba extract (GBE) as an antioxidant was studied using various models of oxidative stress in macrophages and vascular endothelial cells. GEE was incubated with murine macrophages (J774) at 37 degrees C and 5% CO2 for 1 h; oxidative burst was triggered by zymosan. The intensity of fluorescence was measured directly in 96-well plates using a computerized microplate fluorometer at 485 nm excitation and 530 nm emission. GEE exhibited both time- and concentration-dependent suppression of oxidative burst. Confluent monolayers of bovine pulmonary artery endothelial cells (PAEC) were preincubated with different concentrations of GEE for 16 h, washed, and then exposed to an organic oxidant tert-butyl hydroperoxide (tBHP) for 2 h. Lipid peroxidation products of PAEC were determined by measuring thiobarbituric acid-reactive substances (TEARS). Cell injury was assessed by measuring the release of intracellular lactate dehydrogenase (LDH), and cell viability was determined by the methylthiazol tetrazolium (MTT) assay. tBHP increased production of TEARS in PAEC. Preincubation with GEE inhibited the increase of TEARS induced by tBHP. GEE protected biomembranes from oxidative injury by decreasing intracellular LDH leakage from PAEC. MTT assay showed that GEE minimized loss of cell viability induced by oxidative injury. The extensive antioxidant effect of GEE may be valuable to the prevention and treatment of various disorders related to free radical-induced pathology.

Stoppe, G., H. Sandholzer, et al. (1995). Factors influencing the prescribing of >>nootropic<< medications: Results of a representative enquiry in Lower Saxony. Deutsche Medizinische Wochenschrift. Nov 120(47): 1614-1619.

Aim of investigation: To discover (1) to what extent patients' wishes and the extent of any abnormality of brain performance influence the frequency with which >>nootropic<< drugs (those thought to affect brain activity, e.g. piracetam, pyritinol, or improve cerebral circulation, e.g. xanthine derivatives, Ginkgo biloba, secale alkaloids, calcium antagonists) are prescribed; (2) the medical. practitioner's expectations of the effectiveness of such medications.Method: In a personal interview, 145 family doctors and 14 neurologists in private practice in the Gottingen area of Germany (participation rate: 83.2% of those asked to participate) were questioned about fictitious cases (case 1: mild memory problem with or without expressed wish for medication; case 2: moderate dementia, of Alzheimer or multi-infarct type). The previously arranged interviews, which took place in the doctors' practice rooms, consisted of standardized open questions to the written case reports.Results: Regardless of the wish of the patient and the extent and type of the abnormal brain function at-tout 70% of all participating doctors would prescribe those drugs, even though about 56% had doubts about their effectiveness. About 28% expected a positive effect on brain performance. A nearly equal proportion of doctors would continue an existing drug regimen as would prescribe one.Conclusion: The prescription of the named group of drugs is influenced less by medical criteria than by factors which concern doctor-patient relationship.

Ernst, E., K. L. Resch, et al. (1995). Complementary medicine - What physicians think of it: A meta-analysis. Archives Of Internal Medicine. Dec 155(22): 2405-2408.

Background: Complementary (or alternative) medicine has become a prevalent phenomenon in most industrialized countries. At present the evidence from randomized controlled trials investigating its effectiveness is fragmentary and therefore inconclusive.Objective: To assess whether physicians perceive complementary medicine as useful and/or effective.Method: A literature search was performed to retrieve all relevant articles. Twelve surveys addressing this question were found and analyzed by evaluating perceived usefulness and/or effectiveness.Results: The results show a remarkable variability between surveys. On average physicians perceive complementary medicine as moderately effective-the rating was 46+/-18 on a scale of 0 to 100 points. Young physicians seem to judge complementary medicine more optimistically than their more seasoned colleagues. There is no trend to suggest that complementary medicine is increasingly perceived as useful and/or effective. The data do not answer the question whether physicians view complementary medicine as a nonspecific powerful placebo or as specifically effective.Conclusion: Complementary medicine may be useful; however, the notion urgently needs to be tested in randomized controlled trials.

Belougne, E., O. Aguejouf, et al. (1996). Experimental thrombosis model induced by laser beam. Application of aspirin and an extract of Ginkgo biloba: EGb 761. Thrombosis Research. Jun 82(5): 453-458.

Stucker, O., C. Pons, et al. (1996). Effects of Ginkgo biloba extract (EGb 761) on arteriolar spasm in a rat cremaster muscle preparation. International Journal Of Microcirculation Clinical And Experimental. Mar Apr 16(2): 98-104.

The effects of an extract of Ginkgo biloba (EGb 761) on arteriolar spasm were confirmed using a preparation of rat cremaster muscle. When vasospasm was induced by rat serum, arteriolar constriction reached 25-30% of the initial diameter after 10 min. Intravenous injection of EGb 761 (30 mg/kg) 5 min The effects of an extract of Ginkgo biloba (EGb 761) on arteriolar spasm were confirmed using a preparation of rat cremaster muscle. When vasospasm was after inducing spasm inhibited about 80 % of this serum-induced vasoconstriction. As previous studies have shown that EGb 761 has an antiaggregatory effect on platelets, thrombin, serotonin (platelet-derived compounds that are present in the serum) and a thromboxane analogue (U46619) were also used to induce vasospasm. Administration of EGb 761 (30 mg/kg) 5 min after exposure of the preparation to serotonin (10(-3) M) or 10 min after exposure to thrombin (20 units) did not affect vasospasm induced by these agents. In contrast, treatment with this same dose of EGb 761 5 min after exposure of the preparation to U46619 (10(-4) M) abolished the arteriolar constriction induced by this agent in 15 min. The thromboxane/prostaglandin H-2 receptor antagonist SQ29548 antagonized serum-induced vasospasm, indicating an involvement of thromboxane. Other experiments indicated that the effects of EGb 761 of counteracting vasospasm may be mediated in part by ginkgolide B, a triterpene constituent of the extract that is an antagonist of platelet-activating factor and in part by an 'NO-like' action of its proanthocyanidin constituents. Taken together, these results have revealed that EGb 761 treatment can antagonize the vasoconstrictor effect of thromboxane on arterioles. As thromboxane is implicated in many cardiovascular disorders, this property of EGb 761 may explain some of its beneficial clinical effects in such pathologies.

Hierro, M. T. G., G. Robertson, et al. (1996). The fatty acid composition of the seeds of Ginkgo biloba. Journal Of The American Oil Chemists Society. May 73(5): 575-579.

The fatty acid composition of seeds of Ginkgo biloba has been examined by a combination of capillary gas chromatography, silver ion high-performance liquid chromatography and gas chromatography/mass spectrometry. Some of the fatty acids identified are unusual in plants and were rather different from those reported earlier. These include an anteiso-methyl branched fatty acid, 14-methylhexadecanoic acid, 5,9-octadecadienoic acid, and 5,9,12-octadecatrienoic acid. Fourier-transform infrared spectroscopy confirmed that all of the double bonds were of the cis-configuration.

Nakajima, D., E. Kojima, et al. (1996). Presence of 1-hydroxypyrene conjugates in woody plant leaves and seasonal changes in their concentrations. Environmental Science And Technology. May 30(5): 1675-1679.

beta-O-Glucoside and beta-O-glucuronide conjugates of 1-hydroxypyrene (OHPy) were found in the leaves of four kinds of woody plant; cherry, maple, ginkgo, and camphor. The conjugates were quantified by measuring OHPy liberated from the water-soluble fraction of leaves treated with beta-O-glucosidase and beta-O-glucuronidase. Concentrations of beta-O-glucuronide and beta-O-glucoside ranged from 0 to 358 and from 0 to 129 pmol/g of fresh leaves, respectively, in monthly measurement over a period of 1 year. The amounts of glucuronide conjugates were greater than those of glucoside conjugates in most plants examined. Both conjugates were detected at the highest concentrations in summer to autumn. For most plants, the total amounts of the conjugates were greater than that of free OHPy in the leaves in all seasons, and the differences reached 30-fold in maple leaves in September. From these results, the source of the OHPy conjugates in leaves and their implications are discussed.

Kanowski, S., W. M. Herrmann, et al. (1996). Proof of efficacy of the ginkgo biloba special extract EGb 761 in outpatients suffering from mild to moderate primary degenerative dementia of the Alzheimer type or multi-infarct dementia. Pharmacopsychiatry . Mar 29(2): 47-56.

The efficacy of the ginkgo biloba special extract EGb 761 in outpatients with presenile and senile primary degenerative dementia of the Alzheimer type (DAT) and multi-infarct dementia (MID) according to DSM-III-R was investigated in a prospective, randomized, double-blind, placebo-controlled, multi-center study. After a 4-week run-in period, 216 patients were included in the randomized 24-week treatment period. These received either a daily oral dose of 240 mg EGb 761 or placebo. In accordance with the recommended multi-dimensional evaluation approach, three primary variables were chosen: the Clinical Global Impressions (CGI Item 2) for psychopathological assessment, the Syndrom-Kurztest (SKT)(1) for the assessment of the patient's attention and memory, and the Nurnberger Alters-Beobachtungsskala (NAB)(2) for behavioral assessment of activities of daily life. Clinical efficacy was assessed by means of a responder analysis, with therapy response being defined as response in at least two of the three primary variables. The data from the 156 patients who completed the study in accordance with the study protocol were taken into account in the confirmatory analysis of valid cases. The frequency of therapy responders in the two treatment groups differed significantly in favor of EGb 761, with p < 0.005 in Fisher's Exact Test. The intent-to-treat analysis of 205 patients led to similar efficacy results. Thus, the clinical efficacy of the ginkgo biloba special extract EGb 761 in dementia of the Alzheimer type and multi-infarct dementia was confirmed. The investigational drug was found to be well tolerated.

Riedel, W. J. and J. Jolles (1996). Cognition enhancers in age-related cognitive decline. Drugs And Aging. Apr 8(4): 245-274.

A review of recently published studies on the effect of cognition enhancers in non-demented human study participants is presented, The heterogeneity of the therapeutic target, age-associated cognitive decline, can be improved by separately treating groups in whom age-extrinsic factors may underlie cognitive pathology, Standardisation of cognitive assessments is necessary, since many different tests are applied to answer the same question, Modelling cognitive dysfunction, either by pharmacological or nonpharmacological means, in humans is highly recommended since it allows hypotheses to be tested in a clearly operationalised way. Predictive validity of the currently applied models for the clinical situation remains a problem, however. The scopolamine (hyoscine) model has, to a reasonable extent, predictive validity for the cholinergic agents.The results of 67 single-dose studies and 30 multiple-dose studies are summarised. All single-dose studies and 14 multiple-dose studies were carried out in young or elderly human volunteers. In 45 of 81 volunteer studies,;models of cognitive dysfunction were employed. The scopolamine model was the most used (n = 21); the other studies induced cognitive dysfunction by means of benzodiazepines (8), hypoxia (7), alcohol (5) and sleep-deprivation (4). The remaining 16 multiple-dose studies were clinical trials of a duration varying between 2 weeks and 1 year (average duration was 14 weeks). In these trials, the effects of cognition enhancers were assessed in elderly people in whom impairment of memory, psychomotor performance or cognitive function was determined. These included age-associated memory impairment (AAMI) and age-associated cognitive decline (AACD).There were many studies in which the cognition enhancing properties of substances in humans were reliably demonstrated. The cognition enhancing properties of substances that are widely used, such as caffeine, nicotine and vitamins, may already be active against AACD. New developments such as serotonin (5-hydroxytryptamine(3); 5-HT3) antagonists and N-methyl-D-aspartate (NMDA) antagonists have provided marginal and disappointing results in AAMI. There is no cognition enhancer that has reliably and repeatedly been demonstrated to be efficacious for the treatment of AACD. However, this situation may change as the selectivity, specificity and adverse effect profiles of substances that are being developed for the treatment of AD may be expected to be improved in the future.

Laurain, D., J. C. Chenieux, et al. (1996). Somatic embryogenesis from immature zygotic embryos of Ginkgo biloba. Plant Cell Tissue And Organ Culture. Jan 44(1): 19-24.

Immature zygotic embryos of G. biloba were taken, at various developmental stages, from ovules harvested in November 1993. Zygotic embryos showing the beginning of the cotyledonary development cultured on modified Murashige and Tucker (1969) media proliferated intensely. In fact, 98.5% of the immature zygotic embryos produced embryogenic and undifferentiated tissues (calluses), in proportions varying depending on the hormonal composition of the induction media. After two weeks of culture, direct embryogenesis was observed on the hypertrophic cotyledons when benzyladenine 10 mu M was used as the sole plant growth regulator in the induction media. The addition of different concentrations of NAA (5-10-20 mu M) and of BA (5 mu M) to the induction media led to an indirect embryogenesis after two months, when the calluses were transferred to the development media without auxin. The highest frequency of embryogenic tissues (90-95%) and the highest number of somatic embryos per explant (9.6) were obtained with benzyladenine (10 mu M) as the sole exogenous growth factor. Some embryos isolated mechanically or 'in situ' on the callus developed as far as the later cotyledonary stage.

DroyLefaix, M. T., J. Cluzel, et al. (1995). Antioxidant effect of a Ginkgo biloba extract (EGb 761) on the retina. International Journal Of Tissue Reactions Experimental And Clinical Aspects 17(3): 93-100.

Several investigations have recently shown that the retina is very sensitive to oxygenated free radicals (O-2-, OH .) at the origin of the membrane phospholipids peroxidation. Peroxy radical (ROO .) release is responsible for the induction of electrophysiological disturbances leading to retinopathy development. As Ginkgo biloba extract (EGb 761, IPSEN, France) was reported to scavenge primary (O-2-, OH .) and secondary (ROO .) free radicals, we evaluated its antioxidant effect on retinas of albino rats submitted to different types of aggressors. On isolated rat retina, EGb 761 given orally significantly protected against lipoperoxidation induced by a mixture of ferrous sulfate and sodium ascorbate added to the perfusion solution. With EGb 761, the decrease of the b-wave ERG amplitude was less pronounced and the retina survival was increased. EGb 761 was also effective against ischaemia-reperfusion disorders due to occlusion of the central retinal artery or by intraocular hypertony, like other antioxidants such as superoxide dismutase tested on these models, EGb 761 significantly attenuated according to a dose-response effect, the free-radical injury, EGb 761 reduces the decrease of the b-wave amplitude, the oedema, necrosis and ion homeostasis disturbances. Xenobiotics are also responsible for the retinotoxicity partly due to free radicals and PAF release. We noted an EGb 761 dose-dependent protective effect against acute and chronic chloroquine toxicity to the retina. The deleterious effect of chloroquine was characterized by a delayed b-wave and an asymmetry of the signal with slow declining b-wave. After EGb 761 treatment, the ERG aspect was partially normal. in conclusion, EGb 761, by its general free-radical scavenger properties, is an antioxidant that inhibits or reduces the functional and morphological retina impairments observed after lipoperoxide release.

Oyama, Y., L. Chikahisa, et al. (1996). Ginkgo biloba extract protects brain neurons against oxidative stress induced by hydrogen peroxide. Brain Research. Mar 712(2): 349-352.

Effect of Ginkgo biloba extract was examined on dissociated rat cerebellar neurons suffering from oxidative stress induced by hydrogen peroxide using a flow cytometer and ethidium bromide. Hydrogen peroxide at a concentration of 3 mM increased the number of neurons stained with ethidium (presumably dead neurons) in a time-dependent manner. Pretreatment of neurons with G. biloba extract (10 mu g/ml) greatly delayed a time-dependent increase in number of dead neurons during exposure to hydrogen peroxide. It was true, but less effective, in the case of treatment with G. biloba extract immediately or 60 min after start of oxidative stress. Results implicate G, biloba extract as a potential agent in protecting the neurons suffering from oxidative stress induced by hydrogen peroxide.

Kamm, A., R. L. Doudrick, et al. (1996). The genomic and physical organization of Ty1-copia-like sequences as a component of large genomes in Pinus elliottii var elliottii and other gymnosperms. Proceedings Of The National Academy Of Sciences Of The United States Of America. Apr 93(7): 2708-2713.

A DNA sequence, TPE1, representing the internal domain of a Ty1-copia retroelement, was isolated from genomic DNA of Pinus elliottii Engelm. var, elliottii (slash pine), Genomic Southern analysis showed that this sequence, carrying partial reverse transcriptase and integrase gene sequences, is highly amplified within the genome of slash pine and part of a dispersed element >4.8 kbp. Fluorescent in situ hybridization to metaphase chromosomes shows that the element is relatively uniformly dispersed over all 12 chromosome pairs and is highly abundant in the genome, It is largely excluded from centromeric regions and intercalary chromosomal sites representing the 18S-5.8S-25S rRNA genes. Southern hybridization with specific DNA probes for the reverse transcriptase gene shows that TPE1 represents a large subgroup of heterogeneous Ty1-copia retrotransposons in Pinus species, Because no TPE1 transcription could be detected, it is most likely an inactive element-at least in needle tissue, Further evidence for inactivity was found in recombinant reverse transcriptase and integrase sequences. The distribution of TPE1 within different gymnosperms that contain Ty1-copia group retrotransposons, as shown by a PCR assay, was investigated by Southern hybridization, The TPE1 family is highly amplified and conserved in all Pinus species analyzed, showing a similar genomic organization in the three- and five-needle pine species investigated, It is also present in spruce, bald cypress (swamp cypress), and in gingko but in fewer copies and a different genomic organization.

Smith, P. F., K. Maclennan, et al. (1996). The neuroprotective properties of the Ginkgo biloba leaf: A review of the possible relationship to platelet-activating factor (PAF). Journal Of Ethnopharmacology. Mar 50(3): 131-139.

Ginkgo biloba (Ginkgoaceae) is an ancient Chinese tree which has been cultivated and held sacred for its health-promoting properties. There is substantial experimental evidence to support the view that Ginkgo biloba extracts have neuroprotective properties under conditions such as hypoxia/ischemia, seizure activity and peripheral nerve damage. Research on the biochemical effects of Ginkgo biloba extracts is still at a very early stage. One of the components of Ginkgo biloba, ginkgolide B, is a potent platelet-activating factor (PAF) antagonist. Although the terpene fraction of Ginkgo biloba, which contains the ginkgolides, may contribute to the neuroprotective properties of the Ginkgo biloba leaf, it is also likely that the flavonoid fraction, containing free radical scavengers, is important in this respect. Taken together, the evidence suggests that Ginkgo biloba extracts are worthy of further investigation as potential neuroprotectant agents.

Cott, J. (1995). Natural product formulations available in Europe for psychotropic indications. Psychopharmacology Bulletin 31(4): 745-751.

Until the middle of this century, development of medical treatment for human disease was intimately connected with the plant kingdom. Despite advances of the last three decades in utilizing chemical synthetic approaches to drug design and sophisticated structure-activity studies, there is still a great need for novel compounds with unique mechanisms of action in the field of medicine. While many thousands of structural analogs have been synthesized and tested, numerous gaps remain in the therapeutic armamentarium for psychiatric illnesses. Most new drugs marketed for psychotherapeutic indications in recent years have been only incremental improvements on existing medications. Major breakthroughs have resulted primarily from the study of natural products. Some of our most valuable drugs have been isolated from plant and animal sources, including aspirin, morphine, reserpine (the first antipsychotic), almost all of our antibiotics, digitalis, and such anti-cancer agents as vincristine, vinblastine, and taxol. Recent political and social events suggest that new emphasis will be placed on natural products research in the years to come. This article highlights therapeutic applications of Ginkgo biloba, Hypericum perforatum, Valerian officinalis, and Panex ginseng.

White, H. L., P. W. Scates, et al. (1996). Extracts of Ginkgo biloba leaves inhibit monoamine oxidase. Life Sciences. Mar 58(16): 1315-1321.

Extracts of Ginkgo biloba leaves produce reversible inhibition of rat brain monoamine oxidase (MAO). Both MAO-A and -B types were inhibited to a similar extent. The MAO inhibitory compound(s) were present in dried or fresh Ginkgo biloba leaves as well as in commercially available capsules of Ginkgo biloba and appear to be heat stable with relatively low molecular weight. MAO inhibition by Ginkgo biloba may be a mechanism underlying reported anti-stress and anxiolytic activities of this natural product.

vanStaden, J. (1996). Changes in foliar cytokinins of Salix babylonica and Ginkgo biloba prior to and during leaf senescence. South African Journal Of Botany. Feb 62(1): 1-10.

With leaf maturity, there was a trend towards an increase in the proportion of cytokinin O-glucosides. This may contribute to the onset of senescence. After separation of the ethanolic leaf extracts by Sephadex LH-20 and HPLC, detection of cytokinin-like activity by the soybean callus bioassay illustrated that the two species differed markedly in their pattern of change of cytokinin content with leaf age. Mature leaves of Salix babylonica contained high levels of O-glucoside conjugates, which decreased prior to the initiation of chlorophyll loss and during the course of senescence. A similar pattern was observed with the free base cytokinins, mainly zeatin (Z) and isopentenyladenine (iP) in this species. Gingko biloba, on the other hand, exhibited an extremely complex qualitative cytokinin profile for mature leaves. Riboside, O-glucoside and O-glucoside riboside derivatives of both zeatin and dihydrozeatin (DHZ) appeared to dominate, although the latter was of greater importance. Senescence was characterized by a decrease in free base forms, Z, DHZ and iP, and a corresponding increase in O-glucosides, ribosides and one unknown compound, right up until abscission. It therefore appears that although cytokinins are implicated in the control of foliar senescence in both species studied, this is achieved by very different mechanisms.

SeifElNasr, M. and A. A. A. ElFattah (1995). Lipid peroxide, phospholipids, glutathione levels and superoxide dismutase activity in rat brain after ischaemia: Effect of ginkgo biloba extract. Pharmacological Research. Nov 32(5): 273-278.

The influence of ginkgo biloba extract on the lipid peroxide product (malondialdehyde, MDA), glutathione (GSH) and phospholipids levels as well as superoxide dismutase (SOD, 1.15.1.1) and lactate dehydrogenase (LDH, 1.1.1.27) activities in rat brain after occlusion of common carotid arteries was investigated. Two experimental models were studied: 60 min ischaemia without reperfusion and 60 min ischaemia followed by 60 min reperfusion. Compared to sham-operated animals, ischaemia followed by reperfusion increased cytosolic LDH activity and mitochondrial lipid peroxide content and decreased the superoxide dismutase activity and mitochondrial total phospholipids level.Preischaemic administration of ginkgo biloba extract (150 mg kg(-1), p.o.) could normalize the SOD activity of the rat brain. The extract was also able to reduce the lipid peroxide and phospholipids contents of the mitochondrial rat brain. These effects could be explained on the basis of the antioxidant property of ginkgo biloba extract and suggests its beneficial role in the protection against post-ischaemic injury. (C) 1995 The Italian Pharmacological Society

VanHoute, H. A., R. H. Busson, et al. (1996). Synthesis of [1-C-14] nordolichoic acid. Chemistry And Physics Of Lipids. Jul 82(1): 79-83.

We describe the synthesis of nordolichoic acid and [1-C-14]nordolichoic acid starting from polyprenol isolated from the leaves of Ginkgo biloba. Coupling of polyprenol with ethyl acetoacetate, using 1,1'-(azodicarbonyl)dipiperidine/tributylphosphine, followed by hydrolysis, decarboxylation and reduction, yielded the 2-polyprenyl-1-methylethanol. This alcohol was converted into a mesylate, subjected to one-carbon elongation with KCN, and finally converted to the acid by hydrolysis of the nitrile.

vanStaden, J. (1996). Cytokinin-like compounds in bark and shoot tissue of Salix babylonica and bark tissue of Ginkgo biloba after leaf abscission and during bud burst. South African Journal Of Botany. Aug 62(4): 178-182.

It appears that putative cytokinin O-glucosides are stored in both root and bark tissue of Salix babylonica and in bark tissue of Ginkgo biloba. The levels of cytokinins were high in these plant parts after leaf abscission, but decreased markedly after bud burst. It is possible that cytokinins are stored in the bark and root tissue after export, and are possibly re-utilized during renewed shoot growth at the beginning of the new growing season.

Ni, Y. C., B. L. Zhao, et al. (1996). Preventive effect of Ginkgo biloba extract on apoptosis in rat cerebellar neuronal cells induced by hydroxyl radicals. Neuroscience Letters. Aug 214(2-3): 115-118.

The ability of oxidative stress to induce apoptosis, and the effect of Ginkgo biloba extract (EGb761) on this induction were studied in primary cultured rat cerebellar neuronal cells. Cells were exposed to hydroxyl radicals by treating them with 20-50 mu M hydrogen peroxide (H2O2) and 100 mu M ferrous sulfate. Hydroxyl radical treatment fragmented the DNA in a manner typical of apoptosis cells, producing a ladder pattern of 200 base pair increments on 1% agarose gel electrophoresis. Pretreatment of cells with 100 mu g/ml EGb reduced hydroxyl radical induced cells apoptosis (determined by flow cytometry) and DNA fragmentation. The results indicate that hydroxyl radicals induce apoptosis in rat cerebellar neuronal cells, and this induction can be prevented by EGb.

Haase, J., P. Halama, et al. (1996). Efficacy of short-term treatment with intravenously administered Ginkgo biloba special extract EGb 761 in Alzheimer type and vascular dementia. Zeitschrift Fur Gerontologie Und Geriatrie. Jul Aug 29(4): 302-309.

In a placebo-controlled, randomized, double-blind clinical trial, 40 patients with a mean age of Bs (+/- 12.5) years suffering from moderate dementia (Alzheimer, vascular, or mixed type) according to DSM-III-R criteria were included. Severity of the disease had to correspond to stages 4 or 5 of Reisberg's Global Deterioration Scale. Infusions of either EGb 761 or placebo were administered 4 days per week for 4 weeks. Primary outcome measure was the activities of daily living as assessed by the Nurnberger-Alters-Beobachtungsskala (NAB). The Clinical Global Impressions of change (CGI, item 2) and the actual intelligence as assessed by the Kurztest fur Allgemeine Intelligent (KAI) were further target variables.No relevant group differences could be detected at baseline. After therapy, patients of the active substance group scored significantly better (p < 0.05) on each outcome measure than those who received placebo. Using a sequential testing procedure, a global significance level of p < 0.05 could be assured. Superiority of EGb 761 therapy was also found with respect to a self-rating scale for instrumental activities of daily living (Nurnberger-Alters-Alltagsaktivitatenskala), the improvement of the most prominent symptom of illness, and the decrease of depression. Thus clinical efficacy of EGb 761 could be shown on 3 planes of assessment: the behavioral, the psychopathologic and the psychometric plane. it could be confirmed that, in patients with moderate dementia, short-term intravenous infusion therapy with EGb 761 results in an improvement of psychopathology and cognitive performance, which is reflected in an increased ability to cope with the demands of daily living.

Blume, J., M. Kieser, et al. (1996). Placebo-controlled double blind study on the efficacy of Gingko biloba extract EGb 761 in trained patients suffering from intermittent claudication. Vasa Journal Of Vascular Diseases 25(3): 265-274.

This monocenter, randomized, placebo-controlled double-blind study with parallel-group comparison was carried out in order to demonstrate the efficacy of Ginkgo biloba special extract EGb 761 on objective and subjective parameters of the walking performance in trained patients suffering from peripheral arterial occlusive disease in Fontaine stage IIb. In total 60 patients were recruited (42 men; aged 47-82 years) with angiographically proven peripheral arterial occlusive disease of the lower extremities and an intermittent claudication existing for at least 6 months. No improvement had been shown despite consistent walking training and a maximum pain-free walking distance on the treadmill of less than 150 m was recorded at the beginning of the study. The therapeutic groups were treated with either Ginkgo biloba special extract EGb 761 at a dose of 3 times 1 film-coated tablet of 40 mg per day by oral route or placebo over a duration of 24 weeks following a two-week placebo run-in phase. The main outcome measure was the difference of the walking distance between the start of treatment and after 8, 16 and 24 weeks of treatment as measured on the treadmill (walking speed 3 km/h and slope of 12%). As secondary parameters the corresponding differences for the maximum walking distance, the relative increase of the pain-free walking distance, the Doppler index and the subjective evaluation of the patients were analyzed. The absolute changes in the pain-free walking distance in treatment weeks 8, 16 and 24 as against the treatment beginning (median values with 95% confidence interval) led to the following values for the patients treated with Ginkgo biloba special extract EGb 761: 19 m (14, 33), 34 m (18, 50) and 41 m (26, 64). The corresponding values in the placebo group were as follows: 7 m (-4, 12), 12 m (5, 22) and 8 m (-1, 21). The advantage of the EGb 761-treated group as compared to the placebo group could be verified statistically at the 3 time points with p < 0.0001, p = 0.0003 and p < 0.0001. The test for the presence of a clinically relevant difference of 20% between EGb 761 and placebo also produced a statistically significant result (p = 0.008). The Doppler index remained unchanged in both therapeutic groups: A corresponding statistically significant advantage for the EGb 761 group was observed on a descriptive level for the other parameters tested. The tolerance of the treatment was very good. The results of this placebo-controlled study show that treatment with Ginkgo biloba special extract EGb 761 produces a statistically highly significant and clinically relevant improvement of the walking performance in trained patients suffering from intermittent claudication with very good tolerance of the study preparation.

Wang, J., C. Yang, et al. (1996). The nuclear lamina in male generative cells of Ginkgo biloba. Sexual Plant Reproduction. Jul 9(4): 238-242.

Using selective extraction and diethylene glycol distearate embedment and embedment-were electron microscopy, we demonstrated nuclear lamina-like structures in sperm cells of Ginkgo biloba. A well-organized nuclear matrix network was also observed. Further studies were undertaken to determine whether or not lamin-like components exist in the pollen and sperm cells, Immunofluorescence staining using monoclonal antibodies against different animal lamins revealed lamins localized in the nuclear compartment of the sperm cells. Western blotting showed that in pollen grains there are two positive crossreaction bands at 66 kDa and 86 kDa, recognized by antibodies specific to animal lamins: in sperm cells there was only one, at 66 kDa. These results indicate that nuclear lamina containing both A-type and B-type lamins was present in male generative cells of G. biloba. The data imply that plant lamins share some homology with animal lamins and may be conserved during evolution.

Rogue, P. and A. N. Malviya (1996). Inhibition of protein kinase C by Ginkgo biloba extract (EGb 761). Effects Of Ginkgo Biloba Extract Egb 5: 1-6.

Rabin, O., M. C. J. Chang, et al. (1996). Effects of Ginkgo biloba extract (EGb 761) on cerebral postischemic lipid metabolism. Effects Of Ginkgo Biloba Extract Egb 5: 7-19.

Pardon, M. C., M. Barkats, et al. (1996). Effect of long-term treatment with Ginkgo biloba extract (EGb 761) on age-dependent structural changes in the hippocampus and spatial memory performance of inbred mice. Effects Of Ginkgo Biloba Extract Egb 5: 21-33.

Ravel, N., P. Chabaud, et al. (1996). Ginkgo biloba extract and short-term olfactory memory. Effects Of Ginkgo Biloba Extract Egb 5: 35-43.

Didier, A., D. Rouiller, et al. (1996). Effects of Ginkgo biloba extract (EGb 761) on apoptosis and regeneration of primary olfactory neurons following target 'lesioning' in rats. Effects Of Ginkgo Biloba Extract Egb 5: 45-52.

Ramassamy, C., M. C. Delisle, et al. (1996). Effects of Ginkgo biloba extract (EGb 761) on apolipoprotein E and apolipoprotein J release by astrocytes after lipoperoxidation and on the level of hippocampal apolipoprotein E after entorhinal cortex 'lesioning'. Effects Of Ginkgo Biloba Extract Egb 5: 53-60.

Shifman, M. I., Z. L. Fulop, et al. (1996). Effects of Ginkgo biloba extract (EGb 761) on behavioral recovery and expression of NGF, GAP-43 and beta-actin mRNA after inducing unilateral entorhinal cortex lesions. Effects Of Ginkgo Biloba Extract Egb 5: 61-73.

Brailowsky, S. and T. Montiel (1996). Ginkgo biloba extract (EGb 761), hemiplegia and aging. Effects Of Ginkgo Biloba Extract Egb 5: 75-83.

Kelche, C., C. Roeser, et al. (1996). Ginkgo biloba extract (EGb 761) can promote some behavioral recovery after septohippocampal damage in the rat, but its effects depend upon the degree of hippocampal deafferentation. Effects Of Ginkgo Biloba Extract Egb 5: 85-99.

Jastreboff, P. J., S. Zhou, et al. (1996). Testing the efficacy of Ginkgo biloba extract (EGb 761) for tinnitus attenuation in an animal model. Effects Of Ginkgo Biloba Extract Egb 5: 101-112.

Jule, Y. and M. T. DroyLefaix (1996). Ginkgo biloba extract (EGb 761) and the postlesion neuronal plasticity of rat sympathetic ganglia. Effects Of Ginkgo Biloba Extract Egb 5: 113-119.

Cesaro, P. (1996). Neuronal plasticity: A mechanism in the clinical effects of the standardized Ginkgo biloba extract. Effects Of Ginkgo Biloba Extract Egb 5: 121-126.

Punkt, K., A. Unger, et al. (1996). Hypoxia-dependent changes of enzyme activities in different fibre types of rat soleus and extensor digitorum longus muscles. A cytophotometrical study. Acta Histochemica. Jul 98(3): 255-269.

Using cytophotometry activity changes of succinate dehydrogenase, glycerol-3-phosphate dehydrogenase and myofibrillar adenosine triphosphatase were measured in 3 fibre types of soleus and extensor digitorum longus muscles under normal and experimental conditions. Fibres were typed by means of cytophotometrical data into slow-oxidative, fast-oxidative glycolytic and fast-glycolytic ones. After experimental hypoxia of 20 min duration a significant increase of enzyme activities was observed especially in slow-oxidative and fast-oxidative glycolytic fibres of both muscles, e.g, succinate dehydrogenase activity increased by 21% in these fibres of soleus muscle and by 23-26% in these fibres of extensor digitorum longus muscle. Moreover, an increase of glycerol-3-phosphate dehydrogenase activity by 10% in slow-oxidative fibres and by 28% in fast-oxidative glycolytic fibres and a 10-12% increased ATPase activity in all fibres of extensor digitorum longus muscle were measured. Treatment with Ginkgo biloba extract for 3 months before exposure to hypoxia resulted in increased adenosine triphosphatase activity in all fibres of both muscles and in decreased succinate dehydrogenase activity of slow-oxidative and fast-oxidative glycolytic fibres of extensor digitorum longus muscle. These results could be interpreted as a protective effect of Ginkgo biloba extract.

Oyama, Y., D. O. Carpenter, et al. (1996). Flow-cytometric estimation on glutamate- and kainate-induced increases in intracellular Ca2+ of brain neurons: A technical aspect. Brain Research. Jul 728(1): 121-124.

=Effects of glutamate and kainate on the intracellular Ca2+ concentration ([Ca2+](i)) in a large population (several thousand) of dissociated cerebellar granule cell neurons were evaluated using a flow-cytometer and a combination of two fluorescent dyes, fluo-3-AM for estimating [Ca2+](i) and ethidium bromide for removing neurons that had compromised membranes from the cell population examined. The number of neurons responding to glutamate or kainate in augmenting the fluo-3 fluorescence increased in a dose-dependent manner. The number of neurons responding to kainate was much greater than that to glutamate. CNQX, a blocker of non-NMDA receptors, completely blocked the response elicited by kainate while the complete blockade of this glutamate-induced response was made by a combination of MK-801, a NMDA receptor blocker, and CNQX. Nicardipine, a calcium antagonist, decreased the number of neurons responding to glutamate and kainate, suggesting involvement of voltage-dependent calcium channels. These results indicate that the flowcytometric measurement of glutamate and kainate responses has the potential to provide answers to such questions as what percentage of the population of neurons respond to these amino acids and what is the resulting distribution of [Ca2+](i).

Palacios, D. M. (1996). On the specimen of the ginkgo-toothed beaked whale, Mesoplodon ginkgodens, from the Galapagos Islands. Marine Mammal Science. Jul 12(3): 444-446.

Stoll, S., K. Scheuer, et al. (1996). Ginkgo biloba extract (EGb 761) independently improves changes in passive avoidance learning and brain membrane fluidity in the aging mouse. Pharmacopsychiatry . Jul 29(4): 144-149.

Decreases in cell membrane fluidity may be a major mechanism of age-related functional decline. A prime cause for the decline of membrane fluidity may be the presence of free radicals. Gingko biloba extract EGb 761 protects neuronal cell membranes from free radical damage in vitro. Further, EGb 761 has repeatedly been shown to improve cognitive functions in man and in laboratory animals. To test if there is a link between these two actions we assessed the effects of EGb 761 on passive avoidance learning and on neuronal membrane fluidity in vivo in young (three-month-old), middle-aged (12-month-old) and aged (22 to 24-month-old) female NMRI mice. The animals were treated daily with 100 mg/kg EGb 761 for three weeks. There was a significant improvement in short-term memory, measured by the avoidance latency 60 seconds after the aversive stimulus (p < 0.0311), and of membrane fluidity(p < 0.01) in the aged animals, but no improvement in long-term memory as measured by the avoidance latency 24 hours after shock. However, no significant correlation between membrane fluidity and short-term memory performance was found. Taken together, these results indicate that EGb 761 independently improves changes in passive avoidance learning and brain membrane fluidity.

Stoppe, G., H. Sandholzer, et al. (1996). Prescribing practice with cognition enhancers in outpatient care: Are there differences regarding type of dementia? Results of a representative survey in Lower Saxony, Germany. Pharmacopsychiatry . Jul 29(4): 150-155.

Previous studies of cognition enhancers have mainly focused on insufficiently defined groups of cognition disorders, e.g., ''cerebral insufficiency''. With regard to the various biological changes in senile dementia of Alzheimer's type (SDAT) and in vascular dementia (VD), which together make up the great majority of senile dementias, many authors have encouraged different studies of these types of dementias, especially since both can be diagnosed clinically with satisfying certainty. Since primary care physicians treat the majority of elderly and demented patients, they have their own experience with cognition enhancers. We were therefore interested to know, how far these physicians differ in their treatment of SDAT and VD. We performed a representative survey (response rate 83.2%: 145 family physicians and 14 neuropsychiatrists) in the Goettingen area. A written case vignette described a 70-year-old widow with moderate dementia and vascular risk factors which are easily treated with drugs. Two, Versions were randomly assigned, in which (version A) either a ''typical'' VD history or a typical SDAT history (version B) were described. After perusal, the physician was asked whether and which drugs he would choose to treat the cognitive disorders in this patient, Most frequently, piracetam (A/B: 25.6%/30.9%), ginkgo biloba (24.4%/28.4%), and nimodipine (14.1%/25.9%) were considered. Aspirin was cited by 29.5% (A) and 17.3% (B) of the physicians respectively. As far as the type of dementia was concerned, significant differences were found only for co-dergocrine, which was prefered in SDAT. The following inter-group trends were observed: family physicians considered ginkgo biloba more often than nimodipine or co-dergocrine. The results show the apparent importance of cost- and safety aspects, while the type of dementia has hardly any impact. The latter impression corresponds to the results of drug trials demonstrating no different efficacy. In our opinion, aspirin was not sufficiently taken into consideration.

Strode, J. T. B., L. T. Taylor, et al. (1996). Supercritical fluid chromatography of ginkgolides A, B, C and J and bilobalide. Journal Of Chromatography A. Jun 738(1): 115-122.

Supercritical fluid chromatography (SFC) can be used to separate the five different ginkgo terpenetrilactones occurring in Ginkgo biloba leaf. The separation is carried out at 280 atm on a packed deactivated aminopropyl silica HPLC column with CO2 modified with 12% methanol. The separation is better than what is currently achievable with RP-HPLC. Detection was done with evaporative light scattering (ELSD). The limit of detection was around 10 ng. The method can be used for the analysis of any ginkgo sample that has undergone an SPE clean-up and in some cases it is useful for samples without prior clean-up. This is due to the greater selectivity of the SFC separation mechanism relative to the RP-HPLC mechanism.

vanBeek, T. A. and L. T. Taylor (1996). Sample preparation of standardized extracts of Ginkgo biloba by supercritical fluid extraction. Phytochemical Analysis. Jul Aug 7(4): 185-191.

A method of sample preparation of standardized extracts of Ginkgo biloba using supercritical fluid extraction (SFE) is described. Ginkgolides and bilobalide could be selectively extracted with carbon dioxide containing 10% methanol at 335 atm and 45 degrees C from a methanolic solution of the extract. An In-line filter of silica gel was found to be essential for obtaining clean samples, Trapping was carried out with a solid silica gel trap at 80 degrees C, After eluting the trap with methyl acetate, the sample could be analysed by gas liquid chromatography or high performance liquid chromatography, Recoveries of the five terpenes relative to a standard solid phase extraction (SPE) procedure varied for two different extracts from 98.6 to 102.3%. Relative standard deviations were better for SFE than for SPE, A further advantage of the SFE over the SPE method is that it is much less laborious. A disadvantage is that it requires an automated supercritical extractor, With a small adaptation, the SFE method could also be used for finished ginkgo drugs in an aqueous alcoholic solution.

vanStaden, J. (1996). Metabolism of [H-3]-DHZ in mature leaves of Ginkgo biloba and Salix babylonica. South African Journal Of Botany. Apr 62(2): 111-116.

Mature leaves of both Ginkgo biloba and Salix babylonica metabolized [H-3]-DHZ, but this process is apparently different in the two species. In G. biloba, O-glucosylation of the free base to (OG)DHZ appears to be the main metabolic route. While (OG)DHZ is also formed in mature S. babylonica leaves, and is the major metabolite detected, there appears to be a second route of metabolism in Salix babylonica leaves, as a number of unknown polar compounds were also detected. Whether these compounds are formed as a result of other forms of conjugation, or is due to a degree of side-chain cleavage, is not known at this stage.

Loas, G., D. Rose, et al. (1996). To amitriptyline: Exploratory pilot study of the French center (A report from the Who project on the combined utilization of an antidepressant (amitriptyline) and an antioxidant (ginkgo biloba) in the treatment of therapy-resistant depression). Annales Medico Psychologiques. Jun 154(3): 202-203.

A multicountry, multicentre double-blind study in a group of depressives, coordinated by the Mental Health Division of the World Health Association (WHO) has been done. The goal of the study is to determine whether the therapeutic effects of amitriptyline can be enhanced and potentiated by combining it with an antioxydant (gingko biloba). An exploratory study has preceded the main study which had the objective to estimate the proportion of non-response patient to amitriptyline. We report the results concerning the French center. 23 inpatients meet the ICD-10 criteria for depression (F32 and F33) and were treated during 6 weeks by amitriptyline with the initial daily dose of 50 mg until the maximum dose of 200 mg. The proportion of non-responsive patient to amitriptyline was 34.78 (95% confidence interval: 15.32 to 54.24%), all clinically deteriorated.

(1996). To amitriptyline: Exploratory pilot study of the French center (A report from the Who project on the combined utilization of an antidepressant (amitriptyline) and an antioxidant (ginkgo biloba) in the treatment of therapy-resistant depression) - Discussion. Annales Medico Psychologiques. Jun 154(3): 203-203.

Mizuno, M., M. T. DroyLefaix, et al. (1996). Gingko biloba extract EGb 761 is a suppressor of AP-1 transcription factor stimulated by phorbol 12-myristate 13-acetate. Biochemistry And Molecular Biology International. May 39(2): 395-401.

Transcription factors are activated in response to a wide variety of extracellular stimuli. The present study investigated which step Gingko biloba extract (EGb 761), a flavonoid phytochemical rich preparation can affect signal transduction during AP-1 activation. Kinetic experiments with human Jurkat T-cell lines demonstrate that it takes 1 to 1.5 h to activate AP-1 DNA binding activity. These data indicate that c-fos mRNA is expressed and then AP-1 DNA binding activity is activated. Pretreatment of Jurkat T cells with 10 mu g/ml EGb 761 suppresses AP-1 DNA activation and c-fos mRNA expression. These results suggest that the step in the signal transduction pathway for AP-1 activation that is inhibited by EGb 761 is upstream to c-fos mRNA expression.

Erdincler, D. S., Y. Karakoc, et al. (1996). The effect of ginkgo biloba glycoside on the blood viscosity and erythrocyte deformability. Clinical Hemorheology. May Jun 16(3): 271-276.

In this study, we investigated the effect of ginkgoglycoside in two different doses (19.2 mg/day and 28.8 mg/day) on blood viscosity and erythrocyte deformability in 27 patients suffering from cerebrovascular insufficiency. The patients were divided into two groups randomly consisting of 13 and 14 patients respectively. Both groups received 28.8 mg/day ginkgoglycoside between the 1st and 15th day. The first group received the same dose until the end of the 30th day, whereas the dose administrated to the second group was reduced to 19.2 mg/day. In the first group, during 30 days a significant decrease in blood viscosity and a significant increase in erythrocyte deformability were observed. In the second group on the other hand, after dose reduction, the effect of the drug on blood viscosity and erythrocyte deformability were diminished. Improvement of symptoms including vertigo, tinnutus, headache and forgetfulness in the first group was found to be significantly different from the 2nd group at day 30 in a dose dependent manner.

Rowin, J. and S. L. Lewis (1996). Spontaneous bilateral subdural hematomas associated with chronic Ginkgo biloba ingestion. Neurology . Jun 46(6): 1775-1776.

DeDeyn, P. P. and R. Dhooge (1996). Placebos in clinical practice and research. Journal Of Medical Ethics. Jun 22(3): 140-146.

The main current application of placebo is in clinical research. The term placebo effect refers to diverse non-specific, desires or non-desired effects of substances or procedures and interactions between patient and therapist. Unpredictability of the placebo effect necessitates placebo-controlled designs for most trials. Therapeutic and diagnostic use of placebo is ethically acceptable only in few well-defined cases. While ''therapeutic'' application of placebo almost invariably implies deception, this is not the case for its use in research. Conflicts may exit between the therapist's Hippocratic and scientific obligations. The authors provide examples in neuropsychiatry, illustrating that objective scientific data and well-considered guidelines may solve the ethical dilemma. Placebo control might even be considered and ethical obligation but some previous should be kept in mind: (a) no adequate therapy for the disease should exist and/or (presumed) active therapy should have serious side-effects; (b) placebo treatment should not last too long; (c) placebo treatment should not inflict unacceptable risks, and (d) the experimental subject should be adequately informed and informed consent given.

Amri, H., S. O. Ogwuegbu, et al. (1996). In vivo regulation of peripheral-type benzodiazepine receptor and glucocorticoid synthesis by Ginkgo biloba extract EGb 761 and isolated ginkgolides. Endocrinology . Dec 137(12): 5707-5718.

Glucocorticoid excess has broad pathogenic potential including neurotoxicity, neuroendangerment, and immunosuppression. Glucocorticoid synthesis is regulated by ACTH, which acts by accelerating the transport of the precursor cholesterol to the mitochondria where steroidogenesis begins. Ginkgo biloba is one of the most ancient trees, and extracts from its leaves have been used in traditional medicine. A standardized extract of Ginkgo biloba leaves, termed EGb 761 (EGb), has been shown to have neuroprotective and antistress effects. In vivo treatment of rats with EGb, and its bioactive components ginkgolide A and B, specifically reduces the ligand binding capacity, protein, and messenger RNA expression of the adrenocortical mitochondrial peripheral-type benzodiazepine receptor (PER), a key element in the regulation of cholesterol transport, resulting in decreased corticosteroid synthesis. As expected, the ginkgolide-induced decrease in glucocorticoid levels resulted in increased ACTH release, which in turn induced the expression of the steroidogenic acute regulatory protein. Because ginkgolides reduced the adrenal PER expression and corticosterone synthesis despite the presence of high levels of steroidogenic acute regulatory protein, these data demonstrate that PER is indispensable for normal adrenal function. In addition, these results suggest that manipulation of PER expression could control circulating glucocorticoid levels, and that the antistress and neuroprotective effects of EGb are caused by to its effect on glucocorticoid biosynthesis.

Rong, Y. Q., Z. H. Geng, et al. (1996). Ginkgo biloba modulates glutathione redox cycle in vascular endothelial cells. Nutrition Research. Nov Dec 16(11-12): 1913-1923.

We recently reported that Ginkgo biloba extract (GEE) suppressed oxidative burst in macrophages and protected bovine pulmonary artery endothelial cells (PAEC) from oxidant injury. In this study the effects of GBE on glutathione (GSH) redox cycle and activity of antioxidant enzymes were investigated. Confluent monolayers of PAEC were incubated with GEE for 8-48 h, washed, and then lysed with Triton X-100. Biochemical assays were performed with the lysate. GEE caused both dose- and time-dependent increase in GSH level and glutathione disulfide (GSSG) reductase activity while GSH peroxidase and superoxide dismutase activity remained unaffected. Exposure of PAEC to an organic oxidant tert-butyl hydroperoxide (tBHP) resulted in decreased GSH level, increased lipid peroxidation, and elevated leakage of intracellular lactate dehydrogenase. Preincubation or simultaneous treatment of PAEC with GEE prevented these changes induced by tBHP. Our data suggest that the antioxidant effect of GBE may be due to its modulation of the GSH redox cycle in PAEC as well as direct scavenging of the oxidant. Copyright (C) 1996 Elsevier Science Inc.

Tosaki, A., T. Pali, et al. (1996). Effects of Ginkgo biloba extract and preconditioning on the diabetic rat myocardium. Diabetologia . Nov 39(11): 1255-1262.

Effects of preconditioning and Ginkgo biloba extract (EGb 761) were studied in isolated non diabetic and diabetic ischaemic and re-perfused rat hearts. Hearts were randomly divided into five groups in both the age-matched non-diabetic and the 8-week streptozotocin-induced diabetic groups: Group I, hearts were subjected to 30 min of global ischaemia followed by 30 min of re-perfusion; Group II, one cycle of preconditioning consisting of 5 min ischaemia and 10 min re-perfusion before the induction of 30 min of ischaemia and 30 min of re-perfusion; Group III, two cycles of preconditioning; Group IV, three cycles; and Group V, four cycles before the onset of 30 min ischaemia followed by 30 min of reperfusion. Four cycles of ischaemic preconditioning resulted in a reduction of arrhythmias in non-diabetic rats. Thus, in non-diabetics, the incidence of ventricular fibrillation and tachycardia fell from 92 % and 100 % (no preconditioning) to 33 % (p < 0.05) and 42 % (p < 0.05), respectively. Four cycles of preconditioning failed to reduce the incidence of re-perfusion arrhythmias in diabetic subjects. Preconditioning reduced the formation of oxygen free radicals measured by electron spin resonance spectroscopy, but the recovery of cardiac function was low in all non-diabetic and diabetic preconditioned groups. EGb 761 at 25 and 50 mg/kg improved cardiac function in non-preconditioned and preconditioned non-diabetic and diabetic hearts. During re-perfusion in the four-cycle preconditioned non-diabetic and diabetic groups, the amount of free radicals was reduced approximately by 50 and 70 % using 25 and 50 mg/kg of EGb 761, respectively. EGb 761 improved cardiac function after ischaemia in both non-preconditioned and preconditioned non-diabetic and diabetic rats. Our data suggest that diabetes could abolish the precondition-induced protection.

Lang, F. and E. Wilhelm (1996). Quantitative determination of proanthocyanidins in Ginkgo biloba special extracts. Pharmazie . Oct 51(10): 734-737.

Different analytical methods were compared on quantitative determination of proanthocyanidins in a purified extract of Ginkgo biloba. With partially specific methods the proanthocyanidin content was found to be between 0.9 to 2.3%, whereas non specific methods resulted in much higher values by interference of other constituents. The rule of proper calibration factors is discussed.

Kinghorn, A. D. and E. K. Seo (1996). Plants as sources of drugs. Agricultural Materials As Renewable Resources 647: 179-193.

Plants have a historically important role as sources of prescription drugs in western medicine, and their active principles also serve as templates for synthetic drug optimization and provide intermediates that are used in the production of semi-synthetic drugs. Worldwide, hundreds of higher plants are cultivated for substances useful in medicine and pharmacy. Although the anticancer agent taxol (paclitaxel) is the first naturally occurring plant-derived drug to have gained the approval of the U.S. Food and Drug Administration for more than 25 years, analogs of other plant constituents such as artemisinin, camptothecin, and forskolin are currently under development for drug use in western medicine. Another recent development has occurred in Western Europe, where there is currently a well-developed phytomedicinal market, with extractives of many plants being used for therapeutic purposes. An underlying concern with the production of plant-derived drugs is the question of supply, which must be stable and reliable, and frequently necessitates cultivation rather than collection in the wild. Information on the cultivation, constituents, and therapeutic uses of two examples of important medicinal plants (Panax ginseng; Korean ginseng and Ginkgo biloba; Ginkgo) will be provided in this chapter.

Haramaki, N., L. Packer, et al. (1996). Antioxidant actions and health implications of Ginkgo biloba extract. Handbook Of Antioxidants 3: 487-510.

Paick, J. S. and J. H. Lee (1996). An experimental study of the effect of Gingko biloba extract on the human and rabbit corpus cavernosum tissue. Journal Of Urology. Nov 156(5): 1876-1880.

Purpose: To investigate the effect of subfractions of extract from the ginkgo on human and rabbit corpus cavernosal tissue and their possible use for the treatment of impotence.Materials and Methods: Among the fractions of ginkgo biloba extract (GBE), nonginkgolide nonflavonoid fraction (NGF) has the most potent relaxing effect on vascular smooth muscle, We subfractionated NGF and speculated that some of the subfractions might have a very potent relaxing effect on corpus cavernosal tissue. Thereafter we have studied their effect on human and rabbit corpus cavernosum using organ bath and electrical field stimulation experiments.Results: In the tissue precontracted by norepinephrine (10(-5) M.), corpus cavernosal tissue of human and rabbit showed relaxation in response to subfractions of NGF in a dose-dependent manner. 304U-1 showed the most potent relaxing effect (ED(50) = 0.74 mg./ml. in human, ED(50) = 0.66 in rabbit). 304U-1 elicits pharmacological actions on corpus cavernosum smooth muscle via the signal transduction pathway whereby relaxation induced by 304U-1 is mediated by intracellular cAMP and perhaps partially by antagonizing of the adrenergic nervous system. A hyperpolarizing effect via potassium channel opening might also be related to this relaxing effect.Conclusion: The subfractions of NGF, especially 304U-1, have a relaxing effect an corpus cavernosum tissue. 304U-1, which showed the most potent relaxing effect, can possibly be used as a drug for intracavernosal injection therapy. Considering the fact that the value of ED(50) is too high, further fractionation and in vivo study are needed before clinical use in an oral form.

Poort, R. J., H. Visscher, et al. (1996). Zoidogamy in fossil gymnosperms: The centenary of a concept, with special reference to prepollen of late Paleozoic conifers. Proceedings Of The National Academy Of Sciences Of The United States Of America. Oct 93(21): 11713-11717.

This year is the centenary of the surprising discovery in 1896 of zoidogamy in extant cycadophytes and Ginkgo. But by coincidence, also in the same year, the concept of prepollen was introduced. The morphology of prepollen was considered justification for the probable production of motile antherozoids in extinct gymnosperms. In this paper, the history of the prepollen concept is briefly outlined. It is emphasized that, in addition to well-known examples in pteridosperms and cordaitaleans, a prepollen condition also occurred among late Paleozoic conifers.

McElwain, J. C. and W. G. Chaloner (1996). The fossil cuticle as a skeletal record of environmental change. Palaios . Aug 11(4): 376-388.

The plant cuticle with its stomatal pores represents an important interface between the plant and its surrounding environment. The potential of cuticular features such as cuticle thickness, stomatal density, stomatal index and stomatal ratio to signal the environment in which they grew and developed have been reviewed. In particular new stomatal data from three Yorkshire Middle Jurassic species, Brachyphyllum crucis Kendall, Brachyphyllum mamillare Lindley and Hutton and Ginkgo huttonii (Sternberg) Heer, have been compared with those of two selected nearest living equivalent (NLE) species Athrotaxis cupressoides and Ginkgo biloba, in an attempt to deduce the atmospheric carbon dioxide concentration from that time, It appears that the development of a thick cuticle can represent an adaptation to more than one kind of environmental constraint and evidently is a feature of certain taxonomic groups. It was concluded therefore that cuticle thickness, taken on its own was nor a suitable palaeo-ecological indicator In contrast however stomatal parameters of fossil plants seem to have great potential as palaeo-atmospheric indicators of carbon dioxide and in this sense as ''skeletal evidence of palaeo-ecological change.'' The stomatal density and index results of the Jurassic species were significantly lower (P < 0.0001) than those of their selected NLE species, therefore indicating elevated atmospheric CO2 concentrations for the Middle Jurassic. In addition the stomatal ratios of the Jurassic species were in agreement with those of previous Devonian and Carboniferous stomatal ratio results. These results are consistent with the evidence from carbon cycle modelling and carbon isotopic data which infer elevated atmospheric CO2 concentrations curing the Middle Jurassic of 4 to 5 times and 6 to 10 times the present atmospheric level respectively.

Letzel, H., J. Haan, et al. (1996). Nootropics: Efficacy and tolerability of products from three active substance classes. Journal Of Drug Development And Clinical Practice. Sep 8(2): 77-94.

This paper reviews and evaluates all the currently available clinical trials on the efficacy of three nootropics. Only randomised, double-blind, placebo-controlled clinical trials were taken into account which produced 44 studies allowing comparison of the patient populations, efficacy and tolerability of Ginkgo biloba special extracts, nimodipine and tacrine.Taking all the studies together, statistically significant results were obtained at three relevant levels of efficacy (psychopathological, psychometric behavioural) for all three substances. Nine studies produced significant results at all three efficacy levels. One study on Ginkgo biloba and one on tacrine also Produced significant results according to the latest measures now demanded (operationalised diagnosis of dementia, inclusion of mild-to-moderate cases, statistical proof at all three levels of efficacy and global clinical evaluation). The clinical efficacy of all three substances has thus been demonstrated.

Carrier, D. J., J. Archambault, et al. (1996). Formation of terpenoid products in Ginkgo biloba L cultivated cells. Plant Cell Reports. Sep 15(12): 888-891.

Ginkgolides are diterpenes arising from the terpenoid precursor: geranylgeranyl pyrophosphate (GGPP). Incorporation of [1-C-14] isopentenylpyrophosphate ([1-C-14]IPP) into GGPP was monitored throughout the cultivation cycle of G. biloba L. cultivated cells. Because incorporation of [1-C-14]IPP into GGPP had never been monitored in G. biloba, in either the whole plant or cultivated cell system, modifications to existing protocols were necessary. Modifications consisted of extracting the cells with an extraction buffer supplemented with Triton-X-100. Farnesylpyrophosphate (FPP) was the major product formed. The amount of GGPP detected was about one tenth that of FPP.

Grosche, J., W. Hartig, et al. (1995). Expression of glial fibrillary acidic protein (GFAP), glutamine synthetase (GS), and Bcl-2 protooncogene protein by Muller (glial) cells in retinal light damage of rats. Neuroscience Letters. Feb 185(2): 119-122.

In retinal light damage, degeneration of photoreceptors may cause alterations of glial (Muller) cells. We performed immunocytochemical studies on Muller cells isolated from retinae of rats exposed to enhanced illumination for 24 months, a procedure which leads to complete loss of photoreceptor cells. One group of rats was fed daily with Ginkgo biloba extract (EGb 761, an established free radical-scavenger) during the last 8 months of life when the remaining photoreceptors (about 50%) die. We found that (1) Muller cells respond to photoreceptor damage by increased expression of glial fibrillary acidic protein, (2) Muller cells reduce expression of glutamine synthetase when the major glutamate-releasing neurons are lost, and (3) the application of exogenous free radical scavengers prevents the expression by Muller cells of the protooncogene protein Bcl-2, a molecule assumed to activate endogenous free radical-scavenging activities.

Chinn, E., J. Silverthorne, et al. (1995). Light-regulated and organ-specific expression of types 1, 2, and 3 light-harvesting complex b mRNAs in Ginkgo biloba. Plant Physiology. Feb 107(2): 593-602.

In a prior study (E. Chinn and J. Silverthorne [1993] Plant Physiol 103: 727-732) we showed that the gymnosperm Ginkgo biloba was completely dependent on light for chlorophyll synthesis and chloroplast development and that expression of light-harvesting complex b (Lhcb) mRNAs was substantially increased by light. However, dark-grown seedlings that were transferred to constant white light took significantly longer than angiosperm seedlings to initiate a program of photomorphogenesis and the stems failed to green completely. We have prepared type-specific probes for mRNAs encoding major polypeptides of light-harvesting complex II (Lhcb1, Lhcb2, and Lhcb3) and have used these to analyze the expression of individual Lhcb mRNAs during greening. All three sequences accumulated in the top portions of dark-grown seedlings transferred to light, but, as was seen previously for total Lhcb mRNAs, there was a transient, reproducible decline in the levels of all three mRNAs after 4 d in the light. This transient decrease in Lhcb mRNA levels was not paralleled by a decrease in Chi accumulation. By contrast, there were significantly lower levels of all three Lhcb mRNAs in the lower portions of greening dark-grown stems as well as lower Chi levels. We conclude that although the tops of the plants have the capacity to etiolate and green, Gingko seedling stems continue a program of development into woody tissue in darkness that precludes greening when the seedlings are transferred to the light.

Punkt, K., K. Welt, et al. (1995). Changes of enzyme activities in the rat myocardium caused by experimental hypoxia with and without Ginkgo biloba extract EGb 761 pretreatment. A cytophotometrical study. Acta Histochemica. Jan 97(1): 67-79.

Using cytophotometry activity changes of succinate dehydrogenase, glycerol-3-phosphate dehydrogenase and myofibrillar adenosine triphosphatase, were measured in the rat myocardium under normal and different experimental conditions. After hypoxia all enzyme activities were significantly decreased in comparison to the normal situation, and the alterations differed in both ventricles. Ginkgo biloba extract treatment over three months before exposition to hypoxia resulted in a lower inhibition of succinate dehydrogenase, a higher inhibition of glycerol-3-phosphate dehydrogenase and an unchanged activity of adenosine triphosphatase after hypoxia of 20 min. These results were interpreted as a protective effect of the Ginkgo biloba extract on the hypoxic myocardium.

Kose, K. and P. Dogan (1995). Lipoperoxidation induced by hydrogen peroxide in human erythrocyte membranes. 1. Protective effect of Ginkgo biloba extract (EGb 761). Journal Of International Medical Research. Jan Feb 23(1): 1-8.

The antioxidant potential of Ginkgo biloba extract (EGb 761) on healthy human erythrocyte membranes was investigated. Lipoperoxidation was induced in erythrocyte suspensions using hydrogen peroxide, in the presence of EGb 761 at 37 degrees C; malondialdehyde production was determined as the indicator of lipoperoxidation during the incubation period. The results for EGb 761 at concentrations of 0, 25, 50, 125, 250 and 500 mu g/ml suggest that the antioxidant potential of EGb 761 in erythrocyte membranes increases with dose. Similarly, using different incubation periods (0, 15, 30, 45 or 60 min) indicated that the antioxidant effect of EGb 761 increased by the incubation time

Kose, K. and P. Dogan (1995). Lipoperoxidation induced by hydrogen peroxide in human erythrocyte membranes. 2. Comparison of the antioxidant effect of Ginkgo biloba extract (EGb 761) with those of water-soluble and lipid-soluble antioxidants. Journal Of International Medical Research. Jan Feb 23(1): 9-18.

An in vitro model using healthy human erythrocyte suspensions was used to compare the antioxidant effect of standardized Ginkgo biloba extract (EGb 761) with those of water-soluble (ascorbic acid, glutathione and uric acid) and lipid-soluble (a-tocopherol and retinol acetate) antioxidants. Lipid peroxidation was induced by hydrogen peroxide in the absence (control) and presence of antioxidants at low (25 mu g/ml) and high (250 mu g/ml) concentrations. Malondialdehyde production was determined as the indicator of lipid peroxidation during the incubation period. The results suggest that all of the antioxidants, except ascorbic acid, have antioxidant potential in this system in a concentration-dependent manner. When the antioxidants were compared, EGb 761 was found to be more effective than water-soluble antioxidants, and as effective as lipid-soluble antioxidants. Among the lipid-soluble antioxidants there was no significant difference in potency between alpha-tocopherol and retinol acetate, but uric acid was the most potent of the water-soluble antioxidants. The antioxidant potency of EGb 761 appears to be comparable with that of the well-known antioxidants alpha-tocopherol and retinol acetate.

Markova, T. A. and K. Z. Gamburg (1995). Endogenous N-malonyltryptophan in plant cell suspension cultures. Russian Journal Of Plant Physiology. Jan Feb 42(1): 106-111.

Endogenous N-malonyltryptophan (MTrp) was found in the cell suspension cultures of soybean (Glycine max L.), ginkgo (Ginkgo biloba L.), wheat (Triticum timopheevii Zhuk.), and potato (Solanum tuberosum L.) plants, amounting to 10 to 22 nmoles per 1 g fr wt, and was not detected in the suspension cultures of scorcenera (Scorcenera hispanica L.) and ginseng (Panax ginseng Mey). The accumulation of MTrp in soybean cells occurred mainly during the long-term stationary phase of the culture. During this period, MTrp constituted up to 22% of Trp + MTrp content. Soybean cell culture supplied with L-Trp and, especially, with D-Trp, accelerated MTrp accumulation. The specific radioactivity of MTrp, synthesized after feeding with L-C-14-Trp, was about the same as that of exogenous L-Trp, but in endogenous L-Trp, the specific radioactivity decreased by a factor of 2.3. The experiments with L-amino acid and D-amino acid oxidases and chiral chromatography showed that L-Trp was a precursor of endogenous MTrp in the cultured soybean and ginkgo cells. The addition of L-Trp to the suspension of soybean cells resulted in the accumulation of N-malonyl-L-tryptophan, whereas the addition of D-Trp caused mainly N-malonyl-D-tryptophan accumulation. It was assumed that the considerable amount of endogenous L-Trp was malonylated during the aging of some plant cell cultures; however, the physiological significance of this process remains unclear.

Shen, J. G. and D. Y. Zhou (1995). Efficiency of Ginkgo biloba extract (EGb 761) in antioxidant protection against myocardial ischemia and reperfusion injury. Biochemistry And Molecular Biology International. Jan 35(1): 125-134.

The cardio-protective mechanisms of EGb 761, an extract of Ginkgo biloba leaves, on myocardial ischemia-repel-fusion injury were investigated using rabbits subjected to 30 minutes of regional cardiac ischemia and 120 min of reperfusion under anesthesia. Compared to the saline perfused group, EGb 761 treatment (10 mg/kg, injected into the coronary artery) significantly inhibited the increase in lipid peroxidation and maintained total and CuZn-SOD levels in both plasma and tissue during and at the end of reperfusion. Both the decrease in tissue type plasminogen activator (t-PA) and the increase in plasminogen activator inhibitor-1 (PAI-1) caused by ischemia-reperfusion were also significantly suppressed by EGb 761 treatment. Furthermore, the ultrastructure of the myocytes of the EGb 761 treated heart was slightly damaged after ischemia-reperfusion, while the control ischemic-repel-fused hearts demonstrated severe histological damages such as swelling and vacuolization of the mitochondria. These results suggest that EGb 761 protects hearts by its antioxidant properties and by its ability to adjust fibrinolytic activity.

Petkov, V. D., S. Belcheva, et al. (1994). Participation of the serotonergic system in the memory effects of Ginkgo biloba L and Panax ginseng C A Mey. Phytotherapy Research. Dec 8(8): 470-477.

The 7-day oral administration of the extracts from Giakgo biloba (GK501) and Panax ginseng (G115) as well as their combination PHL-00701 (Gincosan(R)) produced changes in rat behaviour suggesting memory-enhancing effects. Single doses of agonists and antagonists of different serotonin receptor subtypes influenced the rat's capability for retention of learned behaviour and the behavioural effects of the drugs tested. GK501 decreased the density (B-max) of 5-HT1 receptors in the frontal cerebral cortex and hippocampus. Data concerning the effects of the drugs tested suggest the participation of the serotonergic transmitter system as an important neurochemical correlate of rat behaviour and of the memory effects of the drugs studied. This participation is modulated by the differences in the functions of the serotonin receptor subtypes.

Baudouin, C., M. Ettaiche, et al. (1994). Inhibition of preretinal proliferation by free radical scavengers in an experimental model of tractional retinal detachment. Experimental Eye Research. Dec 59(6): 697-706.

An original model of experimental proliferative vitreoretinopathy consisting of an intravitreal injection of 10(7) human platelets and 1 IU of hyaluronidase was developed in pigmented rabbits. One group of 11 eyes served as non-treated controls. Two other groups of 11 eyes each received Ginkgo Biloba extracts which are known free radical scavengers (EGb761, Ipsen, France), given orally in two doses, 50 mg.kg(-1) day(-1) and 100 mg kg(-1) day(-1) respectively, from the day after the platelet injection to the end of the first month. The fourth group (11 eyes) was intravenously injected with a unique dose of 15 000 U kg(-1) of superoxide dismutase the day after platelet injection. All animals were ophthalmoscopically examined in a masked fashion twice a week for 1 month and killed at the end of the experiment for histological analysis. Vitreoretinal proliferation was graded according to a six-stage classification. The non-treated eyes showed a high rate of retinal detachment (11/11 eyes), with a mean final score of 3.91 +/- 0.94. Histologic examinations consistently showed retinal retraction by fibrocellular preretinal membranes spreading to both surfaces of the retina as well as preretinal neovascularization. Many cells positively reacted with anti-cytokeratin or anti-vimentin monoclonal antibodies. All three groups of treated eyes showed significantly lower scores of vitreoretinal proliferation at almost each time point of examination. At the end of the study, five retinal detachments were found in the EGb761 group at 50 mg kg(-1) day(-1) (mean final score 2.45 +/- 1.37), only one in the group receiving 100 mg kg(-1) day(-1) (mean score 1.64 +/- 1.03), and one in the SOD treated eyes. The lowest mean score found at day 28 was observed in the group receiving SOD (1.36 +/- 1.43), although this group presented during the first 3 weeks with an intense vitreous and sometimes anterior chamber inflammation. Statistical comparison between treatments did not show significant differences at most time points of the study. These results demonstrate that antioxidants may efficiently prevent preretinal proliferation, in clinicopathological entities where free radicals had not yet been shown to play a direct pathogenetic role. They are also among the first attempts for inhibiting preretinal proliferations with non-cytotoxic agents and using a non-ocular route.

Barkats, M., P. Venault, et al. (1994). Effect of long-term treatment with EGb 761 on age-dependent structural changes in the hippocampi of three inbred mouse strains. Life Sciences. Dec 56(4): 213-222.

Female mice of the inbred strains C57BL/6J, BALB/cJ and DBA/2J were used to determine the possible existence of a genetically-based differential susceptibility to the effects of treatment with an extract of Ginkgo biloba (EGb 761). Timm's silver-sulphide staining method was used to visualize and determine changes in the areas of the hippocampal structures of aged subjects, and more specifically on the projection fields of the messy fibers which appear to decrease as a function of ageing. Experiments were begun when the animals were 15 months old. Treated animals received EGb 761 (50 mg/kg/day, p.o.) for 7 months in their drinking water. Inter-strain differences existed for the areas of the whole regio inferior, stratum pyramidale, stratum lacunosum moleculare and hilus (CA4) and for the projection field of intra- and infrapyramidal mossy fibers (iipMF) in the CA3 region of the hippocampus. Chronic treatment with EGb 761 significantly increased the projection field of iipMF and significantly reduced the area of the stratum radiatum, as compared with control mice. No differential sensitivity to EGb 761 existed among the mouse strains tested. Antioxydant properties of EGb 761 may explain its neuroprotective and neurotrophic actions on the hippocampus, and might explain certain improvements in memory and other cognitive functions in both humans and experimental animals.

Deberdt, W. (1994). Interaction between psychological and pharmacological treatment in cognitive impairment. Life Sciences 55(25-26): 2057-2066.

In contrast to other kinds of psychotropic drugs, nootropics or cognition enhancing drugs may be indicated, not for the direct treatment of the pathology itself, but for improving or restoring the remaining brain functions. Brain functions are normally trained during various kinds of non-medical therapy, such as physiotherapy, speech therapy, occupational therapy, memory training etc... In research little attention has been paid to the combination of both kinds of therapeutic approaches, probably because of the important methodological difficulties. This combination however, offers various interesting perspectives: L. ISRAEL examined in two placebo-controlled studies the effects of either 160 mg/d of ginkgo biloba extractum (GBE) or piracetam 2.4 or 4.8 g/d, combined with a memory training program, in nondemented patients complaining of memory problems. The results of both studies suggest that nootropic drug treatment and memory training have each an effect on different cognitive functions and, hence, are complementary. Some functions, like attention/perception in the GBE study and learning in the piracetam study, seem to benefit from both treatments, suggesting a mutually potentiating effect of drug treatment and training. This potentiation is very clear in the treatment of dyslexic children: in a placebo-controlled study piracetam 3.3 g/d, in combination with normal school teaching and more specific logopedic therapy, allowed a normal progression during the full school year in reading accuracy and reading comprehension, while the placebo treated children getting a similar training progressed only with 50%.Recently promising results were obtained in the treatment of dysphasic patients with a combination of speech therapy and piracetam 4.8 g/d, especially when given during the first months after the stroke, or otherwise in combination with an intensive speech training. In both double-blind studies the piracetam treated group improved about 60% more than the group who only got speech therapy and placebo. All these data may be explained by the restorative or enhancing influence of nootropic drugs on neurotransmitter systems closely related to learning and memory functions. E.g. piracetam restores the availability and function of muscarinic and NMDA receptors in aging animals, most probably through a modulation of the psychico-chemical properties of the neuronal membrane such as the membrane fluidity.

Fourtillan, J. B., A. M. Brisson, et al. (1995). Pharmacokinetics of bilobalide, Ginkgolide A and Ginkgolide B in healthy volunteers following oral and intravenous administrations of Ginkgo biloba extract (EGb 761). Therapie . Mar Apr 50(2): 137-144.

The pharmacokinetics of Ginkgolide A, Ginkgolide B and Bilobalide, which are compounds extracted from the dried leaves of the Ginkgo biloba tree, were investigated in 12 young healthy volunteers (six men and six women; mean +/- SD age = 25 +/- 5 years) after single-dose administration of Ginkgo biloba extract. Subjects were given, on three occasions, Ginkgo biloa extract as a solution either orally (in fasting conditions and after a standard meal) or intravenously ; corresponding to single doses of Ginkgolide A, Ginkgolide B and Bilobalide ranging from 0.90 mg to 3.36 mg.After each dosing, blood and urine samples were collected for up to 36 h and 48 h, for measurements of Ginkgolide A, Ginkgolide B and Bilobalide.Plasma and urine concentrations of these compounds were quantitatively measured by gas chromatography/mass spectrometry using negative chemical ionization, by applying a very sensitive method which allowed plasma concentrations as low as 0.2 ng/ml of each compound to be measured.When given orally, while fasting, the extents of bioavailability are high, as shown by bioavailability coefficients (F-AUC) mean (+/- SD) values equal to 0.80 (+/- 0.09), 0.88 (+/- 0.21) and 0.79 (+/- 0.30) for Ginkgolide A, Ginkgolide B and Bilobalide respectively. Food intake does not change AUC quantitatively but increases T-max. For the three compounds of interest, after oral dosing while fasting, differences can be noted for the elimination half-lives (T-1/2Z), which exhibit mean values equal to 4.50, 10.57 and 3.21 h, as well as mean residence times (MRT), equal to 5.86, 11.25 and 4.89 h, for Ginkgolide A, Ginkgolide B and Bilobalide respectively. Such values suggest that Ginkgo biloba extract (EGb 761) could be given twice daily in multiple oral dosing.

Camponovo, F. F., J. L. Wolfender, et al. (1995). Evaporative Light Scattering and Thermospray Mass Spectrometry - 2 Alternative Methods for Detection and Quantitative Liquid Chromatographic Determination of Ginkgolides and Bilobalide in Ginkgo-Biloba Leaf Extracts and Phytopharmaceuticals. Phytochemical Analysis. May Jun 6(3): 141-148.

Evaporative light scattering and thermospray mass spectrometry have been investigated as two alternative methods for the liquid chromatographic detection of ginkgolides and bilobalide. Both techniques were used to quantify these metabolites in leaf extracts and in some phytopharmaceuticals. Only a minimum of sample prepurification was required. Results were compared with those obtained by gas chromatography (flame ionization detection), which is one of most suitable methods for routine determinations of such compounds. The isolation of ginkgolides A, B, C, and J and bilobalide from leaves of Ginkgo biloba is also described.

Koc, R. K., H. Akdemir, et al. (1995). Lipid peroxidation in experimental spinal cord injury - Comparison of treatment with Ginkgo biloba, TRH and methylprednisolone. Research In Experimental Medicine. Apr 195(2): 117-123.

Ischaemia-induced lipid peroxidation is one of the most important factors producing tissue damage in spinal cord injury. In our study, the protective effects of Ginkgo biloba, thyroid releasing hormone (TRH) and methylprednisolone (MP) on compression injury of the rat spinal cord were investigated. For this study 45 rats in four groups, including control, MP, TRH and Gingko biloba, were used to determine the formation of malondialdehyde (MDA). All the animals were made paraplegic by the application clip method of Rivlin and Tator. Rats were divided randomly and blindly to one of four treatment groups (ten animals in each). MP and Ginkgo biloba treatments significantly decreased MDA levels (F=54.138, P<0.01). These results suggest that MP and Ginkgo biloba may have a protective effect against ischaemic spinal cord injury by the antioxidant effect.

BolanosJimenez, F., R. M. deCastro, et al. (1995). Stress-induced 5-HT1A, receptor desensitization: Protective effects of Ginkgo biloba extract (EGb 761). Fundamental And Clinical Pharmacology 9(2): 169-174.

The effects of sub-chronic cold stress on the functioning of hippocampal 5-HT1A receptors in old isolated rats and the possible protective effects of Ginkgo biloba extract (EGb 761) were investigated. Cold exposure during five days, produced a significant reduction of the inhibitory effect of 8-hydroxy-2-(di-n-propylamino) tetraline (X-OH-DPAT) on forskolin-stimulated adenylyl cyclase activity. In contrast, neither the affinity nor the density of hippocampal [H-3]8-OH-DPAT binding sites were affected indicating that the reduced sensitivity of 5-HT1A receptors induced by stress is probably due to a modification of their coupling mechanisms to adenylyl cyclase. The stress-induced desensitization of 5-HT1A receptors was prevented by the administration of EGb 761 (50 mg/kg per os/14 days). These results clearly indicate that 5-HT1A receptors are desensitized by stress and point out the reduced capacity of old rats to cope with the adverse effects of a chronic stressor. EGb 761 appears to restore the age-related decreased capacity to adapt to a chronic stressor.

Emerit, I., R. Arutyunyan, et al. (1995). Radiation-induced clastogenic factors: Anticlastogenic effect of Ginkgo biloba extract. Free Radical Biology And Medicine. Jun 18(6): 985-991.

Clastogenic factors (CFs) were first described in the blood of persons irradiated accidentally or for therapeutic reasons. Work of our laboratory has shown that they occur also under other circumstances, which are characterized by oxidative stress, and that CF-induced chromosome damage is regularly prevented by superoxide dismutase (SOD). Recently we found CFs in a high percentage of salvage personnel of the Chernobyl reactor accident. These liquidators represent a high-risk population and might benefit from cancer chemoprevention by antioxidants. SOD would have to be injected and is not appropriate for longterm prophylactic treatment. In the present study, we therefore evaluated the anticlastogenic effect of the Ginkgo biloba extract EGb 761, which is known for its superoxide scavenging properties. EGb 761 was tested on CF-treated blood cultures of healthy donors. After establishing the optimal protective EGb concentration, using CFs produced by irradiation of whole blood from healthy volunteers, the extract was tested on cultures exposed to CFs from plasma of persons irradiated as liquidators. The anticlastogenic effect could be confirmed for a final concentration of 100 mu g/ml. In 12 consecutive experiments, CFs induced an average of 18.00 +/- 4.41 aberrations/100 cells. This was reduced to 7.33 +/- 3.08 in the parallel cultures receiving 100 mu g/ml EGb 761 (p < .001). SOD was anticlastogenic in the same system at concentrations of 30 cytochrome C units/ml (approximately 10 mu g/ml). Preliminary results obtained in a small series of liquidators showed regression or complete disappearance of CFs in the plasma after 2 months of treatment with EGb 761 (3 x 40 mg/d).

Barnabas, S., S. Krishnan, et al. (1995). The branching pattern of major groups of land plants inferred from parsimony analysis of ribosomal RNA sequences. Journal Of Biosciences. Mar 20(2): 259-272.

The parsimony and bootstrap branching pattern of major groups of land plants derived from relevant 5S rRNA sequence trees have been discussed in the light of paleobotanical and morphological evidences. Although 5S rRNA sequence information a not useful for dileneating angiosperm relationships, it does capture the earlier phase of land plant evolution. The consensus branching pattern indicates an ancient split of bryophytes and vascular plants from the charophycean algal stem. Among the bryophytes, Marchantia and Lophocolea appear to be phylogenetically close and together with Plagiomnium form a monophyletic group. Lycopodium and Psilotum arose early in vascular land plant evolution, independent of fern-sphenopsid branch. Gymnosperms are polyphyletic; conifers, Gnetales and cycads emerge in that order with ginkgo joining Cycas. Among the conifers, Metasequoia, Juniperus and Taxus emerge as a branch independent of Pinus which joins Gnetales.The phylogeny derived from the available ss-RNA sequences shows that angiosperms are monophyletic with monocots and dicots diverging from a common stem. The nucleotide replacements during angiosperm descent from the gymnosperm ancestor which presumably arose around 370 my ago indicates that monocots and dicots diverged around 180 my ago, which is compatible with the reported divergence estimate of around 200 my ago deduced from chloroplast DNA sequences.

Joyeux, M., A. Lobstein, et al. (1995). Comparative antilipoperoxidant, antinecrotic and scavenging properties of terpenes and biflavones from Ginkgo and some flavonoids. Planta Medica. Apr 61(2): 126-129.

Ginkgo biloba extract is known to be efficient in diseases associated with free radical generation. This study compares the in vitro effect of some constituents of Ginkgo against lipid peroxidation and cell necrosis of isolated rat hepatocytes, and against superoxide anion which is generally implicated in cell damages.

Struillou, L., Y. Cohen, et al. (1995). Ginkgo biloba extract EGb 761 is not active against Mycobacterium avium infection in C57BL/6 mice. Antimicrobial Agents And Chemotherapy. Apr 39(4): 1013-1014.

Krieglstein, J., F. Ausmeier, et al. (1995). Neuroprotective effects of Ginkgo biloba constituents. European Journal Of Pharmaceutical Sciences. Feb 3(1): 39-48.

The neuroprotective effects of Ginkgo biloba extract (EGb 761) and some of its constituents were tested by using the mouse and the rat model of focal cerebral ischemia, the rat model of global cerebral ischemia and primary cultures of neurons obtained from newborn rat hippocampi and chick embryo telencephalic hemispheres. In the models of focal ischemia, 2 days after occlusion of the middle cerebral artery the infarct area on the mouse brain surface and the infarct volume of the rat brain were measured. The infarct area on the mouse brain was dose-dependently (5-20 mg/kg, s.c.) reduced by bilobalide administered 60 min before ischemia. When administered immediately after ischemia, 10 mg/kg bilobalide also diminished the infarct area. The same dose of bilobalide administered to rats 60 min before occluding the middle cerebral artery reduced the cortical and the total infarct volume significantly. Ginkgolide A (50 mg/kg, s.c.) and ginkgolide B (100 mg/kg, s.c.) also had cerebroprotective effects in the mouse model of focal cerebral ischemia, but ginkgolides C and J did not. EGb 761 (2 x 100 mg/kg,i.v.) increased the cerebral blood flow after 10 min of global ischemia in rats but neuroprotection was not demonstrable. Ginkgolide B (1 mu M) and bilobalide (10 mu M) were shown to protect cultured rat hippocampal neurons against damage caused by glutamate. Bilobalide (0.1 mu M) also enhanced the percentage of viable neurons in primary cultures from chick embryo hemispheres when damaged with 1 mM cyanide. The results demonstrate different types of neuroprotective and cerebrovascular effects of the Ginkgo biloba extract and some of its constituents.

Smith, P. F., C. L. Darlington, et al. (1995). Ginkgo biloba: An ancient Chinese tree with neuroprotective properties. Asia Pacific Journal Of Pharmacology. Mar 10(1): 3-4.

Semlitsch, H. V., P. Anderer, et al. (1995). Cognitive psychophysiology in nootropic drug research: Effects of Ginkgo biloba on event-related potentials (P300) in age-associated memory impairment. Pharmacopsychiatry . Jul 28(4): 134-142.

Extracts from the leaves of Ginkgo biloba have been suggested to be useful in the treatment of various symptoms of impaired brain functions in advanced age. To elucidate specific mechanisms of the possible clinical benefit, the effects of Ginkgo biloba extract Ginkobene(R) on cognitive information-processing were investigated by means of long-latency auditory event-related potentials. In a double-blind placebo-controlled study, 48 patients (29 women and 19 men) aged between 51 and 79 years with the diagnosis of age-associated memory impairment had 57 days' treatment with a daily dosage of 3 x 40 mg Ginkobene(R) or placebo. To evaluate acute, chronic, and superimposed drug effects, psychophysiological investigations were carried out on day 7 and day 57 before and 3 hours after drug administration. ERP investigations were carried out by means of a two-tone auditory oddball paradigm. In addition to 17 EEC leads, vertical and horizontal EOGs were recorded. After minimizing ocular artifacts and visual artifact rejection, latencies and topographic distributions of N1 and P2 components (non-targets) and N2 and P300 components (targets) were calculated by an automatic procedure. When compared to the placebo group, in the Ginkobene(R) group no consistent and unequivocal changes on N1, PZ, N2, and P300 amplitudes or on N1, PZ, and NZ latencies were observed. P300 latency was shortened by 31 ms, 38 ms, and 32 ms in the Ginkgo biloba group after acute, chronic, and superimposed drug administration. It may therefore be hypothesized that the decrease of P300 latency in the Ginkgo biloba group may reflect shorter stimulus-evaluation time. As this effect was not accompanied by positive effects on subjective wellbeing, it may be concluded that it is not mediated by thymopsychic alterations.

Plath, P. and J. Olivier (1995). Results of combined low-power laser therapy and extracts of Ginkgo biloba in cases of sensorineural hearing loss and tinnitus. Lasers In Otorhinolaryngology And In Head And Neck Surgery 49: 101-104.

vonWedel, H., L. Calero, et al. (1995). Soft-laser/Ginkgo therapy in chronic tinnitus - A placebo-controlled study. Lasers In Otorhinolaryngology And In Head And Neck Surgery 49: 105-108.

Frisch, C., R. U. Hasenohrl, et al. (1995). Blockade of lithium chloride-induced conditioned place aversion as a test for antiemetic agents: Comparison of metoclopramide with combined extracts of Zingiber officinale and Ginkgo biloba. Pharmacology Biochemistry And Behavior. Oct 52(2): 321-327.

The present study tests the hypothesis that the blockade of lithium chloride-induced conditioned place aversion might be a suitable model to assess antiemetic properties of drugs, especially in species that do not vomit, like rats. The effects of the known antiemetic compound metoclopramide were compared with those of zingicomb(R), a combination preparation of extracts of Ginkgo biloba and Zingiber officinale, also presumed to have antiemetic properties. Place conditioning was performed using a conventional three-compartment test procedure. On three successive conditioning trials, rats received an intraperitoneal (IF) injection of lithium chloride (125 mg/kg) and were placed into the compartment that they had preferred over three baseline trials. During the test, rats treated with lithium chloride (LiCl) spent less time in the treatment compartment, indicative of a conditioned place aversion (CPA). In the first experiment, metoclopramide (MCP) was administered intragastrically (IG) in doses of 2 or 10 mg/kg 60 min prior to LiCl injection. The pretreatment with 10 mg/kg MCP blocked the LiCl-produced CPA, whereas injections of 2 mg/kg had no effect. In the second experiment, zingicomb was administered IG in a dose range of 10-100 mg/kg 60 min prior to LiCl injection. The pretreatment with 50 and 100 mg/kg zingicomb attenuated the LiCl-produced CPA, whereas a dosage of 10 mg/kg had no effect. These findings suggest that LiCl-induced CPA is a viable procedure with which to assess the antiemetic properties of metoclopramide. Furthermore, the data confirm the hypothesis that the phytopharmacon zingicomb might have antiemetic properties that are comparable to those of metoclopramide.

Duverger, D., F. V. Defeudis, et al. (1995). Effects of repeated treatments with an extract of Ginkgo biloba (EGb 761) on cerebral glucose utilization in the rat: An autoradiographic study. General Pharmacology. Oct 26(6): 1375-1383.

1. The autoradiographic method based on 2-deoxy-D[1-C-14]glucose ([C-14]DG) was used to determine glucose utilization in 49 discrete structures of rat brain under control conditions and after the animals had received repeated treatment with an extract of Ginkgo biloba (EGb 761).2. Oral administration of EGb 761 (50 or 150 mg/kg/day) to adult male rats for 15 days did not modify body weight, mean arterial blood pressure, the concentrations of glucose or hemoglobin in blood, blood gases or arterial pH.3. EGb 761 treatments produced only slight-to-moderate changes in glucose utilization in the various brain structures; i.e. decreases to an extent not exceeding 18.4% at the 50 mg/kg dose or 11.7% at the 150 mg/kg dose.4. Glucose utilization was significantly decreased only in the frontoparietal somatosensory cortex, nucleus accumbens, cerebellar cortex and pens and only with the 50 mg/kg dose of EGb 761.5. Although the four brain structures affected by EGb 761 treatment do not, in themselves, constitute a specific functional system of the CNS, these effects appear useful in explaining mechanisms underlying the clinical use of EGb 761 in treating problems associated with deficient somatosensory processing (e.g. impairment of ''vigilance'') and vestibular mechanisms (e.g. vertiginous syndromes).

Cott, J. (1995). Introduction. Psychopharmacology Bulletin 31(1): 131-137.

Itil, T. and D. Martorano (1995). Natural substances in psychiatry (Ginkgo biloba in dementia). Psychopharmacology Bulletin 31(1): 147-158.

Natural substances and/or their synthetically developed active ingredients are frequently used in medicine, In psychiatry, two of the most well known natural compounds are reserpine and Ginkgo biloba extract (EGb). EGb is among the most popular over-the-counter medicines in Europe and is also available in the United States, primarily in health food stores, Already the European medical community has recognized EGb as an effective compound in the treatment of cerebral insufficiency. In a pilot bioequivalency study, the effects of three different commercially available EGb products were examined, Findings indicated significant quantitative central nervous system (CNS) effects in, at least, one of the three. Furthermore, the CNS effects of Ginkgold were similar to other psychoactive compounds classified as cognitive activators, Recent studies in which EGb 761 demonstrated therapeutic effects in the treatment of dementia have earned EGb the approval of the German EGA (Bundesgesundheit Amt) for use in the treatment of dementia.

Inselmann, G., A. Blohmer, et al. (1995). Modification of cisplatin-induced renal p-aminohippurate uptake alteration and lipid peroxidation by thiols, Ginkgo biloba extract, deferoxamine and torbafylline. Nephron . Aug 70(4): 425-429.

To determine whether inhibition of lipid peroxidation modifies cisplatin-induced changes of renal p-aminohippurate (PAH) uptake, we examined the effects of various radical scavengers and torbafylline on cisplatin-induced lipid peroxidation and PAH accumulation changes in rat renal cortical slices. Renal cortical slices were incubated with different cisplatin concentrations (0.3, 0.6, 1.0 mg/ml) in the presence of either glutathione, N-acetylcysteine, the iron chelator deferoxamine, Ginkgo biloba extract or the xanthine derivate torbafylline. Lipid peroxidation monitored as the production of malondialdehyde (MDA) was stimulated by increasing cisplatin concentrations in a dose-related manner. At a cisplatin concentration of 1.0 mg/ml, MDA production was twofold compared to controls (0.69 +/- 0.06 vs. 1.36 +/- 0.07 nmol/mg; p < 0.05). In turn, cisplatin decreased PAH uptake of kidney slices dose-dependently from 13.3 +/- 1.3 to 2.6 +/- 0.2 (p < 0.01). All agents tested inhibited cisplatin-induced lipid peroxidation; however, at a cisplatin concentration of 1.0 mg/ml, none of them prevented the decline of cisplatin-induced PAH uptake. Of the agents tested, deferoxamine proved to be the most effective antioxidant, completely inhibiting cisplatin-induced lipid peroxidation but in contrast preventing the decrease in PAH uptake only at a cisplatin concentration of 0.3 mg/ml. No strict association between lipid peroxidation and decline of PAH uptake was found, suggesting that lipid peroxidation may only in part participate in cisplatin-induced alterations of PAH uptake.

Parliment, T. H. (1995). Characterization of the putrid aroma compounds of Ginkgo biloba fruits. Fruit Flavors 596: 276-279.

The Ginkgo family of trees is represented by a single surviving species, Ginkgo biloba. It is an ancient line unlike any other living conifer and may represent a Link between the conifers and the tree-ferns. In the fall female trees produce yellow-orange fruits with a thick fleshy layer surrounding an edible kernel. The odor of these fruits is described as putrid, This study identified the odorous principles as high levels of butanoic and hexanoic acids.

Jeon, M. H., S. H. Sung, et al. (1995). Ginkgolide B production in cultured cells derived from Ginkgo biloba L leaves. Plant Cell Reports. May 14(8): 501-504.

Callus cultures and cell suspension cultures derived from Ginkgo biloba L. leaves produced ginkgolide B. In cell suspension cultures, the production reached a maximum by the 13th day of subculture and followed by a sharp decrease. The medium of Murashige and Skoog induced the highest ginkgolide B content in cultures while the medium of Schenk and Hildebrandt promoted cell growth. For the maximal production of ginkgolide B, cells were cultured in Murashige and Skoog medium modified to contain 1.0 mg/l of alpha-naphthaleneacetic acid, 0.1 mg/l of kinetin, 30 g/l sucrose and 1.25 mM potassium phosphate with a molar ratio of ammonium to nitrate ions of 1 : 3.

Koltringer, P., W. Langsteger, et al. (1995). Dose-dependent hemorheological effects and microcirculatory modifications following intravenous administration of Ginkgo biloba special extract EGb 761. Clinical Hemorheology. Jul Aug 15(4): 649-656.

In a randomized open and placebo-controlled clinical trial including 48 patients with vascular dementia, the effects of infusions of the Ginkgo biloba special extract EGb 761 at doses of 50, 100 and 200 mg were investigated as against placebo infusions. For this purpose, the 48 patients were randomly alloted to 4 groups with group I receiving placebo, group II 50 mg EGb 761, group III 100 mg EGb 761 and group IV 200 mg EGb 761.Primary variables chosen were microperfusion of the skin as well as whole-blood viscosity and elasticity. The values were determined previous to the beginning of the infusion and then 10, 20, 30, 45, 60, 80 and 120 minutes later; microperfusion of the skin was additionally measured 5 minutes after the beginning of the infusion.No statistically significant differences were found between group I (placebo) and group II (50 mg EGb 761) as concerns microperfusion. The comparison between group III (100 mg EGb 761) and group IV (200 mg EGb 761) showed significant differences after 45 and 120 minutes in favor of the higher dose. Furthermore, it was possible to demonstrate an increase in microperfusion in groups III and IV which was significant as compared to group I from 20 and 30 minutes on after infusion beginning as well as over the subsequent period till 120 minutes. Whole-blood viscoelasticity also showed dose-dependent changes with statistically significant differences between group IV and group I after 60 minutes as well as between group IV and group II after 45 minutes in each case in favor of the higher dose.

Yan, L. J., M. T. DroyLefaix, et al. (1995). Ginkgo biloba extract (EGB 761) protects human low density lipoproteins against oxidative modification mediated by copper. Biochemical And Biophysical Research Communications. Jul 212(2): 360-366.

The antioxidant effects of Ginkgo biloba extract (EGb 761) on copper-mediated human low density lipoprotein (LDL) oxidative modification were evaluated by several techniques. Human LDL (0.5 mg/ml) in phosphate buffered saline, pH 7.4, was incubated with 10 mu M cupric sulfate at 37 degrees C under air for 8 hours and 24 hours in the presence of varying concentrations of EGb 761. Increases in LDL apoB carbonylation, lipid peroxidation, apoB electrophoretic mobility and LDL fluorescence were all inhibited when the incubation mixture contained EGb 761 at concentrations less than 100 mu g/ml. This inhibition was EGb 761-concentration-dependent. Thus, EGb 761 has powerful antioxidant effects on cooper-mediated LDL oxidative modification. (C) 1995 Academic Press, Inc.

Toussaint, O., F. Eliaers, et al. (1995). Protective effect of Ginkgo biloba extract (EGb 761) and bilobalide against mortality and accelerated cellular aging under stressful conditions. Effects Of Ginkgo Biloba Extract Egb 4: 1-16.

Spinnewyn, B., N. Blavet, et al. (1995). Effect of Ginkgo biloba extract (EGb 761) on oxygen consumption by isolated cerebral mitochondria. Effects Of Ginkgo Biloba Extract Egb 4: 17-22.

Packer, L., N. Haramaki, et al. (1995). Ginkgo biloba extract (EGb 761): Antioxidant action and prevention of oxidative stress-induced injury. Effects Of Ginkgo Biloba Extract Egb 4: 23-47.

GardesAlbert, M., A. Khalil, et al. (1995). Protective effect of Ginkgo biloba extract (EGb 761) against the lipid peroxidation of low-density lipoproteins initiated by center dot OH and O-2(-center dot) free radicals. Effects Of Ginkgo Biloba Extract Egb 4: 49-63.

Goureau, O. and Y. Courtois (1995). Nitric oxide and retinal aging: A potential role for a Ginkgo biloba extract (EGb 761). Effects Of Ginkgo Biloba Extract Egb 4: 65-69.

Madruga, M. H., S. DeCastro, et al. (1995). Effects of Ginkgo biloba extract (EGb 761) on brain aging and oxygen free-radical metabolism in the rat. Effects Of Ginkgo Biloba Extract Egb 4: 71-76.

Huguet, F., K. Drieu, et al. (1995). Cerebral adrenergic and serotonergic receptor loss in rats during aging can be reversed by Ginkgo biloba extract (EGb 761). Effects Of Ginkgo Biloba Extract Egb 4: 77-88.

Barkats, M., P. Venault, et al. (1995). Age-dependent structural changes in the hippocampus: Effect of long-term Ginkgo biloba extract (EGb 761) treatment on three inbred strains of mice. Effects Of Ginkgo Biloba Extract Egb 4: 89-98.

Rapin, J. R., I. Lamproglou, et al. (1995). Anti-stress activity of Ginkgo biloba extract (EGb 761) on a learning test and neuroendocrine response. Effects Of Ginkgo Biloba Extract Egb 4: 99-106.

Luthringer, R., P. dArbigny, et al. (1995). Ginkgo biloba extract (EGb 761), EEG and event-related potentials mapping profile. Effects Of Ginkgo Biloba Extract Egb 4: 107-118.

Israel, L., M. Myslinski, et al. (1995). Onset of memory disorders: Specific and combined contributions of memory-training programs and Ginkgo biloba extract (EGb 761) treatment. Effects Of Ginkgo Biloba Extract Egb 4: 119-129.

Allain, H., A. Lieury, et al. (1995). The dual-coding test in elderly subjects: Psychometric assessment of properties of Ginkgo biloba extract (EGb 761). Effects Of Ginkgo Biloba Extract Egb 4: 131-139.

Hofferberth, B. (1995). Influence of Ginkgo biloba extract (EGb 761) on neurophysiological and neuropsychological measurements in patients suffering from psychoorganic syndrome. Effects Of Ginkgo Biloba Extract Egb 4: 141-148.

Kanowski, S. (1995). Proof of efficacy of the Ginkgo biloba special extract (EGb 761) in outpatients suffering from primary degenerative dementia of the Alzheimer type and multi-infarct dementia. Effects Of Ginkgo Biloba Extract Egb 4: 149-158.

Ramassamy, C., F. Girbe, et al. (1995). Peroxidation of synaptosomes alters the dopamine uptake complex but spares the exocytotic release of dopamine. Neurodegeneration . Jun 4(2): 155-160.

Synaptosomes, prepared from the striata of mice, and incubated for 1 h in a Krebs-Ringer medium with the peroxidative combination of ascorbic acid (0.1 mM)/Fe2+ (1 mu M), lose their ability to take up [H-3] dopamine. This effect is associated with a decrease in binding of the dopamine uptake inhibitor [H-3] GBR 12783. The free radical scavenger trolox C (0.1 mM) and the Ginkgo biloba extract EGb 761 (10 mu g/ml) prevent both effects. Although submitted to these peroxidative conditions after loading with [H-3] DA, superfused synaptosomes retain their ability to release [H-3] DA when depolarized by high potassium concentrations (40 mM). This release is higher than that observed when synaptosomes are incubated without ascorbic acid/Fe2+, and does not seem to depend upon peroxidation, since it is also observed when incubation is performed in the presence of the free radical scavengers EGb 761 (10 mu g/ml) and trolox C (0.1 mM).

Bonhomme, B., M. Doly, et al. (1995). Increasing retinal glucose tolerance with a Ginkgo biloba (EGb761) extract. Vision Et Adaptation 6: 163-169.

Szabo, M. E., M. T. DroyLefaix, et al. (1995). EGb 761 and the recovery of ion imbalance in ischemic reperfused diabetic rat retina. Ophthalmic Research. Mar Apr 27(2): 102-109.

We studied the effects of a free-radical scavenger, EGb 761, on electrolyte shifts (Na+, Ca2+, and K+) induced by ischemia and reperfusion in the retinas obtained from streptozotocin-induced diabetic rats. Eyes were subjected to 90 min ischemia followed by 24 h of reperfusion by clamping and releasing the central retinal artery. Ten days before the induction of ischemia and reperfusion, diabetic rats received a daily dose of 25, 50, and 100 mg/kg p.o. of EGb 761, respectively (n = 12 in each group). In the drug-free diabetic control group, 90 min ischemia followed by 24h of reperfusion resulted in an increase in retinal Na+ and Ca2+ (measured by atomic absorption spectrophotometry) compared to nonischemic control values of 73 +/- 4 and 2.6 +/- 0.3 mu mol/g dry weight to 113 +/- 5 (p < 0.05) and 5.3 +/- 0.3 mu mol/g dry weight (p < 0.05), respectively. Tissue Kf content was significantly reduced compared to its nonischemic diabetic control value of 268 +/- 7 to 213 +/- 6 mu mol/g dry weight (p < 0.05). EGb 761 dose-dependently reduced reperfusion-induced ion imbalance, improving the recovery of ion content in diabetic rat retina. EGb 761 did not reduce blood glucose in streptozotocin-induced diabetic rats. Therefore we may conclude that these protective effects of EGb 761 are independent of blood glucose content or of the severity of diabetes and protect against electrolyte shifts directly in retinal cells.

Parkin, C. and R. Dawe (1995). Ginkgo biloba extract has no effect on benzodiazepine-induced short-term memory deficit. Medical Science Research. May 23(5): 295-296.

Maitra, I., L. Marcocci, et al. (1995). Peroxyl radical scavenging activity of Ginkgo biloba extract EGb 761. Biochemical Pharmacology. May 49(11): 1649-1655.

Antioxidant mechanisms have been proposed to underlie the beneficial pharmacological effects of EGb 761, an extract from Ginkgo biloba leaves used for treating peripheral vascular diseases and cerebrovascular insufficiency in the elderly. In vitro evidence has been reported that EGb 761 scavenges various reactive oxygen species, i.e. nitric oxide, and the superoxide, hydroxyl, and oxoferryl radicals. However, the ability of EGb 761 to scavenge peroxyl radicals (reactive species mainly involved in the propagation step of lipid peroxidation) has not been investigated. To characterize further the antioxidant action of EGb 761, we measured the protective effects of EGb 761 during: (1) the oxidation of B-phycoerythrin by peroxyl radicals generated in aqueous solution by 2,2'-azobis (2-amidinopropane) hydrochloride (AAPH); and (2) the reaction of luminol or cis-parinaric acid with peroxyl radicals generated from 2,2'-azobis (2,4-dimethylvaleronitrile) (AMVN) in liposomes or in human low density lipoprotein (LDL), respectively. To evaluate the peroxyl radical scavenging activity of EGb 761 in a more physiologically relevant model of damage to lipid-containing systems, we also analyzed the effect of the extract on the oxidation of human LDL exposed to the ate-initiators in terms of: (1) accumulation of cholesterol linoleate ester hydroperoxides, (2) depletion of alpha-tocopherol and beta-carotene, and (3) changes in intrinsic tryptophan fluorescence. EGb 761 afforded protection against oxidative damage in all the systems we analyzed; thus, it is an efficient scavenger of peroxyl radicals. This result extends the oxygen radical scavenging properties of the extract and supports the hypothesis of an antioxidant therapeutic action of EGb 761

Dumont, E., P. Darbigny, et al. (1995). Protection of polyunsaturated fatty acids against iron-dependent lipid peroxidation by a Ginkgo biloba extract (EGb 761). Methods And Findings In Experimental And Clinical Pharmacology. Mar 17(2): 83-88.

Iron can induce a peroxidative degradation of the membrane polyunsaturated fatty acids by the well-known Fenton reaction. Chelated iron can also form a complex with oxygen, called perferryl ion, which is able to induce lipoperoxidation without a detectable production of hydroxyl radicals. The antioxidant properties of a titrated and standardized extract of Ginkgo biloba leaves (EGb 761) against iron-dependent peroxidative degradation of the membrane polyunsaturated fatty acids were studied. Rat liver microsomes were exposed to a mixture of NADPH, ADP and FeCl3 hypothesized to produce iron-oxygen complexes. The results of the analysis of the microsomal polyunsaturated fatty acids by gas chromatography show that the susceptibility to peroxidation of the different polyunsaturated fatty acids increases with their unsaturation level, and that EGb 761 protects these membrane polyunsaturated fatty acids regardless of their susceptibility to peroxidation. This protective effect is correlated with the decrease in the thiobarbituric acid-reactive substances concentration, bur the calculation of the antioxidant potency of EGb 761 as an IC50 value using results of the the thiobarbituric acid reaction leads to an underestimated evaluation when the reaction is carried out in the presence of iron ions.

Pietta, P. G., C. Gardana, et al. (1995). Identification of flavonoid metabolites after oral administration to rats of a Ginkgo biloba extract. Journal Of Chromatography B. Nov 673(1): 75-80.

An extract of Ginkgo biloba leaves (EGb) was administered by gastric probe to Wistar female rats, and urine and faeces samples were collected for 5 days and whole blood samples were withdrawn every 30 min for 6 h. After purification with SPE C-18 cartridges, the samples were analysed by reversed-phase LC-diode array detection (LC-DAD) for residual flavonoid glycosides, aglycones and metabolites. No glycosides or aglycones were detected in urine, faeces or blood and extensive degradation of EGb flavonoids within 24 h was detected. Among the seven different phenylalkyl acids detected by LC-DAD, 3,4-dihydroxyphenylacetic acid (I), hippuric acid (II), 3-hydroxyphenylacetic acid (III), homovanillic acid (IV) and benzoic acid (VII) were directly confirmed by on-line mass spectrometry using an electrospray interface (ES-MS). Peaks V and VI needed to be collected and separately examined and they were found to be 3-(4-hydrophenyl)propionic acid and 3-(3-hydrophenyl)propionic acid, respectively. As further evidence, the identity of metabolites I, II, III, IV, V and VII was confirmed by co-chromatography with authentic standards.

Rascol, O., T. C. Hain, et al. (1995). Antivertigo medications and drug-induced vertigo: A pharmacological review. Drugs . Nov 50(5): 777-791.

The approach to drug treatment of vertigo is almost exclusively symptomatic. There are 3 major goals for drug treatment of vertigo. The first one is to eliminate the hallucination of motion. Drugs with vestibular 'suppressant' properties are used for this purpose. The major vestibular suppressants are anticholinergic and antihistamine drugs. The second goal is to reduce the accompanying neurovegetative and psychoaffective signs (nausea, vomiting, anxiety). Antidopaminergics are used for this purpose. The third goal is to enhance the process of 'vestibular compensation' to allow the brain to find a new sensory equilibrium in spite of the vestibular lesion. Until now, the pharmacological manipulation of vestibular compensation has been assessed in animals but not in humans with vestibular lesions. Vestibular suppressant drugs delay rather than enhance compensation. A variety of other drugs is also used in the treatment of vertigo, including benzodiazepines, histaminergic agents, sympathomimetics and calcium antagonists. Their mechanism of action is poorly understood.The data base derived from clinical trials evaluating antivertigo medications is often questionable because of methodological limitations. This explains why habits of prescription are mainly empirical, and why striking differences can be noticed from one country to another. We can hope that new treatments may emerge from the present interest in receptor subclasses and neuromodulators of the vestibular system, and we must be ready to evaluate these potential new pharmacological agents with reliable clinical methods in humans.

Emerit, I., N. Oganesian, et al. (1995). Clastogenic factors in the plasma of Chernobyl accident recovery workers: Anticlastogenic effect of Ginkgo biloba extract. Radiation Research. Nov 144(2): 198-205.

Clastogenic factors are found in the plasma of persons irradiated accidentally or therapeutically. They persisted in the plasma of A-bomb survivors over 30 years. Clastogenic factors were found in 33 of 47 Chernobyl accident recovery workers (often referred to as liquidators) in a previous study (I. Emerit ct QI., J. Cancer Res. Clin. Oncol. 120, 558-561, 1994). In the present study, we show that there is a positive correlation between clastogenic activity and dose and that these biomarkers of oxidative stress can be influenced successfully by appropriate antioxidant treatment. With the authorization of the Armenian Ministry of Health, 30 workers were treated with antioxidants from Ginkgo biloba leaves. The extract EGb 761 containing flavonoids and terpenoids was given at a daily dose of 3 x 40 mg (Tanakan, IPSEN, France) during 2 months. The clastogenic activity of the plasma was reduced to control levels on the first day after the end of the treatment. A I-year follow-up showed that the benefit of the treatment persisted for at least 7 months. One-third of the workers again had clastogenic factors after 1 year, demonstrating that the process which produced clastogenic factors continued. However, the observation that antioxidants do not have to be given continuously is encouraging for intervention trials on a large-scale basis. These appear justified, since clastogenic factors are thought to be risk factors for the development of late effects of irradiation. (C) 1995 by Radiation Research Society

Baghai, N. L. and R. B. Jorstad (1995). Paleontology, paleoclimatology and paleoecology of the late Middle Miocene Musselshell Creek flora, Clearwater County, Idaho. A preliminary study of a new fossil flora. Palaios . Oct 10(5): 424-436.

The Musselshell Creek flora (12.0-10.5 Ma) of northern Idaho is used to reconstruct paleoclimatic and paleoecologic parameters of the Pacific Northwest during the late Middle Miocene. Other megafossil and microfossil floral records spanning 12.0-6.4 Ma are unknown from this region. The Musselshell Creek fossil flora, previously undescribed,, is preserved in lacustrine clays and sediments that accumulated in a narrow valley surrounded by rugged terrain. Dominant taxa include dicotyledons and conifers. Most of the leaves are preserved as impressions or compressions. Some fossil leaves retained their original pigmentation, cellular anatomy, and organic constituents. Other fossils include excellent remains of pollen and spores, dispersed leaf cuticle, pyritized wood, and disarticulated fish bones.A destructive statistical analysis of one block of sediment, approximately 30 cm x 45 cm (1.5 so. ft) recovered 14 orders, 23 families, and 34 genera of spermatophyte plant fossils. These floral elements are compared with two other earlier Miocene floras which were similarly sampled. Common megafossil genera include Quercus, Zizyphoides, Taxodium, Alnus, Castanea, Magnolia, Acer, Exbucklandia, Sequoia, Populus, and Betula. The rare occurrence of Ginkgo leaves is a first record of this taxon in the Idaho Miocene. Additional plant taxa are represented by palynomorphs. Common pollen taxa are Pinus, Abies, Carya, Quercus, and Tilia. Most of the megafossil and microfossil flora assemblage is characteristic of a streambank to floodplain environment that existed in a warm to cool temperate climate similar to the modern Mid-Atlantic coast of the United States.

Liang, N., K. Maruyama, et al. (1995). Interactions of elevated CO2 and drought stress in gas exchange and water-use efficiency in three temperate deciduous tree species. Photosynthetica 31(4): 529-539.

The effect of CO2 increase on gas exchange and water-use efficiency (WUE) in three temperate deciduous species (Fagus crenata, Ginkgo biloba and Alnus firma) under gradually-developing drought-stress was assessed. Seedlings were grown within transparent open-top cabinets and maintained for 4 months at mean CO2 concentrations of either 350 (ambient; C-350) Or 700 mu mol mol(-1) (elevated; C-700) and combined with five water regimes [leaf water potential, Psi(w), higher than -0.3 (well-watered), -0.5 and -0.8 (moderate drought), -1.0 and fewer than -1.2 MPa (serious drought-stress)]. Increase in CO2 concentration induced a 60 % average increase in net photosynthetic rate (P-N) under well-watered conditions. The effect of C-700 became more pronounced with drought stress established, with an 80 % average increase in P-N at Psi(w), as low as -0.8 MPa; leaf conductance to water vapour transfer (g(s)) and transpiration rate (E), however, were significantly decreased. Consequently, WUE increased under drought, through drought stress affected potential E sooner than potential P-N. The interaction of CO2 x drought stress on WUE was significant in that P-N was stimulated while E in C-700 enriched plants resembled that of C-350 plants under drought. Hence if a doubling of atmospheric CO2 concentration occurs by the mid 21(st) century, then greater P-N in F. crenata, G. biloba and A. firma may be expected and the drought susceptibility of these species will be substantially enhanced.

Janssens, D., C. Michiels, et al. (1995). Protection of hypoxia-induced ATP decrease in endothelial cells by Ginkgo biloba extract and bilobalide. Biochemical Pharmacology. Sep 50(7): 991-999.

Due to their localization at the interface between blood and tissue, endothelial cells are the first target of any change occurring within the blood, and alterations of their functions can seriously impair organs. During hypoxia, which mimics in vivo ischemia, a cascade of events occurs in the endothelial cells, starting with a decrease in ATP content and leading to their activation and release of inflammatory mediators. EGb 761 and one of its constituents, bilobalide, were shown to inhibit the hypoxia-induced decrease in ATP content in endothelial cells in vitro. Under these conditions, glycolysis was activated, as evidenced by increased glucose transport, as well as increased lactate production. Bilobalide was found to increase glucose transport under normoxic but not hypoxic conditions. In addition, EGb and bilobalide prevented the increase in total lactate production observed after 60 min of hypoxia. However, after 120 min of hypoxia, the total lactate production was similar under normoxic and hypoxic conditions, and both compounds increased this production. These results indicate that glycolysis slowed down between the 60th and 120th minute of hypoxia, while EGb and bilobalide delayed the onset of glycolysis activation. In another experimental model, both compounds were shown to increase the respiratory control ratio of mitochondria isolated from liver of rats treated orally. Since ischemia is known to uncouple mitochondria, the protection of ATP content and the delay in glycolysis activation observed during hypoxia in the presence of EGb 761 or bilobalide is best explained by a protection of mitochondrial respiratory activity, at least during the first 60 min of hypoxia incubation. Both products retain the ability to form ATP, thereby reducing the cell's need to induce glycolysis, probably by preserving ATP regeneration by mitochondria as long as oxygen is available.

Brailowsky, S., T. Montiel, et al. (1995). Acceleration of functional recovery from motor cortex ablation by two Ginkgo biloba extracts in rats. Restorative Neurology And Neuroscience. Sep 8(4): 163-167.

We studied the effects of two extracts of Ginkgo biloba, with and without terpenes, on motor recovery from cortical hemiplegia. Both extracts of the reference product (EGb761-IPSEN) produced a dose-dependent acceleration of behavioral recovery and diminished ventricular dilation in lesion rats. These results indicate that the active substance(s) participating in the beneficial effect of EGb761 is (are) contained in the non-terpenic fraction of the extract.

Hager, K. P., H. Braun, et al. (1995). Evolution of seed storage protein genes: Legumin genes of Ginkgo biloba. Journal Of Molecular Evolution. Oct 41(4): 457-466.

Legumin-like seed storage proteins have been intensively studied in crop plants. However, little is known about the molecular evolution of these proteins and their genes and it was assumed that they originated from an ancestral gene that already existed at the beginning of angiosperm evolution. We have evidence for the ubiquitous occurrence of homologous proteins in gymnosperms as well. We have characterized the major seed storage globulin from Ginkgo biloba by amino acid sequencing, which reveals clear homology to legumin-like proteins from angiosperms. The Ginkgo legumin is encoded by a gene family; we describe two of its members. The promoter regions contain sequence motifs which are known to function as regulatory elements involved in seed-specific expression of angiosperm legumins, although the tissues concerned are different in gymnosperms and angiosperms. The Ginkgo legumin gene structure is divergent from that of angiosperms and suggests that the evolution of legumin genes implicated loss of introns. From our data and from functional approaches recently described it becomes obvious that the posttranslational processing site of legumin precursors is less conserved than hitherto assumed. Finally, we present a phylogenetic analysis of legumin encoding sequences and discuss their utility as molecular markers for the reconstruction of seed plant evolution.

Kozik, A. and M. RapalaKozik (1995). Protein-attributable thiamine-binding activity in gymnosperm seeds. Journal Of Plant Physiology. Sep 146(5-6): 760-762.

To detect thiamine binding by extracts of gymnosperm seeds, a competition of thiamine and [C-14]thiamine for extract macromolecular binders was studied by equilibrium dialysis. Binding parameters were numerically estimated from the resulting displacement plots. All seed batches under study bound thiamine, though much variability in the binding capacity as well as in the contribution of <<non-specific>>, (non-saturable) binding was registered. The dissociation constants of binder-thiamine complexes were in a micromolar range. The thiamine binders appeared to be proteins, as judged from their sensitivity to proteinases, heat and ethanol treatments.As the species studied represent all four gymnosperm classes, and as other authors have already detected the thiamine-binding activity in angiosperm seeds, it is suggested that seed thiamine-binding proteins may ubiquitously occur in Spermatophyta.

Brinkman, J. A. and R. E. J. Boerner (1994). Nitrogen-Fertilization Effects on Foliar Nutrient Dynamics and Autumnal Resorption in Maidenhair Tree (Gingko-Biloba L). Journal Of Plant Nutrition 17(2-3): 433-443.

We quantified seasonal foliar nutrient dynamics and autumnal N and P resorption of individuals of the deciduous gymnosperm Gingko biloba (maidenhair tree) growing in compacted, urban soils over two years following a single fertilization with 150 kg/ha/yr of N (and no P). Mean foliar nutrient concentrations were more similar to those reported for angiosperm trees than for other gymnosperms. During the autumn following fertilization; 46% and 48 of foliar N and P were resorbed, respectively; during the second year both increased significantly, to 68% of foliar N and 74% of foliar P. Absolute N resorption was also greater during the second year, whereas absolute P resorption did not differ significantly between years. During the second year, the level of N resorption rates was similar to that reported for Larix laricina (larch or tamarack), a needle-leafed, deciduous gymnosperm, and greater than those reported for broad-leafed deciduous angiosperms. The level of 1992 P resorption was similar to those reported for a wide range of gymnosperms and greater than those reported for most angiosperms. N fertilization allowed Gingko trees to maintain typical foliar N dynamics even during a persistent drought during which foliar P dynamics were significantly altered.

Rapin, J. R., P. Provost, et al. (1994). Effects of Repeated Treatments with an Extract of Ginkgo-Biloba (Egb-761) and Bilobalide on Glucose-Uptake and Glycogen-Synthesis in Rat Erythrocytes - an Ex-Vivo Study. Drug Development Research. Mar 31(3): 164-169.

The metabolic action of an extract of Ginkgo biloba (EGb 761) has been examined in an ex vivo study of rat erythrocytes. Oral administration of EGb 761 (100 mg/kg/day) for 5 days to Wistar rats caused an increase in the in vitro uptake of glucose by erythrocytes, especially in high-glucose (13.32 mM) medium, an effect that was associated with an increase in intracellular energy metabolism and reflected as a significant reduction in free glucose concentration. In contrast, the lactate concentration of the erythrocytes and lactate release to the bathing medium were not modified. Conversion of glucose into glycogen was significantly increased in the erythrocytes of EGb 761-treated animals. Taken together, these findings indicate that in vivo administration of EGb 761 exerts an action favoring the transformation of glucose into glycogen, its storage form. Oral administration of the EGb 761 constituent bilobalide (4 or 8 mg/kg/day) for 5 days caused similar changes in the uptake of glucose and its conversion into glycogen. However, in contrast to the total extract, bilobalide treatment did not increase the energy-yielding consumption of glucose.

Doly, M., B. Bonhomme, et al. (1994). Enhancement of Retinal Tolerance to Glucose by Administration of a Ginkgo-Biloba Extract (Egb 761). Investigative Ophthalmology And Visual Science. Mar 35(4): 1587-1587.

Droylefaix, M. T., M. Doly, et al. (1994). Evidence of the Involvement of Oxygen-Free Radical in Experimental Diabetic-Retinopathy - Protective Effect of a Ginkgo-Biloba Extract (Egb-761). Investigative Ophthalmology And Visual Science. Mar 35(4): 1593-1593.

Misra, S. and M. Green (1994). Legumin-Like Storage Polypeptides of Conifer Seeds and Their Antigenic Cross-Reactivity with 11s Globulins from Angiosperms. Journal Of Experimental Botany. Feb 45(271): 269-274.

The aim of the present work was to investigate the homology of seed storage proteins in a wide variety of conifers for most of which the gene sequences are not yet identified. Rabbit antiserum antibodies against the purified 57 kDa non-reduced crystalloid protein complex of white spruce seed were obtained. The antibodies were used in the immunobrot assays with seed proteins of various members of Pinaceae; Ginkgo biloba, and several representatives of angiosperms. Under reducing conditions, 35 kDa and 22 kDa range polypeptides, homologous to white spruce crystalloids, were identified in all members of the Pinaceae examined except Abies amabilis and Tsuga heterophylla. In Ginkgo the antibodies cross-reacted with the previously reported legumin-like polypeptides of 28, 20 and 13 kDa range. In angiosperms, the crystalloid antibodies cross-reacted to the 35 kDa and 20 kDa range of 11S storage polypeptides of Brassica napus, Ricinus communis and Nicotiana tabacum. No cross-homology was observed with the polypeptides of Phaseolus vulgaris, Glycine max, Pisum sativum, and Medicago sativa seeds. Based on the antigenic homology the wide occurrence of legumin-like proteins in gymnosperms is confirmed. Also, the pattern of serological reactivity suggests that the legumin-like proteins of gymnosperms are more closely related to members of Euphorbiaceae, Brassicaceae and Solanaceae than to those of the Fabaceae.

Holgers, K. M., A. Axelsson, et al. (1994). Ginkgo-Biloba Extract for the Treatment of Tinnitus. Audiology . Mar Apr 33(2): 85-92.

Previous studies have shown contradictory results of Ginkgo biloba extract (GBE) treatment of tinnitus. The present study was divided into two parts: first an open part, without placebo control (n = 80), followed by a double-blind placebo-controlled study (n = 20). The patients included in the open study were patients who had been referred to the Department of Audiology, Sahlgren's Hospital, Goteborg, Sweden, due to persistent severe tinnitus. Patients reporting a positive effect on tinnitus in the open study were included in the double-blind placebo-controlled study (20 out of 21 patients participated). 7 patients preferred GBE to placebo, 7 placebo to GBE and 6 patients had no preference. Statistical group analysis gives no suppport to the hypothesis that GBE has any effect on tinnitus, although it is possible that GBE has an effect on some patients due to several reasons, e.g. the diverse etiology of tinnitus. Since there is no objective method to measure the symptom, the search for an effective drug can only be made on an individual basis.

Pietta, P., R. M. Facino, et al. (1994). Thermospray Liquid-Chromatography Mass-Spectrometry of Flavonol Glycosides from Medicinal-Plants. Journal Of Chromatography A. Feb 661(1-2): 121-126.

High-performance liquid chromatography interfaced with thermospray mass spectrometry is described for the identification of various flavonol glycosides from Ginkgo biloba, Calendula officinalis and Tilia cordata. Thermospray ionization gave parent species with few and diagnostic fragment ions, thus allowing structure elucidation as well as discrimination between different glycosylation sites.

Vismer, H. F. and A. Eicker (1994). Growth of Human Pathogenic Isolates of Sporothrix-Schenckii on Indigenous and Exotic Wood Species in South-Africa. Mycological Research. Jan 1: 121-124.

Sporotrichosis in South Africa is associated with soil and plant material contaminated with Sporothrix schenckii. In gold mines, workers contract the disease from contaminated eucalyptus and wattle wood props underground. The natural occurrence of the fungus on plants or decaying vegetation is not well understood and the factors determining its occurrence in soil are still obscure. In an attempt to determine the ability of S. schenckii to grow on wood, sapwood samples of 37 exotic and indigenous species were inoculated with pathogenic isolates of the fungus and its growth documented for 90 d. Fungal growth on the wood was also examined microscopically. S. schenckii grew best on some exotic wood species, particularly Eucalyptus grandis, E. sideroxylon, Cinnamomum camphora, Acacia melanoxylon and Ginkgo biloba. It grew on relatively few of the other wood species. No obvious correlation was found between its abundance of growth and the wood species on which it grew. Its microscopic features remained characteristic.

Vasseur, M., T. Jean, et al. (1994). Effects of Repeated Treatments with an Extract of Ginkgo-Biloba (Egb 761), Bilobalide and Ginkgolide-B on the Electrical-Activity of Pancreatic Beta-Cells of Normal or Alloxan-Diabetic Mice - an Ex-Vivo Study with Intracellular Microelectrodes. General Pharmacology. Jan 25(1): 31-46.

1. The effects of repeated (5-day) treatments with an extract of Ginkgo biloba leaves (EGb 761), bilobalide, and ginkgolide B on the in vitro electrical activity of insulin-secreting pancreatic beta cells of mice have been examined using intracellular microelectrodes.

Oyama, Y., P. A. Fuchs, et al. (1994). Myricetin and Quercetin, the Flavonoid Constituents of Ginkgo-Biloba Extract, Greatly Reduce Oxidative-Metabolism in Both Resting and Ca2+-Loaded Brain Neurons. Brain Research. Jan 635(1-2): 125-129.

The antioxidant action of myricetin and quercetin, the flavonoid constituents of the extract of Ginkgo biloba (EGb), on oxidative metabolism of brain neurons dissociated from the rats was examined using 2',7'-dichlorofluorescin (DCFH) which is retained within the neuron and then is oxidized by cellular hydrogen peroxide to be highly fluorescent. Incubation with myricetin or quercetin reduced the oxidation of DCFH in resting brain neurons, more profoundly than EGb. Myricetin decreased the oxidative metabolism at concentrations of 3 nM or more. It was 10 nM or more for the case of quercetin. Incubation with each flavonoid constituent also reduced the Ca2+-induced increase in the oxidative metabolism without affecting the cellular content of DCFH or the intracellular concentrations of Ca2+ Such an antioxidant action of myricetin or quercetin may be responsible for a part of the beneficial effects of EGb on brain neurons suject to ischemia.

Danieli, B. and A. Bertario (1993). Chemoenzymatic Synthesis of 6''-O-(3-Arylprop-2-Enoyl) Derivatives of the Flavonol Glucoside Isoquercitrin. Helvetica Chimica Acta 76(8): 2981-2991.

A chemo-enzymatic approach to some 6''-O-(3-arylprop-2-enoyl) derivatives of the flavonol glucoside isoquercitrin (2a) was explored to overcome the inability to directly introduce these acyl moieties by an enzyme-catalyzed reaction of 2a with the corresponding activated esters. This new approach was based on the regioselective introduction of a methyl malonate residue at the CH2OH of the sugar moiety by catalysis with the protease subtilisin (--> 22a). The mixed diester 22a was then subjected to chemoselective hydrolysis of the methoxycarbonyl function by another enzyme, biophine esterase (--> 23). Finally, the malonic monoester 23 was reacted in a Knoevenagel-type condensation with benzaldehyde, 4-hydroxybenzaldehyde, or 4-hydroxy-3-methoxybenzaldehyde to afford the target 6''-O-(3-arylprop-2-enoyl) isoquercitrins 2b-d.

Droylefaix, M. T., M. E. Szabo, et al. (1993). Ischemia and Reperfusion-Induced Injury in Rat Retina Obtained from Normotensive and Spontaneously Hypertensive Rats - Effects of Free-Radical Scavengers. International Journal Of Tissue Reactions Experimental And Clinical Aspects 15(2): 85-91.

The authors have studied the effects of free radical scavengers, superoxide dismutase (SOD) and extract of Ginkgo biloba (EGb 761, flavone-rich extract) on ion shifts (Na, K and Ca) induced by ischaemia and reperfusion in rat retina obtained from normotensive and spontaneously hypertensive rats. Eyes were subjected to 90 min of ischaemia by occlusion of the retinal artery, followed by 4 and 24 hours of reperfusion, SOD (15,000 U/kg, i.v.) or EGb 761 (50 mg/kg, per os) was administered in a daily dose for 10 days. In the drug-free control groups, 90 min of ischaemia significantly increased tissue Na gains from their pre-ischaemic control values of 63 +/- 7 muM/g dry weight (in retina obtained from normotensive rats) and 76 muM/g dry weight (in retina obtained from hypertensive rats) to 89 +/- 9 muM/g dry weight and 101 +/- 7 muM/g dry weight, respectively. During reperfusion, a further elevation was found in retinal Na in both the normotensive and hypertensive groups, Probably, because of the ischaemia-induced inhibition of Na-K-ATPase, retinal K loss was detected after ischaemia and reperfusion, respectively. An accumulation of retinal Ca was measured after ischaemia and reperfusion in the normotensive and spontaneously hypertensive groups. Both free radical scavengers significantly reduced the maldistribution of ions induced by ischaemia and reperfusion, but the effectiveness of drugs was more evident in normotensive than hypertensive groups. The present results indicate that the elimination of free radicals by free radical scavengers may reduce, probably via an indirect mode, the reperfusion-induced ionic imbalance and improve the ionic homeostasis in injured retinal cells obtained from normotensive and spontaneously hypertensive rats.

Ramassamy, C., F. Girbe, et al. (1993). Ginkgo-Biloba Extract Egb-761 or Trolox-C Prevent the Ascorbic Acid/Fe2+ Induced Decrease in Synaptosomal Membrane Fluidity. Free Radical Research Communications 19(5): 341-350.

The ability of synaptosomes, prepared from striata, to take up H-3-dopamine declined rapidly during incubation at 37-degrees-C, in an oxygenated Krebs-Ringer medium with 0.1 mM ascorbic acid. Ascorbic acid was responsible for this decrease. Its effectiveness after a 60 min incubation was concentration dependent from 1 muM and virtually complete for 0.1 mM. Furthermore, a decrease of synaptosomal membrane fluidity was revealed by measurements of fluorescence polarization using 1,6-diphenyl-1,3,5-hexatriene. This decrease was potentiated by Fe2+ ions (1 muM). In contrast, it was prevented by the Fe2+ ion chelator, desferrioxamine (0.1 mM), by the Ginkgo biloba extract EGb 761 [2-16 mug/ml], as well as by the flavonoid quercetin (0.1 muM). This preventive effect was shared by trolox C (from 0.1 mM). It is concluded that peroxidation of neuronal membrane lipids induced by ascorbic acid/Fe2+ is associated with a decrease in membrane fluidity which, in turn, reduces the ability of the dopamine transporter to take up dopamine.

Marcocci, L., J. J. Maguire, et al. (1994). The Nitric Oxide-Scavenging Properties of Ginkgo-Biloba Extract Egb-761. Biochemical And Biophysical Research Communications. Jun 201(2): 748-755.

Ginkgo biloba extract EGb 761 was found to be a scavenger of nitric oxide in in vitro acellular systems, under physiological conditions. EGb 761 competed with oxyhemoglobin for reaction with nitric oxide generated during the interaction Complex I of catalase. An EGb 761 dose-dependent decrease formed in the reaction of oxygen with nitric oxide produced from nitroprusside was also observed. These data implicate it as a potential therapeutic conditions of altered production of nitric oxide. (C) 1994 Academic Press, Inc.

Choukchoubraham, N., Y. Asakawa, et al. (1994). Isolation, Structure Determination and Synthesis of New Dihydroisocoumarins from Ginkgo-Biloba L. Tetrahedron Letters. Jun 35(23): 3949-3952.

New optically active 8-hydroxy-3-alk(en)yl-3,4-dihydroisocoumarins 2a-c were isolated from Ginkgo biloba L. fruits. The absolute configuration was determined to be R by comparison with both enantiomers of the 8-hydroxy-3-tridecyl-3,4-dihydroisocoumarin synthesized from optically active epichlorhydrins.

Mouren, X., P. Caillard, et al. (1994). Study of the Antiischemic Action of Egb 761 in the Treatment of Peripheral Arterial Occlusive Disease by Tcp(2) Determination. Angiology . Jun 45(6): 413-417.

In a randomized, placebo-controlled, double-blind, parallel study of 20 patients, the antiischemic effect of EGb 761 (Ginkgo biloba Extract) was studied by measuring the transcutaneous partial pressure of oxygen (TcPo2) during exercise. Transcutaneous oximetry during exercise provides a good, noninvasive estimation of local arterial perfusion and constitutes a real index of local and regional capillary perfusion.Twenty patients between the ages of forty-four and seventy-three years suffering from claudicating atherosclerotic arterial occlusive disease in stage II according to the Leriche and Fontaine classification, diagnosed for more than a year and stable for three months, were included.The eligible patients received placebo for fifteen days under single-blind conditions. At the end of this preinclusion period, the eligibility criteria were checked and the patients were randomized to two treatment groups. The first group received 320 mg per day of EGb 761 for four weeks and the second group received placebo. The treadmill walking test was performed under standardized conditions at the same time of day and by the same investigator.In a comparison of the differences before and after treatment, the areas of ischemia decreased by 38% in the EGb 761 group but remained essentially stable (+5%) in the placebo group. This difference between groups is significant (F [1.18]=4.91; P=0.04) and the 95% confidence interval for the difference ranges from 0.89 to 3.87.This study confirmed significantly the rapid antiischemic action of EGb 761 and its value in the management of peripheral arterial occlusive disease at the stage of intermittent claudication.

Haramaki, N., S. Aggarwal, et al. (1994). Effects of Natural Antioxidant Ginkgo-Biloba Extract (Egb-761) on Myocardial Ischemia-Reperfusion Injury. Free Radical Biology And Medicine. Jun 16(6): 789-794.

Recently, it was reported that Ginkgo biloba extract (EGb 761), which is known to have antioxidant properties, also has antiarrhythmic effects on cardiac reperfusion-induced arrhythmias. In the present study, effects of EGb 761 on cardiac ischemia-reperfusion injury were investigated from the point of view of recovery of mechanical function as well as the endogenous antioxidant status of ascorbate. Isolated rat hearts were perfused using the Langendorff technique, and 40 min of global ischemia were followed by 20 min of reperfusion. EGb 761 improved cardiac mechanical recovery and suppressed the leakage of lactate dehydrogenase (LDH) during reperfusion. Furthermore, EGb 761 diminished the decrease of myocardial ascorbate content after 40 min of ischemia and 20 min of reperfusion. Interestingly, EGb 761 also suppressed the increase of dehydroascorbate. These results indicate that EGb 761 protects against cardiac ischemia-reperfusion injury and suggest that the protective effects of EGb 761 depend on its antioxidant properties.

Masson, F., C. Neliat, et al. (1994). Effects of an Extract of Ginkgo-Biloba on the Action-Potential and Associated Transmembrane Ionic Currents in Mammalian Cardiac Myocytes - Inhibition of Isoproterenol-Induced Chloride Current. Drug Development Research. May 32(1): 29-41.

Ventricular myocytes of guinea pig heart were used to examine the effects of an extract of Ginkgo biloba (EGb 761) on the action potential and individual transmembrane ionic currents. Electrophysiological events were recorded using the ''whole-cell'' configuration of the patch-clamp technique. A systematic analysis of the data revealed that EGb 761 (5-50 mu g/ml) did not affect the normal action potential or the various ionic currents involved in its generation; i.e., fast inward sodium current (I-Na), inward calcium currents (I-CaT and I-CaL), delayed outward potassium current (I-K), inward rectifying potassium current (I(K)1), and ATP-sensitive potassium current (I-K-ATP) evoked by 2,4-dinitrophenol (2,4-DNP). However, EGb 761 (greater than or equal to 5 mu g/ml) elicited a pronounced concentration-dependent and reversible inhibition of isoproterenol-induced CI- current (I-Cl), the maximal effect being observed at 50 mu g/ml. This current may be significantly involved in sympathetic hyperactivity, hypoxia, and ischemia, pathophysiological conditions for which EGb 761 offers therapeutic benefit. The basic mechanism(s) underlying the inhibitory effect of EGb 761 on I-Cl and the constituent(s) of EGb 761 responsible for this action remain to be identified, but it seems clear, from results which showed that neither ginkgolide B (50-500 ng/ml) nor bilobalide (150-1,500 ng/ml) influenced this current, that a terpenoid constituent of EGb 761 is probably not involved. (C) 1994 Wiley-Liss, Inc.

Ozutemi, A. O., T. Tanyalcin, et al. (1994). The Protective Effect of Ginkgo-Biloba Extract on Ethanol-Induced Gastric Damage in Rats. GASTROENTEROLOGY 106(4): Suppl.

Xie, Y. M., D. R. Robert, et al. (1994). Selective Carbon-13 Enrichment of Side-Chain Carbons of Ginkgo Lignin Traced by Carbon-13 Nuclear-Magnetic-Resonance. Plant Physiology And Biochemistry. Mar Apr 32(2): 243-249.

Although carbon 13 nuclear magnetic resonance spectroscopy (C-13-NMR) is widely used in lignin structural studies, serious difficulties are encountered in the assignments of C-13 signals because of their extensive overlaps resulting from the complex structure of lignin and of delicate detection of minor structures. To overcome these difficulties, specifically C-13-enriched precursors of lignin biosynthesis, coniferin-[side chain-beta-C-13] and coniferin-[side chain-gamma-C-13], were administered to growing stems of ginkgo (Ginkgo biloba). The NMR analysis of the milled wood lignins isolated from the newly formed xylem showed that selective enrichment of specific carbons of protolignin in the cell wall was achieved without seriously disturbing the lignin biosynthesis. The presence of saturated methylene side chains in the protolignin was shown for the first time by this selective enrichment technique in combination with NMR analysis.

Yoshioka, K. (1994). Changes in Saccharides and Enzyme-Activities Related to Metabolism of Saccharides During Growth and Development of Ginkgo Nut (Ginkgo-Biloba L) on Tree. Journal Of The Japanese Society For Food Science And Technology Nippon Shokuhin Kagaku Kogaku Kaishi 41(4): 259-264.

Changes in carbohydrates and related enzyme activities of ginkgo nut (Ginkgo biloba L.) on tree were investigated during growth and development. A tremendous increase in starch contents of the endosperm found at the beginning of pit-hardening. The increasing rate, however, gradually reduced thereafter and starch contents reached to a plateau at full ripening, the level of which was 35%. In contrast, total sugar contents in endosperm stayed relatively low level (approximately 4%) until first appearance of the skin surface yellowing. Thereafter, it rose continuously until full ripening, the level of which was about 7%. Biphasic increases of maltase, sucrase and sucrose synthetase activities during growth and development of ginkgo nut on the tree were noted both in endosperm and episperm. The first peaks were coincident with the stage of completion of pit-hardening and second increases corresponded with yellow color development of skin surface. These biochemical changes in connection to flavor during growth and development of ginkgo nut was discussed.

Stein, D. G., M. M. Glasier, et al. (1993). Conceptual and Practical Issues in the Pharmacological Treatment of Brain Injury. Journal Of Neural Transplantation And Plasticity. Jul Sep 4(3): 227-237.

It is only within the last ten years that research on treatment for central nervous system (CNS) recovery after injury has become more focused on the complexities involved in promoting recovery from brain injury when the CNS is viewed as an integrated and dynamic system. There have been major advances in research in recovery over the last decade, including new information on the mechanics and genetics of metabolism and chemical activity, the definition of excitotoxic effects and the discovery that the brain itself secretes complex proteins, peptides and hormones which are capable of directly stimulating the repair of damaged neurons or blocking some of the degenerative processes caused by the injury cascade. Many of these agents, plus other nontoxic naturally occurring substances, are being tested as treatment for brain injury. Further work is needed to determine appropriate combinations of treatments and optimum times of administration with respect to the time course of the CNS disorder. In order to understand the mechanisms that mediate traumatic brain injury and repair, there must be a merging of findings from neurochemical studies with data from intensive behavioral testing.

Laquerriere, A., O. Jin, et al. (1994). Comparative Effect of B-Fgf, Gk11 and Gingko-Biloba Extracts on Peripheral-Nerve through a Collagen Guide over a Long-Distance. NEUROLOGY 44(4): Suppl.

Huguet, F., K. Drieu, et al. (1994). Decreased Cerebral 5-Ht1a Receptors During Aging - Reversal by Ginkgo-Biloba Extract (Egb-761). Journal Of Pharmacy And Pharmacology. Apr 46(4): 316-318.

Investigation of [H-3]8-hydroxy-2(di-n-propylamino)tetralin binding to 5-HT1A receptors in cerebral cortex membranes of Wistar rats showed that the maximal number of binding sites (B-max) was reduced significantly (22%) in aged (24-month-old) as compared with young (4-month-old) animals. Chronic treatment with Ginkgo biloba extract did not alter binding in young rats but increased binding density significantly (33%) in aged rats. These results confirm previously described age-related 5-hydroxytryptaminergic alterations. Together with data in the literature, they also suggest a restorative effect in aged rats, associated with decreased receptor density resulting from the protective action of Ginkgo biloba extract treatment on neuronal membrane.

Eschrich, W. and J. Fromm (1994). Evidence for 2 Pathways of Phloem Loading. Physiologia Plantarum. Apr 90(4): 699-707.

The minor veins of small leaf discs, punched out of mature leaves and incubated in C-14-sucrose solution, appear labeled in macro- and microautoradiographs. Discs with a labeled vein pattern and with labeled sieve tubes in microautoradiographs were found in Beta vulgaris, Vicia faba, Gomphrena globosa and Antirrhinum majus. However, in several other plant species, minor veins appeared unlabeled in macroautoradiographs when the discs were incubated in C-14-sucrose. Mesophyll cells (Acer pseudoplatanus, Juglans regia, Fagus sylvatica, Syringa vulgaris, Laburnum anagyroides), bundle-sheath cells of major veins (Salix viminalis, Robinia pseudoacacia, Commelina communis) or epidermal layers (Ginkgo biloba, Chlorophytum comosum) appeared labeled. Lack of radioactivity in sieve tubes of this latter group was confirmed by microautoradiography. Using C-14-glucose instead of C-14-sucrose, leaf discs of Beta vulgaris showed no labeled vein pattern and in microautoradiographs the sieve tubes appeared unlabeled. In view of the by-pass phloem loading, this study provides evidence for two pathways of phloem loading.

Fontanel, A., I. Serraf, et al. (1994). Regeneration in Ginkgo-Biloba L - Induction of Embryogenesis from Megagametophyte According to the Development Stage. Comptes Rendus De L Academie Des Sciences Serie Iii Sciences De La Vie Life Sciences. Feb 317(2): 149-155.

Embryogenesis was induced from megagametophyte of ginkgo biloba L. Proembryos were obtained using various media, from prothallus of various trees. The best production of proembryos was observed from explants collected 8 to 11 weeks after pollination. The development of haploid proembryos was observed up to heart-shaped stage.

Pritzhohmeier, S., T. I. Chao, et al. (1994). Effect of in-Vivo Application of the Ginkgo-Biloba Extract Egb-761 (Rokan(R)) on the Susceptibility of Mammalian Retinal Cells to Proteolytic-Enzymes. Ophthalmic Research. Mar Apr 26(2): 80-86.

Lesions, inflammations, or degenerative insults of the human retina are accompanied by the release of proteolytic enzymes. Their deleterious effect may be enhanced by the release of free radicals. Ginkgo biloba extracts are known to exert protective influences against the action of free radicals, and this prompted us to ask whether the application of such extracts might protect retinal tissue against proteolytic damage. Eighteen adult rabbits were fed for 3 weeks (+/- 3 days) with 40 mg/kg of G. biloba extract (EGb 761) or a terpene-free fraction of this extract, dissolved in their drinking water. Twelve control rabbits received no G. biloba extract. The animals were then euthanatized and their retinae isolated. After appropriate enzymatic treatment, the tissue was dissociated and the number of isolated Muller cells counted as an indication of the strength of the proteolytic effects. There was a significant protective action of EGb 761: in an average control rabbit 5,200 cells per milligram retinal tissue were isolated; application of EGb 761 markedly reduced this number to 2,500 (terpene-free fraction; CP 205) or 3,050 (terpene-containing fraction). It is concluded that G. biloba extracts may have a significant therapeutic value in cases of retinal damage.

Hoffmann, F., C. Beck, et al. (1994). Ginkgo Extract Egb-761 (Tebonin(R)) Haes Versus Naftidrofuryl (Dusodril(R)) Haes - a Randomized Study on Sudden Hearing-Loss Therapy. Laryngo Rhino Otologie. Mar 73(3): 149-152.

80 patients with idiopathic sudden hearing loss existing no longer than 10 days were included in a randomised reference-controlled study. The therapeutic value of Ginkgo EGb 761 (Tebonin(R)) + HAES was compared to that of Naftidrofuryl (Dusodril(R)) + HAES. The main mechanisms of action of EGb 761 are a vasoregulating activity (increased blood flow), the platelet activating factor antagonism and a prevention of membrane damage caused by free radicals (7). Naftidrofuryl has antiserotonergic and therefore vasodilatory properties (12). The statistical analysis of the audiometric data was performed in measuring the relative hearing gain as described by Eibach 1979 (4). After one week of observation, 40% of the patients in each group showed a complete remission of hearing loss. This was also observed by other authors who had compared other drugs (13,15). Therefore, in these cases, it is most likely that spontaneous recovery is the most important factor. After two and three weeks of observation, measuring the relative hearing gain, there was a significant borderline benefit of EGb 761 (p = 0,06) without any side effects. Some patients of the reference group developed side effects such as orthostatic dysregulation or headache or sleep disturbances. Minimising side effects should be one of the most important goals in therapy of sudden hearing loss until the efficiency of infusion therapy is proved.

Meurergrimes, B. and D. W. Stevenson (1994). The Biflavones of the Cycadales Revisited - Biflavones in Stangeria-Eriopus, Chigua-Restrepoi and 32 Other Species of Cycadales. Biochemical Systematics And Ecology. Sep 22(6): 595-603.

The biflavone patterns in leaves of 34 species of the Cycadales representing all of the 11 genera in three families were investigated. Known biflavones were isolated from Gingko biloba and Dioon spinulosum, and then used as internal standards for HPLC and TLC analysis of leaf extracts. Biflavone patterns in the new genus Chigua were found to be closely related to those detected in Zamia. Four specimens of Stangeria eriopus were all found to exhibit complex patterns of biflavones. Most members of the Zamiaceae were found to contain hinokiflavone. A first attempt of the chemotaxonomic re-evaluation of biflavone patterns in the Cycadales is made.

Fortun, A., A. Khalil, et al. (1994). Effect of Egb(761) on the Peroxidation of Human Low-Density Lipoproteins (Ldl) Initiated by Oxyradicals Generated by Water Radiolysis. Journal De Chimie Physique Et De Physico Chimie Biologique. Jul Aug 91(7-8): 1078-1084.

Human low-density lipoproteins (LDL) aqueous solutions (3 g/l, 10(-2) M sodium phosphate buffer, pH 7) have been irradiated in the presence of Ginkgo biloba extract (EGb(761)) in order to determine the protective effect of EGb(761) against lipid peroxidation. Oxy free radicals, OH. and O-2(.-), were simultaneously produced from water radiolysis and their action on LDL was followed by determining the vitamin E and beta-carotene contents, the formation of TBARS (thiobarbituric acid reactive substances) and conjugated dienes. Two concentrations of EGb(761) (15 and 30 mu g/ml) have been studied, the better antioxidant effect being obtained for the highest EGb(761) concentration.

Guerrant, R. L. (1994). 12 Messages from Enteric Infections for Science and Society. American Journal Of Tropical Medicine And Hygiene. Jul 51(1): 26-35.

Diarrheal diseases hold profound messages as well as opportunities that range from public health to basic science. From the spread of cholera around the world, we are reminded of the global impact of tropical diseases, that disease may provide a litmus test for poverty to drive a sanitary revolution, that disease spread may be worsened by political denial, and that many ecologic and epidemiologic secrets such as interepidemic microbial niches remain poorly understood. Diarrheal diseases other than cholera teach us that heavy disease burdens do not control population growth but are associated with population overgrowth (i.e., improved health is key to controlling the population explosion), the societal impact of diarrhea morbidity may exceed even that of its mortality, that new agents continue to emerge, and that nosocomial diarrhea is an underrecognized threat in our hospitals. Finally, from the laboratory of the developing world also come messages for basic science. Microbial toxins continue to elucidate a new understanding of cell signaling, and mechanisms once thought to be clear (such as that of cholera toxin) now appear much more complex. Traditional remedies hold new pharmacologic secrets, e.g., such as gingko extracts that inhibit platelet-activating factor. Finally, from basic physiology can come widely applicable practical solutions such as oral rehydration therapy and simplified diagnostics for inflammatory diarrhea. Health problems such as diarrheal diseases that plague the disadvantaged are linked to population overgrowth and provide some of the greatest challenges to modern science and the industrialized world.

Arahira, M. and C. Fukazawa (1994). Ginkgo 11s Seed Storage Protein Family Messenger-Rna - Unusual Asn-Asn Linkage as Posttranslational Cleavage Site. Plant Molecular Biology. Jul 25(4): 597-605.

By reducing the amount of ginkgo water-soluble polysaccharides, which occupy about 35% of the wet seed mass and interfere with the extraction of RNA, cDNA-quality mRNA was obtained from developing seeds of Ginkgo biloba. Based on the NH2-terminal 17-amino acid sequence and an internal 12-amino acid sequence derived from the basic subunit of ginnacin, 11S-seed storage protein family of ginkgo, two degenerate oligonucleotide primers were synthesized and used for polymerase chain reaction (PCR). The resulting PCR product was used for screening the above endosperm cDNA library, and a plaque carrying the 1614 bp cDNA insert, which contained the entire coding region for a precursor of ginnacin was isolated. This is the first reported cloning of cDNA from ginkgo seeds. The deduced primary sequence is composed of a signal peptide segment (25 amino acid residues) and an acidic subunit (248 residues) followed by a basic subunit (187 residues). It was also found that the post-translational cleavage site in the ginnacin precursor is the Asn-Asn rather than the Asn-Gly bond found in a variety of the major subunit precursors in 11S seed protein family known to date. We showed that a purified soybean extract and an extract of ginkgo seeds can specifically hydrolyze -Asn(248)-Asn(249)- but not -Asn(249)-Val(250)-, in the heptapeptide Gly-Asn(248)-Asn-Val-Glu-Glu-Leu that corresponds to the ginnacin cleavage region.

Monte, M., L. E. Davel, et al. (1994). Inhibition of Lymphocyte-Induced Angiogenesis by Free-Radical Scavengers. Free Radical Biology And Medicine. Sep 17(3): 259-266.

Solid tumors induce an angiogenic response by the host blood vessels to form a new vascular network for the supply of fresh nutrients and oxygen responsible for tumor growth. Furthermore, tumor growth and metastatic spread is abrogated or markedly reduced in the absence of neovascularization. Spleen T lymphocytes from tumor-bearing mice elicit a strong neovascular response. It is well known that certain T cell responses require the presence of active oxygen radicals. Because these metabolites are produced during tumor growth, we studied whether oxygen free radicals play a role in the angiogenesis induction by lymphocytes. In this study, we demonstrated that the administration of a free radical scavenger (EGb-761) to tumor-bearing mice, blocked the angiogenic response and decreased the lung metastatic incidence. On the other hand, when normal lymphocytes were incubated with the xanthine-xanthine oxidase system (X-XO), a known superoxide anion generator, this elicited a dose-response positive angiogenic reaction in normal recipient mice. No angiogenic response was observed in the absence of X-XO, or when EGb-761 or superoxide dismutase (SOD) plus catalase (CAT) were added to the incubation medium. These results suggest that free radicals are involved in some step of the angiogenic process, and that the EGb-761 treatments block this response due to the free radical scavenging activity of this compound.

Vanhoute, H. A., R. H. Busson, et al. (1994). Synthesis of [1-C-14] Dolichoic Acid. Chemistry And Physics Of Lipids. Jun 72(1): 103-107.

Dolichoic acid and [1-C-14] dolichoic acid were synthesized from polyprenol isolated from the leaves of the Ginkgo biloba. Grignard coupling with 3-bromo-2-methylpropyl benzyl ether afforded, after deprotection, the 3-polyprenyl-2-methyl propanol. The alcohol was converted into a mesylate followed by a one-carbon elongation via cyanide and hydrolysis of the nitrile to the acid.

Nixon, K. C., W. L. Crepet, et al. (1994). A Reevaluation of Seed Plant Phylogeny. Annals Of The Missouri Botanical Garden 81(3): 484-533.

Seed plant phylogeny is evaluated using a data set of 46 terminals (taxa) and 103 morphological and anatomical characters. Cladistic analyses using the criterion of parsimony were performed on the complete data set as well as on subsets of the data, e.g., excluding fossils and/or combining various complex taxa into single terminals. The results support the placement of the cycads as the sister group of a monophyletic group that includes several fossil ''seed ferns'' as well as extant Ginkgo, conifers, gnetopsids, and angiosperms. When fossils were included, Bennettitales (cycadeoids) were part of an ''anthophyte'' clade that included gnetopsids and angiosperms. Pentoxylon was a sister taxon to the core anthophyte clade, in some, but not all, of the most parsimonious trees. Caytonia was not found to be closely associated with the anthophyte clade, but instead was often associated as a sister taxon of the glossopterids, and these two taxa were consistently outside of the Ginkgo-conifer-anthophyte clade. In all most parsimonious trees for all analyses, Ephedra was to the outside of a clade that included all angiosperm taxa, Gnetum, and Welwitschia, thus rendering the traditional gnetopsid clade paraphyletic. New information is provided on the morphology of Caytonia and some previous interpretations of homology of the caytonian ''cupule'' are rejected. The effects of sampling, compartmentalization, and polymorphism are explored in these data, showing how different results may be obtained when polymorphic or ''summary'' terminals are used. The need for more work on gnetopsids and fossil taxa is suggested.

Matile, P. (1994). Fluorescent Idioblasts in Autumn Leaves of Ginkgo-Biloba. Botanica Helvetica. Jun 104(1): 87-92.

Towards the end of the senescence period, the foliage of Ginkgo biloba turns into a brilliant golden colour. This is in part due to an outstandingly high retention of carotenoids during the almost complete breakdown of chlorophyll. Besides, a kind of optical brightener, 6-hydroxykynurenic acid, is accumulated in scattered cells of the mesophyll but also of the vascular parenchyma and even in some epidermal cells. Thus, during senescence a group of cells appears to run through a second differentiation which, in the case of mesophyll cells, is characterized by the development of chloroplasts into gerontoplasts and the simultaneous production of brightly fluorescent 6-hydroxykynurenic acid. These cells may be apostrophized as secondary idioblasts.

Bilgihan, A., A. Aricioglu, et al. (1994). The Effect of Egb-761 on Retinal Lipid-Peroxidation and Glutathione-Peroxidase Level in Experimental Lens-Induced Uveitis. International Ophthalmology 18(1): 21-24.

An acute lens-induced necrotizing intraocular inflammation was produced in pigmented guinea pigs. Treatment of these animals by 100 mg/kg/day EGb 761 a free oxygen radical scavenger for 10 days, reduced retinal lipid peroxidation (p > 0.05) and increased the retinal glutathione peroxidase level (p > 0.05). Although not significantly, these findings suggest that EGb 761 could be combined with other antiinflammatory drugs and may be beneficial in the treatment of uveitis.

Tosaki, A., D. T. Engelman, et al. (1994). Ginkgo-Biloba Extract (Egb-761) Improves Postischemic Function in Isolated Preconditioned Working Rat Hearts. Coronary Artery Disease. May 5(5): 443-450.

Background: We studied the effect of preconditioning and Ginkgo biloba extract (EGb 761) in relation to the recovery of contractile function after global ischemia in the isolated working rat heart.Methods: Hearts (n = 12 in each group) were randomly divided into five groups: In group I, hearts were subjected to 30 min of normothermic global ischemia followed by 30 min of reperfusion; in group II, they were subjected to one cycle of preconditioning consisting of 5 min ischemia and 10 min reperfusion before the induction of 30 min of ischemia and 30 min of reperfusion; group III hearts underwent two cycles of preconditioning; group IV hearts underwent three cycles of preconditioning; and group V hearts underwent four cycles of preconditioning before the onset of 30 min ischemia followed by 30 min of reperfusion.Results: Ventricular fibrillation (total) and ventricular tachycardia (no preconditioning) both fell from 100% to 50% (P < 0.05) after four cycles of preconditioning. In relation to ventricular fibrillation, preconditioning significantly reduced the formation of oxygen free radicals, measured by electron spin resonance spectroscopy (ESR), but recovery of cardiac function was low in all preconditioned groups. Because of the relatively low incidence of arrhythmias (50% ventricular fibrillation and 50% ventricular tachycardia) and relatively low cardiac function in Group V, EGb 761, a free-radical scavenger, was chosen to improve myocardial contractile function in preconditioned hearts. Fifty and 100 mg/kg of EGb 761 (per os) significantly improved coronary flow, aortic flow, left ventricular developed pressure (LVDP), and the first derivative of LVDP (LVDdP/dt(max)) in the four-cycle preconditioned group. Thus, after 30 min of reperfusion, aortic flow was improved from 11.6 +/- 0.9 ml/min to 19.7 +/- 1.2 ml/min (P < 0.05) with a dose of 50 mg/kg of EGb 761 and to 22.0 +/- 1.5 ml/min (P < 0.05) with a dose 100 mg/kg of EGb 761, in the four-cycle preconditioned group. During reperfusion, the formation of free radicals was reduced by approximately 50 and 60% using 50 mg/kg and 100 mg/kg of EGb 761, respectively, when compared with the four-cycle preconditioned drug-free control group.Conclusion: We have demonstrated that EGb 761 can improve contractile function after global ischemia in the isolated working rat heart by reducing the formation of oxygen free radicals, and we have shown that this protection is additive to that of ischemia-induced preconditioning.

Richard, M., C. Tremblay, et al. (1994). Chloroplastic Genomes of Ginkgo-Biloba and Chlamydomonas-Moewusii Contain a Chlb Gene Encoding One Subunit of a Light-Independent Protochlorophyllide Reductase. Current Genetics. Aug 26(2): 159-165.

We have cloned and sequenced a Chlamydomonas moewusii chloroplastic DNA fragment that includes a 563 amino-acid open reading frame (ORF563, chlB) presenting 89% amino-acid homology with ORF513 from Marchantia polymorpha. It is also homologous to ORF510 from Pinus thunbergii but includes two insertions absent in both M. polymorpha and P. thunbergii. The derived polypeptide is 54% similar to the product of bchB from Rhodobacter capsulatus, identified as one subunit of a light-independent NADH-protochlorophyllide reductase. We also isolated and sequenced an homologous chloroplastic gene from the gymnosperm Ginkgo biloba. Northern hybridizations performed on RNA isolated from synchronized Chlamydomonas eugametos cells showed higher expression between the tenth hour of light and the eighth hour of darkness, peaking during the first 2 h of darkness.

Hofferberth, B. (1994). The Efficacy of Egb-761 in Patients with Senile Dementia of the Alzheimer-Type, a Double-Blind, Placebo-Controlled Study on Different Levels of Investigation. Human Psychopharmacology Clinical And Experimental. May Jun 9(3): 215-222.

Forty patients diagnosed as suffering from senile dementia of the Alzheimer type received either 80 mg Ginkgo biloba special extract (GBE)* or matching placebo t.i.d. for three months in a randomized, double blind study of the efficacy and tolerance of GBE. The patients were assessed using a test battery at baseline and at 1, 2 and 3 months. The test battery included the SKT (a brief test of cognitive function, memory and attention), the Sandoz Clinical Assessment Geriatric Scale, choice reaction time, saccadic eye movements and EEG. Memory and attention, as measured by the SKT, improved significantly in the active treatment group after one month, as did psychopathology, psychomotor performance, functional dynamics and neurophysiology as measured by the above tests. The drug was well tolerated and no adverse drug reactions were recorded during the trial.

Liang, N. and K. Maruyama (1994). Comparison of Diurnal Patterns of Leaf Conductance and Photosynthetic Capacity in the Leaves of Seedlings of 3 Species. Photosynthetica 30(1): 25-34.

Diurnal variations in leaf conductance for water vapour (g(s)), and in rates of net photosynthesis (P-N) and transpiration (E) were investigated for individual Fagus crenata, Ginkgo biloba and Alnus firma trees during the growing season (May 12, June 3, August 19 and October 22, 1992), to define the effects of main climatic factors limiting the photosynthetic capacity of leaves. Measurements were undertaken at 1 h intervals in fully expanded leaves from 04.00 to 20.00 under sunny day and favourable water supply. Diurnal patterns of g(s) and P-N in F. crenata were similar to G. biloba, showing strong dependence on irradiance in the early morning and early evening, in May, June and August, The maximum values of P-N, g(s) and water-use efficiency (WUE) were recorded at 07.00 to 08.00 when photosynthetically active radiation (PAR) and leaf temperature (T-1) were approximately 1200 mu mol m(-2) s(-1) and below 25 degrees C, respectively. P-N, g(s) and WUE decreased from 08.00 to 13.00 continuously, followed by a slight recovery at about 17.00 and a steep decline until darkness. A. firma remained at maximum PN from 07.00 to 14.00, and P-N, g(s) and E were much higher than for the other two species. The peak of E in all three species always occurred at midday, coincident with maximum PAR and highest T-1. But in October, P-N and E in all three species were highest around noon, also parallel to the maximum PAR and T-1.

Deberdt, W. (1994). Interaction between Psychological and Pharmacological Treatment in Cognitive Impairment. Life Sciences 55(25-26): 2057-2066.

In contrast to other kinds of psychotropic drugs, nootropics or cognition enhancing drugs may be indicated, not for the direct treatment of the pathology itself, but for improving or restoring the remaining brain functions. Brain functions are normally trained during various kinds of non-medical therapy, such as physiotherapy, speech therapy, occupational therapy, memory training etc... In research little attention has been paid to the combination of both kinds of therapeutic approaches, probably because of the important methodological difficulties. This combination however, offers various interesting perspectives: L. ISRAEL examined in two placebo-controlled studies the effects of either 160 mg/d of ginkgo biloba extractum (GBE) or piracetam 2.4 or 4.8 g/d, combined with a memory training program, in nondemented patients complaining of memory problems. The results of both studies suggest that nootropic drug treatment and memory training have each an effect on different cognitive functions and, hence, are complementary. Some functions, like attention/perception in the GBE study and learning in the piracetam study, seem to benefit from both treatments, suggesting a mutually potentiating effect of drug treatment and training. This potentiation is very clear in the treatment of dyslexic children: in a placebo-controlled study piracetam 3.3 g/d, in combination with normal school teaching and more specific logopedic therapy, allowed a normal progression during the full school year in reading accuracy and reading comprehension, while the placebo treated children getting a similar training progressed only with 50%.Recently promising results were obtained in the treatment of dysphasic patients with a combination of speech therapy and piracetam 4.8 g/d, especially when given during the first months after the stroke, or otherwise in combination with an intensive speech training. In both double-blind studies the piracetam treated group improved about 60% more than the group who only got speech therapy and placebo. All these data may be explained by the restorative or enhancing influence of nootropic drugs on neurotransmitter systems closely related to learning and memory functions. E.g. piracetam restores the availability and function of muscarinic and NMDA receptors in aging animals, most probably through a modulation of the psychico-chemical properties of the neuronal membrane such as the membrane fluidity.

Matsui, N., K. Fukushima, et al. (1994). On the Behavior of Monolignol Glucosides in Lignin Biosynthesis .2. Synthesis of Monolignol Glucosides Labeled with H-3 at the Hydroxymethyl Group of Side-Chain, and Incorporation of the Label into Magnolia and Ginkgo Lignin. Holzforschung 48(5): 375-380.

For selective radio-labeling of specific structural units of protolignin in the cell wall, three kinds of precursor of lignin biosynthesis, p-glucocoumaryl alcohol, coniferin and syringin labeled with H-3 at the hydroxymethyl group of side chain (gamma-position) were synthesized, and administered to magnolia and ginkgo trees. The newly formed radioactive lignin gave thioacidolysis products in which radioactivities were distributed not only in the C6-C3 units corresponding to the administered precursor but also other C6-C3 units. These results indicate that the modification of aromatic ring moiety occurs among the intermediates which retain the gamma-H-3. It suggests a new mechanism of modification of aromatic ring may participate in the pathway of lignin biosynthesis.

Rapin, J. R., I. Lamproglou, et al. (1994). Demonstration of the Antistress Activity of an Extract of Ginkgo-Biloba (Egb-761) Using a Discrimination-Learning Task. General Pharmacology. Sep 25(5): 1009-1016.

1. Young(4-month-old) and old (20-month-old) rats, maintained under water restriction, were trained to discriminate to obtain a small amount of drinking water as a reward. Each animal had to learn to press a lever corresponding to a light that was randomly distributed on the left or right.2. Introduction of an auditory perturbation (''stress'') during the discriminative phase of learning modified the capacity and rate of acquisition in both young and old animals, changes that were correlated with increases in plasma concentrations of epinephrine, norepinephrine and corticosterone.3. Stress-induced detrimental changes in both discrimination learning and plasma hormones were suppressed by 20 days of oral treatment with an extract of Ginkgo biloba leaves (EGb 761; 50 or 100 mg/kg/day) in both young and old rats, effects that became statistically significant by the third day of learning (time of maximal acquisition rate).4. EGb 761 treatment was less effective in increasing the percentage of efficient lever presses in old than in young rats, but more effective in decreasing the number of inefficient lever presses and reaction time in the older animals.5. These results indicate that EGb 761 can facilitate behavioral adaptation despite adverse environmental influences, a property that supports its clinical use in treating cognitive impairment, especially in elderly patients.

Hopfenmuller, W. (1994). Proof of the Therapeutic Effectiveness of a Ginko-Biloba Special Extract - Metaanalysis of 11 Clinical-Trials in Aged Patients with Cerebral Insufficiency. Arzneimittel Forschungdrug Research. Sep 2(9): 1005-1013.

Proof of the Therapeutical Effectiveness of a Ginkgo biloba Special Extract/Meta-analysis of 11 clinical trials in aged patients with cerebral insufficiency.Eleven controlled clinical trials were evaluated in a meta-analysis in order to proof the effectiveness of the ginkgo biloba special extract LI 1370 (Kaveri(R) forte).All included studies were placebo controlled randomized double blind studies, using in most of the cases a daily dosage of 150 mg extract. The requirements for the quality of the studies were the basic criteria for the performance of clinical drug tests analysed from the biometrical scope. The analysis of the individual studies revealed that three studies had to be excluded from the meta-analysis according to methodological or objective reasons. In two further studies the evaluation of the physician or the patients was missing, therefore the studies could not be used for the analysis of the ''global effectiveness''.All other studies were comparable with regard to diagnoses, inclusion and exclusion criteria as well as methodology. Therefore a statistical meta-analysis could be performed for them, analysing the parameters ''single symptoms'', total score of clinical symptoms and ''global effectiveness.''For all analyzed single symptoms significant differences could be concluded, indicating the superiority of ginkgo biloba in comparison to placebo. The analysis of the total score of clinical symptoms from all relevant studies indicated that 7 studies confirmed the effectiveness (Ginkgo biloba being better compared to placebo) while only one study was inconclusive (the medications were not different). This relation confirms the therapeutical effectiveness of ginkgo biloba regarding the clinical symptom complex. Finally the parameter ''global effectiveness'' was evaluated. Five studies confirmed this parameter to one study, which was not conclusive. Also this relation indicates clearly the therapeutical effectiveness of ginkgo biloba in comparison to placebo.The biometrical analysis concludes that the treatment with ginkgo biloba reveals a better therapeutical effect compared to placebo, which was evaluated as statistically different.

Dute, R. R. (1994). Pit Membrane-Structure and Development in Ginkgo-Biloba. Iawa Journal 15(1): 75-90.

Pit membrane ontogeny in radial walls of Ginkgo biloba tracheids was followed using transmission electron microscopy. Torus initiation occurs prior to initiation of the pit border and without benefit of a microtubule plexus. The developing pit membrane is associated with masses of wall material located within plasmalemma invaginations. Wall material is added in such a manner as to form a torus with highly irregular surfaces. Margo and torus are traversed by plasmodesmata, whose channels are connected by extensive median cavities. Matrix material is removed from both margo and torus shortly after hydrolysis of the adjacent cytoplasms. Matrix removal begins at the pit membrane surface and is not preferentially associated with the plasmodesmata. Tori in aspirated pit membranes have compacted fibrils, and their fibrillar compaction might reduce permeability to air embolisms.

Buer, C. S. Applications of Optical Manipulation in Plant Biology (Ginkgo Biloba, Agrobacterium Rhizogenes, Agrobacterium Tumefaciens, Nicotiana Tabacum, Laser Microsurgery). 59: 5738.

Measuring small forces in biology is important for determining basic physiological parameters of a cell. The plant cell wall provides a primary defense and presents a barrier to research. Magnitudes of small forces are impossible to measure with mechanical transducers, glass needles, atomic force microscopy, or micropipet-based force transduction due to the cell wall. Therefore, a noninvasive method of breaching the plant cell wall to access the symplastic region of the cell is required. Laser light provides sub-micrometer positioning, particle manipulation without mechanical contact, and piconewton force determination. Consequently, the extension of laser microsurgery to expand an experimental tool for plant biology encompassed the overall objective. A protocol was developed for precisely inserting microscopic objects into the periplasmic region of plant callus cells using laser microsurgery. <italic> Ginkgo biloba</italic> and <italic>Agrobacterium rhizogenes</italic> were used as the model system for developing the optical tweezers and scalpel techniques. Better than 95% survival was achieved after plasmolyzing <italic>G. biloba </italic> cells, ablating a 2&ndash;4 &mu;m hole through the cell wall using a pulsed UV laser beam, trapping and manipulating bacteria into the periplasmic region, and deplasmolyzing the cells. Optical trapping experiments implied a difference existed between the bacteria models. Determining the optical trapping efficiency of <italic>Agrobacterium rhizogenes</italic> and <italic>A. tumefaciens</italic> strains indicated the <italic>A. rhizogenes</italic> strain, ATCC 11325, was significantly less efficiently trapped than strains A4 and ATCC 15834 and the <italic>A. tumefaciens </italic> strain LBA4404. Differences were also found in capsule generation, growth media viscosity, and transmission electron microscopy negative staining implying that a difference in surface structure exists. Calcofluor fluorescence suggests the difference involves an exopolysaccharide. Callus cell plasmolysis revealed Hechtian strands interconnecting the plasma membrane and the cell wall. The spring tension of these strands was measured in normal and cold-hardened <italic>G. biloba</italic> and <italic> N. tabacum</italic> callus cells. There was little change in flexibility between the groups of cultured cells in either species studied. Microspheres were attached to Hechtian strands in normal cultured <italic> Nicotiana tabacum</italic> and the cells were deplasmolyzed and replasmolyzed to determine the fate of Hechtian strands. The microspheres either moved to the plasma membrane and adhered or moved to the cell wall and adhered. The attached microspheres occasionally moved independently on the same strand. Inserted microspheres provided a visual probe to follow physiological events within a plant cell.

Spence, K. E. Effects of Starch Structure on the Enzymatic Resistance of Starch, Viscoelasticity of Starch Gels, and Biodegradability of Starch in Plastics (Ginkgo). 59: 5638.

Starch isolated from mature <italic>Ginkgo biloba</italic> seeds and a commercial normal maize starch were subjected to &alpha;-amylolysis and acid hydrolysis. Ginkgo starch was more resistant to pancreatic &alpha;-amylase hydrolysis than the normal maize starch granules, which became highly pitted and degraded. The chain length distribution of debranched amylopectin of the starches was analyzed by using high performance anion-exchange chromatography equipped with an amyloglucosidase reactor and a pulsed amperometric detector. The chain length distribution of ginkgo amylopectin showed higher amounts of both short and long chains compared to maize starch. Naegeli dextrins of the starches prepared by extensive acid hydrolysis over 12 days demonstrated that ginkgo starch was more susceptible than normal maize to acid hydrolysis. Gingko dextrins also demonstrated a lower concentration of singly branched chains than maize dextrins and debranched ginkgo showed no multiply branched chains. The ginkgo starch displayed a C-type X-ray diffraction pattern, compared to an A-type pattern for maize. Ginkgo starch and maize starch contained 24.0% and 18.4% absolute amylose contents, respectively. Dynamic mechanical analysis (DMA) was used to examine the effects of retrogradation and chemical modification of the viscoelastic properties of starch gels. The viscoelastic properties of gels produced from maize starch, potato starch and monophosphorylated maize starch were studied. Maize starch gels exhibited greater elastic character than potato starch, which formed weak gels. Storage at 4&deg;C promoted retrogradation and an increased modulus. The modulus in modified maize starch decreased as the level of phosphorylation increased. Thermal scans (from 25&deg;C to 100&deg;C) on gels stored up to 504 h showed a decrease in modulus and the development of a peak in the loss tangent (tan D) between 43&deg;C to 64&deg;C for gels with low modification. Highly phosphorylated starch demonstrated limited retrogradation. Starch has been shown to be a useful component for the manufacture of biodegradable plastics. Plastics produced from blends of maize starch and soy protein were determined to be biodegradable in marine and soil environments. Respirometric studies, measuring CO₂ evolution, showed the protein/starch plastics to have a faster rate of biodegradation than that of the individual raw materials. Native starch granules demonstrated a longer lag phase to biodegradation than processed starch in the plastics and this was attributed to the partially-crystalline granule being more resistant to enzymatic and chemical degradation.

Estime, L. A Comparative Study of Polychlorinated Biphenyl (Pcb) Metabolism by Different Plant Species in Vitro (Nicotiana Tabacum, Typha Angustifolia, Simmondsia Chinensis, Nephrolepis Exaltata, Daucus Carota, Ailanthus Altissima, Vetiveria Zizanioides, Ginkgo Biloba). 59: 5761.

Polychlorinated biphenyls (PCBs) have wide industrial usage as dielectric fluids, refrigerants, and plasticizers. The environmental persistence of PCB's and their demonstrated toxicity to animals and humans have made this class of compounds a focal point of environmental concern around the world. Although no longer manufactured in this country, their prior use and disposal have resulted in their accumulation in sediments of streams, rivers, and the food chain. This study was done to determine the capacity of plants from diverse taxonomic groups and habitats to degrade non-recalcitrant and recalcitrant PCBs <italic>in vitro</italic>. During these phytoremediation experiments, cell lines from four dicots, <italic>Nicotiana tabacum, Simmondsia chinensis, Daucus carota, Ailanthus altissima</italic>; one monocot, <italic>Vetiveria zizanioides</italic>; one gymnosperm, <italic>Gingko biloba</italic>; and the leaf fragments from one monocot, <italic>Typha angustifolia</italic>; and one fern <italic>Nephrolepis exaltata</italic>, were tested. The cells were grown in continuous axenic culture at 25C under 12 hr LD photoperiods. Both the callus cell and the leaf fragments were grown separately in liquid culture containing a six congener PCB mixture. Analysis of the extracts from the plants and their media by a gas chromatograph containing an electron capture detector, indicated that all the plants used in this study possess varying capacities to aerobically degrade PCB's of low and high chlorine content. Among the plants tested, the amount of the PCB mixture metabolized was as high as sixty percent.

Lu, M. Z. Genetic Properties of Rapd Markers and Rna Editing in Gymnosperms (Gene Transfer, Phylogenetic). 60: 74.

This thesis is based on results presented in the six accompanying papers (designated I to VI). The first studies (Papers I and II), on RAPD variation in haploid and diploid tissues from individuals, controlled crosses, and populations of Pinus sylvestris (L.), showed that RAPD fragments have a high level of reproducibility. Most of the RAPD fragments amplified were inherited as dominant Mendelian traits. Furthermore, the data showed that when complete genotype information is available, RAPD markers give estimates of genetic parameters similar to those obtained from allozyme data. However, the dominant character of RAPDs limits their usefulness for population genetic analysis of diploid material because gene frequencies must be derived indirectly assuming Hardy-Weinberg equilibrium, which may lead to biased estimates of population differentiation. Analysis described in Paper III involving re-amplification of RAPD bands and further Southern analysis of RAPD profiles revealed that individual RAPD fragments contain additional sequences, but the amount of these is usually too small to produce distortions in the expected segregation proportions. RAPD fragments amplified from P. sylvestris did not appear to be generated from repetitive sequences, and the absence of RAPD bands was not due to the absence of the corresponding sequences in the genome but due to lack of their amplification. Studies discussed in Papers IV to VI concentrated on evaluation of inheritance, evolution and variation of organellar DNA, as summarised in the following paragraph. The inheritance of mitochondrial (mt) DNA in Pinus was confirmed to be strictly maternal. However, the presence of chloroplast (cp) DNA in macrogametophytes and mtDNA in pollen suggests that in Pinus, the elimination of alternative mt- and cpDNA occurs after fertilization. RNA editing of the coxI gene is known to be generally more extensive in gymnosperms than in angiosperms, but the data showed that the coxI sequences of Larix sibirica and Ginkgo biloba were not edited, suggesting that these sequences originated from edited mitochondrial coxI transcripts. Furthermore, in contrast to earlier suggestions based on the analysis of angiosperm mtDNA, the results indicated that there was a high rate of nucleotide substitution of the mt coxI in gymnosperms. Thus, by allowing for free, random accumulation of T-C substitutions, RNA editing can contribute to accelerated sequence divergence. The differences in substitution rate among different lineages may cause bias in phylogenetic analysis. Finally, because of the low number of informative characters, cDNAs may not be suitable for the phylogenetic analysis of closely related species.

Gahagan, K. T. Optical Manipulation of Microparticles and Biological Structures (Vortex Trap). 58: 6646.

We report experimental and theoretical investigations of the trapping of microparticles and biological objects using radiation pressure. Part I of this thesis presents a technique for trapping both low and high index microparticles using a single, stationary focused laser beam containing an optical vortex. Advantages of this vortex trap include the ease of implementation, a lower exposure level for high-index particles compared to a standard Gaussian beam trap, and the ability to isolate individual low-index particles in concentrated dispersions. The vortex trap is modeled using ray-tracing methods and a more precise electromagnetic model, which is accurate for particles less than 10 $\mu$m in diameter. We have measured the stable equilibrium position for two low-index particle systems (e.g., hollow glass spheres (HGS) in water, and water droplets in acetophenone (W/A)). The strength of the trap was measured for the HGS system along the longitudinal and transverse directions. We also demonstrate simultaneous trapping of a low and high index particle with a vortex beam. The stability of this dual-particle trap is found to depend on the relative particle size, the divergence angle of the beam, and the depth of the particles within the trapping chamber. Part II presents results from an interdisciplinary and collaborative investigation of an all-optical genetic engineering technique whereby Agrobacterium rhizogenes were inserted through a laser-ablated hole in the cell wall of the plant, Gingko biloba. We describe a protocol which includes the control of osmotic conditions, culturing procedures, viability assays and laser microsurgery. We succeeded in placing up to twelve viable bacteria into a single plant cell using this technique. The bacteria are believed to be slightly heated by the Gaussian beam trap. A numerical model is presented predicting a temperature rise of just a few degrees. Whereas G. biloba and A. rhitogenes were chosen for this study because of Ginkgo's pharmaceutical importance, only slight modification of the protocol is needed for other plant species.

Wan, Z. The Lower Cretaceous Flora of the Gates Formation from Western Canada (Deciduous). 58: 6458.

The Lower Cretaceous Gates Formation (late Early Albian) of western Canada is a sequence of paralic coal-bearing strata composed of siltstone, sandstone and coal. Macrofossil plants are abundant in the Gates Formation; most fossils are impressions; others include casts and molds of tree trunks. No permineralized fossils are found. The Gates flora consists of bryophytes (Marchantiolites and Thallites), Equisetites, ferns (Gleichenites, Acanthopteris and Coniopteris of Dicksoniaceae, Cladophlebis, Sphenopteris and a new genus), seed-ferns (Sagenopteris and a new genus), conifers (Pityocladus and Pityophyllum of Pinaceae, Athrotaxites and Elatides of Taxodiaceae, Elatocladus), cycads (Chilinia, Ctenis, Pseudocycas and Pterophyllum and two new genera), Gingko and Ginkgoites; leptostrobans (a new genus), Taeniopteris and unidentified angiosperms. In total, 52 species from 28 genera are described, including 5 new genera, 15 new species and 3 new combinations. Most plants of the Gates flora appears to have been deciduous. Only Elatides curvifolia and Elatocladus manchurica are convincingly evergreen. The interpreted paleoclimate based on the Gates flora is strongly seasonal with winter minimum temperature possibly below $-$15$\sp\circ$C. Rainfall appears to have been abundant since coal deposits are common in the Gates Formation. Although low winter minimum temperature appears to be the main factor causing deciduousness of the Gates flora, low winter light levels may have also contributed to the deciduousness of the Gates flora, as the paleolatitude of the study area was situated at 50$\sp\circ$-60$\sp\circ$ N. Three Early Cretaceous floral provinces are recognized: the Arctic Province, which lacks Cheirolepidiaceae; the Equatorial Province, which has Cheirolepidiaceae; and the Antarctic Province, which also lacks Cheirolepidiaceae. Floras similar to the Gates flora have been reported from throughout the Arctic Province, including Montana, the western Interior of Canada, the Bowser Basin of northwestern Canada, Alaska, western Greenland, Spitzbergen, Siberia, northern Mongolia, northeastern China and the Inner Zone of Japan. The Pacific-rim areas are excluded from the Arctic Province. Plant deciduous habit appears to have prevailed within the Arctic Province during the Early Cretaceous.

Bowe, L. M. Seed Plant Evolution: A Study Comparing the Three Plant Genomes and Morphological Data, with Special Emphasis on Mitochondrial DNA (Coxi, Rbcl, Rrna, Angiosperm Origins). 58: 4001.

Efforts to resolve Darwin's "abominable mystery"--the origin of angiosperms-- have led to the conclusion that Gnetophytes are the sister group to Angiosperms. While many morphological characters appear to support this conclusion, it is not supported by molecular evidence from chloroplast and nuclear genes. This study adds a large data set from the slowly-evolving mitochondrial gene, coxI, including sequences from every family of gymnosperms. T to C transitions contribute most of the variation at first and second positions of coxI, and are often the result of a high level of RNA editing--editing allows "synonymous" base substitutions in the DNA that are corrected during mRNA processing. While conifer, angiosperm and cycad sequences appear to require substantial editing, Ginkgo and gnetophyte sequences require little if any; hence the data are analyzed with and without known and putative RNA editing sites. Although editing should not give misleading phylogenetic analyses, it allows T to C substitutions which might be the source of homoplasy in analyses of gymnosperm coxI sequences; also, some sequences may have been processed and reinserted into the genome, becoming processed paralogs. Sequences from all three plant genomic compartments (mitochondria: coxI; chloroplast: rbcL; nucleus: 18S rRNA) are shown to give congruent trees that conflict with the morphological "anthophyte" conclusion. In fact, coxI, 18S rRNA, and combined data (coxI, 18S, and rbcL) parsimony trees have a highly supported alternate topology: a monophyletic gymnosperm clade is sister to the angiosperms. Maximum likelihood and distance trees from all three genes indicate that gnetophytes are sister to the conifers, concurring with some morphological characters, and suggesting that certain characters supporting the anthophyte clade might represent convergences or symplesiomorphies. An initial angiosperm-gymnosperm split supports a pre-Cretaceous angiosperm origin and implies that there is no one extant seed plant group sister to the angiosperms. The relationships among the families of extant conifers have also been elusive, and data from coxI suggests that the oldest extant conifer groups are the Pinaceae, the Podocarpaceae and the Araucariaceae.

Allen, T. B. A Fine Structural Analysis of Chloroplast Developmental Stages in the Fern Davallia Fejeensis with Comparisons to Chloroplasts of Other Major Plant Groups (Gametophyte, Sporophyte, Pogonatum Urnigerum, Woodwardia Virginica, Dennstaedtia Punctilobula, Pinus Strobus, Ginkgo Biloba, Chrysanthemum Leucanthemum). 58: 2216.

Chloroplast development has been widely studied in angiosperms (flowering plants) and gymnosperms (naked seed plants). However, relatively little work on chloroplast ontogenesis, differentiation and division has been done in pteridophytes (ferns). Even less is understood about gametophytic fern chloroplast ultrastructural development, especially in homosporous leptosporangiate ferns which generally release non-green spores from the under-surfaces of their sporophytic leaves or fronds. In this research, chloroplast development was primarily characterized in sequential stages of gametophytic tissues of Davallia fejeensis by transmission electron microscopy. Methods of scanning electron and light microscopy were also used. Duvallia fejeensis was selected for its relatively thin outer spore wall characteristics, its epiphytic nature and production of abundant spores. This research further describes similarities and differences in chloroplast ultrastructure and development between gametophytic and sporophytic chloroplasts of Davallia fejeensis. Comparisons were made to chloroplasts of other major plant groups including, Pogonatum urnigerum (a bryophyte), Woodwardia virginica (Virginia chain fern), Dennstaedtia punctilobula (hay-scented fern), Pinus strobus (white pine) and Ginkgo biloba (two gymnosperms), and Chrysanthemum leucanthemum (an angiosperm). The fine structure of Davallia fejeensis chloroplasts were analyzed in gametophytic tissues. Ungerminated spores contain undifferentiated chloroplasts, few grana and numerous membrane-bound vesicles. Chloroplasts within primary emergent protonemal and apical filament cells contain lobes and constrictions possibly mediating ontogenesis and plastid division. Starch deposits and membrane-bound vesicles are present. Undifferentiated proplastids within mature gametophyte prothallus cells contain single, elongated spans of transverse thylakoids with numerous plastoglobuli. Gametophyte chloroplasts possess elongated, thinly-stacked grana and prolamellar body-like membrane membrane organizations, while sporophyte chloroplasts contain thicker granal thylakoids. Davallia fejeensis spores visibly swell before germination and develop localized green chloroplast clusters. The external spore morphology of Davallia fejeensis, determined by scanning electron microscopy, has characteristics similar to other members of this genus. Specific findings of this research on gametophyte ultrastructure and development in Davallia fejeensis may further link information on chloroplast differentiation and division in the ferns, with other lower plant groups and angiosperms.

Guthrie, G. H. (1343). A High-Resolution Palaeoecological Analysis of an Eocene Fossil Locality from Quilchena, British Columbia. 35(05): 1343.

An exposure of Eocene lake sediments was systematically analyzed to determine the changing distributions of plants, insects and aquatic vertebrates in order to reconstruct local palaeoenvironments. The Quilchena sediments were deposited in a lake formed by faulting, and incorporate an unusually rich and diverse assemblage of fossil impressions. This locality provided data which enabled testing of a previously proposed model designed to identify distance from shore in Early Tertiary lacustrine deposits based on organic remains. Three source areas are proposed for fossils deposited at the site. Upland taxa include rare occurrences of gymnosperms such as Sequoia, Ginkgo, Picea, and Pseudolarix, whose modern relatives are usually associated with well-drained soils. Riparian taxa include a wide range of deciduous trees and shrubs that would have been associated with floodplains and shorelines, as well as abundant insects including Diptera, Hymenoptera, and Coleoptera. Littoral flora include monocots, floating ferns (Azolla), and the swamp trees Taxodium and Glyptostrobus. Fish, aquatic insects, and a single crocodile tooth are also classified as littoral taxa. The strata at this locality comprise two distinct facies; an older fissile platy shale (facies 1), and a younger deposit of blocky shale (facies 2). Marked differences in fossil distributions occur between these facies. Facies 1 is interpreted as an offshore environment with deeper, less turbulent water and facies 2 represents a near-shore location. The transition between facies 1 and 2 is abrupt and several possible interpretations are discussed. The results of this study confirm and expand upon previously proposed distance from shore criteria.

Strode, J. T., III (1041). Impact of Modified Carbon Dioxide Mobile Phases on Detection in Packed-Column Supercritical Fluid Chromatography. 57.

The advantages of supercritical fluid chromatography (SFC) and supercritical fluid extraction (SFE) which utilize supercritical fluids (SF) as the mobile phase are being realized by the scientific community. SF are more advantageous than traditionally used organic solvents because SF exhibits the solvating strength of liquids while maintaining the higher mass transport properties of gases. Currently, the most common SF which is CO$\sb2$ is available in two preparations of pure CO$\sb2$ and helium headspace CO$\sb2.$ SFC of polychromatic hydrocarbons (PAH) was performed with pure carbon dioxide and helium headspace carbon dioxide at various cylinder fill levels. The capacity factors of the PAH's increased when helium headspace carbon dioxide was used as a carrier fluid relative to pure carbon dioxide. As more liquid carbon dioxide was removed from the cylinder, the effect of helium on the solvating power of CO$\sb2$ was reduced because the relative amount of helium dissolved in the liquid phase decreased. Furthermore, the effect of helium headspace carbon dioxide was investigated with methanol-modified carbon dioxide mobile phases for the analysis of steroids. The capacity factors of the steroids increased when helium headspace CO$\sb2$ was used relative to pure CO$\sb2.$ Although two types of carbon dioxide can be utilized, both have found widespread use in packed-column SFC. Unfortunately, the activity of the stationary phase of packed-columns may prevent the elation of moderately polar analytes when using 100% carbon dioxide. The stationary phase activity can usually be overcome by adding a modifier or modifier with an additive. Unfortunately, the introduction of modifier/additive can interfere with the use of most commonly used detectors like the flame ionization detector (FID) and ultraviolet detector (UV). Therefore, a detector is needed in which the modifier/additive does not interfere and detection is possible. Two such detectors are the electron capture detector (ECD) and evaporative light scattering detector (ELSD). Response surfaces were obtained for packed-column SFC-ECD under various detector conditions to optimize the ECD for use with modified CO$\sb2.$ Limits of detection, correlation coefficient, and linear dynamic range were found to vary with increasing amounts of modifier for several nitrogen containing and halogenated compounds. Low detection (pg) was achieved in the presence of 5% methanol-modified CO$\sb2.$ Applications of packed column SFC-ECD to the separation of nitrogen containing compounds extracted from propellants, phenylurea herbicides, and felodipine extracted from a sustained release tablet by SFE are presented. A high performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD) has been modified and interfaced with SFC. The detector performance was evaluated by monitoring the response of several steroids. Specifically, the effect of N$\sb2$ make-up gas flow rate, CO$\sb2$ modifier type, modifier concentration, ELSD orifice size, and detector temperature was determined. As the N$\sb2$ gas flow rate was increased the response of the analyte decreased, but the increased flow improved the peak shape to mimic that seen by ultraviolet detection. Furthermore, increasing detector temperature caused the response of the analyses to decrease. A detection limit of 10 ng or less was determined for progesterone and testosterone using 2% and 20% (v/v) methanol-modified CO$\sb2$ on a Delfabond$\sp\circler$ cyano column (4.6 mm x 15 cm, 5 $\mu m)$ at 150 mL/min and 1000 mL/min decompressed CO$\sb2.$ Using the detector's optimized conditions, the separations of polyethylene glycols and Ginkgo biloba leak extract are reported.

Hoffman, S. W. Mechanisms of Damage and Repair Following Contusion Injury of the Medial Frontal Cortex in Rats (Traumatic Brain Injury, Antioxidants). 56: 4751.

Most experimental studies using cortical contusions have made unilateral sensorimotor cortex injuries. However, the clinical literature indicates that bilateral contusions to the orbital frontal cortex are more common in head injury. The objectives of this dissertation were to: (1) design a better and more reliable model of traumatic brain injury, that would reflect the kinds of injury seen in human traumatic brain injury patients, (2) develop a lipid peroxidation assay that would reliably measure the efficacy of systemically administered antioxidants; (3) investigate actions of antioxidant treatments on enhancement of functional recovery after traumatic brain injury. Bilateral frontal cortical contusion produced reliable and lasting impairments on spontaneous motor activity and on spatial performance in the Morris water maze. Bilateral frontal cortical contusion created a necrotic cavity that was surrounded by various types of glial tissue. Gliosis and neuronal loss was also noted in sites distal to the injury. The diffuse injury mimics what is often observed in human head trauma. Lipid peroxidation enzyme immunoassay at 24 hours postinjury showed a tenfold increase in 8-isoprostaglandin F$\sb{2\alpha}$ (8-isoPGF$\sb{2\alpha};$ a marker for lipid peroxidation) concentration, returning to sham levels 72 hours later. When EGb 761 (an extract of Ginkgo biloba) was given, the rise in 8-isoPGF$\sb{2\alpha}$ was prevented. Subsequent analyses showed that cerebral edema peaked at 24 hours postinjury and remained constant for up to 72 hours postinjury, before resolving by 7 days. EGb 761 reduced edema to sham levels at these time points. Postinjury EGb 761 treatment improved spatial performance of rats with bilateral frontal cortical contusion in the Morris water maze and normalized their spontaneous motor activity. The extract reduced gliosis and neuronal loss in the mediodorsal thalamus, caudate-putamen, and nucleus basalis. To determine if these results were due to its antioxidant properties, we compared EGb 761 to the known free radical scavenger, U-83836E (a tocopherol analog). The anatomical, behavioral, and biochemical effects of U-83836E were the same as EGb 761, suggesting that EGb 761 can also act as an antioxidant. In conclusion, these experiments demonstrated that bilateral frontal cortical contusion is a viable model for the study of traumatic brain injury, and that antioxidant treatments can reduce secondary neuronal injury and improve functional recovery after traumatic brain injury.

He, K. A. N. Phytochemical Investigations of Medicinal Plants from Chile and the Fiji Islands (Baccharis Linearis, Aristotelia Chilensis, Dysoxylum Lenticellare). 56: 2641.

In this dissertation, three different medicinal plants from Chile and the Fiji Islands, Baccharis linearis (R. et P.) Pers, Aristotelia chilensis (Mol.) Stuntz, and Dysoxylum lenticellare Gillespie were chemically studied. Fourteen compounds isolated from Baccharis linearis were identified based on IR, NMR and mass spectroscopic methods. These constituents included three new neo-clerodane type diterpenes, baclinal (1), baclinepoxide (2), and 13-epi-baclinepoxide (3), as well as one new perhydroazulene derivative, baclinic acid (6). The other identified compounds included portulide B (4), jewenol A (5), oleanolic acid (7), stigmasta-7, 22-dien-3$\beta$-ol (8), stigmasta-7, 22-dien-3$\beta$-ol $\beta$-D-glucopyranoside (9), maslinic acid (10), lachnophyllum ester (11), nepetin (12), quercetin 3-methyl ether (13) and werneria chromene (14). With the exception of oleanolic acid, lachnophyllum ester, and werneria chromene, all the other compounds are reported for this species for the first time. Oleanolic acid was isolated as the major component with a yield of 0.3% of dry plant material. Werneria chromene and lachnophyllum ester displayed anti-Mycobacterium tuberculosis activity as well as activity in the brine shrimp test (BST). Six alkaloids isolated from Aristotelia chilensis were identified as aristoteline (15), aristotelinone (16), serratoline (17), aristone (18), 2-epi-aristotelone (19), and aristotelone (20). Serratoline was previously isolated from Aristotelia serrata, a species native to New Zealand. This is the first study that reports serratoline as a natural constituent of A. chilensis from Chile. Another alkaloid, 2-epi-aristotelone, was previously obtained as a synthetic product and is reported here for the first time as naturally occurring. Aristoteline was isolated as the major compound (370 mg) with a yield of only 0.04% as based on dry biomass. Aristoteline showed a weak activity in the brine shrimp test. This work also led to the isolation and characterization of three biflavonoids from Dysoxylum lenticellare. Two biflavonoids were identified as isoginkgetin (21) and bilobetin (22), two of the active components in extracts of Ginkgo biloba, which are used to increase blood-flow and as vascular dilating agents. The third compound was elucidated as the novel natural product robustaflavone 4$\sp\prime$, 7$\sp{\prime\prime}$-dimethyl ether (23).

Chinn, E. E. Isolation of Complementary DNA Sequences and Expression of the Major Light-Harvesting Chlorophyll a/B-Binding Protein Genes from the Gymnosperm Ginkgo Biloba. 55: 5152.

Ginkgo biloba is an ancient gymnosperm and one of the oldest seed-bearing plants. It is the sole living member of the Division Ginkgophyta and has remained unchanged for 200 million years. Traditional and modern methods used to determine lineage have failed to place Ginkgo with certainty on an evolutionary tree. Information regarding sequences and expression patterns of conserved genes and proteins in Ginkgo biloba would help place it on an evolutionary tree with greater confidence. The genes encoding the major light-harvesting chlorophyll a/b-binding proteins (Lhcb) comprise a highly-conserved, nuclear multigene family in higher plants. The genes are subdivided into three classes, termed Type 1, 2, and 3, which are characterized by specific amino acid signature sequences as well as by the number of introns present in the gene. One gene from each of the three classes was isolated and characterized in Ginkgo biloba. Each gene was examined for sequence conservation and expression patterns in different organs and during greening. The Type 1 gene was isolated from a cDNA library prepared with RNA from Ginkgo seed and the Type 2 and Type 3 genes were isolated using the technique of Rapid Amplification of cDNA Ends (RACE). Gene family size was estimated by Southern hybridization and expression patterns of the individual genes were investigated by northern hybridization using gene-specific probes. From analysis of genomic Southern hybridization patterns, the Lhcb family size was estimated to be at least six, a number far fewer than most angiosperms. The deduced amino acid sequences of the isolated genes indicate that the proteins encoded by the Lhcb genes (LHC IIb) are highly conserved when compared with other known LHC IIb sequences. It was discovered that the 3$\sp\prime$ ends of the messenger RNA (mRNA) for the Type 2 and Type 3 genes are differentially processed. Expression of the individual Lhcb genes was examined for organ-specificity and during greening of dark-grown seedlings. Results indicate that these genes are differentially regulated with respect to each other and that both transcriptional and post-transcriptional regulation are probably involved.

Richard, M. Caracterisation Du Gene Chloroplastique Chlb Chez Diverses Especes Vegetales Et Son Implication Pour L'etude De L'evolution Des Plantes Non-Angiospermes (French Text). 55: 4719.

With the development of modern molecular biology techniques, direct sequencing of DNA has become an important source of information for evolutionary studies. The first objective of this work is to identify chloroplastic genes and the function of their products by sequencing DNA fragments known to be expressed in the green alga Chlamydomonas moewusii. The second objective of this work is based on the use of a sequence thus identified as a probe to study the evolution of chloroplastic genomes in land plants and to resolve some phylogenetic uncertainties in non-angiosperm groups. We identified a 563 amino acid open reading frame in the chloroplastic genome of C. moewusii. This ORF563 is very similar to ORF513 from the liverwort Marchantia polymorpha and to ORF510 from the conifer Pinus thunbergii. Most differences, apart from two insertions found in C. moewusii, are silent mutations affecting the third base of some codons. We purified chloroplasts from the gymnosperm Ginkgo biloba and from the fern Nephrolepis exaltata. We isolated DNA and cloned similar sequences from these preparations using C. moewusii ORF563 as probe. The alignment of sequences show, well-conserved regions that are distributed along their whole length. A function for the proteins encoded by these ORFs was identified by their homology with bchB from the purple photosynthetic bacteria Rhodobacter capsulatus. This gene encodes a subunit of a light-independent NADH protochlorophyllide reductase. Northern experiments made with an ORF563 probe and total RNA extracted from synchronized Chlamydomonas eugametos cells suggest that the expression of a homologous gene in this species is independent from light. A portion of this gene was isolated and sequenced by the polymerase chain reaction from total DNA of another green alga, three bryophytes (two mosses and one liverwort), three Microphyllophyta (lycopods), one Arthrophyta (horsetail), three Filicophyta (ferns) and six Pinophyta (gymnosperm). No homologous fragment could be amplified with DNA from Psilotum nudum (Rhynopsida) and Gnetum gnemon (Gnetopsida), as well as with DNA from numerous angiosperm species. The homologous fragments were aligned and then we analyzed with parsimony methods to get an insight into the phylogenetic relationships between the corresponding plant taxonomic groups.

Christrup, J. (1576). Potentials of Edible Tree Nuts in Ontario. 32(06): 1576.

Edaphic and climatic conditions in many parts of Ontario are suitable for the successful cultivation of edible nut-bearing trees and shrubs. Walnuts, pines, oaks, hickories, filberts, chestnuts, beech, pecan, ginkgo and almond are now growing in Ontario. Hardy nut trees will grow where apples grow; some introduced pines with edible nuts have a greater range than the apple; filberts grow to the northwestern edge of the commercial forest. Tree nuts are a perennial crop requiring a minimum of annual maintenance for production of a highly nutritious food. Reasons that nut growing is not more widely practiced include social factors as well as biological and economic factors. A small, but steadily increasing, nut-growing community currently exists in Ontario. Nut growers in Ontario were interviewed to ascertain the problems and successes they have encountered and their future hopes and plans concerning nuts and nut trees. Attitudes towards nut growing by the nut growers and by government agencies are compared. Results indicate a potential for further expansion of nut crops as an industry, especially in southern Ontario, particularly with filberts and walnuts.

Jung, D. K. A Total Synthesis of (+,-)-Bilobalide (Ginkgo Tree, Photocycloaddition). 53: 3483.

A total synthesis of the natural product bilobalide is reported. Bilobalide is a sesquiterpene trilactone isolated from the extract of the Ginkgo tree. The key transformation in the synthesis is a stereoselective enone-olefin photocycloaddition. Other synthetically interesting reactions include a stereoselective aldol condensation, a regioselective Baeyer-Villiger oxidation of a cyclobutanone, and a selective oxidation of a hemi-acetal in the presence of a secondary hydroxyl group.

Jung, D. K. A Total Synthesis of (+,-)-Bilobalide (Ginkgo Tree, Photocycloaddition). 53: 3483.

A total synthesis of the natural product bilobalide is reported. Bilobalide is a sesquiterpene trilactone isolated from the extract of the Ginkgo tree. The key transformation in the synthesis is a stereoselective enone-olefin photocycloaddition. Other synthetically interesting reactions include a stereoselective aldol condensation, a regioselective Baeyer-Villiger oxidation of a cyclobutanone, and a selective oxidation of a hemi-acetal in the presence of a secondary hydroxyl group.

Huh, H. Ginkgolide and Polyprenol Production in Ginkgo Biloba L. Plant and Tissue Cultures. 53: 295.

The ginkgo or maiden-hair tree (Ginkgo biloba L.) contains various chemicals and a few of them are known to be biologically active. Ginkgolides are characteristic compounds of the ginkgo tree and they are extracted from ginkgo leaves or roots with polar solvents. Because these diterpenoids are antagonists to platelet activating factor (PAF) which is an inflammatory autacoid related to various physiological and immunological disorders, their therapeutic effects and activities had been observed in animals and human. Because of the high demand of ginkgolides, many scientists seek to economically produce them biologically or by chemical synthesis. The production of both ginkgolides and polyprenols, another major isoprenoid in ginkgo leaf, was studied in ginkgo seedlings, cuttings, plants and tissue cultures. Light effect and some enzyme inhibitors (AMO-1618, ancymidol, N,N-Dimethyldodecylamine N-oxide and fluridone) involved in sterol and carotenoid synthesis were explored. For determination of polyprenols and ginkgolide, new SFC and an improved GC analysis method were used, respectively. Ontogenical studies showed that the polyprenol and ginkgolide content varied with the season and the ginkgolide content appeared to be dependent upon geographic origin and light. For the first time the ginkgolides were discovered to be present in ginkgo stem, stem bark and root inner tissues and the amount of more hydroxylated ginkgolide C (GKC) was increased with the age of the plant. Ginkgolide B and GKC were present in a greater content than GKA in the root bark or stem bark. The results obtained from rooting experiments with cuttings and embryo-derived root cultures strongly suggest that the ginkgolides are biosynthesized both in leaf and root tissues. Significant amount of ginkgolides were produced from organized cultures, however, the production of ginkgolides in unorganized tissue cultures were barely detectable. In metabolic inhibitor application studies, fluridone, a carotenoid synthesis inhibitor, significantly increased the ginkgolide content in the leaves of ginkgo seedlings, greenhouse plants and approximately five-year-old outdoor trees.

Raubeson, L. A. (1147). Structural Variation in the Chloroplast Genome of Vascular Land Plants. 53.

Structure and organization of land plant chloroplast (cp) DNA is considered highly conserved but few groups have been examined. Aspects of the basic structure and organization, primarily gene order and characteristics of the large inverted repeat, were determined in this study for the chloroplast genomes of representatives of each major extant lineage of vascular land plant: Lycopodium, Selaginella, Isoetes, Equisetum, Psilotum, Botrychium, Marattia, Osmunda, Lygodium, Ginkgo, many conifers, Cycas, Encephalartos, Gnetum, Ephedra, and Welwitschia. Comparisons to bryophyte and angiosperm chloroplast DNA (cpDNA) were made based on the published work of others. Osmunda, Adiantum, Ginkgo, and conifers in the family Pinaceae were the only non-angiosperm vascular plant cpDNAs previously characterized. Strategies were developed to rapidly assess the distribution of structural variants. Physical maps were also generated for some regions of the genome. Data were collected to determine: (1) the distribution of the 30-kbp inversion that differentiates the cpDNA gene order of tobacco and liverwort, (2) the pattern of gene duplications during the extension of the inverted repeat, (3) the pattern of loss of one copy of the inverted repeat in conifer cpDNA, and (4) the distribution of inversions within conifers. The 30-kbp inversion data support the basal placement of the lycopsids within vascular plants and contradict the basal placement of the psilopsids. An unusual derived condition, the anomolous position of ORF2280, is found linking Ginkgo and cycads. The loss of the inverted repeat throughout conifers supports the monophyly of the group, including Taxaceae. Gene duplication data support monophyly of Gnetales and a Gnetales-angiosperm sister-group relationship.

Nairn, C. J., III Small Subunit Ribosomal-Rna Sequences from Ginkgo Biloba and Phylogenetic Inferences from Seed Plant Small Subunit Ribosomal-Rna Data. 52: 31.

Ginkgo biloba is a taxonomically isolated seed plant frequently placed in an evolutionary grade group referred to as gymnosperms. Precise phylogenetic relationships between Ginkgo and other gymnosperm groups remain uncertain. Small subunit ribosomal DNA sequences were isolated from a Ginkgo genomic library. One group of clones represents the small subunit rRNA genes from the major ribosomal repeat of Ginkgo and are present in approximately 16,000 copies in the diploid Ginkgo genome. A representative, Gbr-1000, from this group was subcloned and sequenced. A representative, Gbr-6700, from a second group of clones was also sequenced and contains a ss rRNA-like sequence that is interrupted by a 1.1 kb insert 700 bp into the ss rRNA-like region. These ss rRNA-like sequences are present in approximately 3,400 copies in the Ginkgo genome. The Gbr-1000 sequence was compared with homologous sequences from other green plant taxa. Phylogenetic relationships of these taxa were inferred using a cladistic parsimony analysis of the combined sequence data. A single most parsimonious tree was found which supports a monophyletic grouping of Ginkgo and the cycad Zamia pumila. The Gbr-6700 sequence was compared with that of Gbr-1000. The homologous regions of the two Ginkgo sequences are 86% similar compared with 92%-97% sequence similarities observed between ss rRNA sequences of available seed plant taxa. The Gbr-6700 sequence represents a ss rRNA pseudogene which is present in multiple copies in the Ginkgo genome. These sequences appear to be undergoing concerted evolution within the group, similar to that observed for eukaryotic rRNA gene families.

Zimmerman, J. W. Investigation of the Initial Steps of Asparagine-Linked Glycosylation. 51: 4837.

The chemical synthesis of several substrates and analogs of the intermediates found in the dolichol pathway of protein glycosylation is presented. (S)Dolichols, which represent the lipid carrier of the glycosyl moiety destined to be transferred to protein, were synthesized via the asymmetric hydrogenation of polyprenols isolated from the leaves of Ginkgo biloba. The dolichols were phosphorylated to afford (S)dolichyl phosphate, the substrate of Enzyme I of the dolichol pathway which catalyzes the conversion of dolichyl phosphate into dolichyl pyrophosphoryl N-acetylglucosamine. The product of this reaction was also synthesized chemically for use as a substrate to Enzyme II of the pathway, which could be used to enzymatically label the second N-acetylglucosamine residue through the use of uridine 5$\sp\prime$-diphosphoryl N-acetylglucosamine. This product represents an important intermediate in the pathway, as it was used as a glycosyl donor to study the mechanism of oligosaccharyl transferase. The transferase catalyzes the glycosylation of peptides or proteins containing the marker sequence, asparagine-X-threonine/serine, where X is any natural amino acid except proline. Several unnatural amino acids were examined, both in the X position of the marker sequence and replacing asparagine of the sequence. In addition, cyclic hexapeptides were examined for activity as they could contain conformational restraints important in peptide/protein recognition by this enzyme. Synthetic analogs of the sugar donor molecule were examined for interactions with several of the enzymes of the pathway. The phosphonate analogs dolichyl methylphosphonate and dolichyl difluoromethyl phosphonate were synthesized and examined for recognition by Enzyme I as analogs to dolichyl phosphate. The phosphonates were not seen to act as substrate or inhibitor of this enzyme, and were tested further with dolichyl kinase and dolichyl phosphate phosphatase. The phosphatase did seem to recognize the analogs whereas recognition by the kinase was not detected. Additional analogs synthesized and examined for inhibitory properties included dolichyl 2-acetamido-2-deoxy $\beta$-glucopyranoside and dolichyl 2-acetamido-2-deoxy $\beta$-glucopyranosyl, 2-acetamido-2-deoxy $\beta$-glucopyranoside, the glycoside analogs of dolichyl pyrophosphoryl N-acetylglucosamine and dolichyl pyrophosphoryl di-N-acetylchitobiose. The monosaccharide analog was found to have inhibitory properties with oligosaccharyl transferase, despite the $\beta$-linkage of the glycoside replacing the natural $\alpha$-linkage and the absence of the pyrophosphate moiety. The dolichol disaccharide glycoside was found to be too insoluble under the assay conditions for reliable results to be obtained. Several sugar analogs were also tested for inhibitory properties with the oligosaccharyl transferase, including deoxynojirimycin and di-N-acetylchitobiosyl lactone. Recognition of these compounds was not detected by the transferase.

Dorman, D. C. (1688). Bromethalin-Based Rodenticides: Mode of Action, Toxicity, Clinical Effects, and Treatment Efficacy in Rats, Dogs, and Cats. 51.

The purpose of these studies was to define the toxicity of bromethalin-based rodenticides, develop treatments, and determine new modes of action of bromethalin. Bromethalin-based rodenticides are highly neurotoxic to cats (bait LD$\sb{50}$ 0.54 mg bromethalin/kg) and dogs (bait LD$\sb{50}$ 3.56 mg bromethalin/kg). Bromethalin poisoning in the dog and cat produced a dose dependent delayed toxic syndrome. Sublethal doses of bromethalin to dogs and cats resulted in delayed CNS depression, hindlimb ataxia, paresis, and paralysis. Higher doses given to dogs resulted in rapid severe muscle tremors and generalized seizures. Bromethalin toxicosis was also associated with increased cerebrospinal fluid pressure and cerebral edema. Bromethalin toxicosis produces acute and chronic EEG changes. Predominant abnormal EEG changes included: spike and spike-and-wave EEG patterns; high voltage slow wave activity; photoconvulsive or photoparoxysmal irritative responses, and marked voltage depression. Histologic lesions included diffuse white matter spongiosis, mild microgliosis, and optic nerve vacuolization. Ultramicroscopic examination of brainstem revealed occasional swollen axons, intramyelenic vacuolization, and myelin splitting at the intraperiod line. Bromethalin was detected in kidney, liver, fat, and brain tissues using gas chromatography with electron capture detection. Bromethalin caused increased feline hepatic cytochrome P-450 and cytochrome b$\sb5$ concentrations and decreased microsomal aminopyrine N-demethylase and 4-nitrophenetole-O-deethylase activities. Repeated oral administration of a superactivated charcoal/sorbitol (SAC) product was an effective therapy for bromethalin toxicosis in the dog. The administration of combined mannitol/dexamethasone were ineffective therapies in dogs or cats given lethal bromethalin doses. Delayed administration of SAC was ineffective in bromethalin-dosed cats. Extract of Gingko biloba (EGB) given (100 mg/kg) to adult male Sprague-Daley rats immediately after bromethalin (1.0 mg/kg) administration was associated with a decreases in clinical sign severity, brain malonaldehyde concentration, brain % water, and brain sodium concentration. Bromethalin binding to cytochrome P-450 was associated with a modified Type II binding spectrum that had a peak at 420 nm and a trough at 390 nm. Hepatic cytochrome P-450 from the microsomal fractions isolated from cats given bromethalin had a similar difference spectrum (peak at 420 nm, trough at 390 nm) when compared to control cat cytochrome P-450.

Hasler, A. R. FLAVONOIDE AUS GINKGO BILOBA L. UND HPLC-ANALYTIK VON FLAVONOIDEN IN VERSCHIEDENEN ARZNEIPFLANZEN English Translation: FLAVONOIDS OF GINKGO BILOBA L. AND HPLC ANALYSIS OF FLAVONOIDS IN DIFFERENT MEDICINAL PLANTS. 52: 618.

The paper presented describes the isolation, the structure elucidation and the HPLC-analysis of flavonoids of Ginkgo biloba L. and the HPLC-analysis of flavonoids of other medicinal plants. The aim of the present work was to develop an HPLC-analysis which allows quantitative determination of the flavonoids in the leaves or extracts of Ginkgo biloba. Three different HPLC-methods were worked out. The first method includes hydrolysis of flavonoids and subsequent chromatographic analysis of aglycones. This method was not only successful with Ginkgo but also with other medicinal plants containing flavonoids. Such a simple analysis permits standardization of flavonoids in medicinal plants used by the pharmaceutical industry. Method two allows quantitative determination of aglycones and qualitative analysis of biflavones. Method three is a general procedure to determine qualitatively and quantitatively 33 flavonoids of Ginkgo biloba. The polar triglycosides and the apolar biflavones can be separated in one run. For this analysis it was necessary to isolate the main glycosides of the leaves of Ginkgo biloba. Five new flavonoids were found: (1) 3-O- (2-O-($\beta$-D-Glucosyl)-$\alpha$-L-rhamnosyl) kaempferol (Kaempferolbiloside); (2) 3-O- (2-O- (6-O-(p-$\{\beta$-D-Glucosyl$\}$oxy-trans-cinnamoyl)-$ \beta$-D-glucosyl) -$\alpha$-L-rhamnosyl) kaempferol; (3) 3-O- (2-O-($\beta$-D-Glucosyl)-$\alpha$-L-rhamnosyl) quercetin (Quercetinbiloside); (4) 3-O- (2-O- (6-O-(p-$\{\beta$-D-Glucosyl$\}$oxy-trans-cinnamoyl)-$ \beta$-D-glucosyl) -$\alpha$-L-rhamnosyl) quercetin; and (5) 3-O- (2-O- (6-O-(p-Hydroxy-trans-cinnamoyl)-$\beta$-D-glucosyl) -$\alpha$-L-rhamnosyl) -7-O- ($\beta$-D-glucosyl) quercetin. Three flavonoids (7-O- ($\beta$-D-Glucosyl) apigenin, 3$\sp\prime$-O- ($\beta$-D-Glucosyl) luteolin, 3-O- (6-O-($\alpha$-L-Rhamnosyl)-$\beta$-D-glucosyl) myricetin) were isolated for the first time from the leaves of Ginkgo and for other two flavonoids (3-O- (2-O-(6-O-$\{$p-Hydroxy-trans-cinnamoyl$\}$-$ \beta$-D-glucosyl)-$\alpha$-L-rhamnosyl) kaempferol, 3-O- (2-O-(6-O-$\{$p-Hydroxy-trans-cinnamoyl$\}$-$\beta$-D-glucosyl)-$ \alpha$-L-rhamnosyl) quercetin) the structure could be revised. One flavonoid (3-O- (6-O-($\alpha$-L-Rhamnosyl)-$\beta$-D-glucosyl) -3$\sp\prime$-methylmyricetin) was examined the first time by NMR experiments. Structures were elucidated by measurements including UV/VIS-, MS- and NMR-experiments. Combined application of one- and two-dimensional NMR experiments led to reassignment of some carbon signals incorrectly reported in the literature.

Lindahl, M. E. Phospholipase a(2) Activation and Inflammatory Reactions in the Lung (Phospholipase a(2) Activation). 52: 225.

Exposure to respirable noxious agents in the environment can cause airway inflammation and lung disease, but the cellular and biochemical mechanisms underlying the inflammatory processes are not clear. In this study the possible role of phospholipase A$\sb2$ (PLA$\sb2$) activation has been addressed. The effects of two major PLA$\sb2$ products, platelet-activating factor (PAF) and lysophosphatidylcholine (lysoPC), in isolated perfused rat lung were studied. Furthermore, lung PLA$\sb2$ was isolated and characterized and the presence of PLA$\sb2$ inhibitors in the circulation was demonstrated. It was found that calcium ionophore-activated neutrophils prestimulated with endotoxin increased pulmonary arterial pressure and vascular leakage in the lung; these effects were inhibited by the Ginkgo biloba-derived PAF receptor antagonist, BN 52021 and by nordihydroguaiaretic acid, a PLA$\sb2$ inhibitor that prevented the formation of PAF in activated neutrophils. Calcium ionophore-activated neutrophils also produced lysoPC, and both lysoPC and PAF increased vascular leakage and vascular pressure when infused into the pulmonary circulation. The formation of lysoPC in activated neutrophils was associated with lysosomal enzyme release and was blocked by PLA$\sb2$ inhibition, further demonstrating the importance of PLA$\sb2$ activation. Moreover, enhanced airway levels of lysoPC was shown to increase airway epithelial permeability, indicating a potential role of lung PLA$\sb2$ activation. A basic 12 kDa, calcium-dependent PLA$\sb2$ from rat lung was purified to homogeneity with affinity chromatography and identified with two-dimensional gel electrophoresis, and PLA$\sb2$ inhibitors were demonstrated and partially purified from human plasma and plasma from the hedgehog, Erinaceus europaeus. These results show the importance of neutrophil and lung PLA$\sb2$ for inflammatory reactions in the lung and suggest that PLA$\sb2$ activation, with formation of PAF and lysoPC, can induce proinflammatory events such as increased pulmonary pressure and vascular leakage. The findings also point to the possibility that PLA$\sb2$ activity is influenced by circulating inhibitors and that impaired PLA$\sb2$ regulation could lead to uncontrolled inflammatory reactions and development of airway inflammatory disease.

Valette, L. A. ROLE DU SYSTEME PHOSPHODIESTERASIQUE AU COURS DE L'ACTIVATION LYMPHOCYTAIRE PRECOCE: INTER-RELATIONS ENTRE LES DIFFERENTES VOIES DE COMMUNICATION CELLULAIRE English Translation: ROLE OF PHOSPHODIESTERASE SYSTEM IN THE EARLY LYMPHOCYTE ACTIVATION EVENTS: INTERRELATIONS BETWEEN THE DIFFERENT CELLULAR COMMUNICATION PATHWAYS. 52: 254.

Nous avons mis en evidence dans la fraction soluble de thymocytes de rat l'existence de 4 isoenzymes de nucleotides cycliques phosphodiesterase (PDE): une forme GMPc activable, deux formes identiques AMPc-specifiques et rolipram-sensibles, ainsi qu'une forme AMPc-specifique inhibable par le GMPc. Sous l'effet d'une stimulation des thymocytes de 30 minutes par la Concanavaline A, l'activite soluble PDE est augmentee, l'activite membranaire est diminuee, l'activite specifique totale etant stimulee. En parallele, la Con A induit les memes modifications de l'activite ornithine decarboxylase (ODC). L'activite gamma-glutamyl transferase n'est pas affectee par cette stimulation precoce. L'activite PDE est induite apres celle de l'ODC, probablement de facon independante. L'induction de l'activite ODC est aussi precoce que l'accumulation des inositol phosphates. La hausse d'activite PDE est presque exclusivement due a une activation selective des formes rolipram-sensibles, dont la cinetique, en cooperation negative dans les thymocytes quiescents, se linearise sous l'effet de la Con A. Ces processus d'induction de formes enzymatiques pre-existantes pourraient faire intervenir des mecanismes de phosphorylation, et pourraient faire partie des processus de transduction des signaux proliferatifs. De plus, une approche nutritionnelle a permis de montrer que les thymocytes sont capables de controler leur propre composition en acides gras en fonction de leur disponibilite dans le plasma, et que le remplacement des acides gras n-6 par des n-3 dans les phospholipides est associe a une diminution de l'activation de l'ODC et de la PDE induite par la Con A, le niveau basal de ces enzymes n'etant pas affecte. L'effet observe n'est pas du a la modulation de la production d'eicosanoides provenant du remplacement du 20:4n-6 par le 20:5n-3 et le 22:6n-3 dans le regime riche en n-3, main plutot par des modifications du "turnover" du 20:4n-6 parmi les classes de phospholipides. Une approche pharmacologique a permis de montrer que le triethyletain et l'extrait de Ginkgo biloba inhibent de maniere specifique les formes de PDE ainsi que l'ODC, mais ne modifient pas les phenomenes precoces de l'activation. Nos resultats sont en faveur de l'utilisation de facteurs pharmacologiques ou nutritionnels permettant la diminution des phenom'enes d'activation lymphocytaire precoces, dans le cas de desordres immunologiques necessitant une immunosuppression.

Macovschi, O. P. MODIFICATIONS BIOCHIMIQUES AU COURS DE L'OEDEME CEREBRAL CYTOTOXIQUE INDUIT PAR LE CHLORURE DE TRIETHYLETAIN, MODELE EXPERIMENTAL DE MALADIE NEURODEGENERATIVE English Translation: BIOCHEMICAL MODIFICATIONS IN TRIETHYLTIN-INDUCED CYTOTOXIC BRAIN EDEMA: EXPERIMENTAL MODEL OF NEURODEGENERATIVE DISORDERS. 51: 595.

Several membrane associated enzyme activities and some parameters of the protein synthesis are studied during the development of the cytotoxic brain edema induced by triethyltin-chloride (TET) intoxication in the rat. Before the development of the edema, TET effects upon the cyclic nucleotide phosphodiesterase activity (PDE) are due to: (a) a direct action upon the particulate enzyme, presenting high affinity for the substrate, leading to an irreversible inhibition and to the decrease of the V$\sb{\rm MAX}$; (b) an indirect detergent-like action, upon the phospholipid environment of the membrane enzyme; this action is nevertheless specific, as other membrane associated enzyme activities (2$\sp\prime$,3$\sp\prime$-cyclic nucleotide phosphohydrolase or cAMP binding by the protein kinases) are not influenced. Enhanced inhibition of the particulate PDE activities, inhibition of the soluble ones as well as an increase in the cAMP binding by membrane protein kinases are some of the membrane alterations and metabolic changes induced by the edema. The extract of Ginkgo biloba (EGB) leaves, known for its antioedemateous activity, stimulates the TET-inhibited particulate AMPc-PDE enzyme, by enhancing the enzyme V$\sb{\rm MAX}$. The results presented in this study argue for the use of the PDE enzyme system as a potential target when developing antioedemateous therapeutics. Similarly, they show that EGB beneficial effects are due, at least in part, to the regulation of cyclic nucleotides levels in the cell, via modulating PDE activity.

Henrion, A. F. IMPUTABILITE ET MECANISMES DES HEPATITES MEDICAMENTEUSES, A PROPOS DE LA PREMIERE OBSERVATION D'HEPATITE A L'EXIFONE English Translation: IMPUTABILITY AND MECHANISMS OF DRUG INDUCED HEPATITIS, ABOUT THE FIRST OBSERVATION OF EXIFONE HEPATITIS (HEPATITIS). 51: 83.

Les accidents hepatiques medicamenteux sont frequents et tres polymorphes. Il s'agit le plus souvent d'hepatites aigues dont l'etiologie iatrogene ne doit pas etre meconnue puisque leur pronostic est en general lie a l'arret du toxique. Nous rapportons l'observation d'une femme de 78 ans qui etait traitee depuis 17 mois par de l'extrait de gingko-biloba (Tanakan*) et depuis 5 semaines par de l'exifone (Adlone*) lorsqu'elle presenta une hepatite aigue cytolytique qui a gueri spontanement en 3 mois apres l'arret du traitement. Apres avoir elimine les autres etiologies possibles et pour affirmer l'origine medicamenteuse de l'hepatite, nous avons applique la methode francaise d'imputabilite: si la responsabilite du Tanakan* ne peut etre exclue, celle de l'exifone parai t plus vraisemblable. Nous rappelons les notions actuelles concernant les mecanismes d'hepatotoxicite medicamenteuse: celle de l'exifone serait probablement liee a l'apparition de metabolites reactifs lesant les structures macromoleculaires de l'hepatocyte.

Harrison, T. Radical Approaches to the Ginkgolides and Forskolin. 50: 2407.

Available from UMI in association with The British Library. Requires signed TDF. This thesis describes synthetic approaches to the two complex fused-ring natural products forskolin (1), found in the roots of the Indian herb Coleus forskholii, and ginkgolide (50a-d), isolated from the leaves of Ginkgo biloba. The two synthetic approaches have as their unifying feature the exploration of the use of intramolecular radical mediated radical mediated cyclisation reactions. Chapter 1 describes the use of a facile intramolecular 5-$exo$ trigonal cyclisation of a bromo-acetal onto an unactivated, tetrasubstituted double bond. The stereochemistry of the reaction was controlled to provide exclusively the desired trans-fused product (19). Elaboration of this intermediate to a trimethylsilyl enol ether containing an appropriately located ketal moiety, followed by intramolecular Mukaiyama aldolisation then provided the tricyclic lactone (25). Elimination and oxidation from (25) finally gave, in 7 steps from hydroxy ionone, a central enone intermediate used in a total synthesis of forskolin published by Ziegler et al during the period of my studies. A second approach to the forskolin AB ring portion was also briefly explored using $\beta$-damascone as a starting material. This approach was based on a double intramolecular radical cyclisation strategy. Although the first of the proposed cyclisations has been successfully completed, the second cyclisation requires further investigation. Chapter 2 describes further applications of radical cyclisation reactions from bromo-acetal precursors in the synthesis of linear, angular and spiro-fused O-heterocyclic ring systems present in the ginkgolides. Using a range of novel and new electrophores including maleate, furanone and anhydride, the spiro-$bis$-lactone (53), the linear fused "acetal" $bis$-lactone (54), the spiro-anhydride (55) and the bicyclic lactone (56) have been synthesized. In appendices 1 and 2, synthetic approaches to forskolin and the ginkgolides, respectively, are briefly reviewed.

Lamalle, J. F. LE POINT SUR DEUX MEDICAMENTS DITS "DES TROUBLES PSYCHO-COMPORTEMENTAUX DE LA SENESCENCE": EXTRAIT DE GINKGO BILOBA, NAFTIDROFURYL English Translation: THE MATTER OF TWO DRUGS TREATING PSYCHOBEHAVIORAL PROBLEMS IN ELDERLY PATIENTS: GINGKO BILOBA EXTRACT, NAFTIBROFURYL. 51: 89.

Les medicaments dits "des troubles psycho-comportementaux de la senescence" occupent en France pres de dix pour cent de l'ensemble des ventes de medicaments. Ces produits, autrefois appeles "vasodilatateurs cerebraux" font toujours a l'heure actuelle l'objet d'une polemique tres vive quant a leur efficacite therapeutique. Nous avons choisi d'etudier deux produits largement utilises et qui nous ont semble particulierement bien documentes, l'extrait de Ginkgo biloba et le naftidrofuryl. Dans un premier temps, nous avons presente pour chaque produit les etudes pharmacologiques et cliniques les plus recentes. Nous avons ensuite realise une discussion concernant les mecanismes d'action de ces deux medicaments et les essais cliniques: methodologie, mesure des resultats, resultats.

Hall, N. A. A Taxonomic Revision of Some Mesozoic Ginkgoales, Czekanowskiales and Related Gymnosperms. (Volumes I and Ii). 49: 4723.

Available from UMI in association with The British Library. Requires signed TDF. This revision of some Mesozoic Ginkgoales, Czekanowskiales and related gymnosperms centres on the descriptions of 37 species with emphasis on their cuticular features in the light microscope and SEM. It is prefaced by a review of the systematic positions and origins of the orders and an appraisement of ginkgoalean families and genera. The genera Ginkgoites Seward and Baiera Fr. Braun are emended; Psuedotorellia Florin, hitherto considered to be a ginkgoalean leaf-genus is regarded as a gymnosperm form-genus with species attributable to both Ginkgoales and Coniferales, similarities with some species of Sciadopityoides (conifer) are illustrated and one species of each Pseudotorellia and Sciadopityoides is attributed to the new shoot-genus, Sulcatocladus. Examination of type material from the classic German collections has permitted a revision of four leaf-species, allowing claims of their occurrences in other floras to be critically reviewed. One of these species, Baiera muensteriana (Presl) Heer has been attributed to the ovules Allicospermum rhombicum sp. nov.; a possible shoot of this plant (Ginkgoitocladus sp.?) is also described. Most of the ginkgoalean and Czekanowskialean leaf-species described by Harris from the Yorkshire Jurassic flora are re-examined; the SEM being employed for the first time on this material. Four Yorkshire species are also recognised from the Jurassic plant bed collection of Stopes from Brora, Sutherland. The Lower Cretaceous material examined includes museum specimens and dispersed material from the English and German Wealden and Seward's collection from Western Greenland. Six new leaf-species are described: Pseudotorellia botuliformii, Pseudotorellia parvus, Sciadopityoides monilii, Sulcatocladus robustus, Sulcatocladus minuta and Phoenicopsis dolabriformii. One new combination, Pseudotorellia linkii (Roemer) is proposed and a single specimen previously attributed to this species is recognised an an example of Sciadopityoides. Two groups of dispersed leaf fragments from the English Wealden are tentatively assigned to Ginkgoites and Baiera. The sole living representative of the Ginkgoales, Ginkgo biloba L. is studied primarily for purposes of comparison. A new method for establishing the phyllotaxy of short lengths of shoots is appended and use is made of a modern embedding medium for the serial sectioning of fossil cuticle; allowing subsequent reconstructions using techniques of modelling or perspectively deformed graticules. A reprint and manuscript of two publications on a Wealden conifer are included.

Friedman, W. E. (1225). Growth and Development of the Male Gametophyte of Ginkgo Biloba (Gymnosperm). 48.

The mature male gametophyte of Ginkgo biloba can be divided into two regions: a large saccate structure that contains the tube nucleus and several internal cells, and a pervasive, highly branched haustorial system that ramifies through the intercellular air spaces of the apex of the nucellus. This structure appears to differ in many ways from the simpler more typical male gametophytes of most gymnosperms. Growth and development of the male gametophyte were studied using computer reconstruction techniques to generate images of the gametophyte from data derived from serial sections through the ovule. In addition, male gametophytes were grown in vitro to permit ontogenetic studies. These investigations reveal that morphological development of the male gametophyte of Ginkgo biloba is divided into three distinct phases: (1) Germination, characterized by a brief period of diffuse growth; this process has not been described for any other gymnosperm male gametophyte. (2) Initiation of tip growth and the formation of a tubular body, as typifies all seed plant male gametophytes; in Ginkgo, this is accompanied a high degree of branching, giving rise to an extensive haustorial system. Ontogenetic study of gametophytes in vitro shows that branches typically arise at the apex, but may also be initiated laterally (subapically). (3) Late swelling of the proximal unbranched portion of the gametophyte resulting in formation of the saccate structure that is characteristic of the mature gametophyte; this process is very similar to late development in cycad male gametophytes. Division of the generative cell was also examined. Evidence is presented supporting the interpretation that the sterile cell and spermatogenous cell arise from an unusual anticlinal ring-like division of the generative cell. This type of cell division is only known to occur during antheridial development in leptosporangiate ferns and during stomatal development in certain other ferns. Preliminary evidence suggests that division of the generative cell in cycads may be similar to Ginkgo.

Lapasha, C. A. (1410). Paleoecology of the Lower Cretaceous Kootenai Formation Flora in the Great Falls Area, Montana. 43.

This palecological study and preliminary taxonomic revision of the Kootenai Formation flora was based on measured sections and collections of macrofossils from the Lignitic Unit of the Kootenai Formation east of Great Falls. The fossils were deposited in poorly drained swamps. Thirty species have been identified from the flora. The flora is compositionally most similar to the floras of the lower Blairmore and Luscar Formations. Polar ordination and correspondence analysis were used to help identify gradients correlated with compositional differences of the collections. The ordinational axes were correlated with sediment size, diversity of species in the collections, and number of specimens in the collections. Analysis of two way frequency distributions of species with sediment size and species with diversity of species in the collections were used together with fragment size to determine the degree of transport. Species were grouped according to the degree of transport prior to burial. Remains that underwent minimal or no transport probably represent plants that grew in the swamps. These include Marchantiolites, Diettertia, Acrostichopteris, Coniopteris simplex, Sagenopteris williamsii, and Athrotaxites. Remains of Coniopteris hymenophylloides, Cladophlebis, Sphenopteris, Sagenopteris elliptica, Sagenopteris mclearni, Ginkgo, Elatides, and Elatocladus appear to have been transported short distances but beyond the area in which they grew. These plants may have grown in the bottomlands adjacent to the swamps. Equisetum, Klukia, Hausmannia, and Zamites were transported to an uncertain extent. Temperatures probably were moderate with rare or no freezing periods as suggested by the presence of dicksoniaceous and delicate ferns. Sedimentary evidence indicated a seasonally wet climate with periodic flooding. Swamp deposits were not subaerially exposed indicating continuous standing water. Conifers showed an adaptation to water stress by tolerance and avoidance. Avoidance mechanisms included morphological adaptations of leaves for conifers with an evergreen habit and a probable deciduous habit for conifers lacking morphological adaptations. The types of adaptations shown by the conifers suggested a seasonal climate that was periodically unfavorable for plant growth.

Watson, G. W. Root Regeneration of Transplanted Trees in Relation to the Status of Carbohydrate Levels and Root Invading Fungi. 42: 3517.

The natural root distributions of 7 species of shade trees (Norway, red and sugar maple, green ash, redbud, ginkgo and pin oak), growing under nursery conditions were characterized. In general, the vertical distribution of the major roots showed the greatest development at the soil depth of 13-38 cm, with limited growth in the top 12 cm, and decreasing development at depths below 38 cm. The north quadrant of the root systems of these trees was more developed than any other quadrant. Fine roots that develop in rather shallow soil appear to constitute a large portion of the early root system that develops the first year after transplanting. Regenerated roots originate primarily at the severed ends of the roots cut during transplanting. Root systems of approximately 96 trees, 5-10 cm in diameter, (Norway, sugar and red maple, green ash, ginkgo, constituting the majority of these) were wholly or partially excavated 1-3 years after transplanting. Isolations were made from root sections exhibiting mechanical damage, wood discoloration and dieback. Selected fungal isolates were tested for their ability to colonize root and stem tissue of Norway maple, green ash, and ginkgo saplings. Isolates of Geotrichum candidum Link ex Pers. and Fusarium oxysporum Schlecht were successful invaders of root and stem wood tissue. Norway maple was the tree species most susceptible to colonization, with dormant Norway maples more susceptible than nondormant plants. Assays of the total carbohydrate content show an increase in both roots and twigs of transplanted trees over controls. Total sugar content increased in Norway maple and green ash roots while decreasing slightly in ginkgo roots. Sucrose and galactose levels were highest in Norway maple. Glucose and fructose levels were similar in transplants and controls for species tested. Root regeneration was decreased in Norway maples transplanted in early spring. This group of trees was transplanted during the spring period of shoot growth, a time when carbohydrates are in highest demand. This was the only case where season of transplanting appeared to have an impact on root regeneration. Transplanting during this period is not advised. In vitro tests indicate that carbohydrate content of host tissue may be a factor affecting root colonization by soil borne fungi. Growth rate of F. oxysporum was directly related to the amount of sucrose added to the media. G. candidum showed a significant growth response to starch and galactose. The higher carbohydrate content of transplanted tree roots, especially the high sucrose levels in Norway maple, is believed to be partially responsible for the ability of these common soil fungi to colonize the severed roots, so readily.

Griffiths, D. A. (1987). Ginkgo: tree of antiquity. Yearbook West Australian Nut and Tree Crop Association.

Lester, R. and M. Ellis (1992). Significant trees of Woorayl Shire. South Gippsland Conservation Society, PO Box 233(3953).

The environmental changes brought about by the removal of trees were not understood when Woorayl Shire VIC was first settled by Europeans. The importance of preserving and replanting trees and their commercial, social and domestic values is now recognized. Significant trees of the Woorayl Shire are described, to provide a better appreciation and commitment to the treescape environment. Trees are arranged in four groups: ferns, Ginkgo, conifers and flowering trees, and within groups by genus. Details are given of particular species and the locations of specimens by map reference with notes on age and height.

Lester, R., M. Ellis, et al. (1992). Significant trees of Woorayl Shire. South Gippsland Conservation Society, PO Box 233(3953).

The environmental changes brought about by the removal of trees were not understood when Woorayl Shire VIC was first settled by Europeans. The importance of preserving and replanting trees and their commercial, social and domestic values is now recognized. Significant trees of the Woorayl Shire are described, to provide a better appreciation and commitment to the treescape environment. Trees are arranged in four groups: ferns, Ginkgo, conifers and flowering trees, and within groups by genus. Details are given of particular species and the locations of specimens by map reference with notes on age and height.

Lu, M. Z., A. E. Szmidt, et al. (1997). Inhibition of lipid synthesis of bacteria, yeast and animal cells by anacardic acids, glycerol-3-phosphate dehydrogenase inhibitors from ginkgo. Lebensm Wiss Technol. London : Academic Press: 458-463.

Welland, D. (1998). RNA editing in gymnosperms and its impact on the evolution of the mitochondrial coxI gene. Plant mol biol. Dordrecht : Kluwer Academic Publishers. May: 225-234.

Sequence analysis of the mitochondrial coxI gene in eight gymnosperm species revealed a high rate of non-synonymous nucleotide substitutions with a strong (98%) predominance of C-T substitutions. Further analysis of the corresponding coxI cDNA sequences showed that all the non-synonymous C-T changes in the coxI genomic DNA sequences were eliminated by RNA editing resulting in nearly identical mRNA (amino acid) sequences among the species. Pronounced variation in the number and location of edited sites was found among species. Most species had a relatively large number of edited sites (from 25 to 34). However, no RNA editing of the coxI sequence was found in Gingko biloba or Larix sibirira. The sequence composition of the investigated coxI fragment suggests that the coxI gene in G. biloba and L. sibirica originated from edited mitochondrial coxI transcripts by reverse transcription followed by insertion into the nuclear genome or back into the mitochondrial genome. Our results also demonstrate that where there are a large number of edited sites, RNA editing can accelerate the divergence of nucleotide sequences among species.

Wilson, D. (1998). Brain boosters: can supplements sharpen you memory. Environ nutr. New York : Environmental Nutrition, Inc.,. Oct: 4.

Mascolo, N., F. Borrelli, et al. (1998). Nutraceuticals: a natural choice for grain-based products. Cereal foods world. St. Paul, Minn., American Association of Cereal Chemists. Sept: 718-719.

Lee, J. S., Y. S. Cho, et al. (1998). Natural products and cardiovascular disturbances. PTR, Phytother res. Sussex : John Wiley & Sons Ltd: S121-S123.

DeFeudis, F. V. (1998). Phospholipase C gamma 1 inhibitory principles from the sarcotestas of Ginkgo biloba. J nat prod. Washington, D.C. : American Society of Pharmacognosy. July: 867-871.

Franks, P. J., I. R. Cowan, et al. (1998). Ginkgo biloba extract (EGB 761) : from chemistry to the clinic. Wesbaden : Ullstein Medical, c1998. xxii 401.

Niederl, S., T. Kirsch, et al. (1998). A study of stomatal mechanics using the cell pressure probe. Plant cell environ. Oxford, U.K. : Blackwell Science Ltd. Jan: 94-100.

The relationship between stomatal aperture (a) and guard cell pressure (Pg) was measured directly in four different species (Vicia faba, Tradescantia virginiana, Ginkgo biloba and Nephrolepis exaltata) using a special cell pressure probe technique. The effect of epidermal turgor (Pep) on this relationship was also measured in T. virginiana. The relationship was sigmoidal for V. faba and T. virginiana, but entirely convex for G. biloba and N. exaltata. Epidermal turgor was found to have a pronounced closing effect on stomata of T. virginiana. Maximum aperture with full epidermal turgor (0.92 MPa) was about half that with zero epidermal turgor. Also, with full epidermal turgor stomata of T. virginiana did not begin to open until Pg was more than 1.25 MPa. These characteristics were used to develop an expression for a as a function of Pg and Pep. Results for the different species are compared and discussed in terms of possible advantages and limitations of water economy.

Klauser, A. (1926). Co-permeability of 3H-labeled water and 14C-labeled organic acids across isolated plant cuticles. Investigating cuticular paths of diffusion and predicting cuticular transpiration. Plant physiol. Rockville, MD : American Society of Plant Physiologists: 117-123.

Penetration of 3H-labeled water (3H2O) and the 14C-labeled organic acids benzoic acid ([14C]BA), salicylic acid ([14C]SA), and 2,4-dichlorophenoxyacetic acid ([14C]2,4-D) were measured simultaneously in isolated cuticular membranes of Prunus laurocerasus L., Ginkgo biloba L., and Juglans regia L. For each of the three pairs of compounds (3H2O/[14C]BA, 3H2O/[14C]SA, and 3H2O/[14C]2,4-D) rates of cuticular water penetration were highly correlated with the rates of penetration of the organic acids. Therefore, water and organic acids penetrated the cuticles by the same routes. With the combination 3H2O/[14C]BA, co-permeability was measured with isolated cuticles of nine other plant species. Permeances of 3H2O of all 12 investigated species were highly correlated with the permeances of [14C]BA (r2 = 0.95). Thus, cuticular transpiration can be predicted from BA permeance. The application of this experimental method, together with the established prediction equation, offers the opportunity to answer several important questions about cuticular transport physiology in future investigations.

Garcia, G. A., F. Dubois, et al. (1998). EN's herbal medicine cabinet: top 10 herbs you can trust. Environ nutr. New York : Environmental Nutrition, Inc.,. May: 4.

Carrier, D. J., T. A. v. Beek, et al. (1998). Two different modes of early development and nitrogen assimilation in gymnosperm seedlings. Plant j. Oxford : Blackwell Sciences Ltd. Jan: 187-199.

Light-independent chloroplast development and expression of genes encoding chloroplast proteins occur in many but not all species of gymnosperms. Early development in maritime pine (Pinus pinaster) seedlings was strongly light-independent, whereas Ginkgo biloba seedlings exhibited a typical angiosperm-like morphogenesis with differentiated patterns in light and dark. In pine, chloroplast polypeptides were undetectable in the seed embryo and accumulated in cotyledons of both light- and dark-grown plants in good correlation with light-independent chlorophyll synthesis. In contrast, chlorophyll and chloroplast proteins ware only detected in light-grown ginkgo. Pine cytosolic glutamine synthetase (GS) and ferredoxin glutamate synthase (Fd-GOGAT) were present at low levels in the seeds and accumulated at comparable amounts in light- and dark-grown seedlings. Fd-GOGAT was also barely detectable in the seeds of ginkgo and only accumulated in green plants with mature chloroplasts. In G. biloba seeds and etiolated plants only cytosolic GS was identified, while in light-grown seedlings this molecular form was present at low abundance and choroplastic GS was the predominant isoenzyme. The above results have been confirmed by immunolocalization of GS protein in pine and ginkgo plantlets. In pine, GS was present in the peripheral cytoplasm of mesophyll cells and also in the phloem region of the vascular bundle. Immunocytochemical analysis showed that the labelling of mesophyll and phloem cells was only cytoplasmic. In developing ginkgo, GS antigens were present in the chloroplasts of mesophyll parenchyma cells of leaflets and green cotyledons. In contrast, a weak labelling of GS was observed in the parenchyma and phloem cells of. non-green cotyledons enclosed in the seed coat. Taking all this into account, our data indicate the existence of two different modes of GS and GOGAT regulation in gymnosperms in close correlation with the differential response of plants to light. Furthermore, the results suggest that glutamine and glutamate biosynthesis is confined to the chloroplast of mesophyll cells in species with light-dependent chloroplast, development whereas compartmentation would be required in species with light-independent plastid development.

Shi, H. and E. Niki (1998). Distribution of ginkgolides and terpenoid biosynthetic activity in Ginkgo biloba. Phytochemistry Oxford. Oxford : Elsevier Science Ltd. May: 89-92.

The terpene trilactone content (bilobalide and ginkgolides) of extracts prepared from leaves of terminal buds, rosettes and side branches, from stem and root bark, and from root and root meristems of three-year-old Ginkgo biloba plants was determined. The aerial parts were relatively rich in bilobalide while ginkgolides were the major constituents of the underground parts. The formation of farnesyl and geranylgeranyl pyrophosphate was monitored by incubating cell-free extracts prepared from the corresponding plant parts with [1-14C]isopentenyl pyrophosphate. Extracts prepared from leaves of the terminal buds displayed terpenoid biosynthetic activity, suggesting that terpene trilactone synthesis might occur in actively growing tissues.

Neinhuis, C. and W. Barthlott (1966). Stoichiometric and kinetic studies on Ginkgo biloba extract and related antioxidants. Lipids. Champaign, Ill. : American Oil Chemists' Society: 365-370.

Yang, F., J. Quan, et al. (1998). Seasonal changes of leaf surface contamination in beech, oak, and ginkgo in relation to leaf micromorphology and wettability. New phytol. Cambridge : Cambridge University Press. Jan: 91-98.

Hori, T. (1998). Multidimensional counter-current chromatographic system and its application. J chromatogr A New York(Elsevier, 1993-. Apr 17, 1998. v. 803).

Li, C. L. and Y. Y. Wong (1997). Ginkgo biloba, a global treasure : from biology to medicine. Tokyo 427.

Son, Y. and H. W. Kim (1997). The bioavailability of ginkgolides in Ginkgo biloba extracts. Planta med. Stuttgart : Georg Thieme Verlag,. Dec: 563-565.

Dean, K. (1998). Above-ground biomass and nutrient distribution in a 15-year -old ginkgo (Ginkgo biloba) plantation in central Korea. Bioresour technol. Oxford, U.K. : Elsevier Science Limited. Feb: 173-177.

(1998). Plant patents. HerbalGram. Austin, TX : American Botanical Council and the Herb Research Foundation. Spring 42: 21.

Camper, N. D., D. E. Wedge, et al. (1998). JAMA study reports on positive results with Ginkgo in Alzheimer's. HerbalGram. Austin, TX : American Botanical Council and the Herb Research Foundation. Spring 42: 14.

Kirsch, T., F. Kaffarnik, et al. (1995). In vitro culture of ginkgo: ginkgolide detection. Phytochemicals and health proceedings, tenth annual Penn State Symposium in Plant Physiology, May: 333-334.

Holt, B. F. and G. W. Rothwell (1997). Cuticular permeability of the three tree species Prunus laurocerasus L., Ginkgo biloba L. and Juglans regia L.: comparative investigation of the transport properties on intact leaves, isolated cuticles and reconstituted cuticular waxes. J exp bot. Oxford : Oxford University Press. May: 1035-1045.

Cuticular transport properties of intact leaves, isolated cuticular membranes and reconstituted cuticular waxes of the three tree species Prunus laurocerasus L., Ginkgo biloba L. and Juglans regia L. were measured using six different 14C-labelled compounds, benzoic acid, salicylic acid, 2,4-dichlorophenoxy acid, metribuzin, 4-nitrophenol, and atrazine. For the same compound and the same species, the permeance of the intact leaf and the isolated cuticle was equal. This provides strong evidence demonstrating that transport properties of cuticles are not altered during isolation. Additionally, diffusion coefficients of the 14C-labelled compounds in isolated and subsequently reconstituted cuticular wax of the three tree species were measured. Permeances of intact leaves and isolated cuticles could be predicted from diffusion coefficients, wax/water partition coefficients and the thickness of the transport-limiting wax layer with a mean deviation of about 1.7. This provides evidence that transport properties of recrystallized cuticular waxes do indeed reflect barrier properties of isolated cuticular membranes and intact leaves with in situ waxes. Thus, it can be concluded that the investigation of cuticular permeability using the three independent experimental systems of different complexity give comparable results. Finally, it was observed that permeances and diffusion coefficients measured with P. laurocerasus were always significantly lower than those measured with G. biloba and J. regia. This is interpreted as an ecological adaptation of the respective species. The evergreen species P. laurocerasus must be more adapted to environmental stress such as drought and frost. injury compared to the two deciduous species G. biloba and J. regia.

Packer, L., C. Saliou, et al. (1997). Is Ginkgo biloba (Ginkgoaceae) really an oviparous plant. Am j bot. Columbus, Ohio : Botanical Society of America Inc. June: 870-872.

Germination of Ginkgo biloba seeds with intact and removed sarcotesta was compared to test the role of the seed coat in germination biology. The presence of an intact sarcotesta significantly reduced total germination percentage when compared to seeds with the sarcotesta removed. Some seeds were also cold stratified. This treatment was not necessary for germination, but it did improve total germination percentage. The seeds were collected during the period of natural abscission. Contrary to the accepted literature, we found that Ginkgo seeds contain well-developed embryos at the time of dispersal. These data demonstrate that the seed coat contributes to winter dormancy of G. biloba, and that the phenology of this species is less primitive than popularly believed.

Schardt, D. and S. Schmidt (1998). Ginkgo biloba extract EGb 761: biological actions, antioxidant activity, and regulation of nitric oxide synthase. Flavonoids in health and disease /. New York : Marcel Dekker, c1998 1998: 303-341.

Blumenthal, M. (1997). Fear of forgetting. Nutr action health lett. [Washington, D.C. : Center for Science in the Public Interest,. May: 3-6.

The effects of supplements on the memory loss associated with aging are discussed. These supplements are choline, lecithin, ginkgo biloba, and phosphatidylserine. Nutrient deficiencies, infections, high blood pressure, and depression can affect memory.

Leigh, E. (1997). German government limits ginkgolic acid levels in ginkgo leaf extracts. HerbalGram. Austin, TX : American Botanical Council and the Herb Research Foundation. Fall 41: 29.

Laurain, D., G. J. Tremouillaux, et al. (1997). Effectiveness of Ginkgo biloba extract in Alzheimer's and multi-infarct dementia. HerbalGram. Austin, TX : American Botanical Council and the Herb Research Foundation. Fall 41: 17.

Korszun, S. (1997). Production of ginkgolide and bilobalide in transformed and gametophyte derived cell cultures of Ginkgo biloba. Phytochemistry Oxford. Oxford : Elsevier Science Ltd. Sept: 127-130.

Ginkgolide and bilobalide were detected by HPLC analysis in cell cultures established from various G. biloba explants. These secondary metabolites of pharmacological interest were found to occur in concentrations of 0.065 and 0.087% (dry weight) in two cell suspensions. One was derived from a female prothallus and the other one from putatively transformed embryos, by transfection via Agrobacterium rhizogenes agropine type strain CFBP 2409 (A4).

Arenz, A., M. Klein, et al. (1995). The container cultivation of Ginkgo biloba L. and its column cultivar ('Fastigiata' Mast.). Poznan : Wydawnictwo Akademii Rolniczej w Poznaniu 63.

Zhang, H., G. Liu, et al. (1996). Occurrence of neurotoxic 4'-O-methylpyridoxine in Ginkgo biloba leaves, ginkgo medications and Japanese Ginkgo food. Planta med. Stuttgart : Georg Thieme Verlag,. Dec: 548-551.

Yoon, S. Y., W. J. Choi, et al. (1988). Purification and characterization of tubulin from ginkgo pollen. Sex plant reprod. Heidelberg : Springer International: 136-141.

Beek, T. A. v. and G. P. Lelyveld (1997). Selective adsorption of flavonoid compounds from the leaf extract of Ginkgo biloba L. Biotechnol tech. London, UK : Chapman & Hall. Aug: 553-556.

Camper, N. D., P. S. Coker, et al. (1997). Preparative isolation and separation procedure for ginkgolides A, B, C, and J and bilobalide. J nat prod. Downers Grove, Ill. : American Society of Pharmacognosy. July: 735-738.

Ahn, Y. J., M. Kwon, et al. (1997). In vitro culture of Ginkgo. In vitro cell dev biol, Plant. Columbia, MD : Society for In Vitro Biology. Apr/June: 125-127.

Mo, K., C. O. Lora, et al. (1997). Potent insecticidal activity of Ginkgo biloba derived trilactone terpenes against Nilaparvata lugens. Phytochemicals for pest control /. Washington, DC : American Chemical Society 1997: 90-105.

Methanol extracts from 119 samples of 52 domestic plant species, 84 samples of 49 Indian plant species and 31 samples of 21 African plant species were tested for their insecticidal activities against the brown planthopper (BPH), Nilaparvata lugens Stal, using spray or topical application method. A foliar extract of Ginkgo biloba L. (Ginkgoaceae) revealed the most potent insecticidal activity against BPH. The active constituents were isolated by chromatographic techniques and characterized by spectral analysis as ginkgolides A, B and C, and bilobalide. Bilobalide not only revealed much more potent insecticidal activity against susceptible BPH than the commonly used carbamate insecticides carbofuran and fenobucarb, but was also highly effective against three strains of BPH resistant to diazinon, carbofuran, and fenobucarb, respectively. However, this compound was nontoxic to the tobacco cutworm, housefly, house mosquito, german cockroach, and two-spotted spider mite. At a dose of 0.01 microgram/female, topically-applied bilobalide caused signs of toxicity such as tremors and paralysis, and the insects died within 30 min of treatment. This compound was relatively nontoxic to mice (LD50, >1,000 mg/kg) and was not mutagenic, when tested against five strains of Salmonella typhimurium. Additionally, G. biloba-derived materials were not phytotoxic to rice plant seedlings at 2,000 ppm. As active ingredients of a naturally occurring insecticide, G. biloba-derived materials could be useful as a new control agent for BPH.

Tremouillaux, G. J., D. Laurain, et al. (1997). Biodegradation of methyl t-butyl ether by pure bacterial cultures. Appl microbiol biotechnol. Berlin, Germany : Springer Verlag. Jan: 69-72.

Three pure bacterial cultures degrading methyl t-butyl ether (MTBE) were isolated from activated sludge and fruit of the Gingko tree. They have been classified as belonging to the genuses Methylobacterium, Rhodococcus, and Arthrobacter. These cultures degraded 60 ppm MTBE in 1-2 weeks of incubation at 23-25 degrees C. The growth of the isolates on MTBE as sole carbon source is very slow compared with growth on nutrient-rich medium. Uniformly-labeled [14C]MTBE was used to determine 14CO2 evolution. Within 7 days of incubation, about 8% of the initial radioactivity was evolved as 14CO2. These strains also grow on t-butanol, butyl formate, isopropanol, acetone and pyruvate as carbon sources. The presence of these compounds in combination with MTBE decreased the degradation of MTBE. The cultures pregrown on pyruvate resulted in a reduction in 14CO2 evolution from [14C]MTBE. The availability of pure cultures will allow the determination of the pathway intermediates and the rate-limiting steps in the degradation of MTBE.

Mazzanti, G., L. Braghiroli, et al. (1996). Direct embryogenesis in protoplasts of Ginkgo biloba (maidenhair tree). Plant protoplasts and genetic engineering VII /. Berlin: 33-47.

Rong, Y., Z. Geng, et al. (1996). Effects of Panax ginseng and Ginkgo biloba on in vitro prolactin secretion. PTR, Phytother res. Sussex : John Wiley & Sons: S33-S35.

Tremouillaux, G. J., D. Laurain, et al. (1996). Ginkgo biloba modulates glutathione redox cycle in vascular endothelial cells. Nutr res. Tarrytown, N.Y. : Elsevier Science Inc. Nov/Dec: 1913-1923.

We recently reported that Ginkgo biloba extract (GBE) suppressed oxidative burst in macrophages and protected bovine pulmonary artery endothelial cells (PAEC) from oxidant injury. In this study the effects of GBE on glutathione (GSH) redox cycle and activity of antioxidant enzymes were investigated. Confluent monolayers of PAEC were incubated with GBE for 8-48 h, washed, and then lysed with Triton X-100. Biochemical assays were performed with the lysate. GBE caused both dose- and time-dependent increase in GSH level and glutathione disulfide (GSSG) reductase activity while GSH peroxidase and superoxide dismutase activity remained unaffected. Exposure of PAEC to an organic oxidant tert-butyl hydroperoxide (tBHP) resulted in decreased GSH level, increased lipid peroxidation, and elevated leakage of intracellular lactate dehydrogenase. Preincubation or simultaneous treatment of PAEC with GBE prevented these changes induced by tBHP. Our data suggest that the antioxidant effect of GBE may be due to its modulation of the GSH redox cycle in PAEC as well as direct scavenging of the oxidant.

Kurisaki, A., H. Sagami, et al. (1996). Microspore and protoplast culture in Ginkgo biloba. In vitro haploid production in higher plants /. Dordrecht 3: 277-295.

Moscatelli, A., G. Cai, et al. (1997). Distribution of polyprenols and dolichols in soybean plant. Phytochemistry Oxford. Oxford : Elsevier Science Ltd. Jan: 45-50.

Using a convenient two-plate thin layer chromatography method, polyprenols and dolichols in soybean plant were analysed. These polyisoprenoid alcohols were found to occur in different quantities from tissue to tissue. The leaves contained ficaprenols (C50, C55, C60), glycinoprenols (C45, C50, C55) and dolichols (C80, C85) with the major being ficaprenols, while the shoots, roots and seeds contained only dolichols. Analysis of the subcellular distribution of these compounds in the leaves demonstrated that ficaprenols, glycinoprenols and dolichols were mostly located in the chloroplast. When the chloroplast fraction was incubated with a combination of [1-14C]isopentenyl diphosphate and farnesyl diphosphate, radioactive polyprenols composed of C45, C50, C55 and C70, C75 were formed, suggesting that biosynthesis site for these polyprenols is localized in the chloroplast. The shorter chain ficaprenols and the longer chain dolichols were also found in the leaves of spinach, perilla, parsley and evergreen magnolia, which are dicotyledonous plants.

Sper, W. G. L., J. L. Moody, et al. (1988). Dynein-related polypeptides in pollen and pollen tubes. Sex plant reprod. Heidelberg : Springer International: 312-317.

Liston, A., W. A. Robinson, et al. (1996). Universality of mitochondrial RNA editing in cytochrome-c oxidase subunit I (coxI) among the land plants. Biochim biophys acta. Amsterdam : Elsevier Science B: 301-308.

Abstract: Plant mitochondrial pre-mRNAs often undergo C-to-U conversions, a phenomenon termed RNA editing. The molecular source of specificity and phylogenetic depth of the editing machinery remain to be determined. We amplified coxI gene fragments via the polymerase chain reaction from a diversity of taxa within the land plants, and sequenced each. Alignment and comparison of 25 homologous coxI gene sequences with those from plant species having known RNA editing sites which restore amino acid sequence consensus was used to infer sites of C-to-U conversions. Our results, derived using the comparative approach, imply that the plant mitochondrial editing machinery extends throughout vascular plant phylogeny, and also that this phenomenon is present in every major branch of the (non-vascular) Bryophyta: liverworts (Hepaticae), hornworts (Anthocerotae), and mosses (Musci). These results have important consequences for our thoughts on the evolutionary history of the plant RNA editing process, as they imply that editing is older than previously believed.

Hierro, M. T. G., G. Robertson, et al. (1996). Length variation in the nuclear ribosomal DNA internal transcribed spacer region of non-flowering seed plants. Syst botany. Notre Dame, IN :. Apr/June: 109-120.

The nuclear ribosomal DNA (rDNA) internal transcribed spacer (ITS) region was PCR-amplified in 32 genera of non-flowering seed plants. Length of the ITS region was determined by restriction site mapping of PCR products and nucleotide sequences were obtained from the ITS-2 and 5.8S rDNA of selected genera. In contrast to the relatively narrow range of ITS region lengths reported from angiosperms [565-700 base pairs (bp)], substantial length variation (975-3125 bp) is observed in the ITS region of Coniferales, Cycadales, Ginkgoales, and Gnetales. Restriction site analyses indicate that the 5.8S rDNA + ITS-2 ranges from 375-450 bp, while the ITS-1 is responsible for most of the length variation found in gymnosperm ITS regions. The representatives of Pinaceae exhibit the greatest variation in ITS region length (1550-3125 bp), while those of sampled members of Cupressaceae, Taxodiaceae, Cephalotaxaceae, and Taxaceae are relatively stable (975-1125 bp). The observed ITS region lengths in Sciatopityaceae (1250 bp) and Araucariaceae (1325-1350 bp) are somewhat larger than those of Cupressaceae, Taxodiaceae, Cephalotaxaceae, and Taxaceae, while those of sampled Podocarpaceae (2000-2100 bp) fall into the range observed in the Pinaceae. Outside of the Coniferales, ITS region length is similar among Cycadales (1150- 1450 bp), Ginkgoales (1200 bp), and two of the three members of Gnetales, Ephedra (1500 bp) and Gnetum (1200 bp). In contrast, the ITS region of Welwitschia is only 750 bp long, ca. 50 bp longer than the longest known angiosperm ITS region. Levels of nucleotide sequence variation as estimated by restriction site mapping suggest that phylogenetic analysis of the. ITS region will be informative at the intrageneric level in most non-flowering seed plants. In Cupressaceae, intergeneric comparisons may also be feasible. Because the ITS region is relatively long, it may also permit population-level phylogenetic analysis in many non-flowering seed plants.

Poort, R. J., H. Visscher, et al. (1996). The fatty acid composition of the seeds of Ginkgo biloba. J Am Oil Chem Soc. Champaign, IL : AOCS Press. May: 575-579.

Carrier, D. J., J. Archambault, et al. (1996). Zoidogamy in fossil gymnosperms: the centenary of a concept, with special reference to prepollen of late Paleozoic conifers. Proc Natl Acad Sci U S A. Washington, D.C. : National Academy of Sciences,. Oct 15: 11713-11717.

This year is the centenary of the surprising discovery in 1896 of zoidogamy in extant cycadophytes and Ginkgo. But by coincidence, also in the same year, the concept of prepollen was introduced. The morphology of prepollen was considered justification for the probable production of motile antherozoids in extinct gymnosperms. In this paper, the history of the prepollen concept is briefly outlined. It is emphasized that, in addition to well-known examples in pteridosperms and cordaitaleans, a prepollen condition also occurred among late Paleozoic conifers.

Wang, J., C. Yang, et al. (1996). Formation of terpenoid products in Ginkgo biloba L. cultivated cells. Plant cell rep. Berlin, W. Ger. : Springer International: 888-891.

Ginkgolides are diterpenes arising from the terpenoid precursor geranylgeranyl pyrophosphate (GGPP). Incorporation of [1-(14)C] isopentenylpyrophosphate ([1-(14)C]IPP) into GGPP was monitored throughout the cultivation cycle of G. biloba L. cultivated cells. Because incorporation of [1-(14)C]IPP into GGPP had never been monitored in G. biloba, in either the whole plant or cultivated cell system, modifications to existing protocols were necessary. Modifications consisted of extracting the cells with an extraction buffer supplemented with Triton-X-100. Farnesylpyrophosphate (FPP) was the major product formed. The amount of GGPP detected was about one tenth that of FPP.

Schmit, A. C., M. C. Endle, et al. (1988). The nuclear lamina in male generative cells of Ginkgo biloba. Sex plant reprod. Heidelberg : Springer International: 238-242.

Strode, J. T. B., III, L. T. Taylor, et al. (1996). The perinuclear microtubule-organizing center and the synaptonemal complex of higher plants share a common antigen: its putative transfer and role in meiotic chromosomal ordering. Chromosoma New York(Springer-Verlag,. Mar 1996. v. 104).

Recognition of homologous chromosomes during meiotic prophase is associated in most cases with the formation of the synaptonemal complex along the length of the chromosome. Telomeres, located at the nuclear periphery, are preferential initiation sites for the assembly of the synaptonemal complex. In most eukaryotic cells, telomeres cluster in a restricted area, leading to the "bouquet" configuration in leptotene-zygotene, while this typical organization progressively disappears in late zygotene-pachytene. We wondered whether such striking changes in the intranuclear ordering and pairing of meiotic chromosomes during the progression of prophase I could be correlated with activity of the centrosome and/or microtubule-organizing center (MTOC). Plant cells may be used as a model of special interest for this study as the whole nuclear surface acts as an MTOC, unlike other cell types where MTOCs are restricted to centrosomes or spindle pole bodies. Using a monoclonal antibody (mAb 6C6) raised against isolated calf centrosomes we found that the 6C6 antigen is present over the entire surface of the plant meiotic nucleus, in early prophase I, before chromosomal pairing. At zygotene, short fragments of chromosomes become stained near the nuclear envelope and within the nucleus. At pachytene, after complete synapsis, the labeling specifically concentrates within the synaptonemal complexes, although the nuclear surface is no longer reactive. Ultrastructural localization using immunogold labeling indicates that the 6C6 antigen is colocalized with the synaptonemal complex structures. Later in metaphase I, the antigen is found at the kinetochores. Our data favor the idea that the 6C6 antigen may function as a. particular "chromosomal passenger-like" protein. These observations shed new light on the molecular organization of the plant synaptonemal complex and on the redistribution of cytoskeleton-related antigens during initiation of meiosis. They suggest that antigens of MTOCs are relocated to chromosomes during the synapsis process starting at telomeres and contribute to the spatial arrangement of meiotic chromosomes. Such cytoskeleton-related antigens may acquire different functions depending on their localization, which is cell-cycle regulated.

Kamm, A., R. L. Doudrick, et al. (1996). Supercritical fluid chromatography of ginkgolides A, B, C and J and bilobalide. J chromatogr A New York(Elsevier, 1993-. June 28, 1996. v. 738).

Zhang, Q. H. (1996). The genomic and physical organization of Ty1-copia-like sequences as a component of large genomes in Pinus elliottii var. elliottii and other gymnosperms. Proc Natl Acad Sci U S A. Washington, D.C. : National Academy of Sciences,. Apr 2: 2708-2713.

A DNA sequence, TPE1, representing the internal domain of a Ty1-copia retroelement, was isolated from genomic DNA of Pinus elliottii Engelm. var. elliottii (slash pine). Genomic Southern analysis showed that this sequence, carrying partial reverse transcriptase and integrase gene sequences, is highly amplified within the genome of slash pine and part of a dispersed element > 4.8 kbp. Fluorescent in situ hybridization to metaphase chromosomes shows that the element is relatively uniformly dispersed over all 12 chromosome pairs and is highly abundant in the genome. It is largely excluded from centromeric regions and intercalary chromosomal sites representing the 18S-5.8S-25S rRNA genes. Southern hybridization with specific DNA probes for the reverse transcriptase gene shows that TPE1 represents a large subgroup of heterogeneous Ty1-copia retrotransposons in Pinus species. Because no TPE1 transcription could be detected, it is most likely an inactive element--at least in needle tissue. Further evidence for inactivity was found in recombinant reverse transcriptase and integrase sequences. The distribution of TPE1 within different gymnosperms that contain Ty1-copia group retrotransposons, as shown by a PCR assay, was investigated by Southern hybridization. The TPE1 family is highly amplified and conserved in all Pinus species analyzed, showing a similar genomic organization in the three- and five-needle pine species investigated. It is also present in spruce, bald cypress (swamp cypress), and in gingko but in fewer copies and a different genomic organization.

Laurain, D., J. C. Chenieux, et al. (1943). Ginkgo biloba cultivation and processing in China. Annu rep North Nut Grow Assoc. [S.l.] : The Association 85: 156-158.

Smith, P. F., K. Maclennan, et al. (1996). Somatic embryogenesis from immature zygotic embryos of Ginkgo biloba. Plant cell, tissue organ cult. Dordrecht, The Netherlands : Kluwer Academic Publishers. Jan: 19-24.

Immature zygotic embryos of G. biloba were taken, at various developmental stages, from ovules harvested in November 1993. Zygotic embryos showing the beginning of the cotyledonary development cultured on modified Murashige & Tucker(1969)media proliferated intensely. In fact, 98.5% of the immature zygotic embryos produced embryogenic and undifferentiated tissues (calluses), in proportions varying depending on the hormonal composition of the induction media. After two weeks of culture, direct embryogenesis was observed on the hypertrophic cotyledons when benzyladenine 10 micromolar was used as the sole plant growth regulator in the induction media. The addition of different concentrations of NAA (5-10-20 micromolar) and of BA (5 micromolar) to the induction media led to an indirect embryogenesis after two months, when the calluses were transferred to the development media without auxin. The highest frequency of embryogenic tissues (90-95%) and the highest number of somatic embryos per explant (9.6) were obtained with benzyladenine (10 micromolar) as the sole exogenous growth factor. Some embryos isolated mechanically or 'in situ' on the callus developed as far as the later cotyledonary stage.

Parliment, T. H. (1996). The neuroprotective properties of the Ginkgo biloba leaf: a review of the possible relationship to platelet-activating factor (PAF). J ethnopharmacol. Ireland : Elsevier Science Ireland Ltd. Mar: 131-139.

Ginkgo biloba (Ginkgoaceae) is an ancient Chinese tree which has been cultivated and held sacred for its health-promoting properties. There is substantial experimental evidence to support the view that Ginkgo biloba extracts have neuroprotective properties under conditions such as hypoxia/ischemia, seizure activity and peripheral nerve damage. Research on the biochemical effects of Ginkgo biloba extracts is still at a very early stage. One of the components of Ginkgo biloba, ginkgolide B, is a potent platelet-activating factor (PAF) antagonist. Although the terpene fraction of Ginkgo biloba, which contains the ginkgolides, may contribute to the neuroprotective properties of the Ginkgo biloba leaf, it is also likely that the flavonoid fraction, containing free radical scavengers, is important in this respect. Taken together, the evidence suggests that Ginkgo biloba extracts are worthy of further investigation as potential neuroprotectant agents.

Shutov, A. D., I. A. Kakhovskaya, et al. (1974). Characterization of the putrid aroma compounds of Ginkgo biloba fruits. ACS symp ser. Washington, D.C. : American Chemical Society 596: 276-279.

The Ginkgo family of trees is represented by a single surviving species, Ginkgo biloba. It is an ancient line unlike any other living conifer and may represent a link between the conifers and the tree-ferns. In the fall female trees produce yellow-orange fruits with a thick fleshy layer surrounding an edible kernel. The odor of these fruits is described as putrid. This study identified the odorous principles as high levels of butanoic and hexanoic acids.

Hager, K. P., H. Braun, et al. (1995). Legumin-like and vicilin-like seed storage proteins: evidence for a common single-domain ancestral gene. J mol evol. New York, N.Y. : Springer Verlag. Dec: 1057-1069.

Legumin-like 11S and vicilin-like 7S globulins are the main storage proteins of most angiosperms and gymnosperms. The subunits of the hexameric legumin are synthesized as a precursor comprising a N-terminal acidic alpha- and a C-terminal basic beta-chain. The trimeric vicilin molecule consists of subunits composed of two symmetrical N- and C-terminal structural domains. In a multiple alignment we have compared the N-terminal and C-terminal domains of 11 legumins and seven vicilins of several dicot, monocot, and gymnosperm species. The comparisons using all six possible pairwise combinations reveal that the N-terminal and C-terminal domains of both protein families are similar to each other. These results together with data on the distribution of variable and conserved regions, on the positions of susceptible sites for proteolytic attack, as well as on the published 7S protein tertiary structure suggest that both protein families share a common single-domain ancestor molecule and lead to the hypothesis that a triplication event has occurred during the evolution of a putative legumin/vicilin ancestor gene. Moreover, the comparison of the intron/exon pattern reveals that at least three out of five intron positions are precisely conserved between the genes of both protein families, further supporting the idea of a common evolutionary origin of recent legumin and vicilin encoding genes.

Marcocci, L., L. Packer, et al. (1995). Evolution of seed storage protein genes: legumin genes of Ginkgo biloba. J mol evol. New York, N.Y. : Springer Verlag. Oct: 457-466.

Legumin-like seed storage proteins have been intensively studied in crop plants. However, little is known about the molecular evolution of these proteins and their genes and it was assumed that they originated from an ancestral gene that already existed at the beginning of angiosperm evolution. We have evidence for the ubiquitous occurrence of homologous proteins in gymnosperms as well. We have characterized the major seed storage globulin from Ginkgo biloba by amino acid sequencing, which reveals clear homology to legumin-like proteins from angiosperms. The Ginkgo legumin is encoded by a gene family; we describe two of its members. The promoter regions contain sequence motifs which are known to function as regulatory elements involved in seed-specific expression of angiosperm legumins, although the tissues concerned are different in gymnosperms and angiosperms. The Ginkgo legumin gene structure is divergent from that of angiosperms and suggests that the evolution of legumin genes implicated loss of introns. From our data and from functional approaches recently described it becomes obvious that the posttranslational processing site of legumin precursors is less conserved than hitherto assumed. Finally, we present a phylogenetic analysis of legumin encoding sequences and discuss their utility as molecular markers for the reconstruction of seed plant evolution.

Das, D. K. (1994). Antioxidant action of Ginkgo biloba extract EGb 761. Methods enzymol. San Diego, Calif. : Academic Press 234: 462-475.

Rao, V. S. N., J. C. R. Silva, et al. (1994). Naturally occurring flavonoids: structure, chemistry, and high-performance liquid chromatography methods for separation and characterization. Methods enzymol. San Diego, Calif. : Academic Press 234: 410-420.

Joyeux, M., A. Lobstein, et al. (1995). Effects of antiinflammatory plant extracts on ovoimplantation in rats. PTR, Phytother res. Sussex : John Wiley & Sons. Sept: 458-459.

Meurer, G. B. and D. W. Stevenson (1995). Comparative antilipoperoxidant, antinecrotic and scavenging properties of terpenes and biflavones from Ginkgo and some flavonoids. Planta med. Stuttgart : Georg Thieme Verlag,. Apr: 126-129.

Blumenthal, M. (1994). The biflavones of the Cycadales revisited: biflavones in Stangeria eriopus, Chigua restrepoi and 32 other species of Cycadales. Biochem syst ecol. Oxford, U.K. : Elsevier Science Ltd. Sept: 595-603.

The biflavone patterns in leaves of 34 species of the Cycadales representing all of the 11 genera in three families were investigated. Known biflavones were isolated from Gingko biloba and Dioon spinulosum, and then used as internal standards for HPLC and TLC analysis of leaf extracts. Biflavone patterns in the new genus Chigua were found to be closely related to those detected in Zamia. Four specimens of Stangeria enopus were all found to exhibit complex patterns of biflavones. Most members of the Zamiaceae were found to contain hinokiflavone. A first attempt of the chemotaxonomic re-evaluation of biflavone patterns in Cycadales is made.

Chaw, S. M., H. M. Sung, et al. (1995). Canada approves ginkgo for food use. HerbalGram. Austin, TX : American Botanical Council and the Herb Research Foundation. Summer 34: 21.

Yan, L. J., L. M. T. Droy, et al. (1995). The phylogenetic positions of the conifer genera Amentotaxus, Phyllocladus, and Nageia inferred from 18S rRNA sequences. J mol evol. New York, N.Y. : Springer Verlag. Aug: 224-230.

To determine the evolutionary positions of the conifer genera Amentotaxus, Phyllocladus, and Nageia, we obtained 18S rRNA sequences from 11 new taxa representing the major living orders and families of gymnosperms. With the published Chlamydomonas as an outgroup, phylogenetic analyses of our new data and available sequences indicate that (1) the Gnetales form a monophyletic group, which is an outgroup to the conifers, (2) the conifers are monophyletic, (3) Taxaceae, Cephalotaxaceae, Cupressaceae, and Taxodiaceae form a monophyletic group, (4) Amentotaxus is closer to Torreya than to Cephalotaxus, suggesting that Amentotaxus is better to be classified as a member of Taxaceae, (5) Phyllocladus, Dacrycarpus, Podocarpus, and Nageia form a monophyletic group, and (6) Pinaceae is an outgroup to the other families of conifers. Our finding that Phyllocladus is a sister group of the Podocarpaceae disagrees with the suggestion that the phylloclade of the genus is an ancient structure and that the genus is a terminal taxon within the Podocarpaceae. The genus Nageia is more closely related to Podocarpus than to Dacrycarpus and was derived from within the Podocarpaceae. In conclusion, our data indicate that in conifers, the uniovulate cone occurred independently in Taxacaeae and Cephalotaxaceae, and in Podocarpaceae after the three families separated from Pinaceae, and support the hypothesis that the uniovulate cone is derived from reduction of a multiovulate cone.

Jenn, M. H., S. H. Sung, et al. (1995). Ginkgo biloba extract (EGb 761) protects human low density lipoproteins against oxidative modification mediated by copper. Biochem biophys res commun. Orlando, Fla. : Academic Press. July 17: 360-366.

The antioxidant effects of Ginkgo biloba extract (EGb 761) on copper-mediated human low density lipoprotein (LDL) oxidative modification were evaluated by several techniques. Human LDL (0.5 mg/ml) in phosphate buffered saline, pH 7.4, was incubated with 10 micromolar cupric sulfate at 37 degrees C under air for 8 hours and 24 hours in the presence of varying concentrations of EGb 761. Increases in LDL apoB carbonylation, lipid peroxidation, apoB electrophoretic mobility and LDL fluorescence were all inhibited when the incubation mixture contained EGb 761 at concentrations less than 100 microgram/ml. This inhibition was EGb 761-concentration-dependent. Thus, EGb 761 has powerful antioxidant effects on copper-mediated LDL oxidative modification.

Schmid, M. and g. E. H. Schmoll (1995). Ginkgolide B production in cultured cells derived from Ginkgo biloba L. leaves. Plant cell rep. Berlin, W. Ger. : Springer International: 501-504.

Callus cultures and cell suspension cultures derived from Ginkgo biloba L. leaves produced ginkgolide B. In cell suspension cultures. the production reached a maximum by the 13th day of subculture and followed by a sharp decrease. The medium of Murashige and Skoog induced the highest ginkgolide B content in cultures while the medium of Schenk and Hildebrandt promoted cell growth. For the maximal production of ginkgolide B. cells were cultured in Murashige and Skoog medium modified to contain 1.0 mg/l of alpha-naphthaleneacetic acid, 0.1 mg/l of kinelin, 30 g/l sucrose and 1.25 mM potassium phosphate with a molar ratio of ammonium to nitrate ions of 1:3.

Chinn, E., J. Silverthorne, et al. (1994). Ginkgo : ancient tree and medicinal plant. Stuttgart : Wissenschaftliche Verlagsgesellschaft 135.

Richard, M., C. Tremblay, et al. (1926). Light-regulated and organ-specific expression of types 1, 2, and 3-light harvesting complex b mRNAs in Ginkgo biloba. Plant physiol. Rockville, MD : American Society of Plant Physiologists: 593-602.

In a prior study (E. Chinn and J. Silverthorne [1993] Plant Physiol 103: 727-732) we showed that the gymnosperm Ginkgo biloba was completely dependent on light for chlorophyll synthesis and chloroplast development and that expression of light-harvesting complex b (Lhcb) mRNAs was substantially increased by light. However, dark-grown seedlings that were transferred to constant white light took significantly longer than angiosperm seedlings to initiate a program of photomorphogenesis and the stems failed to green completely. We have prepared type-specific probes for mRNAs encoding major polypeptides of light-harvesting complex II (Lhcb1, Lhcb2, and Lhcb3) and have used these to analyze the expression of individual Lhcb mRNAs during greening. All three sequences accumulated in the top portions of dark-grown seedlings transferred to light, but, as was seen previously for total Lhcb mRNAs, there was a transient, reproducible decline in the levels of all three mRNAs after 4 d in the light. This transient decrease in Lhcb mRNA levels was not paralleled by a decrease in Chl accumulation. By contrast, there were significantly lower levels of all three Lhcb mRNAs in the lower portions of greening dark-grown stems as well as lower Chl levels. We conclude that although the tops of the plants have the capacity to etiolate and green, Gingko seedling stems continue a program of development into woody tissue in darkness that precludes greening when the seedlings are transferred to the light.

Beissner, L. (1994). Chloroplastic genomes of Ginkgo biloba and Chlamydomonas moewusii contain a chlB gene encoding one subunit of a light-independent protochlorophyllide reductase. Curr genet New York(Springer-Verlag, 1979-. 1994. v. 26).

We have cloned and sequenced a Chlamydomonas moewusii chloroplastic DNA fragment that includes a 563 amino-acid open reading frame (ORF563, chlB) presenting 89% amino-acid homology with ORF513 from Marchantia polymorpha. It is also homologous to ORF510 from Pinus thunbergii but includes two insertions absent in both M. polymorpha and P. thunbergii. The derived polypeptide is 54% similar to the product of bchB from Rhodobacter capsulatus, identified as one subunit of a light-independent NADH-protochlorophyllide reductase. We also isolated and sequenced an homologous chloroplastic gene from the gymnosperm Ginkgo biloba. Northern hybridizations performed on RNA isolated from synchronized Chlamydomonas eugametos cells showed higher expression between the tenth hour of light and the eighth hour of darkness, peaking during the first 2 h of darkness.

Shen, J. G. and D. Y. Zhou (1909). Handbook of conifer forestry. 2. vollig umgearbeitete, verm. und verb. Aufl. Berlin : P. Parey 742.

Petkov, V. D., S. Belcheva, et al. (1995). Efficiency of Ginkgo biloba extract (EGb 761) in antioxidant protection against myocardial ischemia and reperfusion injury. Biochem mol biol int. Marrickville, N.S.W., Australia : Academic Press. Jan: 125-134.

The catdio-protective mechanisms of EGb 761, an extract of Ginkgo biloba leaves. On myocardial ischemia-reperfusion injury were investigated using rabbits subjected to 30 minutes of regional cardiac ischemia and 120 min of reperfusion under anesthesia. Compared to the saline perfused group, EGb 761 treatment (10 mg/kg, injected into the coronary artery) significantly inhibited the increase in lipid peroxidation and maintained total and CuZn-SOD levels in both plasma and tissue during and at the end of reperfusion. Both the decrease in tissue type plasminogen activator (t-PA) and the increase in plasminogen activator inhibitor-1 (PAI-1) caused by ischemia-reperfusion were also significantly suppressed by EGb 761 treatment. Furthermore, the ultrastructure of the myocytes of the EGb 761 treated heart was slightly damaged after ischemia-reperfusion, while the control ischemic-reperfused hearts demonstrated severe histological damages such as swelling and vacuolization of the mitochondria. These results suggest that EGb 761 protects hearts by its antioxidant properties and by its ability to adjust fibrinolytic activity.

Arahira, M. and C. Fukazawa (1994). Participation of the serotonergic system in the memory effect of Ginkgo biloba L. and Panax ginseng C.A. Mey. PTR, Phytother res. Sussex : John Wiley & Sons. Dec: 470-477.

Carrier, J., N. Chauret, et al. (1994). Ginkgo 11S seed storage protein family mRNA: unusual Asn-Asn linkage as post-translational cleavage site. Plant mol biol. Dordrecht : Kluwer Academic Publishers. July: 597-605.

By reducing the amount of ginkgo water-soluble polysaccharides, which occupy about 35% of the wet seed mass and interfere with the extraction of RNA, cDNA-quality mRNA was obtained from developing seeds of Ginkgo biloba. Based on the NH2-terminal 17-amino acid sequence and an internal 12-amino acid sequence derived from the basic subunit of ginnacin, 11S-seed storage protein family of ginkgo, two degenerate oligonucleotide primers were synthesized and used for polymerase chain reaction (PCR). The resulting PCR product was used for screening the above endosperm cDNA library, and a plaque carrying the 1614 bp cDNA insert, which contained the entire coding region for a precursor of ginnacin was isolated. This is the first reported cloning of cDNA from ginkgo seeds. The deduced primary sequence is composed of a signal peptide segment (25 amino acid residues) and an acidic subunit (248 residues) followed by a basic subunit (187 residues). It was also found that the post-translational cleavage site in the ginnacin precursor is the Asn-Asn rather than the Asn-Gly bond found in a variety of the major subunit precursors in 11S seed protein family known to date. We showed that a purified soybean extract and an extract of ginkgo seeds can specifically hydrolyze -Asn(248)-Asn(249)- but not -Asn(249)-Val(250)-, in the heptapeptide Gly-Asn(248)-Asn-Val-Glu-Glu-Leu that corresponds to the ginnacin cleavage region.

Marcocci, L., J. J. Maguire, et al. (1994). Ginkgo biloba L. (maiden hair tree): in vitro culture and the formation of Ginkgolides. Biotechnol agricult for. Berlin, W. Ger. : Springer Verlag 26: 136-145.

Choukchou, B. N., Y. Asakawa, et al. (1994). The nitric oxide-savenging properties of ginkgo biloba extract EGb 761. Biochem biophys res commun. Orlando, Fla. : Academic Press. June 15: 748-755.

Ginkgo biloba extract EGb 761 was found to be a scavenger of nitric oxide in in vitro acellular systems, under physiological conditions. EGb 761 competed with oxyhemoglobin for reaction with nitric oxide generated during the interaction of hydroxylamine with Complex I of catalase. An EGb 761 dose-dependent decrease in the amount of nitrite formed in the reaction of oxygen with nitric oxide produced from solution of 5 mM sodium nitroprusside was also observed. These data implicate it as a potential therapeutic agent in conditions of altered production of nitric oxide.

Jansson, S., G. G. Meyer, et al. (1994). Isolation, structure determination and synthesis of new dihydroisocoumarins from Ginkgo biloba L. Tetrahedron lett. Oxford : Elsevier Science Ltd. June 6: 3949-3952.

New optically active 8-hydroxy-3-alk(en)yl-3,4-dihydroisocoumarins 2a-c were isolated from Ginkgo biloba L. fruits. The absolute configuration was determined to be R by comparison with both enantiomers of the 8-hydroxy-3-tridecyl-3,4-dihydroisocoumarin synthesized from optically active epichlorhydrins.

Maier, H. K. and D. Laudahn (1994). Nucleotide distribution in gymnosperm nuclear sequences suggests a model for GC-content change in land-plant nuclear genomes. J mol evol. New York, N.Y. : Springer Verlag. July: 34-46.

Nuclear protein coding sequences from gymnosperms are currently scarce. We have determined 4 kb of nuclear protein coding sequences from gymnosperms and have collected and analyzed >60 kb of nuclear sequences from gymnosperms and nonspermatophytes in order to better understand processes influencing genome evolution in plants. We show that conifers possess both biased and nonbiased genes with respect to GC content, as found in monocots, suggesting that the common ancestor of conifers and monocots may have possessed both biased and nonbiased genes. The lack of biased genes in dicots is suggested to be a derived character for this lineage. We present a simple but speculative model of land-plant genome evolution which considers changes in GC bias and CpG frequency, respectively, as independent processes and which can account for several puzzling aspects of observed nucleotide frequencies in plant genes.

Huh, H. and E. J. Staba (1993). Effectiveness of Ginkgo-biloba Special extract in patients after subarachnoid hemorrhage and aneurism surgery suffering from cerebral insufficiency. Acta hortic. Wageningen : International Society for Horticultural Science. Aug 332: 273-279.

Brinkman, J. A. and R. E. J. Boerner (1992). The botany and chemistry of Ginkgo biloba L. J herbs spices med plants. Binghamton, NY : Food Products Press, c1992: 91-124.

Bel, A. J. E. v., A. Ammerlaan, et al. (1994). Nitrogen fertilization effects on foliar nutrient dynamics and autumnal resorption in maidenhair tree (Gingko biloba L.). J plant nutr. New York, N.Y. : Marcel Dekker: 433-443.

We quantified seasonal foliar nutrient dynamics and autumnal N and P resorption of individuals of the deciduous gymnosperm Gingko biloba (maidenhair tree) growing in compacted, urban soils over two years following a single fertilization with 150 kg/ha/yr of N (and no P). Mean foliar nutrient concentrations were more similar to those reported for angiosperm trees than for other gymnosperms. During the autumn following fertilization, 46% and 48 of foliar N and P were resorbed, respectively; during the second year both increased significantly, to 68% of foliar N and 74% of foliar P. Absolute N resorption was also greater during the second year, whereas absolute P resorption did not differ significantly between years. During the second year, the level of N resorption rates was similar to that reported for (larch or tamarack), a needle-leafed, deciduous gymnosperm, and greater than those reported for broad-leafed deciduous angiosperms. The level of 1992 P resorption was similar to those reported for a wide range of gymnosperms and greater than those reported for most angiosperms. N fertilization allowed Gingko trees to maintain typical foliar N dynamics even during a persistent drought during which foliar P dynamics were significantly altered.

Misra, S. and M. Green (1994). A three-step screening procedure to identify the mode of phloem loading in intact leaves. Evidence for symplasmic and apoplasmic phloem loading associated with the type of companion cell. Planta New York(Springer-Verlag, 1925-. 1994. v. 192).

A three-step screening method wits developed to identify the mode of phloem loading in intact leaves. Phloem loading of 14CO2-derived photosynthate was challenged by p-chloromercuribenzenesulfonic acid (PCMBS) in leaves of dicotyledons with either a symplasmic (type 1, with intermediary cells as companion cells) or apoplasmic (type 2b, with transfer cells as companion cells) minor-vein configuration. Firstly, photosynthate export as the result of phloem loading was measured by collection of phloem exudate from the petiole. The PCMBS had virtually no effect on photosynthate export in representatives of type-1 families (Lamiaccae, Lythraceae, Onagraceae, Saxifragaceae). In contrast, photosynthate export was strongly reduced by PCMBS in representatives of type-2b families (Asteraceae, Balsaminaceae, Dipsacaceae, Linaceae, Tropaeolaceae, Valerianaceae) and type-2b members of polytypical families (Fabaceae, Scrophulariaceae). Secondly, densitometric measurements of leaf autoradiographs demonstrated that the contrast between the mesophyll and the lower-order veins was hardly affected by PCMBS treatment in type-1 species, whereas PCMBS strongly reduced the contrast in type-2b species. Thirdly, separate 14C-radioassays of vein and mesophyll tissues confirmed this observation. The three-step procedure thus revealed a strong and consistent reduction of phloem loading by PCMBS in type-2b species which was absent in type-1 species. In conclusion, phloem loading in type-2b species occurs via the apoplast and type-1 species execute an alternative--most likely symplasmic--mode of phloem loading.

Pietta, P., R. M. Facino, et al. (1994). Legumin-like storage polypeptides of conifer seeds and their antigenic cross-reactivity with 11S globulins from angiosperms. J exp bot. Oxford : Oxford University Press. Feb: 269-274.

The aim of the present work was to investigate the homology of seed storage proteins in a wide variety of conifers for most of which the gene sequences are not yet identified. Rabbit antiserum antibodies against the purified 57 kDa non-reduced crystalloid protein complex of white spruce seed were obtained. The antibodies were used in the immunoblot assays with seed proteins of various members of Pinaceae; Ginkgo biloba, and several representatives of angiosperms. Under reducing conditions, 35 kDa and 22 kDa range polypeptides, homologous to white spruce crystalloids, were identified in all members of the Pinaceae examined except Abies amabilis and Tsuga heterophylla. In Ginkgo the antibodies cross-reacted with the previously reported legumin-like polypeptides of 28, 20 and 13 kDa range. In angiosperms, the crystalloid antibodies cross-reacted to the 35 kDa and 20 kDa range of 11S storage polypeptides of Brassica napus, Ricinus communis and Nicotiana tabacum. No cross-homology was observed with the polypeptides of Phaseolus vulgaris, Glycine max, Pisum sativum, and Medicago sativa seeds. Based on the antigenic homology the wide occurrence of legumin-like proteins in gymnosperms is confirmed. Also, the pattern of serological reactivity suggests that the legumin-like proteins of gymnosperms are more closely related to members of Euphorbiaceae, Brassicaceae and Solanaceae than to those of the Fabaceae.

Garcia, G. A., F. R. Canton, et al. (1994). Thermospray liquid chromatography-mass spectrometry of flavonol glycosides from medicinal plants. J chromatogr A New York(Elsevier, 1993-. Feb 11, 1994. v. 661).

Chaw, S. M., H. Long, et al. (1993). Immunochemical analysis of chloroplast polypeptides from maritime pine. Phytochemistry Oxford. Oxford : Elsevier Science Ltd. Sept: 337-341.

Chloroplast polypeptides have been purified to electrophoretic homogeneity from maritime pine cotyledons (Pinus pinaster aiton). Antibodies against the light harvesting chlorophyll a-b binding protein (LHCP) located in the thylakoid membrane and the stromatic ribulose bisphosphate carboxylase/oxygenase (Rubisco holoenzyme) were raised in rabbits by injecting pure preparations. Monospecificity of antibodies was determined by a double immunodiffusion test and further purification was achieved by immunoselection of IgGs with purified proteins immobilized on nitrocellulose membranes. Antisera were used to determine steady-state levels of polypeptides during plant development by slot-blot quantitation. Our data showed that developing Pinus pinaster seedlings accumulated chloroplast proteins in the dark, but no such accumulation was observed in dark-grown Ginkgo biloba seedlings.

Castleman, M. (1993). The phylogenetic position of Taxaceae based on 18S rRNA sequences. J mol evol. New York, N.Y. : Springer Verlag. Dec: 624-630.

The evolutionary position of the yew family, Taxaceae, has been very controversial. Some plant taxonomists strongly advocate excluding Taxaceae from the conifer order and raising its taxonomic status to a new order or even class because of its absence of seed cones, contrary to the case in the majority of conifers. However, other authors believe that the Taxaceae are not fundamentally different from the rest of the conifers except in that they possess the most reduced solitary-ovule cones. To resolve the controversy, we have sequenced the 18S rRNA genes from representative gymnosperms: Taxus mairei (Taxaceae), Podocarpus nakaii (Podocarpaceae), Pinus luchuensis (Pinaceae), and Ginkgo biloba (Ginkgoales). Our phylogenetic analysis of the new sequence data with the published 18S rRNA sequence of Zamia pumila (a cycad) as an outgroup strongly indicates that Taxus, Pinus, and Podocarpus form a monophyletic group with the exclusion of Ginkgo and that Taxus is more closely related to Pinus than to Podocarpus. Therefore, Taxaceae should be classified as a family of Coniferales. Our finding that Taxaceae, Pinaceae, and Podocarpaceae form a clade contradicts both the view that the uniovulate seed of Taxaceae is a primitive character and the view that the Taxaceae are descendants of the Podocarpaceae. Rather, the uniovulate seed of Taxaceae and that of some species of Podocarpus appear to have different origins, probably all reduced from multiovulate cones.

Laurain, D., J. C. Chenleux, et al. (1991). Ginkgo: an herb to keep in mind. Veg times. Mt. Morris, Ill. : Vegetarian Times. Apr 164(62): 66-70.

The author discusses the medicinal benefits of the herb, ginkgo.

Chinn, E. and J. Silverthorne (1993). Direct embryogenesis from female haploid protoplasts of Ginkgo biloba L., a medicinal woody species. Plant cell rep. Berlin, W. Ger. : Springer International: 656-660.

Haploid protoplasts isolated from prothallus (i.e. female gametophyte) of Ginkgo biloba, at densities ranging from 5 X 10(4) to 10(5) protoplasts per milliliter, were able to divide and form microclones which directly evolved into embryos, when they were cultured in two different liquid media. These were: the Murashige and Tucker medium (1969) modified by omitting ammonium ions and supplementing with glutamine, benzyladenine and various levels of naphthaleneacetic acid; or the Bourgin and Nitsch medium (1967) without growth regulators, supplemented with coconut milk. Three months later, the number of embryos ranged from 165 to 1900 embryos ml(-1) depending on the culture medium. After four months, embryos at whatever stage (globular, oblong or heart) exhibited a slow growth, which delayed the transfer onto solid media.

Close, T. J., R. D. Fenton, et al. (1926). Light-dependent chloroplast development and expression of a light-harvesting chlorophyll a/b-binding protein gene in the gymnosperm Ginkgo biloba. Plant physiol. Rockville, MD : American Society of Plant Physiologists: 727-732.

Unlike conifers, the gymnosperm Ginkgo biloba is dependent on light for chlorophyll (Chl) synthesis and initiation of chloroplast development. Dark-grown seedlings show complete etiolation, including no detectable Chl accumulation, no leaf expansion, and increased hypocotyl elongation. When dark-grown seedlings are placed in white light, Chl synthesis and leaf expansion are initiated, but unlike angiosperms, which initiate rapid photomorphogenesis, Ginkgo takes at least 1 week to change to a normal light-regulated pattern of growth. A cDNA clone (pLhcb*Gb1) encoding a Chl a/b-binding protein of light-harvesting complex II from Ginkgo mRNA has been used as a probe for the expression of this family of mRNAs. We have found that, in common with angiosperms but in marked contrast to pines, Lhcb mRNA is expressed in a highly light-dependent manner. In addition to being expressed in light-grown leaves, this sequence is also expressed in the green tissues of immature seeds. The Lhcb mRNA appears during greening in parallel with the onset of Chl synthesis. The complete sequence of pLhcb*Gb1 has been determined and the deduced amino acid sequence was found to be of type I based on comparison with signature sequences of angiosperm and gymnosperm sequences.

Petkov, V. D., C. Hadjiivanova, et al. (1993). A view of plant dehydrins using antibodies specific to the carboxy terminal peptide. Plant mol biol. Dordrecht : Kluwer Academic Publishers. Oct: 279-286.

Dehydrins are characterized by the consensus KIKEKLPG amino acid sequence found near the carboxy terminus, and usually repeated from one to many times within the protein. A synthetic peptide containing this consensus sequence was used to produce specific antibodies that recognize dehydrins in a wide range of plants. This range covered two families of monocots, viz. Gramineae (Hordeum vulgare L., Triticum aestivum L., Zea mays L., Oryza sativa L.) and Liliaceae (Allium sativa L.), and five families of dicots, Malvaceae (Gossypium hirsutum L.), Solanaceae (Lycopersicon esculentum L.), Brassicaceae (Raphanus sativus L.), Fabaceae (Vigna unguiculata L.), and Cucurbitaceae (Cucumis sativus L.). Two families of gymnosperms, Pinaceae (Pinus edulis Engelm.) and Ginkgoaceae (Ginkgo biloba L.), were also included. For several plants in which dehydrin cDNA and genomic clones have previously been characterized, it now appears that the dehydrin family of proteins is larger, and the regulation of dehydrin expression much more complex, than earlier studies have shown.

Tyler, V. E. (1993). Effects of standardized extracts GK501, from Ginkgo biloba L., G115 from Panax ginseng C.A. Meyer, and their combination, Gincosan (PHL-00701), on the brain levels of biogenic monoamines and on the serum content of prolactin, growth hormone and ACTH. PTR, Phytother res. Sussex : John Wiley & Sons. Mar/Apr: 139-145.

Laurain, D., G. J. Tremouillaux, et al. (1974). Phytomedicines in Western Europe: potential impact on herbal medicine in the United States. ACS symp ser. Washington, D.C. : American Chemical Society 534: 25-37.

Laws and regulations governing the sale of phytomedicines (herbal remedies) in several European countries, particularly Germany, are compared to those in the United States. This provides an understanding as to why the development of medicines prepared from long-known plant drugs flourishes there with substantial support from the pharmaceutical industry and the medical community, while such research languishes here. The composition and therapeutic value of several popular European phytomedicinals, including those obtained from ginkgo, echinacea, chamomile, feverfew, valerian, milk thistle, St. John's wort, saw palmetto (sabal), hawthorn, and melissa (lemon balm) are discussed. Unless the regulatory attitude towards phytomedicines changes in the United States, it is likely that even the most exciting European developments will have little impact in this country and that many useful drugs widely used in Europe will continue to be unavailable here.

Maillard, M. P., J. L. Wolfender, et al. (1993). Embryogenesis from microspores of Ginkgo biloba L., a medicinal woody species. Plant cell rep. Berlin, W. Ger. : Springer International: 501-505.

The present work establishes that isolated microspores of Ginkgo biloba L. cultured at densities of 1.5 to 5.10(4) per milliliter in Bourgin and Nitsch (1967) liquid medium are able to divide, both in the presence and in the absence of exogenous growth regulators, and to germinate by growing a pollen tube. In all experiments the microspores exhibited various modes of division leading to embryo formation in the liquid medium. Four weeks later, the microspores which had been previously submitted to various electrical stresses showed pro-embryo development earlier than those which had not. After ten weeks the number of embryos was found to be 300 to 5300 ml(-1) following the experiments. When the embryos exhibited a slower growth in liquid medium, they were transferred onto various solid media for maturation. Two months later, embryos had proliferated visibly.

Huh, H. and E. J. Staba (1993). Use of liquid chromatography-thermospray mass spectrometry in phytochemical analysis of crude plant extracts. J chromatogr. Amsterdam : Elsevier Science Publishers. Sept 10: 147-154.

Huh, H., J. Singh, et al. (1993). Ontogenic aspects of ginkgolide production in Ginkgo biloba. Plant Med. Stuttgart, W. Ger. : Georg Thieme Verlag. June: 232-239.

Bruno, C., R. Cuppini, et al. (1993). Ontogenic aspects of Ginkgo polyprenols. Plant Med. Stuttgart, W. Ger. : Georg Thieme Verlag. Aug: 379-380.

Zhiyan, Z. (1993). Regeneration of motor nerves in bilobalide-treated rats. Plant Med. Stuttgart, W. Ger. : Georg Thieme Verlag. Aug: 302-307.

Steinke, B., B. Muller, et al. (1993). Comparative ultrastructure of fossil and living ginkgoacean megaspore membranes. Rev Palaeobot Palynol. Amsterdam : Elsevier Science Publishers, B: 167-182.

Petkov, V. D., R. Kehayov, et al. (1993). Biological standardization of Ginkgo extracts. Plant Med. Stuttgart, W. Ger. : Georg Thieme Verlag. Apr: 155-160.

Foster, S. (1993). Memory effects of standardized extracts of Panax ginseng (G115), Ginkgo biloba (GK 501) and their combination Gincosan (PHL-00701). Plant Med. Stuttgart, W. Ger. : Georg Thieme Verlag. Apr: 106-113.

Friedman, W. E. (1991). Ginkgo : ginkgo biloba. [Rev.]. [Austin, TX] : American Botanical Council 7.

Krochmal, C. and A. Krochmal (1992). Double fertilization in nonflowering seed plants and its relevance to the origin of flowering plants. Int Rev Cytol. San Diego, Calif. : Academic Press 140: 319-355.

Beek, T. A. v. and G. P. Lelyveld (1993). Ginkgo biloba Maidenhair tree. Arbor Age. Van Nuys, Calif. : Gold Trade Publications. May: 34.

Sticher, O. (1992). Concentration of ginkgolides and bilobalide in Ginkgo biloba leaves in relation to the time of year. Plant Med. Stuttgart, W. Ger. : Georg Thieme Verlag. Oct: 413-416.

DeVerno, L. L., P. J. Charest, et al. (1993). Quality of Ginkgo preparations. Plant Med. Stuttgart, W. Ger. : Georg Thieme Verlag. Feb: 2-11.

Hsieh, L. (1993). Inheritance of mitochondrial DNA in the conifer Larix. Theor Appl Genet. Berlin, W. Ger. : Springer International. Apr: 383-388.

Restriction fragment length polymorphisms between Larix leptolepis and Larix decidua were identified in heterologous hybridization experiments, using wheat mitochondrial DNA probes specific for atp9, coxI, nad3/rps12, and orf25. Analysis of eight individuals of each reciprocal hybrid of these two species revealed that mitochondrial DNA was maternally inherited. Furthermore, sequences homologous to wheat orf25 were also identified in Larix gmelini, Larix siberica, Larix olgensis, and Larix laricina, as well as Ginkgo biloba, Picea mariana, Picea glauca and Pinus contorta.

Tallevi, S. G. and W. G. W. Kurz (1992). Origin and distribution of Ginkgo biloba. For Chron. Ottawa : Canadian Institute of Forestry. Oct: 612-613.

Johri, B. M. (1991). Detection of ginkgolides by thin-layer chromatography. J Nat Prod. Downers Grove, Ill.: American Society of Pharmacognosy. Mar/Apr: 624-625.

Tredici, P. D. (1992). Haustorial role of pollen tubes. Ann Bot. London : Academic Press. Nov: 471-475.

In angiosperms, the pollen tube is siphonogamous and its main function is to carry the male gametes for double fertilization. In some taxa, as in Cucurbitaceae, the tube branches after entering the ovule, prior to fertilization. The tube may even swell and form a bulla. During post-fertilization development of the ovule, a portion of the tube may persist in the micropyle, or in the embryo sac, or in both; sometimes even in the micropyle of the mature seed. Haustorial function has been presumed in a number of taxa. In Grevillea, following fertilization, the pollen tube branches at the micropyle, and the branches grow intercellularly into the ovarian tissue where further branching occurs. A haustorial role of the pollen tube is presumed from circumstantial evidence. In gymnosperms (for example, Cycas, Zamia and Ginkgo) the pollen tube is nonsiphonogamous, arises from the distal (upper) pole of pollen grain, and grows laterally in the apical region of the nucellus. The tube branches in Cycas and Ginkgo but remains unbranched in Zamia. These pollen tube branches are enucleate, and are not concerned with the transport of male gametes for fertilization. However, the haustorial role has been well documented. In Podocarpus, the pollen tube is siphonogamous and arises from the proximal (lower) pole of pollen grain. After traversing the nucellus, the tube forms a bulla at the point of contact with the female gametophyte, and several branches originate from the bulla. The pollen tube branches grow along the inner surface of the nucellus and the outer surface of the female gametophyte. The haustorial role of the pollen tube branches is uncertain. Procedures for convincingly demonstrating the haustorial role of pollen tubes are discussed.

Beek, T. A. v., H. A. Scheeren, et al. (1992). Where the wild Ginkgos grow. Arnoldia. Jamaica Plain, Mass. : Arnold Arboretum. Winter: 2-11.

Del, T. P., H. Ling, et al. (1990). Determination of ginkgolides and bilobalide in Ginkgo biloba leaves, extracts, and phytopharmaceuticals. Plant Med. Stuttgart, W. Ger. : Georg Thieme Verlag. Dec: 509.

Lobstein, A., J. L. Rietsch, et al. (1992). The Ginkgos of Tian Mu Shan. Conserv Biol J Soc Conserv Biol. Cambridge, Mass. : Blackwell Scientific Publications. June: 202-209.

Huxtable, R. J. (1991). Seasonal variations of the flavonoid content from Ginkgo biloba leaves. Plant Med. Stuttgart, W. Ger. : Georg Thieme Verlag. Oct: 430-433.

Tsumura, Y., H. Motoike, et al. (1992). The pharmacology of extinction. J Ethno Pharmacol. Limerick : Elsevier Scientific Publishers. Aug: 1-11.

It is impossible to predict what compounds of pharmacological interest may be present in an unexamined species. The extinction of such species may result, therefore, in the loss of therapeutically significant compounds. The fact that science will never know what has been lost does not lessen the significance of the loss. A number of species are discussed to exemplify the potential loss. Ginkgo biloba is an ancient plant, apparently saved from a natural extinction by human intervention. From this tree, the ginkgolides have been isolated. These are potent inhibitors of platelet activating factor and hold promise in the treatment of cerebral ischemia and brain edema. Two species, the tree Taxus brevifolia and the leech Hirudo medicinalis, are threatened as a result of human activity. Both have recently yielded complex compounds of therapeutic importance. The antitumor agent, taxol, is obtained from T. brevifolia and the thrombin inhibitor, hirudin, is found in H. medicinalis. Catharanthus roseus, source of the anticancer agents vincristine and vinblastine, although not threatened, derives from a largely unexamined but severely stressed ecosystem of some 5000 plant species. In other examples, ethnobotanical knowledge of certain plants may be lost while the species survive, as exemplified by the suppression of the Aztec ethnobotany of Mesoamerica by the invading Spanish. Finally, the fallacy of the 'snail darter syndrome', where species may be viewed as too insignificant to worry about, is exposed by consideration of the pharmacological activities of a sea hare (a shell-less marine mollusc) and various leeches.

Hasler, A., O. Sticher, et al. (1992). Allozyme variation of old Ginkgo biloba memorial trees in western Japan. Can J For Res Rev Can Rech For. Ottawa, Ont. : National Research Council of Canada. July: 939-944.

Allozyme variation of 89 old memorial trees of Ginkgo biloba L. in western Japan were investigated. For 12 loci from 10 enzyme systems, the percentage of polymorphic loci (95% level), the number of alleles per locus, and the observed heterozygosity were 75.0%, 2.5, and 0.234, respectively. The variation of this species is relatively high in comparison with other gymnosperms. Genetic relationships between four regions (Kansai, Shikoku, North Kyushu, and South Kyushu) were investigated by using two multivariate procedures. Based on a principal component analysis, these four regional groups were not separated clearly, except for the Shikoku and South Kyushu groups, which were almost completely separated in opposite peripheral zones of a scatter diagram. The canonical discriminant analysis also almost completely separated the Shikoku and South Kyushu groups. These results indicate that most trees of the Shikoku and South Kyushu groups might be descendants of individuals from the Kansai and North Kyushu groups, respectively, excluding some exceptions.

Markham, K. R., H. Geiger, et al. (1992). Identification and determination of the flavonoids from Ginkgo biloba by high-performance liquid chromatography. J Chromatogr. Amsterdam : Elsevier Science Publishers. July 10: 41-48.

Flesch, V., M. Jacques, et al. (1992). Kaempferol-3-O-glucosyl(1-2)rhamnoside from Ginkgo biloba and a reappraisal of other gluco(1-2, 1-3 and 1-4)rhamnoside structures. Phytochemistry. Oxford : Pergamon Press. Mar: 1009-1011.

A kaempferol-3-O-glucorhamnoside from Ginkgo biloba is defined as the 3-O-alpha-L-[beta-D-glucopyranosyl(1-2)rhamnopyranoside] on the basis of 2D NMR evidence. Complete assignments of the 1H and 13C NMR spectra of this compound and of its known p-coumaroyl derivative are presented for the first time. The NMR distinctions of 1-2, 1-3 and 1-4 linked glucopyranosylrhamnopyranosides are discussed and indicate (i) that the 13C NMR assignments for one published gluco(1-3)rhamnoside are in need of modification, (ii) that the published structure of hordenine-O-[6-O-t-cinnamoyl-beta-glucosyl(1-4)-alpha-rhamnoside] from Selaginella doederleinii is not distinguished from the 1-3 linked glucorhamnoside structure, and (iii) that the 8-prenylkaempferol-3-O-[glucosyl(1-4)rhamnoside]-7-O-glucoside and the equivalent 4'-O-methylated xylosyl(1-4)rhamnoside from Epimedium pubescens and E. washanense, respectively, are (1-2)-linked.

Del, T. P. (1992). Relative importance of growth and light level on terpene content of Ginkgo biloba. Phytochemistry. Oxford : Pergamon Press. June: 1941-1945.

Growth of young Ginkgo biloba cultivated in a greenhouse, in natural light (varying between 125 and 1100 microeinsteins m-2 s-1), at 24-17 degrees and evolution of the terpene content (ginkgolides A, B, C, J and bilobalide) in leaves, shoots and roots were observed at the same moments during the first three years of life. Leaves accumulate more terpenes than roots and especially shoots. Annual mean concentrations of terpenes in leaves remain constant during the first three years of Ginkgo development, whereas those of roots and shoots evenly decrease. During one vegetative season, terpene content fluctuated significantly in leaves. This is mainly due to seasonal variations of ginkgolide A and bilobalide, which reach a maximum value at the end of summer or at the beginning of autumn. When the plants are cultivated in a climate chamber, in constant artificial light with medium photonic flux (250 microeinsteins m-2 s-1) at the same temperatures, the ginkgolide and bilobalide content in leaves remains low and constant. The level of terpene accumulation in G. biloba leaves may be linked to the photonic level and not to leaf or plant growth or to a specific stage of organs.

Huh, H. and E. J. Staba (1992). Natural regeneration of Ginkgo biloba from downward growing cotyledonary buds (basal chichi). Am J Bot. Columbus, Ohio : Botanical Society of America. May: 522-530.

This study describes the origin and early development of a distinct organ of clonal regeneration in Ginkgo biloba, the basal chichi. These aggregates of suppressed shoot buds originate from superficial meristems located in the cotyledonary axils of all Ginkgo seedlings as part of their normal ontogeny. Within 6 wk of germination these buds become embedded in the cortex of the stem, and their subsequent growth and development occurs below the surface of the bark. When stimulated by some traumatic event that damages the seedling axis, one of these embedded cotyledonary buds usually grows down from the trunk to form a woody, rhizomelike basal chichi which, under appropriate conditions, is capable of generating both aerial shoots and adventitious roots. Vegetative regeneration by means of basal chichi has not only contributed to the long-term persistence of G. biloba in the forests of China, but may also have played a role in the remarkable survival of the genus since the Cretaceous.

Hasler, A., G. A. Gross, et al. (1992). Supercritical fluid chromatographic analysis of polyprenols in Ginkgo biloba L. J Chromatogr. Amsterdam : Elsevier Science Publishers. May 29: 364-369.

Del, T. P. (1992). Complex flavonol glycosides from the leaves of Ginkgo biloba. Phytochemistry. Oxford : Pergamon Press. Apr: 1391-1394.

Five new flavonol glycosides were isolated from the leaves of Ginkgo biloba and their structures determined by spectroscopy and hydrolysis experiments.

Dorman, D. C., L. M. Cote, et al. (1991). Ginkgos and people--a thousand years of interaction. Arnoldia. Jamaica Plain, Mass. : Arnold Arboretum. Summer: 2-15.

Braquet, P. and D. Hosford (1992). Effects of an extract of Gingko biloba on bromethalin-induced cerebral lipid peroxidation and edema in rats. Am J Vet Res. Schaumburg, Ill. : American Veterinary Medical Association. Jan: 138-142.

The effects of administration of a commercially available extract of Gingko biloba (EGB) on bromethalin-induced brain lipid peroxidation and cerebral edema in adult male Sprague-Dawley rats was determined. Gingko biloba extract was given (100 mg/kg) by gavage immediately after bromethalin (1.0 mg/kg) administration. Rats were euthanatized at 24 hours after dosing. Brain lipid peroxidation was determined by measurement of brain malonaldehyde-thiobarbituric acid chromophore (MDA-TBA) concentration, brain sodium concentration, and brain water content. Treatment of bromethalin-dosed rats (10/group) with EGB was associated with a statistically significant (P < 0.05) decrease in clinical sign severity, compared with bromethalin-dosed saline solution-treated rats. All rats given bromethalin and saline solution developed clinical signs of toxicosis including CNS depression, hind limb weakness, ataxia, paralysis, and coma. Some rats given bromethalin and EGB developed clinical signs, however, none developed hind limb paralysis. The brain MDA-TBA concentration (2.4 +/- 0.5 delta MDA-TBA concentration/mg of protein), percentage of water in brain tissue (80.3 +/- 0.30%), and brain sodium concentration (6.68 +/- 0.21 mg/g of dry weight) were significantly increased in rats given bromethalin and saline solution, compared with control rats given saline solution (1.0 +/- 0.1 delta MDA-TBA concentration/mg of protein; 78.1 +/- 0.33% water in brain tissue; 4.83 +/- 0.30 mg of brain Na+/g of dry weight) and rats given bromethalin and EGB (1.6 +/- 0.2 delta MDA-TBA concentration/mg of protein; 79.3 +/- 0.31% water in brain tissue; 5.37 +/- 0.34 mg of brain Na+/g of dry weight). The MDA-TBA concentration (1.2 +/- 0.2 delta MDA-TBA concentration/mg of protein), percentage of water in brain tissue (78.7 +/- 0.40%), and brain sodium concentration (4.93 +/- 0.26 mg/g of dry weight) increased slightly in control rats given EGB.

Chauret, N., J. Carrier, et al. (1991). Ethnopharmacology and the development of natural PAF antagonists as therapeutic agents. J Ethno Pharmacol. Limerick : Elsevier Scientific Publishers. Apr: 135-139.

Ginkgolides are unique twenty-carbon terpenes, occurring naturally only in the roots and leaves of Ginkgo biloba. The molecules incorporate a tert-butyl group and six 5-membered rings, and are specific and potent antagonists of platelet-activating factor (PAF), a potent inflammatory autacoid. Studies in animal models with the most potent ginkgolide, BN 52021, and other specific PAF antagonists have demonstrated that PAF plays an important role in pathologies such as asthma, shock, ischemia, anaphylaxis, graft rejection, renal disease, CNS disorders and numerous inflammatory conditions. Ginkgolides are now being developed as therapeutic agents and very promising results have been obtained in clinical trials on shock, organ preservation and thermal injury. In addition to ginkgolides, several other types of natural PAF antagonists have been identified from various medicinal plants. These compounds have not only helped to explain the pharmacological basis of several traditional medicines. but have also provided man with a valuable new class of therapeutic agents.

Pietta, P., P. Mauri, et al. (1991). Gas chromatographic-mass spectrometric analysis of ginkgolides produced by Ginkgo biloba cell culture. J Chromatogr. Amsterdam : Elsevier Science Publishers. Dec 27: 281-287.

Hager, K. P., U. Jensen, et al. (1991). Identification of flavonoids from Ginko biloba L., Anthemis nobilis L. and Equisetum arvense L. by high-perormance liquid chromatography with diode-array UV detection. J Chromatogr. Amsterdam : Elsevier Science Publishers. Aug 16: 223-231.

Kraus, J. (1992). The N-terminal amino acid sequence of the beta-subunit of the legumin-like protein from seeds of Ginkgo biloba. Phytochemistry. Oxford : Pergamon Press. Feb: 523-525.

The sequence of the first 52 amino acids at the N-terminus of the beta-subunit of a legumin-like protein from seeds of the gymnosperm Ginkgo biloba were determined by automated sequencing and DABITC/PITC microsequence analyses of peptides derived from the protein by enzymatic digestions and chemical cleavage with CNBr. The protein from Ginkgo exhibits sequence homologies (32-49% identities) with the 11S globulins and legume-like proteins from seeds of various angiosperm monocotyledons and dicotyledons.

Carrier, D. J., N. Chauret, et al. (1991). Water-soluble polysaccharides from Ginkgo biloba leaves. Phytochemistry. Oxford : Pergamon Press: 3017-3020.

The water-soluble polysaccharides from dried Ginkgo biloba leaves were isolated after exhaustive extraction with organic solvents, The polysaccharide mixture could be separated into a neutral (GF1) and two acidic (GF2 and GF3) polysaccharide fractions by ion exchange chromatography. According to the Mr distribution GF1 and GF3 seemed to be homogenous, whereas GF2 could be further fractionated into two subfractions (GF2a and GF2b) by gel permeation chromatography. GF1 (Mr 23 000) showed the structural features of a branched arabinan. The main chain was composed of 1,5-linked arabinose residues and three in 12 arabinose molecules were branched via C-2 or C-3. GF2a (Mr 500 000) consisted mainly of 1,2,4-branched mannose (29%), 1,4-linked glucuronic (32%) and galacturonic (8%) acid as well as terminal rhamnose (25%). After removal of ca 70% of the terminal rhamnose the remaining polysaccharide showed a decrease in 1,2,4-branched mannose and an increase in 1,2-linked mannose indicating that at least half of the rhamnose residues were linked to mannose via C-4. GF3 (Mr 40 000) consisted of 1,4-linked galacturonic (30%) and glucuronic (16) acid, 1,3,6-branched galactose (15%), 1,2-linked (5%) and 1,2,4-branched (3.5%) rhamnose as well as 1,5-linked arabinose (11%). Rhamnose (5%) and arabinose (10%) were present as terminal groups. Mild acid hydrolysis selectively cleaved arabinose and the remaining polysaccharide showed an increased amount of 1,6-linked and terminal galactose and a decreased quantity of 1,3,6-branched galactose. These results indicated that the terminal as well as the 1,5-linked arabinose were mainly connected to galactose via C-3. The GF3 polysaccharide appeared to be a rhamnogalacturonan with arabinogalactan side chains.

Tyler, V. E. (1991). Detection of ginkgolide A in Ginkgo biloba cell cultures. Plant Cell Rep. Berlin, W. Ger. : Springer International: 256-259.

Ginkgo biloba cells were cultured in two 500 mL shake flasks and in 2 L and 6 L immobilization bioreactors using MS medium supplemented with 1 mg.L-1 NAA, 0.1mg.L-1 K and 30 g.L-1 sucrose. Specific growth rates were 0.06 d-1, 0.11 d-1 and 0.07 d-1 for the 2 L and 6 L bioreactors and shake flask cultures, respectively. Extracellular phosphate, nitrate, ammonium and carbohydrate uptake rates of the bioreactor cultures were approximately 17 to 39% slower than those of shake flask cultures. The specific oxygen uptake and carbon dioxide transfer rates of immobilized Ginkgo biloba cells ranged from 0.027 to 0.041 mmol O2.g-1.d.w.hr-1 (maximum uptake at 14 days) and 0.020 to 0.057 mmol CO2.g.-1.d.w.hr-1 (maximum production at 14 days). Extracts from the biomass of the two immobilized and shake flask suspension cultures were analysed for ginkgolide A by GC-MS. Yields of 7, 17, 19 and 7 ng.g.(-1)d.w. of ginkgolide A were determined for shake flask 1, shake flask 2 and the 2 L and 6 L immobilized cultures, respectively. Traces of ginkgolide B were detected with the signal to noise ratio, however, being too low for positive confirmation of this last product.

Manum, S. B., M. N. Bose, et al. (1991). Ginkgo extract: miracle or. Nutr Forum. Hagerstown, Md. : J.B. Lippincott Company. May/June: 23-24.

The Foundation for the Advancement of Innovative Medicine (FAIM) has as a mission the securing of free choice in health care. They define innovative medicine as "a treatment or therapy of empirical benefit that is yet outside the mainstream of conventional medicine." These ideas are discussed in this article.

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A variety of terrestrial and aquatic plant species were tested for the presence of polyphenol oxidase (PPO), using three different assay protocols. All aquatic green algae (Chlorella, Stigeoclonium, Microspora, Ulva and Spirogyra) tested have no detectable PPO except for a Trebouxioid alga (lichen symbiont), and Coleochaete. Of the Charalean algae Chara and Nitella, only the latter had measurable activity. Some hepatics (Conocephalum and Marchantia) possess the enzyme, but two species of Riccia tested do not. The anthocerotes Phaeoceros, Anthoceros and Notothylas have low, but easily detectable PPO. The mosses, Dicranum, Sphagnum and Thuidium, have no detectable activity. All of the ferns and fern allies tested have PPO activity. Among seed plants, PPO is undetectable in Ginkgo or any of the conifers tested. All but two species of the angiosperms surveyed possessed the enzyme. The Mr, as determined by semi-native electrophoretic mobility, ranged widely from 30 000 to 200 000, depending upon species. All species with PPO activity measured by spectrophotometric or gel assay had cytochemically-detected activity localized to the thylakoid membranes, with cytochemical product accumulating in the lumen of the thylakoid.

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Prideaux, B. H. (1972). The presence of isocitrate lyase and malate synthase activity in germinating Ginkgo biloba seeds. Experientia, Apr 28(4): 405-406.

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Wang, F. H. and Z. K. Chen (1984). Ginkgo tree named Shangri-La [Ginkgo biloba, rapid, compact growth habit growing 55 feet in height with a 40 foot branch spread in 17 years, dense full crown caused by an addition to the basic scaffold, the supplementary or secondary branches occurring throughout the center of the crown giving the tree crown a heavy, full appearance, straight trunk, ease of propagation and freedom from production of foul smelling fruit, varieties]. U S Pat Plant U S Pat Trademark Off. Washington, D.C. : The Office. Apr 17(5221).

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Lobstein, G. A., S. F. Briancon, et al. (1983). Synthesis of mammalian dolichols from plant polyprenols [isolated from Ginkgo biloba]. Tetrahedron Lett. Oxford : Pergamon Press: 5103-5106.

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Zhang, G. Z. and Z. S. Li (1983). Cytokinins in the leaves of Ginkgo biloba. I. The complex in mature leaves. Plant Physiol. Rockville : American Society of Plant Physiologists. Oct: 223-227.

Shim, K. K. and Y. H. Ahn (1981). Preliminary study on Pammene sp. [Ginkgo trees, China]. J Nanjing Tech Coll For Prod. Nan ching shih : Kai hshueh yhuan. Dec 4: 83-89.

Ibata, K., M. Mizuno, et al. (1982). Seasonal changes in nitrogenous compounds in senescing leaf and bark tissues of the gingko trees Ginkgo biloba. Han'guk Wonye Hakhoe Chi J Korean Soc Hortic Sci. Suwon : The Society. Dec: 314-322.

Watson, G. W. and E. B. Himelick (1983). Long-chain betulaprenol-type polyprenols from the leaves of Ginkgo biloba. Biochem J Mol Aspects Rapid Papers. London : The Biochemical Society. Aug 1: 305-311.

Santamour, F. S., Jr., S. A. He, et al. (1982). Seasonal variation in root regeneration of transplanted trees Norway maple, green ash, ginkgo, Acer plantanoides, Fraxinus pennsylvanica, Ginkgo biloba. J Arboric. Urbana : International Society of Arboriculture. Dec: 305-310.

Santamour, F. S., Jr., S. A. He, et al. (1983). Checklist of cultivated ginkgo Ginkgo biloba. J Arboric. Urbana : International Society of Arboriculture. Mar: 88-92.

Kausch, A. P. and H. T. Horner (1983). Growth, survival and sex expression in ginkgo Ginkgo biloba. J Arboric. Urbana : International Society of Arboriculture. June: 170-171.

Rohr, R. (1982). A comparison of calcium oxalate crystals isolated from callus cultures and their explant sources Ginkgo biloba, Canavalia ensiformis, Glycine max, Phaseolus vulgaris, Cissus quadrangularia, Malus domestica, Capsicum annuum, Psychotria punctata. Scanning Electron Microsc. AMF O'Hare : Scanning Electron Microscopy, Inc: 199-211.

Yim, K. B. and K. J. Lee (1981). In vitro culture of female gametophytes of Ginkgo biloba L. = Evolution en culture in vitro des prothalles femelles ages chez Ginkgo biloba L. New Delhi : Amerind Publishing Co. Pvt. Ltd. 13.

Adawadkar, P. D. and S. M. A. El (1980). Alteration of endogenous growth regulators in cold-moist stratified seeds of Ginkgo biloba L. Proceedings of the International Symposium on Forest Tree Seed Storage : September 1982: 204-211.

Briancon, S. F., A. Guth, et al. (1981). Isolation, purification and antimicrobial activity on anacardic acids from Ginkgo biloba fruits. Fitoterapia. Milano, Italy, Inverni della Beffa: 129-135.

Zhong, H. W., Z. H. Yang, et al. (1982). High-performance liquid chromatography of biflavones from Ginkgo biloba L. J Chromatogr. Amsterdam, Netherlands, Elsevier Scientific. Aug 20: 261-267.

Zhu, J. J. and H. Jiang (1982). Peroxidase isozyme pattern as a biochemical test to distinguish the sex of individual plant in Ginkgo biloba L. Lin Yeh Hsueh Sci Silvae Sin. Peking, s.n.: 1-5.

Humphreys, J. D. R. (1982). Analysis on amino acid of pollen anther and stem meristematic tissues of Ginkgo biloba L. and Pinus elliottii Englm. apex. Lin Yeh Hsueh Sci Silvae Sin. Peking, s.n.: 80-84.

Vincieri, F. F., M. T. Vincenzini, et al. (1982). Phoma exigua on Ginkgo biloba Associated with a severe stem die-back, bud and leaf rot. Plant Pathol. London, Eng., Her Majesty's Stationery Office. Mar: 91-93.

McWhannell, R. (1981). Extraction of active compounds from sarcotesta of Ginkgo biloba seed: inhibition on some dehydrogenases activity. Riv Ital Essenze Profum Piante Off Aroma Synd Saponi Cos Aero. Milano, Redazione e Amministrazione. Mar/Apr: 79-82.

Fujimoto, S., S. Nakashima, et al. (1980). In the beginning...Growing of Gingko biloba, Maidenhair tree. Arboric J. Oxford, Arboricultural Association. Oct: 136-141.

Trenin, V. V. (1981). Studies on starches of wild plants in Japan. 3. Starches from Ara-kashi (Quercus glauca), Suda-jii (Castanopsis cuspidata var. sieboldii), Sotetsu (Cycas revoluta), Icho (Ginkgo biloba), Sharin-bai (Rhaphiolepis unbellata) and Biwa (Eriobotrya japonica). Denpun kagaku J Jap Soc Starch Sci. Tokyo, The Society: 180-187.

Del, T. P. (1981). The ultrastructure of the sporogenous cells of Ginkgo biloba microsporangium. Bot Zh. Leningrad, "Nauka". Feb: 275-277.

Kotaeva, D. V. and E. I. Chkhubianishvili (1981). Arnoldia. Jamaica Plain, Mass., Arnold Arboretum. July/Aug: 150-161.

Paterson, A. (1981). Membrane proteins of some dioecious plants Cephalotaxus fortunei, Ginkgo biloba, Acer negundo. zv Akad Nauk Gruz S S R Ser Biol Proc Acad Sci Georgian S S R Biol Ser. Tbilisi, "Metsniereba": 249-253.

Christensen, T. G. (1981). Garden J R Hortic Soc. London, New Perspectives Publishing. May: 224-225.

Yim, K. B. and K. J. Lee (1971). A study of the resistance of Ginkgo biloba L. to fungi : phytoalexin production induced by Botrytis allii Munn. 76.

Hutton, M. J. and S. J. Van (1980). Alteration of endogenous growth substances in cold-moist stratified seed of Ginkgo biloba L. Bull Seoul Natl Univ For Seoul Taehakyo Yonsuplim Pogo. Seoul, Yonsuplim, Seoul Taekkyo. Dec 16: 10-16.

Takaso, T. (1981). Ann Bot. London, Academic Press. Apr: 527-529.

Kobayasi, Y. (1980). Shokubutsu Kenkyu Zasshi J Jap Bot. Tokyo, Tsumura Laboratory. Jan: 14-27.

Gilman, E. F., I. A. Leone, et al. (1980). The maidenhair trees (Ginkgo biloba) planted in several botanical gardens in Europe in Kew, England, Zurich, Leiden and Padua, Italy. Shokubutsu Kenkyu Zasshi J Jap Bot. Tokyo, Tsumura Laboratory. Apr: 122-123.

Rohr, R. (1981). For Sci. Washington, D.C., Society of American Foresters. Mar: 13-18.

Topa, E. (1980). In vitro development of the male gametophyte of Ginkgo biloba L. Developpement in vitro du pollen de Ginkgo biloba L. Cytologia. okyo, Kokusai Saibo Gakkai. Sept: 481-495.

Tanaka, R. and M. Hizume (1977). Ginkgo biloba, an old, stately and venerable worldwide tree, which, however, is not grown, utilized and protected enough Romania. Ginkgo biloba, ein alter, stattlicher und erwurdiger Weltbaum, der jedoch zu wenig gezuchtet, verwertet und geschutzt wird. Lucr Gradin Bot Bucur Acta Bot Horti Bucur. Bucuresti, Gradina Botanica a Universitati Bucuresti.

Joly, M., B. M. Haag, et al. (1980). Bot Mag. Tokyo, Botanical Society of Japan. June: 167-170.

Davies, D. J. G. (1980). 5'-methoxybilobetin, a biflavone isolated from leaves of Ginkgo biloba. La 5'-methoxybilobetine, une biflavone extraite du Ginkgo biloba. Phytochemistry. Oxford, Pergamon Press: 1999-2002.

Furukawa, A., O. Isoda, et al. (1979). Alternative land uses in New Zealand : with emphasis on temperate tree crops : proceedings of a course held at Lincoln College, Canterbury, New Zealand 1979: 103-108.

Ameele, R. J. (1979). Seibutsu Kankyo Chosetsu Environ Control Biol. Fukuoka, Japanese Society of Environment Control in Biology. Dec: 153-159.

Hara, N. (1980). Developmental anatomy of secretory cavities in the microsporophylls of Ginkgo biloba L. Am J Bot. Columbus, Ohio, Botanical Society of America. July: 912-917.

Gifford, E. M., Jr. and S. Larson (1980). Bot Mag. Tokyo, Botanical Society of Japan. Mar: 1-12.

Geiger, H. (1980). Developmental features of the spermatogenous cell in Ginkgo biloba. Am J Bot. Columbus, Ohio, Botanical Society of America. Jan: 119-124.

Kolmakova, A. A., B. F. Abdullaev, et al. (1979). 3'-O-methylmyricetin-3-rhamnoglucoside a new flavonoid from the autumnal leaf of Ginkgo biloba L. 3'-O-methylmyricetin-3-rhamnoglucosid, ein neues Flavonoid aus dem Herbstlaub von Ginkgo biloba L. Z Naturforsch Sec C Biosci. Tubingen. Zeitschrift fur Naturforschung. Sept/Oct: 878-879.

Pourchot, M. E. (1979). Comparative study of the total tRNA in cotton and Ginkgo biloba seeds. Khim Prir Soedin. Tashkent, "Fan" 1: 54-56.

Rohr, R. (1980). Am For. Washington, D.C., American Forestry Association. May.

Kolmakova, A. A., B. F. Abdullaev, et al. (1980). Dedifferentiation of the storage-cells of the Ginkgo biloba endosperm cultured in vitro. Dedifferenciation en culture in vitro des cellules a reserves dans l'endosperme de Ginkgo biloba. Z Pflanzenphysiol Int J Plant Physiol. Stuttgart, Gustav Fischer: 423-434.

Pourchot, M. E. (1979). Comparative study of the total tRNA in cotton and Ginkgo biloba seeds. Khim Prir Soedin. Tashkent, "Fan" 1: 54-56.

Rohr, R. (1980). Am For. Washington, D.C., American Forestry Association. May.

Shim, K. K., K. H. Chung, et al. (1980). Dedifferentiation of the storage-cells of the Ginkgo biloba endosperm cultured in vitro. Dedifferenciation en culture in vitro des cellules a reserves dans l'endosperme de Ginkgo biloba. Z Pflanzenphysiol Int J Plant Physiol. Stuttgart, Gustav Fischer: 423-434.

Chernobrivets, V. T. and F. L. Shchepot'ev (1978). Han'guk Wonye Hakhoe Chi J Korean Soc Hortic Sci. Suwon, The Society. May 13: 78-81.

Rohr, R. (1979). Mutational variability of ginkgo under the influence of gamma rays. Subtrop Kul't. Makharadze, Vsesoiuznyi nauchno issledovatel'skii institut chaia i subtropicheskikh kul'tur 3: 49-50.

Rohr, R. (1978). Existence of a mitochondrial reticulum in the haploid tissue culture of a vascular plant Ginkgo biloba. Existence d'un reticulum mitochondrial dans les cellules d'une culture de tissue haploide d'une plante vasculaire. Biol Cell. Ivry Sur Seine, Societe francaise de microscopie electronique Oct: 89-92.

Noland, T. L. and T. T. Kozlowski (1979). Three-dimensional reconstruction of the chondriome of Ginkgo biloba in tissue culture: study by means of thick sections and serial thin sections. Reconstruction tridimensionnelle du chondriome de ginkgo en culture tissulaire; etude au moyen de coupes epaisses et de coupes fines seriees. Can J Bot. Ottawa Feb 15: 332-340.

Tsuyuki, H., S. Itoh, et al. (1979). Can J For Res. Ottawa, National Research Council of Canada Mar: 57-62.

Molotkovskii, G. K. and A. A. Sokol (1979). Studies on the lipids in Ginkgo biloba seeds. Bull Coll Agric Vet Med Nihon Univ. Tokyo, Nihon Daigaku No Jui Gakkai Mar 36: 156-162.

Casal, H. L. and P. Moyna (1978). Content and topography of proteins and sugars in the leaves of male and female Ginkgo biloba plants and in Asparagus cladodes. Fiziol Rast Mosk. Moskva, "Nauka". Nov/Dec: 1270-1272.

Van, S. J. (1979). Components of Ginkgo biloba leaf wax. Phytochemistry. Oxford, Pergamon Press: 1738-1739.

Swink, F., M. T. Hall, et al. (1979). Z Pflanzenphysiol. Stuttgart, G. Fischer.: 399-405.

Molotkovskii, G. K. and A. A. Sokol (1978). Morton Arbor Q. Lisle, Ill., Morton Arboretum. Summer: 28-32.

Swink, F., M. T. Hall, et al. (1978). Content and topography of proteins and sugars in leaves of male and female ginkgo plants and in asparagus cladodes. Sov Plant Physiol. New York, Consultants Bureau. Nov/Dec: 1006-1008.

Skirvin, R. M. and M. C. Chu (1978). Morton Arbor Q. Lisle, Ill., Morton Arboretum. Summer: 28-32.

(1979). Ginkgo: a beautiful tree with edible seeds. Ill Res. Urbana, The Station. Fall: 10-11.

Baudouin, C., P. J. Pisella, et al. (1999). Effects of EGb761 and superoxide dismutase in an experimental model of retinopathy generated by intravitreal production of superoxide anion radical. Graefe's Archive for Clinical and Experimental Ophthalmology 237(1): 58-66.

Background: A study was carried out to investigate the effect of two antioxidants - Ginkgo biloba extract (EGb761) and superoxide dismutase (SOD) - in an experimental model of vitreoretinopathy obtained by direct production of oxygen free radicals in the vitreous cavity. Methods: Twenty-eight pigmented rabbits were used. Vitreoretinopathy was induced by intravitreal injection of 50 mul of a mixture composed of 40 nmol of xanthine and 0.001 IU of xanthine oxidase. Rabbits were randomly distributed into four groups: Group 1 (n=8) did not receive any treatment and served as a positive control. Groups 2 (n=8) and 3 (n=8) received for 1 month EGb761 given orally at a dose of 100 mg/kg/day, respectively 1 day after and 1 week before induction of retinopathy. Group 4 (n=4) was treated by three intramuscular injections of 15 000 IU/kg of SOD, 24 h before induction and 24 and 48 h thereafter. Clinical evaluations and electroretinograms (ERG) were repeatedly performed until the animals were killed at day 28. Histological examinations and immunohistological procedures were performed to ascertain the origin and characteristics of the cellular proliferation and to compare vitreoretinal structures in the four groups. Results: Intravitreal injection of xanthine-xanthine oxidase produced a strong inflammatory response with vitreous infiltrates and epiretinal membrane formation, inconstantly associated with retinal detachment. ERG showed a decrease of the a-, b- and c-waves beginning within a few hours after injection. Histologic evaluation found an intravitreal and epiretinal infiltration by leukocytes and epithelial-derived cells, dense vitreoretinal membranes and retinal detachments with occasional neovascularization. In the treated groups (groups 2-4), all clinical, electric and histologic data were significantly improved compared to the control group. However, no difference could be found among the three treated groups. Conclusion: This study demonstrates the strong pathologic effects of free radical production on the retina and the close relationships between free radicals, inflammatory pathways and vitreoretinal proliferative disorders. It also confirms the pharmacological interest of prevention by antioxidants and free radical scavengers.

Nguyen, T. T. T., H. Bocherens, et al. (1999). Ecological distribution of Cenomanian terrestrial plants based on 13C/12C ratios. Palaeogeography Palaeoclimatology Palaeoecology 145(1-3): 79-93.

The Cenomanian lagoonal member of the 'Argiles du Baugeois' (Anjou, France) yielded a rich and exceptionally well-preserved fossil leaf flora. Stable carbon isotope ratios of fossil plants were measured in order to investigate the presence of a palaeoenvironmental signal. The small intraspecies variations of delta13C values observed for most of the fossil leaves suggested that the isotopic signal had not been significantly altered. Hence, an isotopic approach was used as an attempt to assist in reconstructing the ecological distribution of the flora. The 13C-enrichment of the fossil leaves suggested that the plants underwent water or salt stress. The occurrence of the conifer Frenelopsis suggested, at least locally, a saline environment such as a lagoon. According to their decreasing delta13C values, all the plants collected could have been distributed along a decreasing salinity transect from the lagoon to a flood plain. The predominant species, Eretmophyllum andegavense, a fossil ginkgo, exhibited a wide range of delta13C values. This could indicate that this taxon grew in a wide range of habitats with varying salinities. The origin of the organic matter appeared to be terrestrial with a major contribution from water-stressed plants such as Frenelopsis, as suggested by the similarity between delta13C values of the conifer and the sedimentary organic matter. delta13C values of the sediment indicated stable palaeoenvironmental conditions during the deposition of the 'Argiles du Baugeois' member. Hence, while detailed palaeovegetation reconstructions are generally limited to the few deposits which present in-situ palaeoflora, the contribution of isotope geochemistry could allow reconstructions for a wider range of fossil plant deposits.

Trovero, F., D. Brochet, et al. (1999). Ginkgo biloba extract EGb761 reduces the development of amphetamine-induced behavioral sensitization: Effects on hippocampal type II corticosteroid receptors. Brain Research 818(1): 135-139.

Pretreatment of rats with the extract of Ginkgo biloba termed EGb761 reduced the behavioral sensitization induced by successive D-amphetamine administrations (0.5 mg/kg) as estimated by increasing values of locomotor activity. EGb761 pretreatment also prevented the reduced density of (3H)dexamethasone binding sites in the dentate gyrus and the CA1 hippocampal regions of D-amphetamine treated animals. These observations suggest that EGb761, by reducing glucocorticoid levels, could modulate the activity of the neuronal systems involved in the expression of the behavioral sensitization.

Vale, S. (1998). Correction of PREVIEWS 01354874. Subarachnoid haemorrhage associated with Ginkgo biloba. Correction of volume number from 253. Lancet North American Edition 253(9121): 36.

Akiba, S., T. Kawauchi, et al. (1998). Inhibitory effect of the leaf extract of Gingo biloba L. on oxidative stress-induced platelet aggregation. Biochemistry and Molecular Biology International 46(6): 1243-1248.

The effect of the leaf extract of Ginkgo biloba L. on platelet aggregation induced by oxidative stress was studied. The extract caused a dose-dependent inhibition of platelet aggregation stimulated with tert-butyl hydroperoxide (t-BHP) and Fe2+. Similar inhibitory activity was observed when platelets were exposed to H2O2 and Fe2+. Synergistic aggregation induced by a combination of t-BHP and Fe2+ or H2O2 and Fe2+ in association with suboptimal concentration of collagen or U46619, was prevented by the extract. However, the extract failed to inhibit aggregation in response to collagen, thrombin or U46619. Ginkgolides A, B and C inhibited platelet-activating factor-induced aggregation, but not oxidant-induced aggregation. These data suggest that the suppressive effect of the extract is specific on platelet aggregation stimulated by oxidative stress, and that this effect is involved in the mechanism related to its protective effect upon cerebral or myocardial injuries.

Winther, K., C. Randlov, et al. (1998). Effects of Gingko biloba extract on cognitive function and blood pressure in elderly subjects. Current Therapeutic Research 59(12): 881-888.

In this randomized, double-masked study, we assessed the effects of a Ginkgo biloba (GB-8) extract on elderly volunteers with age-related cognitive dysfunction. A total of 260 subjects were tested to obtain a homogeneous group of 60 elderly subjects with mild-to-moderate cognitive impairment, as defined by a clinical rating scale. The subjects were allocated to one of three groups and received either GB-8 40 mg or 80 mg or placebo three times daily for 3 months. Before therapy was started and after 1 and 3 months of treatment, standardized testing of attention, concentration, and memory was performed. The subjects completed self-assessments before and after 3 months of therapy, and arterial blood pressure was measured at the same intervals. Clinical ratings were done before and after 3 months of treatment. Six subjects withdrew from the study, whereas 54 subjects (31 women and 23 men; mean age, 74 years; age range, 61 to 88 years) completed the study. After randomization, the groups were similar with respect to age, social class, level of education, and demographic characteristics. Objective test results showed that attention, concentration, and short-term verbal memory improved significantly in subjects receiving the low-dose (standard) treatment. Similar improvements were seen in the results of the self-assessment test and the clinical rating. Diastolic blood pressure decreased significantly during low-dose treatment. Treatment with the GB-8 extract was found to improve objective measures of cerebral function in elderly subjects with mild-to-moderate cognitive impairment; the improvement appeared to be clinically relevant. The possible antihypertensive action of Ginkgo biloba extract is sufficient to warrant further investigation.

Rapin, J. R., M. Zaibi, et al. (1998). In vitro and in vivo effects of an extract of Ginkgo biloba (EGb 761), ginkgolide B, and bilobalide on apoptosis in primary cultures of rat hippocampal neurons. Drug Development Research 45(1): 23-29.

Primary cultures of rat hippocampal neurons were prepared and exposed to increasing concentrations of a peroxyl radical-generator, 2,2'-azobis 2 amidinopropane (AAPH). Addition of AAPH (20 or 50 mM) to the medium caused a decrease in cell viability and an increase in the number of apoptotic cells. Values for the number of nucleosomes were obtained using an ELISA technique. "Factor F," an indicator of enrichment in nucleosomes, was found to be directly proportional to the number of neuronal apoptoses. Addition of an extract of Ginkgo biloba (EGb 761; 5-20 mug/ml) or ginkgolide B (one of its terpenoid constituents; 0.2 or 0.4 mug/ml) to the culture medium in vitro led to increases in cell viability and decreases in the number of hippocampal cells undergoing AAPH-induced apoptosis, whereas addition of bilobalide (another terpenoid constituent of EGb 761; 0.1-1.0 mug/ml) was ineffective. These in vitro results were corroborated and extended when these same substances were administered to rats in vivo. Oral administration of EGb 761 (50 mg/kg/day) for 8 days caused a significant increase in cell viability and a highly significant decrease in the numbers of both spontaneously occurring and AAPH-induced apoptoses. Similar protective effects were observed with ginkgolide B (2 mg/kg/day, p.o.), whereas bilobalide (2 mg/kg/day, p.o.) was ineffective. As AAPH enhances the production of peroxyl radicals, the protective actions of subacute in vivo treatments with EGb 761 and ginkgolide B appear to be associated with an anti-lipoperoxidative effect of these substances.

Roesler, M., W. Retz, et al. (1998). Free radicals in Alzheimer's dementia: Currently available therapeutic strategies. Journal of Neural Transmission Supplement 54: 211-219.

Substantial evidence now exists that oxidative stress may play an important role in the etiopathogenesis of DAT. The different sources of oxidative stress in DAT are suggesting several pharmacological opportunities for influencing the disease. It is possible to distinguish 2 major types of possible therapeutic agents according to their pharmacological point of attack. 1. Radical scavengers, agents directly interacting with free radicals. Candidates of this type are ginkgo biloba, vitamins A,C,E and estrogen. 2. Antioxidants, which are able to prevent or decrease the production of free radicals by use of specific neuropharmacological properties. Candidates are selegiline, a MAO-B inhibitor well established in the therapy of Parkinson's disease, and tenilsetam, which is believed to be an AGE-inhibitor. Recent in vitro studies have demonstrated the efficacy of both types of therapeutic agents by preventing or delaying oxidative neural damage. Some clinical data exist regarding the antidementive properties particularly in terms of ginkgo biloba, selegiline and vitamin E. The efficacy studies about these compounds seem to indicate a promising future strategy in the therapy of DAT. But it is too early to draw definite conclusions since it is well known that all of our candidate substances do not act specifically as radical scavengers or antioxidants.

Janssens, D., C. Michiels, et al. (1999). Increase in circulating endothelial cells in patients with primary chronic venous insufficiency: Protective effect of Ginkor Fort in a randomized double-blind, placebo-controlled clinical trial. Journal of Cardiovascular Pharmacology 33(1): 7-11.

One possible mechanism that accounts for the alterations observed in varicose veins is the activation of endothelial cells by ischemia occurring in the leg veins during blood stasis and the cascade of reactions that follows. Because in vitro data suggest that endothelium alteration is a key event in the development of the pathology, it was important to confirm this hypothesis in patients. We used the number of circulating endothelial cells detached from the vascular wall as a criterion of the endothelium injury. We first compared the number of circulating endothelial cells (CECs) in patients with chronic venous insufficiency (CVI) with those of a control population. A twofold increase in the CEC count (1,001 +- 127 CEC/ml of plasma compared with 514 +- 82 CECs/ml) was observed in CVI patients, which indeed suggests an alteration of the endothelium in this disease. Second, the protective effect of a venotropic drug, Ginkgo biloba extract, troxerutine, and heptaminol (Ginkor Fort), was tested by a randomized double-blind, placebo-controlled clinical trial. In the active-treatment group, the mean values of the CEC count decreased by 14.5% after a 4-week treatment, whereas in the placebo group, the decrease was less (8.4%). The decrease from week 0 to the end of treatment was significantly higher in the active-treatment group than in the placebo group. These results confirm the important role of the endothelium alterations in the development of varicose veins and suggest a potential beneficial action of a venotropic drug on the venous wall.

Han, N. and K. Wang (1998). Study on use of hybrid vigor for gingko. Forest Research 11(5): 533-536.

Experiments on pollination with gingko pollens collected from different places in Zhejiang or Hubei Province were conducted, then the seeds were collected and seedlings from those seeds were cultivated. The result indicated that the descendants from long-distance pollination showed significant growth dominance over those from domestic pollination. Comparing two-year-old seedlings, the increment of height, diameter of root collar, the number of bud and leaf increased by 28.2%apprx55.0%, 13.2%apprx18.3%, 29.5%apprx61.8%, 41.0%apprx68.8% respectively. The growth dominance increased also with the distance between pollen sources and receptor trees. The experiment also revealed that the content of ginkgolide in the leaf is hereditable.

Wang, J., G. Wei, et al. (1998). Annual dynamic of nutrient elements in gingko seeds and relations with dropped seed. Forest Research 11(5): 469-473.

The contents of N, P, K, Ca, Mg, Zn, Fe, Mn in Ginkgo biloba seeds were determined and analyzed. The result shows that the annual dynamic in content of N, P, K, Ca, Mg presents a gradual decreasing trend from spring to autumn, but the decreasing range of every element is different in different growing stages of seeds. From the end of April to the middle of May and from the end of May to the beginning of June are two drastically decreasing stages in content of elements during the whole growing season. Annual contents variation of micronutrients (Zn, Fe, Mn) in seeds are various and irregular. The contents of nutrient elements between normal developmental seeds and dropped seeds are significantly different. The contents of elements in mature seeds are N: 10.4 g/kg, P: 1.3 g/kg, K: 14.9 g/kg, Ca: 1.3 g/kg, Mg: 0.9 g/kg, Zn: 27.6 mg/kg, Fe: 10.0 mg/kg, Mn: 3.2 mg/kg. The contents of N, K, Ca, Zn and Fe are higher in gingko seeds compared with those of other fruit trees.

Maggini, F., R. Marrocco, et al. (1998). Lengths and nucleotide sequences of the internal spacers of nuclear ribosomal DNA in gymnosperms and pteridophytes. Plant Systematics and Evolution 213(3-4): 199-205.

The nucleotide sequences of the internal transcribed spacers (ITS1 and ITS2) of the nuclear ribosomal DNA were analyzed in species belonging to gymnosperms and pteridophytes. The lengths of the ITSs of sixteen species of gymnosperms and seven species of pteridophytes were estimated. The gymnosperms have ITS1 regions larger than those observed in the pteridophytes and angiosperms (ca. 610-3100 bp versus 159-360 bp). On the other hand, the ITS2 regions appear to be of a conserved length (182-370 bp). We have determined the complete nucleotide sequences of ITS regions from four gymnosperm species and five pteridophyte species by cloning the PCR products. Sequence analysis showed the presence of three short tandem arranged subrepeats of about 70 bp in the 1112 bp ITS1 of Ephedra fragilis. Pyrimidine rich (about 90%) DNA segments of 40-50 bp were observed in the ITS1 of Ginkgo biloba. A highly conserved 16 bp long sequence known to be present in the ITS1 of the angiosperm species has been also found in the ITS1 of Cycas revoluta, Taxus baccata and Ephedra fragilis.

Li, C. X., L. Li, et al. (1998). The protective effects of traditional Chinese medicine prescription, Han-Dan-Gan-Le, on CCl4-induced liver fibrosis in rats. American Journal of Chinese Medicine 26(3-4): 325-332.

Han-Dan-Gan-Le, a Chinese medicine preparation composed of Salvia miltorrhiza, Radix paeoniae, Astragalus membranaceus, Stephania tetrandra, and dried leaves of Ginkgo biloba, has been used successfully to treat human liver fibrosis and cirrhosis for years. This study was designed to examine the mechanisms of the protection. Male Wistar rats were given CC14 (1.2 ml/kg, 2 times/week), 20% fat diet, and 30% alcohol in drinking water (every other day) for 6 weeks. Han-Dan-Gan-Le (0.5 and 1.0 g/kg, p.o., daily for 6 weeks) was administered to rats simultaneously to examine the protective effects against CCl4-induced liver fibrosis. The experimentally-induced liver fibrosis and other morphological alterations were significantly ameliorated by Han-Dan-Gan-Le. Han-Dan-Gan-Le treatments decreased CCl4-induced hepatic collagen accumulation by more than 50%, and significantly increased urinary excretion of hydroxyproline. The CCl4-induced lipid peroxidation in liver and serum was ameliorated as a result of Han-Dan-Gan-Le treatment, possibly by restoring the activity of superoxide dismutase activity in liver and erythrocytes, In conclusion, Han-Dan-Gan-Le is effective in protecting against liver fibrosis. The mechanisms of the protection appear to be due to its antioxidant properties and the modulation of hepatic collagen metabolism.

Lee, S. G., Y. D. Kwon, et al. (1997). Occurrence of Mahasena aurea (Butler) (Lepidoptera: Psychidae) attacking Ginkgo biloba L. and its life cycle in Korea. Korean Journal of Applied Entomology 36(3): 243-248.

The local distribution and life cycle of Mahasena aurea (Butler) attacking Ginkgo biloba L. in Seoul and Incheon areas were studied during 1994 apprx 1996. The species had one generation a year. The overwintered 3rd larvae begin to feed on buds of the host plant from mid May and then on the leaves until early June. Newly hatched larvae mostly infested the leaves from mid August to late September. Pupation took place from mid June to early July, and the moths emerged in early July.

Hodisan, T., M. Culea, et al. (1998). Separation, identification and quantitative determination of free amino acids from plant extracts. Journal of Pharmaceutical and Biomedical Analysis 18(3): 319-323.

This research presents the results obtained from the separation, identification and quantitative determination of free amino acids from Gingko biloba and Hedera helix leaf extracts, using three modem techniques: thin layer chromatography (TLC), high performance liquid chromatography (HPLC), and gas chromatography-mass spectrometry. The presence of the determined amino acids explains the utilization of G. biloba and H. helix leaf extracts in cosmetic and pharmaceutical products.

Pitchumoni, S. S. and P. M. Doraiswamy (1998). Current status of antioxidant therapy for Alzheimer's disease. Journal of the American Geriatrics Society 46(12): 1566-1572.

Accumulating evidence from preclinical and clinical studies supports the hypothesis that oxidative stress may be associated with the onset and progression of Alzheimer's Disease (AD). Antioxidant therapies are being promoted in the lay press to enhance mental functions and delay cognitive losses with aging. An increasing number of physicians are also recommending antioxidant therapies, such as high dose vitamin E, for subjects with AD and other neurodegenerative disorders. High dose vitamin E, ginkgo biloba, and selegiline are three putative antioxidants that have been tested in randomized multicenter trial conditions in the US. This paper summarizes the oxidative stress hypothesis of AD and reviews the strengths and limitations of published antioxidant studies in AD in relation to the role of such therapies in practice.

Shen, L., Y. Cui, et al. (1998). Effects of the leaf of Ginkgo biloba L. extract on blood rheology in animals. Zhongguo Zhongyao Zazhi 23(10): 622-623, 640-641.

Objective: To observe the effects of the leaf of Ginkgo biloba extract(GBE) on viscosity and elasticity, coagulation of blood and aggregation of blood platelets. Method: The viscosity and elasticity of the whole blood in rats - determined using an in vitro method. The half inhibitory concentration of the drug inhibiting rabbit platelet aggregation was also determined using ADP as an inducer. The blood coagulation in mice was recorded with a coagulation analyser after GBE was administrated by vein injection. Result: GBE significantly lengthened the recalcium time, lowered the increase ratios of viscosity and elasticity, and reduced the maximum viscosity and elasticity. At doses of 100 and 200 mg/kg administrated by vein injection GBE lengthened the coagulation time, reduced the fibriogenesis and clot retraction ratio significantly in mice. GBE can also inhibit rabbit platelet aggregation induced by ADP and promote the disband of the aggregated platelets. Conclusion: GBE is helpful in reducing viscosity and elasticity of the whole blood, slowing blood coagulation and inhibiting platelet aggregation.

Pietta, P., P. Simonetti, et al. (1998). Antioxidant activity of selected medicinal plant. Journal of Agricultural and Food Chemistry 46(11): 4487-4490.

Commonly used medicinal plant extracts with standardized content of polyphenols were investigated for their total antioxidant activity (TAA). Green tea, oligomeric procyanidins (from grape seed and pine bark), bilberry, and ginkgo exhibited TAA in the range of 5.12-2.57 mM Trolox, thereby indicating a valuable antioxidant capacity. Witch hazel, propolis EPID, artichoke, and hawthorn afforded lower TAA (1.54-0.44 mM Trolox), whereas echinacea, ginseng, passionflower, sweet clover, and eleuthero were rather ineffective (TAA < 0.32 mM Trolox). Excipients normally used to prepare the extracts did not interfere with the assay, and a good correlation between the content of polyphenols and the TAA was assessed. The measured TAA was higher than those calculated from the content and antioxidant potential of specific components, as exemplified for green tea and ginkgo extracts. This may be attributed to the presence in these extracts of other substances with antioxidant capacity. On the other hand, some components (such as ginkgolides in ginkgo extract) insensitive to the TAA assay played an important antioxidant role in vivo. These results suggest that TAA determination is of interest for a comparative evaluation of in vitro antioxidant potential, but it needs to be combined with in vivo data for adequate assessment of the antioxidant capacity of medicinal plant extracts.

Miller, G. L. (1998). Herbal medicinals: Selected clinical considerations focusing on known or potential drug-herb interactions. Archives of Internal Medicine 158(20): 2200-2211.

Herbal medicinals are being used by an increasing number of patients who typically do not advise their clinicians of concomitant use. Known or potential drug-herb interactions exist and should be screened for. If used beyond 8 weeks, Echinacea could cause hepatotoxicity and therefore should not be used with other known hepatoxic drugs, such as anabolic steroids, amiodarone, methotrexate, and ketoconazole. However, Echinacea lacks the 1,2 saturated necrine ring associated with hepatoxicity of pyrrolizidine alkaloids. Nonsteroidal anti-inflammatory drugs may negate the usefulness of fever few in the treatment of migraine headaches. Fever few, garlic, Ginkgo, ginger, and ginseng may alter bleeding time and should not be used concomitantly with warfarin sodium. Additionally, ginseng may cause headache, tremulousness, and manic episodes in patients treated with phenelzine sulfate. Ginseng should also not be used with estrogens or corticosteroids because of possible additive effects. Since the mechanism of action of St John wort is uncertain, concomitant use with monoamine oxidase inhibitors and selective serotonin reuptake inhibitors is ill advised. Valerian should not be used concomitantly with barbiturates because excessive sedation may occur. Kyushin, licorice, plantain, uzara root, hawthorn, and ginseng may interfere with either digoxin pharmacodynamically or with digoxin monitoring. Evening primrose oil and borage should not be used with anticonvulsants because they may lower the seizure threshold. Shankapulshpi, an Ayurvedic preparation, may decrease phenytoin levels as well as diminish drug efficacy. Kava when used with alprazolam has resulted in coma. Immunostimulants (eg, Echinacea and zinc) should not be given with immunosuppressants (eg, corticosteroids and cyclosporine). Tannic acids present in some herbs (eg, St John wort and saw palmetto) may inhibit the absorption of iron. Kelp as a source of iodine may interfere with thyroid replacement therapies. Licorice can offset the pharmacological effect of spironolactone. Numerous herbs (eg, karela and ginseng) may affect blood glucose levels and should not be used in patients with diabetes mellitus.

Crepet, W. L. (1998). The abominable mystery. Science Washington D C 282(5394): 1653-1654.

Akisu, M., N. Kultursay, et al. (1998). Platelet-activating factor is an important mediator in hypoxic ischemic brain injury in the newborn rat. Biology of the Neonate 74(6): 439-444.

Hypoxic-ischemic encephalopathy is still a very important cause of neonatal mortality and morbidity. Recently, platelet-activating factor (PAF) has been accused of being responsible for the neuronal damage in hypoxic-ischemic brain. We investigated tissue PAF concentrations in hypoxic-ischemic brain injury in immature rats. Endogenous PAF concentration in brain tissue showed a marked increase in hypoxic-ischemic pups (85.6 +- 15.5 pg/mg protein) when compared to that of control (9.05 +- 3.1 pg/mg protein). In addition, we examined the effects of flunarizine, a selective calcium channel blocker, and Ginkgo biloba extract (EGb 761) on endogenous PAF concentration in hypoxic-ischemic brain injury. Endogenous PAF concentrations in both flunarizine-pretreated (16.6 +- 4.8 pg/mg protein) and EGb 761-pretreated (33.5 +- 8.9 pg/mg protein) pups were significantly lower than the untreated group. These results indicate that PAF is an important mediator in immature rat model of cerebral hypoxic-ischemic injury. The suppressor effect of flunarizine and EGb 761 on PAF production may open new insight into the treatment of hypoxic-ischemic brain injury.

Cesarani, A., F. Meloni, et al. (1998). Ginkgo biloba (EGb 761) in the treatment of equilibrium disorders. Advances in Therapy 15(5): 291-304.

In an open, controlled study, 44 patients complaining of vertigo, dizziness, or both, caused by vascular vestibular disorders were randomly treated with extract of Ginkgo biloba (EGb 761) 80 mg twice daily or with betahistine dihydrochloride (BI) 16 mg twice daily for 3 months. A complete neuro-otologic and equilibrimetric examination was performed at baseline and after 3 months of treatment, with evaluation of clinical findings. in the first month of therapy, vertigo and dizziness improved in 64.7% of patients treated with BI and in 65% of those who received EGb 761. Compared to baseline, no statistically significant changes were observed in cranial scans for patients with a "central" cranial pattern. Likewise, no changes versus baseline were observed in both groups for the equilibrium score. The comprehensive test battery showed the following findings: EGb 761 induced a slight decrease of saccadic delay and considerably increased saccadic velocities; BI improved saccadic accuracy but did not modify delay; EGb 761 improved smooth pursuit gain at 0.4 Hz 40degree/s three times more than BI; both drugs asymmetrically reduced nystagmus maximum velocity at 40degree/s; both drugs asymmetrically improved the sinusoidal vestibulo-ocular reflex; BI considerably reduced-whereas EGb 761 considerably improved-visuovestibular ocular reflex. No side effects were recorded during the trial except for transient mild headache and gastric upset in 2 patients receiving EGb 761 and transient cyanosis of nails and lips in 1 patient given BI. These results suggest that EGb 761 and BI operate at different equilibrium receptor sites and show that EGb 761 can considerably improve oculomotor and visuovestibular function.

Oken, B. S., D. M. Storzbach, et al. (1998). The efficacy of Ginkgo biloba on cognitive function in Alzheimer disease. Archives of Neurology 55(11): 1409-1415.

Objective: To determine the effect of treatment with Ginkgo biloba extract on objective measures of cognitive function in patients with Alzheimer disease (AD) based on formal review of the current literature. Methods: An attempt was made to identify all English and non-English-language articles in which G. biloba extract was given to subjects with dementia or cognitive impairment. Inclusion criteria for the meta-analysis were (1) sufficiently characterized patients such that it was clearly stated there was a diagnosis of AD by either Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition, or National Institute of Neurological Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria, or there was enough clinical detail to determine this by our review; (2) clearly stated study exclusion criteria, i.e., those studies that did not have stated exclusions for depression, other neurologic disease, and central nervous system-active medications were excluded; (3) use of standardized ginkgo extract in any stated dose; (4) randomized, placebo-controlled and double-blind study design; (5) at least 1 outcome measure was an objective assessment of cognitive function; and (6) sufficient statistical information to allow for meta-analysis. Results: Of more than 50 articles identified, the overwhelming majority did not meet inclusion criteria, primarily because of lack of clear diagnoses of dementia and AD. Only 4 studies met all inclusion criteria. In total there were 212 subjects in each of the placebo and ginkgo treatment groups. Overall there was a significant effect size of 0.40 (P<.0001). This modest effect size translated into a 3% difference in the Alzheimer Disease Assessment Scale-cognitive subtest. Conclusions: Based on a quantitative analysis of the literature there is a small but significant effect of 3- to 6-month treatment with 120 to 240 mg of G. biloba extract on objective measures of cognitive function in AD. The drug has not had significant adverse effects in formal clinical trials but there are 2 case reports of bleeding complications. In AD, there are limited and inconsistent data that preclude determining if there are effects on noncognitive behavioral and functional measures as well as on clinician's global rating scales. Further research in the area will need to determine if there are functional improvements and to determine the best dosage. Additional research will be needed to define which ingredients in the ginkgo extract are producing its effect in individuals with AD.

Wolff, R. L., F. Pedrono, et al. (1998). The seed fatty acid composition and the distribution of DELTA5-olefinic acids in the triacylglycerols of some Taxaceae (Taxus and Torreya). Journal of the American Oil Chemists' Society 75(11): 1637-1641.

The fatty acid compositions of the seeds from three Taxus (yew) species and one Torreya species belonging to the Taxaceae family (Taxus cuspidata (Japanese yew), T. chinensis (Chinese yew), T. baccata (English yew), and Torreya grandis (Chinese nutmeg yew)) have been established. These compositions were compared with those previously published for T. canadensis (Canadian yew) and Torreya nucifera. In Taxus species, as well as in Torreya species, DELTA5-olefinic acids are present in the seed lipids from all species analyzed. In Taxus, 5,918:2 (taxoleic) acid is the prominent DELTA5-olefinic acid. It represents between 9.5 and 16.2% of total fatty acids. Other DELTA5-olefinic acids that occur in low amounts are 5,9,12-18:3 (<3.5%), 5,11-20:2 (<0.3%), 5,11,14-20:3 (<2.2%), and 5,11,14,17-20:4 (<0.3%) acids. In Torreya species, the major DELTA5-olefinic acid is 5,11,14-20:3 (sciadonic) acid (between 6.7 and 11.2%). In contrast to Taxus species, the 5,9-18:2 and 5,9,1218:3 acids are scarce in Torreya species: less than 0.1%. Also, the 9,12,15-18:3 acid content is significantly lower in Torreya than in Taxus. The prominence of taxoleic acid among DELTA5olefinic acids in the seed lipids is a unique characteristic of the genus Taxus that isolates it from all other Coniferophytes analyzed so far. However, this feature is not shared by other Taxaceae species, such as Torreya, and with regard to their seed fatty acid compositions, the family Taxaceae appears particularly heterogeneous. Our observations favor the hypothesis that in Gymnosperm seeds, there might exist two DELTA5-desaturases, one specific for unsaturated acids with a DELTA9-ethylenic bond (active in Taxus but not in Torreya), and the other specific for unsaturated acids with a DELTA11-ethylenic bond (active in Torreya but not in Taxus). Our data also highlight the importance of the elongase(s) in the metabolism of fatty acids in Gymnosperm seeds. 14Methylhexadecanoic acid, a habitual component of Pinaceae and Ginkgo biloba seed lipids, could not be detected in the Taxaceae studied here. 13C nuclear magnetic resonance spectroscopy of the oils from both genera has confirmed that DELTA5olefinic acids are apparently excluded from the internal position of triacylglycerols, which is a characteristic common to all Gymnosperm species analyzed so far, and consequently of great antiquity in their life history.

Wong, A. H. C., M. Smith, et al. (1998). Herbal remedies in psychiatric practice. Archives of General Psychiatry 55(11): 1033-1044.

Patients' use of alternative and complementary health services has created a need for physicians to become informed about the current literature regarding these treatments. Herbal remedies may be encountered in psychiatric practice when they are used to treat psychiatric symptoms; produce changes in mood, thinking, or behavior as a side effect; or interact with psychiatric medications. English-language articles and translated abstracts or articles (where available) found on MEDLINE and sources from the alternative/complementary health field were reviewed. Each herb was assessed for its safety, side effects, drug interactions, and efficacy in treating target symptoms or diagnoses. A synopsis of the information available for each herb is presented. In many cases the quantity and quality of data were insufficient to make definitive conclusions about efficacy or safety. However, there was good evidence for the efficacy of St John's wort for the treatment of depression and for ginkgo in the treatment of memory impairment caused by dementia. More research is required for most of the herbs reviewed, but the information published to date is still of clinical interest in diagnosing, counseling, and treating patients who may be taking botanical remedies.

Woo, J. H., I. S. Ahn, et al. (1998). Changes in chlorophyll contents of leaves and pH of the extracted solutions from the leaves of 7 tree species by pH levels. Journal of Korean Forestry Society 87(2): 145-152.

We conducted this study as a fundamental study on the response of various tree species against acid rain. The tree species used for this study were Zelkova serrata, Robinia pseudoacacia, Quercus acutissima, Prunus serrulata, Ginkgo biloba, Pinus koraiensis and Pinus densiflora. The leaves were examined for the pH changes by treatment time and the chlorophyll content into various pH solution in vitro. The results obtained were as follows; 1. When the leaves were immersed in the solution of various pH(pH3.0 apprx pH6.0) levels, the pH were changed to species specific pH ranges as PH5.0 apprx PH5.5 of Z. serrata, pH5.5 apprx pH6.0 of R. pseudoacacia, PH4.5 apprx PH5.0 of Q. acutissima, pH5.5 apprx pH6.0 of P. serrulata, pH3.5 apprx pH 4.5 of G. biloba, pH 3.5 apprx pH 4.5 of P. koraiensis until 48 hours. However, in case of P. densiflora, it was difficult to find specific pH range of the species. Z. serrata, R. pseudoacacia and P. serrulata showed a little pH increasing by pH 2.0 solution treatment, while other species showed no change by the solution. 2. The amount of chlorophyll contents in Z. serrata, R. pseudoacacia and P. serrulata were decreased after immersing in the pH 2.0 solution. Chlorophyll content was almost constant in other pH levels. Other species showed almost constant chlorophyll contents in various pH levels and treatment time.

Jung, H. W., S. O. Chang, et al. (1998). Effects of Ginkgo biloba extract on the cochlear damage induced by local gentamicin installation in guinea pigs. Journal of Korean Medical Science 13(5): 525-528.

Investigations evaluating the protective effect of Ginkgo biloba extract (EGb) on gentamicin (GM) ototoxicity were undertaken. Guinea pigs treated with 5 mg/kg gentamicin sulfate on the round window niche (RWN) showed acute changes on electrocochleogram and hair cell or microvilli damage on scanning electron microscopy (SEM). There was accumulation of GM in the whole cochlea, especially in the organ of Cord, stria vascularis, and type III fibrocyte on immunohistochemical study. However, the guinea pigs pretreated with local or systemic EGb revealed no significant changes by local GM installation. From these results, we concluded that EGb has a protective effect on the development of GM ototoxicity in the cochlea.

Paasche, G., D. Huster, et al. (1998). The glutathione content of retinal Muller (Glial) cells: The effects of aging and of application of free-radical scavengers. Ophthalmic Research 30(6): 351-360.

The dependence of intracellular glutathione (GSH), an important radical scavenger, on aging with or without externally applied Ginkgo biloba extract EGb 761, another established radical scavenger, was studied in guinea pig Muller (retinal glial) cells by using the fluorescent dye monochlorobimane. The GSH content of freshly dissociated cells from untreated aged animals was significantly lower than that of young controls; most of this reduction was prevented by application of EGb 761. Culturing the cells in amino-acid-free Ringer's solution for 7 h caused a loss of up to 50% of the initial GSH content. When the culture medium contained 100 muM glutamate and 100 muM cystine, ongoing GSH synthesis counteracted the loss of GSH. The rates of net GSH synthesis were equal for the two groups of aged animals but significantly higher for cells from young controls. It is concluded that externally applied radical scavengers may enhance the protective glutathione 'reserve' of Muller cells in cases of neuronal degeneration.

Guo, Z. H., B. S. Wang, et al. (1998). On the characteristics of transpiration and its responses to shade in Ginkgo biloba. Acta Botanica Sinica 40(6): 567-572.

With a CI-301PS portable photosynthesis system as a measuring device, a field study on the characteristics of transpiration (E), stomatal resistance (R) and water use efficiency (WUE) to shade in Ginkgo biloba L. grown in Mt. Lushan was conducted. The results showed that with sufficient water in soil, the highest transpiration rate in a sunny summer day appeared in the afternoon. The WUE was maximum at about 8 a.m. and then decreased at noon remarkably. Different responses of E, R and WUE to shade were noticed which indicated that G. biloba was very suitable to the present climate. Moreover, the temperature of air, photosythetic active radiation and R were the dominant factors affecting transpiration.

Knipschild, P. G., R. Hoerr, et al. (1998). Optimization of placebos for double-blind clinical trials: Experience with a phytopharmaceutical. Arzneimittel Forschung 48(10): 1033-1036.

The maintenance of double-blind conditions in placebo-controlled trials depends on the quality of the placebo preparation. The placebo should match the active substance-containing preparation as closely as possible, but it must not contain any substances that might themselves be pharmacologically active. Active substances characterized by a particular colour, taste, smell or other easily perceptible properties constitute a challenge to researchers. The way of developing a placebo that matches a phytopharmaceutical to a satisfactory extent is described and discussed.

Itil, T. M., E. Eralp, et al. (1998). The pharmacological effects of Ginkgo biloba, a plant extract, on the brain of dementia patients in comparison with tacrine. Psychopharmacology Bulletin 34(3): 391-397.

In 1994, a standardized dry extract of Ginkgo biloba leaves (SeGb), has been approved by German health authorities for the treatment of primary degenerative dementia and vascular dementia. More than 24 different brands of Ginkgo biloba extract are sold in the United States. Tacrine, also known as tetrahydroaminoacrine (THA), and donepezil are currently the only drugs approved in the United States for the treatment of Alzheimer's disease. Previous studies demonstrated that SeGb and tacrine induce significant pharmacological effects on the brains of young, healthy human males, as determined by bioelectrical activity measurements obtained using the quantitative pharmaco-electroencephalogram (OPEEG) method. The type of central nervous system (CNS) effects we have seen on computer-analyzed EEGs (CEEGs) after administration of tacrine or EGb suggests both are "cognitive activators" which are, as a class of products, characterized by a (prepost) relative increase of 7.5 to 13 Hz ("alpha") and decrease of 1.3 to 7.5 Hz ("delta" and "theta") activity. To determine whether EGb or tacrine had noticeable pharmacological effects on elderly subjects diagnosed with possible or probable Alzheimer's, the present open, uncontrolled trial was conducted. Data from 18 subjects (11 males, 7 females) at an average age of 67.4 years with light to moderate dementia (Mini Mental mean score = 23.7, ranges: 15-29 (Geriatric Depression Scale mean scores = 3.7; range: 3.2-5.4)) were analyzed for this presentation. Each subject was randomly administered a single oral "Test-Dose" of either 40 mg of tacrine or 240 mg of EGb2 in two separate sessions within 3- to 7-day intervals. Before drug administration and at 1- and 3-hour intervals after drug administration, CEEGs were recorded for a minimum of 10 minutes. The CEEGs were analyzed using Period Analysis programs we developed for OPEEG. The results indicated that both EGb and, to a lesser degree, tacrine induced pharmacological effects, as established by QPEEG measurements, in the CNS similar to those previously established in healthy, young subjects. The type of CNS effects produced by EGb (as established by HZI's CEEG psychotropic drug database) in elderly dementia patients were similar to those induced by tacrine responders as well as those seen after the administration of other "cognitive activators" (pramiracetam, vinpocetine, BMY21502, suloctidil, and lisuride) and anti-dementia drugs approved in the United States or Europe (tacrine, donepezil, nimodipine, piracetam, and oxiracetam) from our database. The results also showed that 240 mg of EGb has typical cognitive activator CEEG profiles (responders) in more subjects (8 of 18) than 40 mg tacrine (3 of 18 subjects). Because of the small sample size, we could not test the hypothesis that subjects who showed cognitive activator-type pharmacological response to the first Test-Dose of EGb or tacrine also exhibit more therapeutic effects (compared to nonresponders) when drugs are administered chronically.

Tadano, T., O. Nakagawasai, et al. (1998). Effects of Ginkgo biloba extract on impairment of learning induced by cerebral ischemia in mice. American Journal of Chinese Medicine 26(2): 127-132.

The effect of Ginkgo biloba extract (GbE) on cerebral ischemia induced by 10-min bilateral occlusion of the carotid arteries in mice was studied. Severe impairment of memory was apparent when the passive avoidance test was carried out 48 hr after bilaterally induced ischemia. When GbE at doses of 50 and 100 mg/kg was given p.o. 1 hr before the 10-min occlusion, there was a significant improvement in memory. The i.p. injection of ifenprodil (30 mg/kg) also showed improvement on learning tasks. The p.o. administration of flavonoid, a fraction isolated from GbE, showed high step-through latency on scopolamine-induced amnesia. All these findings indicate that GbE is beneficial for clinical use in amnesia accompanied with cerebral vascular disease.

Doraiswamy, P. M. and D. C. Steffens (1998). Combination therapy for early Alzheimer's disease: What are we waiting for? Journal of the American Geriatrics Society 46(10): 1322-1324.

The practical pharmacological approaches currently available to palliate the cognitive and functional losses in early Alzheimer's disease (AD) include cholinesterase inhibitors (ChEI), antioxidants (e.g., vitamin E), anti-inflammatory agents, estrogen, seligiline, vasoactive agents, and ginkgo biloba. Reviewing available data on these therapies and using models from medical illnesses such as cancer and hypertension, we highlight the urgent need for evaluating combination therapies in early AD.

Canturk, N. Z., N. Z. Utkan, et al. (1998). The effects of prostaglandin E2 indomethacin and Ginkgo biloba extract on resistance to experimental sepsis. Indian Journal of Medical Research 108(Sept.): 88-92.

We investigated the effect of 16,16-dimethyl prostaglandin E2 indomethacin and Ginkgo biloba extract on the survival in two experimental sepsis models in rats due to administration of 1 X 107 cfu and 1 X 109 cfu Escherichia coli. Animals in each model were then randomly divided (10/group) into four groups, administered saline, indomethacin, G. biloba extract and prostaglandin E2 respectively. When compared, there was no significant difference in the survival period between the two sepsis models (P>0.05). The best survival rate was observed in the PGE2-administered animals in the first major model (P<0.05). Indomethacin appeared not to decrease the mortality rates. There was no significant difference in PGE2 levels between two sepsis models (P>0.05). Our results suggest that elevated prostaglandin E2 levels following major trauma are not responsible for the postinjury increased susceptibility to infectious complications. Our observations should also discourage aggressive use of cyclo-oxygenase inhibitors for protection against infectious complications after major trauma.

Buer, C. S., K. T. Gahagan, et al. (1998). Insertion of microscopic objects through plant cell walls using laser microsurgery. Biotechnology and Bioengineering 60(3): 348-355.

A detailed protocol is presented for precisely inserting microscopic objects into the periplasmic region of plant callus cells using laser microsurgery. Ginkgo biloba and Agrobacterium rhizogenes were used as the model system for developing the optical tweezers and scalpel techniques using a single laser. We achieved better than 95% survival after plasmolyzing G. biloba cells, ablating a 2-4-mum hole through the cell wall using a pulsed UV laser beam, trapping and translating bacteria into the periplasmic region using a pulsed infrared laser beam, and then deplasmolyzing the cells. Insertion of bacteria is also described. A thermal model for temperature changes of trapped bacteria is included. Comparisons with other methods, such as a reverse-pressure gradient technique, are discussed and additional experiments on plants using laser microsurgery are suggested.

Rabin, O., K. Drieu, et al. (1998). Effects of EGb 761 on fatty acid reincorporation during reperfusion following ischemia in the brain of the awake gerbil. Molecular and Chemical Neuropathology 34(1): 79-101.

Transient cerebral ischemia (5 min) releases unesterified fatty acids from membrane phospholipids, increasing brain concentrations of fatty acids for up to 1 h following reperfusion. To understand the reported anti-ischemic effect of Ginkgo biloba extract (EGb 761), we monitored its effect on brain fatty acid reincorporation in a gerbil-stroke model. Both common carotid arteries in awake gerbils were occluded for 5 min, followed by 5 min of reperfusion. Animals were infused intravenously with labeled arachidonic (AA) or palmitic acid (Pam), and rates of incorporation of unlabeled fatty acid from the brain acyl-CoA pool were calculated by the model of Robinson et al. (1992), using quantitative autoradiography and biochemical analysis of brain acyl-CoA. Animals were treated for 14 d with 50 or 150 mg/kg/d EGb 761 or vehicle. Ischemia-reperfusion had no effect on the rate of unlabeled Pam incorporation into brain phospholipids from palmitoyl-CoA; this rate also was unaffected by EGb 761. In contrast, ischemia-reperfusion increased the rate of incorporation of unlabeled AA from brain arachidonoyl-CoA by a factor of 2.3-3.3 compared with the control rate; this factor was further augmented to 3.6-5.0 by pretreatment with EGb 761. There is selective reincorporation of AA compared with Pam into brain phospholipids following ischemia. EGb 761 further accelerates AA reincorporation, potentially reducing neurotoxic effects of prolonged exposure of brain to high concentrations of AA and its metabolites.

Nakao, Y., A. Tateishi, et al. (1998). Seed set of Ginkgo biloba L. as related to pollination and its optimum pollination time. Journal of the Japanese Society for Horticultural Science 67(5): 753-758.

Ovule set and growth were investigated on ginkgo as related to open- and hand-pollination as well as the critical pollination period. 1. The ginkgo pollen placed on an agar medium under 25degreeC took 3 days to germinate. Over 73% of the pollen stored for less than 7 days after anthesis at room temperature germinated but pollen stored much longer at room temperature did not. 2. All ovules which were covered with paper bags during anthesis to be free from pollen contamination abscised for 41 days after leafing. 3. When non-viable, heat-treated pollen were used for hand-pollination, the ovules began to drop 28 days after leafing; the percentage ovule set decreased from 19 to 47 days after leafing. Thereafter, for 82 days after leafing, fewer ovules dropped; the final seed set was 7%. These female reproductive organs set parthenocarpically because no embryo formed. The seeds and nuts resulting from hand-pollination were larger than those obtained from open-pollination. 4. Of seeds that set by hand-pollination 16 and 19 days after leafing, 59% and 94%, respectively, remained at harvest and their sizes were significantly larger than those obtained from open-pollination. None of the ovules pollinated 23 days after leafing persisted until harvest.

Beerling, D. J., J. C. McElwain, et al. (1998). Stomatal responses of the 'living fossil' Ginkgo biloba L. to changes in atmospheric CO2 concentrations. Journal of Experimental Botany 49(326): 1603-1607.

Leaf stomatal density and index of Ginkgo biloba L. were both significantly (P < 0.05) reduced after 3 years growth at elevated CO2 (560 ppm), with values comparable to those of cuticles prepared from Triassic and Jurassic fossil Ginkgo leaves thought to have developed in the high CO2 'greenhouse world' of the Mesozoic. A reciprocal transfer experiment indicated that reductions in stomatal density and index irreversibly reduced stomatal conductance, particularly at low leaf-to-air vapour pressure deficits and low internal leaf CO2 concentrations (Ci). These effects probably contributed to the high water-use efficiency of Ginkgo spp. in the Mesozoic relative to those of the present, as determined from carbon isotope measurements of extant and fossil cuticles.

Graesel, I. and G. Reuter (1998). Analysis of 6-hydroxykynurenic acid in Ginkgo biloba and Ginkgo preparations. Planta Medica 64(6): 566-570.

Methods for rapid quantitative analysis of 6-hydroxykynurenic acid (6-HKA) by high-performance liquid chromatography (HPLC) and high-performance thin layer chromatography (HPTLC) have been developed. Sample preparation involves solid phase extraction with an ion exchange resin. These methods are used for the determination of the 6-HKA content in various Ginkgo biloba leaf samples, in herbal tea preparations and in a representative number of solid, liquid and homeopathic Ginkgo preparations available in Germany. A simple and effective isolation method for 6-HKA is described.

Li, A. L. S. Y. D., B. Landsmann, et al. (1998). Hemorheology and walking of peripheral arterial occlusive diseases patients during treatment with Ginkgo biloba extract. Acta Pharmacologica Sinica 19(5): 417-421.

AIM: To study the effects of Ginkgo biloba extract 761 (GbE)5 from the points of view of hemorheology for patients of peripheral arterial occlusive diseases (PAOD). METHODS: The treatment with GbE (240 mg cntdot d-1, po) and the pain-free walking distance (PFWD) were carried out for 24 PAOD patients (12 nondiabetic, ND and 12 diabetic, D) over 48 wk. The parameters erythrocyte stiffness (ES) and relaxation time (RT), the blood plasma viscosity (eta), the plasma fibrinogen concentration (Cf) and the blood sedimentation rate (BSR), the PFWD, and maximal walking distance (MWD) were determined at 6 wk before treatment (-6), at the beginning of the treatment (0), and after 6, 11, 16, and 48 wk of treatment. RESULTS: At wk -6, ES and RT of both the ND- and D-group were not significantly different from a healthy control group. At wk 0, stiffness and RT were significantly higher than healthy control, and the mean PFWD was only 111 m. The eta value was significantly elevated and Cf and BS were enhanced. Throughout 11 wk of treatments ES, RT, eta, and Cf decreased gradually and PFWD improved. Between 16 and 48 wk, ES, and RT were not longer significantly different from the controls, whereas eta and Cf decreased gradually but remained higher than normal, BSR decreased, and the PFWD improved by a factor of 3.8 times (D) and 3.3 times (ND). CONCLUSION: GbE gives therapeutic effects in PAOD patients.

Boveris, A. D. and S. Puntarulo (1998). Free-radical scavenging actions of natural antioxidants. Nutrition Research 18(9): 1545-1557.

A dose-dependent inhibitory effect of wheat, alfalfa and ginkgo biloba (EGb) extracts on TBARS production was measured. The half-inhibition concentration (IC50) of the tested antioxidants were 2.7+-0.2, 1.3+-0.1, and 0.20+-0.02 mg/ml for wheat, alfalfa and EGb extracts, respectively. Lipid radicals combined with the spin trap POBN resulted in adducts that gave a characteristic EPR spectrum. The IC50 of the tested antioxidants on lipid radical content, were 12.4+-0.2, 7.7+-.3, and 1.20+-0.06 mg/ml for wheat, alfalfa and EGb extracts, respectively. Rat liver microsomes in the presence of DMPO, NADPH and ironcitrate generate an EPR spectra with characteristics of the DMPO-OH spin adduct. The basic system, without the addition of any scavenger showed an area of 3.5 AU/mg protein. The areas in the presence of 1.5 mg/ml EGb, 4 mg/ml wheat or alfalfa, were of 1.7+-0.2, 3.4+-0.3, and 3.6+-0.2 AU/mg protein, respectively. O2- generation rate by the microsomes exposed to EGb extract was decreased by 40%, as compared to the rate measured in microsomes incubated in the absence of the extract. However, the supplementation of rat liver microsomes with either wheat or alfalfa extracts did not affect microsomal generation of O2-. Iron reduction rate was not affected by the addition -of any of the tested extracts. The data presented here showed that EGb extracts were able to limit lipid peroxidation and scavenge lipid radicals in rat liver microsomes more efficiently than alfalfa and wheat bran extracts. Moreover, wheat and alfalfa extracts were not able to inhibit O2- and -OH generation by biological membranes, suggesting that their potentiality to be successfully used in human health in the treatment of diseases involving free radical and oxidative damage are not as promising as that for the use of EGb extracts.

van, B. T. A., E. Bombardelli, et al. (1998). Ginkgo biloba L. Fitoterapia 69(3): 195-244.

The chemistry, analysis, pharmacology and clinical applications of extracts of the maidenhair tree (G. biloba) are reviewed. This botanically unique tree contains some unusual secondary metabolites, among others a number of highly oxidized terpene trilactones (ginkgolides, bilobalide) which, together with some flavonoids, are considered to be responsible for the pharmacological activities of standardized leaf extracts: vaso- and tissue-protective action, cognition-enhancing and antiageing activity, including stress-alleviating and neuraprotectivelneurotrophic effects. All these properties support the therapeutic applications against cerebral insufficiency and impaired peripheral blood circulation.

Kim, H. K., K. H. Son, et al. (1998). Amentoflavone, a plant biflavone: A new potential anti-inflammatory agent. Archives of Pharmacal Research Seoul 21(4): 406-410.

Biflavonoid is one of unique classes of naturally-occurring bioflavonoids. Certain biflavonoids including amentoflavone were previously reported to have inhibitory effect on the group II phospholipase A2 activity. Amentoflavone was also found to inhibit cyclooxygenase from guinea-pig epidermis without affecting lipoxygenase. In this study, anti-inflammatory and analgesic activities of amentoflavone were evaluated. When amentoflavone was administered intraperitoneally, it showed a potent anti-inflammatory activity as determined by amelioration of croton-oil induced mouse ear edema. It also showed a potent anti-inflammatory activity in the rat carrageenan paw edema model (ED50 = 42 mg/kg) compared to the activity of prednisolone (35 mg/kg) and indomethacin (10 mg/kg). However, amentoflavone did not show a significant inhibitory activity against rat adjuvant-induced arthritis, a chronic inflammatory model. In addition, amentoflavone was found to possess a potent analgesic activity in the acetic acid writhing test (ED50 = 9.6 mg/kg) compared to the activity of indomethacin (3.8 mg/kg). These results suggest that amentoflavone may be a potential lead for a new type of anti-inflammatory agents having dual inhibitory activity of group II phospholipase A, and cyclooxygenase.

Sun, S., W. G. Liu, et al. (1998). The effect of ecological conditions on flavonoid accumulation in Ginkgo biloba leaves. Journal of Plant Resources and Environment 7(3): 1-7.

The relations between flavonoid accumulation in Ginkgo biloba L. leaves and the ecological conditions are studied by principal component analysis and multiple regression analysis. The principal effect of environmental factors on flavonoid content are latitudes, annual precipitation and annual mean sunshine percentage, and annual mean temperature. The multiple linear regression equation has a predictable effectiveness on the flavonoid content in over hundred-year-old tree's leaves. The most suitable ecological conditions for it by nonlinear regression analysis is as follows: Latitudes is 28degree19' +- 2degree34'N or 38degree6' +- 2degree34'N; Annual precipitation 762.3 +- 114.5 mm; Annual mean sunshine percentage 35.3% +- 6.3%; Annual mean temperature 15.95 +- 2.15degreeC, but these conditions seem to be not optimum for the growth and development of ginkgo. The viewpoint is put forward that ginkgo leave-cultivation for higher content of flavonoid should be settled in the circumstances with certain stresses.

Hably, L. and Z. Kvacek (1998). Pliocene mesophytic forests surrounding crater lakes in western Hungary. Review of Palaeobotany and Palynology 101(1-4): 257-269.

Two new palaeobotanical sites, Gerce and Pula from western Hungary, found in volcanic craters are characterized in terms of floristic composition, vegetation, and palaeoclimate. Radiometric dating of adjacent volcanic bodies indicates the age of the fossiliferous deposits near the Lower/Upper Pliocene boundary. Deciduous broad-leaved, woody plants prevail in both localities (Quercus, Ulmus, Zelkova, Acer, Salicaceae) and are associated with some rare exotic elements (Ginkgo, Torreya, Engelhardia, Eucommia, Sassafras) and Buxus. The climatic conditions inferred from the reconstructed vegetation indicate a Cf-type of climate with a mean annual temperature of 10-13degreeC and some dry periods during the year.

Lee, S. L., W. W. Wang, et al. (1998). Superoxide scavenging effect of Ginkgo biloba extract on serotonin-induced mitogenesis. Biochemical Pharmacology 56(4): 527-533.

We have reported previously that serotonin (5-HT) stimulates the mitogenesis of bovine pulmonary artery smooth muscle cells (SMCs) through active transport of 5-HT and cellular signaling that includes elevation of superoxide (O2.-) and enhancement of protein tyrosine phosphorylation. Ginkgo biloba extract 501 (EGb 501), which has been demonstrated to act as an antioxidant, was found to block both the elevated O2.- and the proliferative and hypertrophic influences of 5-HT on SMCs, but not to directly inhibit the associated activation of NAD(P)H oxidase or the stimulation of phosphorylation of GTPase-activating protein (GAP). A similar effect of Ginkgo biloba extract 501 occurred on Chinese hamster lung fibroblasts (CCL-39), where 5-HT receptor, as opposed to transporter, action has been associated with mitogenesis. We conclude from these studies that Ginkgo biloba extract 501 quenches O2.- formation by 5-HT, thereby blocking its mitogenic effect. Stimulation of protein tyrosine phosphorylation of GAP by 5-HT appears to precede the elevation of O2.-.

Rao, M. and M. N. A. Rao (1998). Protective effects of cystone, a polyherbal ayurvedic preparation, on cisplatin-induced renal toxicity in rats. Journal of Ethnopharmacology 62(1): 1-6.

Cystone, a polyherbal ayurvedic preparation, was found to protect rats partially but significantly against cisplatin-induced renal toxicity, when given intraperitoneally 1 h before cisplatin. At 500 and 1000 mug/ml, it also inhibited lipid peroxidation induced by cisplatin in renal cortical slices by 62.7 and 71.6%, respectively. The rats pretreated with cystone (1000 mg/kg i.p.) had significantly lower blood urea nitrogen (BUN) and serum creatinine (33.8 and 0.92 mg/dl, respectively) compared to cisplatin alone (51.5 and 1.41 mg/dl, respectively). The control animals had 17.1 and 0.63 mg/dl, respectively. The cystone treated animals lost 5.63 g body weight compared to 12.5 g for cisplatin alone treated animals on day S. Renal functions like urine to serum creatinine ratio and creatinine clearance showed significant improvement when cystone was given 1 h before cisplatin. However, cystone did not protect increased excretion of urinary protein and decreased WBC count caused by cisplatin. The present study suggests that the cystone protects kidney against cisplatin-induced toxicity and the protection may be mediated through its ability to inhibit lipid peroxidation.

Al, Z. H., F. A. A. A. El, et al. (1998). The effect of meclofenoxate with ginkgo biloba extract or zinc on lipid peroxide, some free radical scavengers and the cardiovascular system of aged rats. Pharmacological Research 38(1): 65-72.

Aged rats are highly prone to many physiological changes such as blood pressure and heart rate. These changes could be due to modification in membrane phospholipid composition of their blood vessels. Lipid peroxide in vivo has been identified as a basic deteriorative reaction in cellular mechanisms of aging in human. The effect of a nootropic drug, meclofenoxate (MF) or its combination with extract of ginkgo biloba (EGb-761) or zinc (Zn) on malondialdehyde (MDA) product as an index of endogenous lipid peroxidation; phospholipid; glutathione (GSH) and protein thiols (PrSHs) contents as well as superoxide dismutase (SOD) activity in blood, brain, heart and liver of 24-month-old male rats was investigated. Aged rats were treated with MF once daily at oral doses of 100 mg kg-1 body wt. alone or with either EGb at a dose of 150 mg kg-1 body wt. or Zn at 10.5 mg kg-1 body wt. for 4 weeks. This study showed that aging caused a higher increment in MDA level of brain and heart than liver and plasma accompanied with reduction in brain and heart phospholipid contents as well as alteration of the antioxidant systems as compared to 4-month-old rats. Treatment of aged rat; with MF alone or combined with either EGb or Zn caused improvement in the measured free radical scavengers especially in brain and heart tissues. Our results also showed that both EGb and Zn induced a significant potential effect of MF action on blood pressure and heart rate. The results were explained in the light of the antioxidant properties of EGb and Zn. Thus it is concluded that EGb and Zn have a beneficial role with MF in diminishing cumulative oxidative changes in aging.

Kobayashi, A. and E. Fukusaki (1998). Potentiality of plant disease resistance. Nippon Nogeikagaku Kaishi 72(5): 646-652.

Kim, M. S., W. K. Lee, et al. (1998). Effect of environmental factors on flavonol glycoside production and phenylalanine ammonia-lyase activity in cell suspension cultures of Ginkgo biloba. Journal of Microbiology and Biotechnology 8(3): 237-244.

A study was carried out to elucidate the relation between the production of flavonol glycosides and the change of phenylalanine ammonia-lyase activity in cell suspension cultures of Ginkgo biloba by the unassisted and synergistic effects of various factors. The quercetin production showed a mixed-growth-associated pattern in cell suspension cultures. Fluorescent light and UV radiation increased phenylalanine ammonia-lyase (PAL) activity, and resulted in the increase of the production of quercetin and kaempferol ten- and four-fold, respectively, as compared to that obtained in the normal culture condition. The cell growth of Ginkgo biloba was enhanced at higher temperatures whereas the quercetin production was at its maximum at low temperatures. Moreover, the quercetin production was increased by temperature change during the culture period. In particular, the quercetin production was at the highest level when the culture temperature was elevated from 10degreeC to 30degreeC. The addition of phenylalanine as a precursor in the culture medium stimulated an 8-fold increase in the production of quercetin; the addition of naringenin caused a 10-fold increase. The quercetin production was also greatly increased by feeding enzyme cofactors such as 2-ketoglutarate and ascorbic acid in the culture medium, but specific PAL activity was not increased except with phenylalanine feeding. The synergistic effect of UV radiation and naringenin feeding was observed, resulting in the increase of flavonol glycoside production at a rate higher than in any other case investigated.

Chen, J. X., W. Z. Chen, et al. (1998). Protective effects of Ginkgo biloba extract against lysophosphatidylcholine-induced vascular endothelial cell damage. Acta Pharmacologica Sinica 19(4): 359-363.

AIM: To study the protective effects of Ginkgo biloba extract (GbE) against endothelial cell damage induced by lysophosphatidylcholine (LK). METHODS: The vasorelaxation response to acetylcholine (ACh) were investigated in the isolated rabbit thoracic aorta. Lipid peroxidation products were determined by measuring thiobarbituric acid reactive substance. RESULTS: GbE attenuated the inhibition of vasorelaxation response to ACh and prevented the LPC-induced increase of malondialdehyde (MDA) content both in thoracic aortae. GbE prevented the leakage-of LDH and the increase of MDA content in cultured endothelial cells in a concentration-dependent manner. GbE also markedly increased epoprostenol level in cultured endothelial cells treated with LPC. CONCLUSION: GbE protected endothelial cells against LPC-induced damage due to reduction in lipid peroxidation and facilitation of synthesis and/or release of epoprostenol.

Asami, I., T. Fujita, et al. (1997). Studies on the quality and the freshness retention of the Gingko (Ginkgo birobra) nuts, 'Kinbe' and 'Kyuju' during short storage at various temperatures. Research Bulletin of the Aichi ken Agricultural Research Center(29): 225-230.

Ginkgo nuts 'Kinbe' were picked twice during the first ten days of August and the second ten days of September. 'Kyuju' nuts were picked on the first ten days of November. Their qualities and freshness retention after short periods of storage at 30, 20, 10 and 0degreeC were investigated. The weight of seed and endosperm increased with late harvest and the respiration rate at various temperatures and weight loss during storage increased with early harvest. The sugar contents increased and the rate of reducing sugars in total sugars decreased with late harvest. During storage, total sugars decreased rapidly at higher temperature conditions, and the rate of decrease was larger with earlier harvests. The chlorophyll contents of the early harvest Ginkgo nuts were larger by ten times than the late harvest and the green colors of the endosperm were more vivid with early harvest. Molds grown on the surface of a shell (middle seed coat) were mostly Penisillium sp. and Rbizopus sp. was barely found. Anti-fungus actions were found very effective, using the anti-fungicide agents (principal component was Allyl Isothiocynate) during storage, in addition to the post period ethyl alcohol atomizing processing after harvest.

Han, Y. and R. Liu (1998). Effect of phosphate buffer on membrane lipid peroxidation of plants and its relation to sulphurous acid harm. Yingyong Shengtai Xuebao 9(2): 201-205.

Three kinds of plant treated with sulphurous acid were used to study the protective function of phosphate buffer in respect of membrane lipid peroxidation. The result shows that after the plants were sprayed with phosphate buffer, they had an obvious protective function to the harm caused by sulphurous acid. The phosphate buffer could stabilize the cell membrane structure, decrease the content of MDA, and increase the degree of chlorophyll-protein binding. It also had a coordinated effect on SOD activity with sulphurous acid at low concentration. The protective effect of phosphate buffer was different with plant species. In the same polluted environment, the plants with high MDA concentration and low chlorophyll binding degree had greater protective function, and the effect order of tested plants was Ginkgo biloba > Forsythia suspensa > Triticum aestivum.

Schneider, P. H. A. W., U. Kolukisaoglu, et al. (1998). Non-angiosperm phytochromes and the evolution of vascular plants. Physiologia Plantarum 102(4): 612-622.

The phytochromes, a class of plant light-sensing pigments, are a gene family with a long, complex evolutionary history. Angiosperms each have five or more phytochromes (designated A to E in Arabidopsis) with distinct functions as light receptors and only moderate sequence identities for different types within a species. The long-term challenge taken up here is to trace the origin and function of the various motifs within the angiosperm phytochromes through gymnosperm phytochromes (types N, O and P) and lower plant phytochromes, sometimes reaching even to bacterial progenitor molecules. Particularly intriguing are the findings of homology of a C-terminal region of phytochromes with bacterial transmitter modules and of a large N-terminal region with a protein encoded by a gene from the cyanobacterum Synechocystis. Phylogenetic analysis helps to answer general questions such as the times of divergence of mono- and dicotyledons, of groups of gymnosperms or of ferns. Phytochrome sequences suggest (1) that mono- and dicotyledons became separated 150-200 million years earlier than indicated by the fossil record and (2) that Ginkgo and Cycas have been separated unexpectedly late from the lineage giving rise to the Pinidae. (3) The status of Psilotum as a close relative of the primeval vascular plants is not supported. Phytochrome gene sequences additionally reveal that (4) moss and fern phytochromes have erratically acquired C-termini which, though kinase-like, are different from the common ones and that (5) introns have been lost, gained or shifted in position from algae to angiosperms. Phytochromes promise to be a rich source of phylogenetic information into the future as more sequences and functional data emerge, not least from studies of lower plants.

Vale, S. (1998). Subarachnoid haemorrhage associated with Ginkgo biloba. Lancet North American Edition 253(9121): 36.

Fan, Y., Y. Wang, et al. (1998). Seasonal and sexual variety of ginkgo flavonol glycosides in the leaves of Ginkgo biloba L. Zhongguo Zhongyao Zazhi 23(5): 267-269, 319.

HPLC methods have been developed for the determination of Ginkgo flavonol glycosides in the Ginkgo biloba leaves obtained from May to November in the fallen leaves and i the leaves obtained from female and male trees. The method includes hydrolysis of the leaves and subsequent quantitative chromatographic assay of the aglycones, followed by calculation of Ginkgo flavonol glycosids content. The result shows that the leaves obtained in May have the highest content of 0.96%, and then the content decreases from may to August, and from August to November remains almost the same, that is 0.5% also. Fallen leaves have the lowest content of 0.44%. The content range is 0.96% to 0.44%. Male trees have higher content of glycosides than female trees.

Son, Y., Z. S. Kim, et al. (1998). Fertilization effects on growth, foliar nutrients and extract concentrations in Ginkgo seedlings. Journal of Korean Forestry Society 87(1): 98-105.

We measured seedling growth, foliar nutrient and extract concentrations of 3-year-old Ginkgo biloba seedlings growing in a nursery following a single fertilization with nitrogen (N), phosphorus (P) and nitrogen plus phosphorus (N+P) fertilizers. Fertilization did not change foliage, stem and root biomass of the seedlings except for the high N+P treatment. Foliar N and P concentrations following fertilization varied according to the amount of fertilizers. In general, foliar N and P concentrations increased with fertilization, but fertilization with 400kg N/ha and 100kg P/ha decreased foliar N and P concentrations, respectively. Seedling growth and foliar nutrient concentrations showed that N and P were the growth-limiting nutrients in our study site. It was found that fertilization reduced the concentrations of secondary metabolites (Ginkgo flavon glycosides and terpene lactones) in foliages. It seemed there was a relationship between foliage biomass production and secondary chemicals in G. biloba seedlings.

Chi, J. and L. Xu (1998). Studies on a flavonoid compound in Ginkgo biloba L. leaves. Zhongguo Zhongyao Zazhi 23(4): 233-234, 256.

One compound was isolated for the first time from ethyl acetate extract of Ginkgo biloba leaves and identified as kaempferol-3-O-rhamnoside by spectroscopic methods.

Chi, J. and L. Xu (1998). Studies on chemical constituents of flavonoids in the leaf of Ginkgo biloba L. Zhongguo Zhongyao Zazhi 23(1): 40-41, 63.

A compound was isolated from the ethyl acetate extract of Ginkgo biloba leaves for the first time and was identified as 5,7,4'-trihydroxy-flavone by spectroscopic methods.

Zhu, L., J. Gao, et al. (1997). Neuron degeneration induced by verapamil and attenuated by EGb761. Journal of Basic and Clinical Physiology and Pharmacology 8(4): 301-314.

Calcium channel blockers are used as neuroprotective agents, as glutamate antagonists. However, it has been found that calcium channel blockers may compromise neuronal survival after long-term exposure. To explore the mechanisms of the toxicity of calcium channel blockers on neurons, we studied the morphological characteristics and biochemical changes of cultured cortical neurons treated with verapamil, a calcium channel blocker. We now report that cerebral cortical cultures exposed to verapamil for 48 h undergo neuronal degeneration in both concentration-dependent and time-dependent fashion, possibly partially through the activation of apoptosis. On the other hand, it was found that Ginkgo biloba extract (EGb761) attenuated verapamil-induced neuronal injury, suggesting the possibility of using verapamil combined with EGb761 clinically. Furthermore, both B-50 immunoactivity (BIA) and the concentration of intracellular calcium in single neurons ((Ca2+)i) decreased after a 48-h exposure to verapamil, suggesting that the mechanisms of verapamil-induced degeneration may be associated with the disruption of intracellular calcium homeostasis and the inhibition of normal axonal elongation.

Wang, J., C. Yang, et al. (1998). Fine structure and assembly in vitro of nuclear lamina in plant cells. Science in China Series C Life Sciences 41(1): 71-79.

The fine structure of the nuclear lamina (NL) in sperm cells of Ginkgo biloba was visualised using high resolution low-voltage scanning electron microscopy (LVSEM). It was shown that the nuclear lamina was composed of 10 nm filaments which formed a fine network. Lamina were purified from cultured carrot suspension cells and assembled in vitro. Long 8-12 nm diameter filaments were seen and sometimes subfilaments could be distinguished. Western blot of filament preparations showed that these contained the 66 and 84 ku lamins. These data demonstrate that plant lamina are capable of assembling into filaments in vitro.

Fang, J. and G. Que (1998). Relation between callus growth and flavonoids accumulation of Ginkgo biloba. Forest Research 11(2): 124-129.

Young stem of Ginkgo biloba were used to induce callus, and the relation between callus growth and flavonoids accumulation were studied. The result indicated that the ideal medium for a large volume of callus induction is MS supplemented with 2.5 mg/L 1-Naphthaleneacetic acid and 1 mg/L kinetin. In order to subculture callus for several cycles, it is suitable to subculture the callus by using middle salt concentration medium in 25 apprx 30 days. The flavonoids were identified in the callus cultured under light. The supreme quantity of flavonoids reached to 1.2 mg/gDW, within it there were 17.5 mug/gDW quercetin. Production of flavonoids was related to callus growth,and the con. of NH4+ was an effective factor.

Carrier, D. J., B. T. A. Van, et al. (1998). Distribution of ginkgolides and terpenoid biosynthetic activity in Ginkgo biloba. Phytochemistry Oxford 48(1): 89-92.

The terpene trilactone content (bilobalide and ginkgolides) of extracts prepared from leaves of terminal buds, rosettes and side branches, from stem and root bark, and from root and root meristems of three-year-old Ginkgo biloba plants was determined. The aerial parts were relatively rich in bilobalide while ginkgolides were the major constituents of the underground parts. The formation of farnesyl and geranylgeranyl pyrophosphate was monitored by incubating cell-free extracts prepared from the corresponding plant parts with (1-14C)isopentenyl pyrophosphate. Extracts prepared from leaves of the terminal buds displayed terpenoid biosynthetic activity, suggesting that terpene trilactone synthesis might occur in actively growing tissues.

Li, X. G., W. Wei, et al. (1998). Preparation of dry extract rich in ginkgolides from Ginkgo biloba L. leaves. Zhongguo Yiyao Gongye Zazhi 29(1): 8-9.

Flavonoid glycosides rich in ginkgolides were extracted from Ginkgo biloba L. green leaves with boiling ethanol and purified by means of adsorbent polyamide resin in 2.48% yield. HPLC showed that the product contained 27.4% flavonoid glycosides and 10.6% ginkgolides.

Li, X. G., W. Chen, et al. (1998). Extraction of a mixture of ginkgolide and bilobalide from Ginkgo biloba L. leaves. Zhongguo Yiyao Gongye Zazhi 29(1): 7-8.

Ginkgolides and bilobalide were extracted from Ginkgo biloba L. green leaves by boiling water, the condensed extract was treated with hot ethanol, after removing alcohol, the residue was extracted with ethyl acetate to obtain the white crystalline product, which contained 81.5% of ginkgolides and bilobalide by HPLC. The yield was 0.6permill.

Wang, C. Z., Q. Yu, et al. (1998). Purification of flavonoid glycosides from Ginkgo biloba. L. leaves. Zhongguo Yiyao Gongye Zazhi 29(1): 5-6, 9.

The flavonoid glycosides, which contained more than 24%, were prepared in about 1.3% yield by means of purifications via flocculating agent treatment, pH adjustment and D101/polyamide resin adsorption from yellow leaves of Ginkgo biloba. L.

Peters, H., M. Kieser, et al. (1998). Demonstration of the efficacy of ginkgo biloba special extract EGb 761 on intermittent claudication: A placebo-controlled, double-blind multicenter trial. Vasa 27(2): 106-110.

Background: A multicentric, randomized, placebo-controlled double-blind study on ginkgo biloba special extract EGb 761 (Tebonin forte) in patients suffering from peripheral occlusive arterial disease (POAD) in Fontaine stage II b was carried out in order to prove its clinical efficacy in this indication according to guidelines of European Community authorities and the German Angiological Society and to confirm the results of former clinical studies with EGb 761. Patients and methods: In total, 111 patients with angiographically proven POAD in Fontaine stage II b and intermittent claudication (pain-free walking distance < 150m on the treadmill) were recruited in 5 centers and treated with either EGb 761 or placebo at a daily dose of 3 times 1 film-coated tablet over a duration of 24 weeks following a 2-week placebo run-in period. The primary response variable was the difference of the pain-free walking distance between the start of treatment and after 8, 16 and 24 weeks as measured on the treadmill (walking speed 3 km/h and slope of 12%) under standardized conditions. Results: At the start of the treatment period, the mean pain-free walking distances were very similar with 108.5 m in the EGb 761 group and 105.2 m in the placebo group. At the end of the treatment period these values increased to 153.2 m and 126.6 m, respectively. The group differences were statistically significant at all three control visits with p = 0.017, p = 0.007, and p = 0. 016. The differences for the maximum walking distance and the relative increases of the pain-free walking distance and the maximum distance were also significantly higher in the EGb 761 group with p-values < 0.05 each. In both groups Doppler indices remained nearly unchanged during therapy. The subjective assessment of the patients demonstrated an amelioration of complaints in both groups. Tolerability was very good with no adverse events under EGb 761 and one case of heartburn and gastric pain in the placebo group. Conclusions: It can be concluded from the results of this study that treatment with EGb 761 in POAD patients with Fontaine stage II b is very safe and causes a significant and therapeutically relevant prolongation of the patients' walking distance.

Marcilhac, A., N. Dakine, et al. (1998). Effect of chronic administration of Ginkgo biloba extract or ginkgolid on the hypothalamic-pituitary-adrenal axis in the rat. Life Sciences 62(25): 2329-2340.

The hypersecretion of glucocorticoids during exposure to various stressors may induce or worsen pathological states in predisposed subjects. Therefore it is of interest to evaluate drugs able to reduce glucocorticoid secretion. It has recently been shown that chronic administration of a Ginkgo biloba extract (EGb 761) inhibits stress-induced corticosterone hypersecretion through a reduction in the number of adrenal peripheral benzodiazepine receptors. The present study was designed to analyze the effect of EGb 761 and one of its components, Ginkgolide B on the biosynthesis and secretion of CRH and AVP, the hypothalamic neurohormones that regulate the pituitary adrenal axis. Chronic administration of EGb 761 (50 or 100 mg/kg p.o. daily for 14 days) reduced basal corticosterone secretion and the subsequent increase in CRH and AVP gene expression. Under the same conditions, surgically-induced increase in CRH secretion was attenuated while the activation of CRH gene expression, ACTH and corticosterone secretion following insulin-induced hypoglycemia remained unchanged. Chronic i.p. injection of Ginkgolide B reduced basal corticosterone secretion without alteration in the subsequent CRH and AVP increase. However, the stimulation of CRH gene expression by insulin-induced hypoglycemia was attenuated by Ginkgolide B. These data confirm that the administration of EGb 761 and Ginkgolide B reduces corticosterone secretion. In addition, these substances act also at the hypothalamic level and are able to reduce CRH expression and secretion. However the latter effect appears to be complex and may depend upon both the nature of stress and substance (Ginkgolide B or other compounds of EGb 761).

Kimura, Y., S. Matsuo, et al. (1998). Enzymatic properties of a Ginkgo biloba endo-beta-N-acetylglucosaminidase and N-glycan structures of storage glycoproteins in the seeds. Bioscience Biotechnology and Biochemistry 62(2): 253-261.

An endo-beta-N-acetylglucosaminidase has been purified to homogeneity from mature seeds of Ginkgo biloba. The molecular mass of the endo-beta-N-acetylglucosaminidase, named Endo-GB, was estimated to be around 63 kDa by SDS-PAGE and around 62 kDa by Hiprep S-200 chromatography, respectively. The substrate specificity has been explored with regard to the pyridylaminated N-glycans. Several high mannose-type sugar chains bearing of 1,2-mannosyl residue(s), Man9-6GlcNAc2-PA, were the most favored substrates followed by Man5GlcNAc2-PA and a typical hybrid-type structure (GlcNAc1Man5GlcNAc2-PA) which does not bear an alpha-mannosyl residue. On the contrary, endo-GB could hardly hydrolyze the common core pentasaccharide of N-glycan (Man3GlcNAc2-PA) and the xylose-containing sugar chains (Man4-3Xyl1GlcNAc2-PA, Man3Fuc1Xyl1GlcNAc2-PA) being widely distributed in plant glycoproteins. Furthermore, we analyzed the structures of N-glycans conjugated to storage glycoproteins in the mature Ginkgo seeds to see the occurrence of endogenous substrates for Endo-GB. The structural analysis showed, however, only xylose-containing type N-glycans (Man3Fuc1Xyl1GlcNAc2 (95%) and Man3Xyl1GlcNAc2 (5%)), which can not be substrate for Endo-GB, predominantly occur in the storage glycoproteins.

Colak, O., A. Sahin, et al. (1998). The effect of Ginkgo biloba on the activity of catalase and lipid peroxidation in experimental strangulation ileus. International Journal of Clinical and Laboratory Research 28(1): 69-71.

This study was designed to assess the therapeutic effect of Ginkgo biloba extract (EGb 761) in experimental strangulation ileus. Rats were divided into control (n = 7), placebo (n = 11), and EGb-treated (n = 11) groups. No surgical procedure was carried out on the control group. Strangulation ileus was produced in the placebo and EGb groups for 2.5 h. At the end of this period, 100 mg/kg EGb in 1 ml of saline was injected intraperitoneally to the EGb-treated group. In the placebo group, animals received an equivalent amount of saline intraperitoneally; 24 h later, repeat laparotomies were performed to take blood and intestinal tissue samples. The EGb treatment decreased tissue malondialdehyde levels and increased catalase activities compared with the placebo group (P<0.05 for both). Serum creatine kinase and phosphorus levels were also determined in all groups. In the placebo group these were significantly higher than in the control group (P<0.01 and P<0.05, respectively). In the EGb group these were not different from controls and the increase in creatine kinase activity in the EGb group was not as high as in the placebo group (P<0.05). Our results suggest that EGb could be preventive against the effects of strangulation ileus in a rat model.

Chen, P., X. L. Su, et al. (1998). Analysis of ginkgolides and bilobalides in Ginkgo biloba L. Extract for its production process control by high-performance liquid chromatography. Journal of Chromatographic Science 36(4): 197-200.

A high-performance liquid chromatographic (HPLC) method is developed for the determination of the pharmacologically active terpenoids Ginkgolide A, B, and C and bilobalide in Ginkgo biloba L. leaves extract (GBE). The extracts are dissolved in methanol-water (1:4) and extracted by ethyl acetate after evaporation of the organic solvent, the residue is dissolved in methanol, and the terpenoids in the resultant solution are determined by means of HPLC on a C18 column with methanol-water (23:77) as an eluent. The recovery provided by the method is above 96.5%, and the minimum concentration that can be determined is 80 pg of terpenoid per gram of GBE. The method is suitable for GBE production process control.

Lu, M. Z., A. E. Szmidt, et al. (1998). RNA editing in gymnosperms and its impact on the evolution of the mitochondrial coxI gene. Plant Molecular Biology 37(2): 225-234.

Sequence analysis of the mitochondrial coxI gene in eight gymnosperm species revealed a high rate of nonsynonymous nucleotide substitutions with a strong (98%) predominance of C-T substitutions. Further analysis of the corresponding coxI cDNA sequences showed that all the non-synonymous C-T changes in the coxI genomic DNA sequences were eliminated by RNA editing resulting in nearly identical mRNA (amino acid) sequences among the species. Pronounced variation in the number and location of edited sites was found among species. Most species had a relatively large number of edited sites (from 25 to 34). However, no RNA editing of the coxI sequence was found in Gingko biloba or Larix sibirica. The sequence composition of the investigated coxI fragment suggests that the coxI gene in G. biloba and L. sibirica originated from edited mitochondrial coxI transcripts by reverse transcription followed by insertion into the nuclear genome or back into the mitochondrial genome. Our results also demonstrate that where there are a large number of edited sites, RNA editing can accelerate the divergence of nucleotide sequences among species.

Yang, F., J. Quan, et al. (1998). Multidimensional counter-current chromatographic system and its application. Journal of Chromatography A 803(1-2): 298-301.

A multidimensional counter-current chromatographic system was set up for the first time with two sets of high-speed counter-current chromatography instruments. This system was successfully applied to the preparative separation of isorhamnetin, kaempferol and quercetin from crude flavone aglycones of Ginkgo biloba L. and Hippophae rhamnoides L. with a two-phase solvent system composed of chloroform-methanol-water (4:3:2, v/v/v).

Sugiyama, C., T. Itoh, et al. (1998). Improvement of oral absorption of Ginkgo biloba extract by use of excipients. Yakuzaigaku 58(1): 52-58.

To improve the oral absorption of water-insoluble Ginkgo biloba extract (GBE), acacia was added to GBE by the spray-drying of a solution containing GBE and acacia. As an indicator of the oral absorptivity of GBE, the concentrations of GBE-derived flavonoid aglycones, such as quercetin, kaempferol and isorhamnetin, in the plasma of rat were determined with time after the administration of GBE (150 mg/kg). Acacia-added GBE showed greater AUC (0-24 h), by about 90% (P < 0.05), than that with GBE without acacia. In particular, the enhanced absorption of quercetin was observed. Examination of acacia-added GBE by X-ray diffractometry indicated that GBE and acacia each crystallize basically in lamellar structures though their crystallite sizes are small. The interplanar spacings of GBE and acacia are seriously decreased when they are hydrated. However, even under hydration conditions, the addition of acacia prevents the lamellar structure of GBE from shrinking, which possibly promotes the access of gastrointestinal juice onto the lamella of GBE followed by an increase in the dissolution of GBE in the juice.

Shi, H. and E. Niki (1998). Stoichiometric and kinetic studies on Ginkgo biloba extract and related antioxidants. Lipids 33(4): 365-370.

Owing to increasing evidence showing the importance of lipid peroxidation in oxidative stress in vivo, the role and evaluation of antioxidants have received much attention. Gingko bilobo extract (GBE), well-known as an efficient drug against diseases induced by free radicals, has been suggested to exert its effect by antioxidant action. A method was established to determine the activity of GBE as a hydrogen donor by stoichiometric and kinetic studies, and GBE was compared with several other antioxidants such as alpha-tocopherol, propyl gallate, and two kinds of flavonoids which are found in GBE, quercetin, and kaempferol. It was found that there were 6.62 X 1019 active hydrogens in 1 g of GBE. Stoichiometric studies showed that one molecule of alpha-tocopherol reacted with one molecule of galvinoxyl radical. For quercetin, kaempferol and propyl gallate, the experimental stoichiometric numbers were 4.0, 1.9, and 3.1, respectively. The rates of reaction of antioxidants with galvinoxyl in ethanol were determined spectrophotometrically, using a stopped-flow technique. The second-order rate constant, k2, obtained at 25degreeC was 0.13 (g/L)-1 s-1 for GBE and 5.9 X 103, 2.1 X 103, 1.2 X 104, and 2.4 X 103 M-1 s-1 for quercetin, kaempferol, propyl gallate, and alpha-tocopherol, respectively. The second-order rate constant, k2', on the molar basis of active hydroxyl groups in the tested substances obtained at 25degreeC decreased in the order of propyl gallate > alpha-tocopherol > quercetin > GBE apprxeq kaempferol. This is the first study on GBE as an antioxidant which reports both stoichiometric and kinetic results.

Nardi, M. C., E. Giacomelli, et al. (1998). Ginkgo biloba expressed calreticulin, the major calcium-binding reticuloplasmin in eukaryotic cells. Botanica Acta 111(1): 66-70.

Calreticulin, the main Ca2+ binding protein in the endoplasmic reticulum of eukaryotic cells, was characterized in Ginkgo biloba L. pollen and seeds. Electrophoretic analysis of the partly purified extracts showed the presence of two protein bands of 57 and 5 kDa apparent molecular masses, which strongly cross-reacted with antibodies against plant calreticulins. Amino acid sequence comparison with other plant and animal calreticulins revealed a much higher similarity of the N-terminus of Ginkgo calreticulins with the homologue from angiosperms rather than with that from mammals. The finding of calreticulin in Ginkgo is indicative of the conservation also in gymnosperms of Ca2+ homeostatic mechanisms, which seem to rely on the same molecular components as all eukaryotic cells.

Wang, H., Y. Wang, et al. (1998). Protective effects of folium Ginkgo extract on experimental cerebral ischemia of mice. Zhongguo Zhongyao Zazhi 23(3): 169-171, 193.

Folium Ginkgo extract(EGb761) has been proved able to significantly prolong the survival time of mice suffering from cerebral ischemia induced by occluding bilateral common carotids, and reduce the inhibition of cerebral GSHPx and Na+ -K+ -ATPase activities during reperfusion processes of these mice. Pretreatment with EGb761 also helps alleviate the subcellular damages in hippocampus of cerebral ischemic mice.

Kirste, T., B. Hauns, et al. (1998). Complete remission in patients with pancreatic cancer: A rare but sometimes achievable event. Onkologie 21(1): 64-66.

Background: Treatment of nonresectable pancreatic cancer is often controversial, and best supportive care is considered a sufficient control group for investigational drug trials. Individual cases with remarkable responses call this caution regarding therapy into question. Case Report. We report 2 patients with histologically proven nonresectable primary or recurrent pancreatic cancer. The initial CT scan showed well demarcated pancreatic tumors in head and tail of the pancreas, respectively. Both patients achieved complete remission after 6 cycles of chemotherapy. Patient I (61 years, male); was treated with gemcitabine 1,000 mg/m2 on days 1, 8, and 15 starting the next cycle on day 29. Patient II (76 years, male) was included into a phase II trial with 5-fluorouracil (500 mg/m2 i. v. days 2-6) plus Ginkgo biloba extract (GBE-761-ONC, 350 mg total dose i. v. days 1-6) starting the next cycle on day 21. Both regimens were generally well tolerated and showed no major side effects. Both patients were controlled by CT scan. Patient I showed a complete remission (CR) after 6 cycles. Remission was confinned at the end of treatment and 2, 4, 6, and 8 months after starting the treatment. No evidence of disease was found in the CT scan, although CA 19-9 began to rise 2 months after stop of treatment with gemcitabine. The patient remains well and without measurable disease 14 months after initial diagnosis of the metastatic pancreatic carcinoma. Patient II was first diagnosed 2 years before his first visit in our center. Initially, the patient underwent complete surgical resection and a local recurrence occurred 1 month before the chemotherapy was started. CR was achieved 6 weeks after the treatment initiation and confirmed after 2, 6, and 8 months. The recurrence was diagnosed gastroscopically without evidence of disease in CT scans 2 months after the 9th cycle of chemotherapy. The patient died 13 months after the initial diagnosis of local recurrence and 12 months after treatment initiation. Conclusion: This case report underlines the possibility to offer a palliative therapy to patients with nonresectable pancreatic carcinoma. Such results raises questions to the use of placebo within clinical trials.

Kazimierczak, B., J. Hertel, et al. (1997). On the specific pattern of long chain polyprenols in green needles of Pinus mugo Turra. Acta Biochimica Polonica 44(4): 803-808.

In green needles of Pinus mugo the most abundant polyprenols occur as a mixture of prenologues in which the dominant alcohol is built of 16 isoprene units. The characteristic spectrum of polyprenols (prenol-15, -16 and -17) was the same irrespective of the location of plant and of distinct morphological differences observed in the various selected forms of this species. The constant pattern of the polyprenols spectrum was preserved throughout the 2-year life span of needles, although the level of polyprenols was increased 2-3-fold. The polyprenol pattern in Pinaceae family differs from species to species, thus it may serve as chemotaxonomic criterion within this systematic group.

Franks, P. J., I. R. Cowan, et al. (1998). A study of stomatal mechanics using the cell pressure probe. Plant Cell and Environment 21(1): 94-100.

The relationship between stomatal aperture (a) and guard cell pressure (Pg) was measured directly in four different species (Vicia faba, Tradescantia virginiana, Ginkgo biloba and Nephrolepis exaltata) using a special cell pressure probe technique. The effect of epidermal turgor (Pep) on this relationship was also measured in T. virginiana. The relationship was sigmoidal for V. faba and T. virginiana, but entirely convex for G. biloba and N. exaltata. Epidermal turgor was found to have a pronounced closing effect on stomata of T. virginiana. Maximum aperture with full epidermal turgor (0.92 MPa) was about half that with zero epidermal turgor. Also, with full epidermal turgor stomata of T. virginiana did not begin to open until Pg was more than 1.25 MPa. These characteristics were used to develop an expression for a as a function of Pg and Pep. Results for the different species are compared and discussed in terms of possible advantages and limitations of water economy.

Zhang, H., X. Liu, et al. (1997). Comparative study of pollen actin content in ginkgo and maize. Acta Botanica Sinica 39(11): 998-1002.

Ginkgo (Ginkgo biloba L.) is a famous gymnosperm species, originated from China and known as "living fossil". Western blotting analysis has proved that actin also exists in ginkgo pollen like in angiosperm, but its content was only about one sixth as much as that of maize (Zea mays L.) pollen based on the densitometry of SDS polyacrylamide gel electrophoresis. Assay on actin inhibition of DNase I activity demonstrated that actin content of maize pollen was as about 7 times as that of ginkgo pollen. The plausible relationship between the actin content and the evolution of plant kingdom was discussed.

Zhang, Y. N., J. Zhang, et al. (1997). Protective effects of extract of Ginkgo biloba (EGb) of lysophosphatidylcholine induced damages of vascular endothelial cells in vitro. Yaoxue Xuebao 32(10): 735-739.

Effects of EGb on cultured bovine aortic endothelial cells (BAEC) damaged by lysophosphatidylcholine (LPC) were investigated. When endothelial cells were incubated with LPC (2. 5 mug cntdot ml-1) for 24 h, the endothelial cells turned round pyknotic, exfoliated and broken, and the contents of malondialdehyde (MDA), lactate dehydrogenase (LDH) and plasminogen activator inhibitor (PAI) were markedly increased and the superoxide dismutase (SOD) activity was inhibited. Treatment with EGb at concentrations of 125 and 250 mug cntdot ml-1, caused a reduction in MDA, LDH and PAI contents, while the SOD activity in the medium was increased and the morphologically damaged BAECs were alleviated. These results suggest that EGb afforded protection against BAECs damages induced by LPC and that the protective effect of EGb may be due to anti-lipid peroxidation via free-radical scavenging activity.

Satyan, K. S., A. K. Jaiswal, et al. (1998). Anxiolytic activity of ginkgolic acid conjugates from Indian Ginkgo biloba. Psychopharmacology 136(2): 148-152.

Ginkgolic acid conjugates (GAC) (6-alkylsalicylates, namely n-tridecyl-, n-pentadecyl-, n-heptadecyl-, n-pentadecenyl- and n-heptadecenylsalicylates) isolated from the leaves of Indian Ginkgo biloba Linn., (IGb) were tested for their putative role in anxiety in rats. Elevated plus maze, open-field behaviour, novelty-induced feeding latency and social interaction were the rodent behavioural models used in this study GAC (0.3 and 0.6 mg/kg, each, PO) on single acute administration, showed dose-related changes in the behaviour. GAC (0.6 mg/kg) and DZ augmented open arm entries, the open arm/closed arm entries ratio and increased time spent in the open arm on the elevated plus maze. In the open field, GAC (0.6 mg/kg) and DZ significantly increased ambulation and reduced the immobility time. EGb 761 showed a similar profile. GAC (0.6 mg/kg) and DZ significantly attenuated the increased latency to feed in novel environment. By contrast, EGb 761 and Ginkocer further augmented feeding latency. None of the drugs tested showed any significant effect in the social interaction test. GAC showed consistent and significant anxiolytic activity in all the variables investigated. By contrast, EGb 761 and Ginkocer, which are devoid of GAC, did not evoke significant activity However, increased rearing and decreased immobility time only in open field behaviour shown by EGb 761 may be due to some antianxiety activity of a lesser degree. Our observations suggest that GAC may be the active constituents of Ginkgo biloba responsible for the anxiolytic activity.

Lee, K. H. (1997). Scientific Chinese herbal medicine: Research and movements toward worldwide acceptance. Journal of Food and Drug Analysis 5(4): 233-234.

Soholm, B. (1998). Clinical improvement of memory and other cognitive functions by Ginkgo biloba: Review of relevant literature. Advances in Therapy 15(1): 54-65.

Ginkgo biloba is a plant extract used to alleviate symptoms associated with cognitive deficits, eg, decreased memory performance, lack of concentration, decreased alertness, tinnitus, and dizziness. Pharmacologic studies have shown that the therapeutic effect of ginkgo is based on several active constituents with vasoactive and free radical-scavenging properties. The use of ginkgo extract in either dementias of the Alzheimer or multi-infarct type or in the case of cerebral insufficiency, a symptom complex related to age-dependent impairment of cerebral circulation, is based mainly on positive results from good-quality placebo-controlled studies that enrolled approximately 1200 patients with criteria established by International Classification of Diseases (9th and 10th revisions, ICD-9 and ICD-10) or the 3rd revision of the Diagnostic and Statistical Manual (DSM-III-R) (uncomplicated dementia). Effect on cognitive symptoms was within the range of a 25% reduction. Memory, concentration, and alertness were the first symptoms to be relieved, with tinnitus and dizziness improving somewhat later. A minimum of 4 to 6 weeks were needed before a pronounced effect could be expected. The pharmacologic advantage of ginkgo seems to be a very tolerable side-effect profile, with a side-effect frequency at the placebo level.

Le, B. P. L., M. M. Katz, et al. (1997). A placebo-controlled, double-blind, randomized trial of an extract of Gingko biloba for dementia. JAMA Journal of the American Medical Association 278(16): 1327-1332.

Context.-EGb 761 is a particular extract of Ginkgo biloba used in Europe to alleviate symptoms associated with numerous cognitive disorders. Its use in dementias is based on positive results from only a few controlled clinical trials, most of which did not include standard assessments of cognition and behavior. Objective.-To assess the efficacy and safety of EGb in Alzheimer disease and multi-infarct dementia. Design.-A 52-week, randomized double-blind, placebo-controlled, parallel-group, multicenter study. Patients.-Mildly to severely demented outpatients with Alzheimer disease or multi-infarct dementia, without other significant medical conditions. Intervention.-Patients assigned randomly to treatment with EGb (120 mg/d) or placebo. Safety, compliance, and drug dispensation were monitored every 3 months with complete outcome evaluation at 12, 26, and 52 weeks. Primary Outcome Measures.-Alzheimers Disease Assessment Scale-Cognitive subscale (ADAS-Cog), Geriatric Evaluation by Relative's Rating Instrument (GERRI), and Clinical Global Impression of Change (CGIC). Results.-From 309 patents included in an intent-to-treat analysis, 202 provided evaluable data for the 52-week end point analysis. In the intent-to-treat analysis, the EGb group had an ADAS-Cog score 1.4 points better than the placebo group (P=.04) and a GERRI score 0.14 points better than the placebo group (P=.004). The same patterns were observed with the evaluable data set in which 27% of patients treated with EGb achieved at least a 4-point improvement on the ADAS-Cog, compared with 14% taking placebo (P=.005); on the GERRI, 37% were considered improved with EGb, compared with 23% taking placebo (P=.003). No difference was seen in the CGIC. Regarding the safety profile of EGb, no significant differences compared with placebo were observed in the number of patients reporting adverse events or in the incidence and severity of these events. Conclusions.-EGb was safe and appears capable of stabilizing and, in a substantial number of cases, improving the cognitive performance and the social functioning of demented patients for 6 months to 1 year. Although modest, the changes induced by EGb were objectively measured by the ADAS-Cog and were of sufficient magnitude to be recognized by the caregivers in the GERRI.

Son, Y. and H. W. Kim (1998). Above-ground biomass and nutrient distribution in a 15-year-old ginkgo (Ginkgo biloba) plantation in Central Korea. Bioresource Technology 63(2): 173-177.

Above-ground tree biomass and distribution of nutrients between tree components and within the major components of the ecosystem were determined for a 15-year-old ginkgo (Ginkgo biloba L.) plantation in central Korea. Total ecosystem biomass (excluding roots) was 160.6 Mg ha-1, of which 79% was soil organic matter, 6% was forest floor and 15% was living, above-ground biomass. Total above-ground tree biomass was 23.8 Mg ha-1 of which 10% was foliage. Concentrations of N, P, and Mg were greatest in foliage, while concentrations of Ca and K were greater in branch or stembark than foliage. Total ecosystem nutrient contents were (kg ha-1) 5544 for N, 1384 for Ca, 554 for K, 480 for P, and 145 for Mg, respectively. The forest floor had the largest accumulation of N, P, K, Ca, and Mg in live and dead above-ground components. The greatest proportion of total ecosystem nutrient capital was contained in the mineral soiL Of the total contents of N and P, more than 90% were contained in the upper 20 cm mineral soiL Foliage-only harvesting of ginkgo trees commonly practiced in Korea might degrade site-quality, proper plans for nutrition-management should be considered if foliages were to be harvested regularly.

Rattan, S. I. S. (1998). Is gene therapy for aging possible? Indian Journal of Experimental Biology 36(3): 233-236.

Throughout human history, search for means to prevent or slow down aging has followed three main lines-(1) removing waste products and cleansing impurities; (2) using products of plants and animals as medicine; and (3) compensating for decrease in various hormones, vitamins and other chemicals in the body. Even in modern times, immense popularity of various spas and water therapies is an example of the first type of anti-aging approach for which there are no real scientific basis. Some pre support from laboratory and/or clinical tests is available for various herbal and other medicinal plant products, such as ginseng, ginkgo biloba and garlic, as nutritional supplemental. Replacement therapy, especially hormonal replacement therapy as an anti-aging treatment has been used and misused for quite some time.

Kuang, X. and J. Wu (1998). The application of HPLC to determination of flavonoids in extract of Ginkgo Biloba L. Sichuan Daxue Xuebao Ziran Kexueban 35(1): 147-150.

Arnould, T., C. Michiels, et al. (1998). Effect of Ginkor Fort of hypoxia-induced neutrophil adherence to human saphenous vein endothelium. Journal of Cardiovascular Pharmacology 31(3): 456-463.

This study was performed to evaluate the effects of Ginkor Fort, a venotropic drug composed of Ginkgo biloba extract troxerutine, and heptaminol, on neutrophil adherence to the endothelium of saphenous veins. When saphenous veins were incubated 2 h in hypoxic conditions, they showed a five- to six-fold increase in neutrophil adherence to the endothelium. Ginkor Fort at 0.3 mg/ml was able to inhibit this increase by 69%. These results were confirmed by observations in scanning electron microscopy. Ginkor Fort also inhibited the subsequent activation of these neutrophils, as evidenced by the inhibition of superoxide anion release. The biochemical mechanism of this inhibition of neutrophil adherence was studied on endothelial cells in culture. We observed that Ginkor Fort was able to inhibit the different steps of the activation of endothelial cells by hypoxia: the activation of phospholipase A2 and the decrease in adenosine triphosphate (ATP) content. By preventing the first step of the activation cascade, the decrease in ATP content, Ginkor Fort blocks the subsequent increase in neutrophil adherence as well as neutrophil activation. The biochemical mechanism evidenced in this work might explain the beneficial effect of this drug in the treatment of patients with chronic venous insufficiency.

Wesnes, K. A., R. A. Faleni, et al. (1997). The cognitive, subjective, and physical effects of a Ginkgo biloba/Panax ginseng combination in healthy volunteers with neurasthenic complaints. Psychopharmacology Bulletin 33(4): 677-683.

We evaluated the effects of a Ginkgo biloba/ginseng combination on cognitive function in this 90-day, double-blind, placebo-controlled, parallel-group study. Sixty-four healthy volunteers (aged 40 to 65 years), selected on the basis of fulfilling the ICD-10 F48.0 criteria for neurasthenia, were again at Days 1, 30, and 90 at 1 hour after the morning dose and 1 hour after the afternoon dose. The assessments included the Cognitive Drug Research (CDR) computerized assessment system, the Vienna Determination Unit, cycle ergometry, and various questionnaires. The treatments were well tolerated by all volunteers. On Day 90 at 1 hour post morning dosing, dose-related improvements were seen on the CDR tests, the 320 mg dose being significantly superior to placebo. These effects, however, were reversed 1 hour after the afternoon dose, possibly suggesting that a longer inter-dosing interval would be preferable. The 80-mg dose produced a significant benefit on the ergometry assessment of heart rate at maximum load. There were also several supporting changes from other assessments, including an advantage of 320 mg over placebo on the global score from the Symptom Checklist-90-revised (SCL-90-R) at Day 90.

Chun, I. K. and E. H. Seo (1998). Solubilization of quercetin, and permeability study of quercetin and rutin to rabbit duodenal mucosa. Yakhak Hoeji 42(1): 59-69.

To increase the solubility of quercetin, which is a practically insoluble flavonoid of Ginkgo biloba leaf, the effects of nonaqueous vehicles, their cosolvents, water-soluble polymers and modified cyclodextrins (CDs) were observed. Polyethylene glycols, diethyleneglycol monoethyl ether, and their cosolvents with water showed a good solvency toward quercetin. Also the aqueous solutions of povidone, copolyvidone and Cremophor RH 40 was effective in solubilizing quercetin. Complex formation of quercetin with beta-cyclodextrin (beta-CD), dimethyl-beta-cyclodextrin (DMCD), 2-hydroxypropyl-beta-cyclodextrin (HPCD) and beta-cyclodextrin sulfobutyl ether (SBCD) in water was investigated by solubility method at 37degreeC. The addition of CDs in water markedly increased the solubility of quercetin with increasing the concentration. AL type phase solubility diagrams were obtained with CDs studied. Solubilization efficiency by CDs was in the order of SBCD mchgt DMCD > HPCD > beta-CD. The dissolution rates of quercetin from solid dispersions with copolyvidone, povidone and HPCD were much faster than those of drug alone and corresponding physical mixtures, and exceeded the equilibrium solubility (3.03+-1.72 mug/ml). The permeation of quercetin through duodenal mucosa did not occur even in the presence of enhancers such as bile salts, but the permeation was observed when the mucus layer was scraped off. This was due to the fact that quercetin had a strong binding to mucin (58.5 mug/mg mucin). However rutin was permeable to the duodenal mucosa. The addition of enhancer significantly increased the permeation of rutin in the order of sodium glycocholate ltoreq sodium deoxycholate<ammonium glycyrrhizinate.

Castelli, D., L. Colin, et al. (1998). Pretreatment of skin with a Ginkgo biloba extract/sodium carboxymethyl-beta-1,3-glucan formulation appears to inhibit the elicitation of allergic contact dermatitis in man. Contact Dermatitis 38(3): 123-126.

The clinical efficiency of mitigating contact dermatitis with a Ginkgo biloba extract and carboxymethyl-beta-1,3-glucan formulation was investigated in a double-blind versus placebo study using 22 subjects (Caucasian women aged 22-55 years) with allergic contact dermatitis from various substances in the European standard series. The formulation was applied to intact skin 2X a day for 2 weeks ("in use" application) prior to a single application of a selected contact allergen under a Finn Chamber for 24 h. Readings were carried out in a blind study by a dermatologist 2 and 3 days after patch removal. Representative photographs were taken of treated, placebo and untreated test areas. 68.2% of the panelists showed significantly reduced skin reactivity (p=0.037*) on the treated site 2 days after patch removal, versus untreated and/or placebo sites. This finding indicates that the Ginkgo biloba/carboxymethyl-beta-1,3-glucan formulation can mitigate against allergic contact dermatitis.

Yang, F. Q., T. Y. Zhang, et al. (1998). Preparative separation and purification of kaempferol, isorhamnetin, and quercetin by high-speed countercurrent chromatography. Journal of Liquid Chromatography and Related Technologies 21(1-2): 209-216.

High-speed countercurrent chromatography was used for the preparative separation and purification of kaempferol, isorhamnetin, and quercetin from leaf extracts of Ginkgo biloba L. and the commercial quercetin standard with a two-phase solvent system composed of chloroform-methanol-water (4:3:2, v/v/v). HPLC analyses of the CCC fractions revealed that all three main flavone aglycones were over 99% pure. Their chemical structures were identified by mass spectrometric analysis.

Neinhuis, C. and W. Barthlott (1998). Seasonal changes of leaf surface contamination in beech, oak, and ginkgo in relation to leaf micromorphology and wettability. New Phytologist 138(1): 91-98.

The leaf surfaces of beech, oak and ginkgo have been investigated with respect to contamination with particles during one growing season. Based on the observation that particles are removed from water-repellent leaves by rain (Lotus effect) the three species were selected because they differ in leaf surface micromorphology and wettability. Leaves of beech are smooth, lacked wax crystals and were +- wettable. Those of ginkgo were rough because their cells were convex and were densely covered by wax crystals, resulting in permanent water repellency. Leaves of oak were covered by waxes and were water repellent when young, but, a few weeks after leaf expansion had ceased the waxes were rapidly eroded. These differences in wettability resulted in different amounts of contamination. Ginkgo collected a very small number of particles during the whole vegetation period. In beech the contamination was significantly higher, but fairly constant, whereas oak leaves accumulated particles with age.

Scorolli, L., S. Z. Scalinci, et al. (1997). Evolution of color vision in early diabetic retinopathy treated by Ginko biloba extract. Annali di Ottalmologia e Clinica Oculistica 123(6-8): 245-251.

The therapeutic efficiency of the Ginkgo biloba extract was estimated in a double-blind trial, during a 1 year period, in 32 diabetic subjects with an early diabetic retinopathy evidenced by angiography and associated with a blue-yellow dyschromatopsia. The functional criterion was the color vision evolution, studied by the Desatured Panel D-15 and the 100-Hue Farnsworth test at the beginning of the trial and 1 year later. An improvement tendency was evidenced in subjects treated by Ginkgo biloba extract and an aggravation in subjects with placebo, this improvement being statistically significative with the Desatured Panel D-15 among subject without retinal ischemia. These clinical results on visual function corroborate the pharmacological actions of Ginkgo biloba extract on diabetic retina.

Watson, D. G. and A. R. Pitt (1998). Analysis of flavonoids in tablets and urine by gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry. Rapid Communications in Mass Spectrometry 12(4): 153-156.

A method was developed for the analysis and characterization of quercetin and kaempferol in urine following ingestion of Ginkgo biloba tablets. The method utilized gas chromatography/negative ion chemical ionization mass spectrometry of the trimethysilyl derivatives of the flavonoids. Limits of detection for these compounds using this method were ca. 20 pg on column. Liquid chromatography with electrospray mass spectrometry in the negative ion mode was utilized to characterize the complex mixture of glycosides present in the G. biloba tablets, the limit of detection with this technique was ca. 10 ng on column.

Niederl, S., T. Kirsch, et al. (1998). Co-permeability of 3H-labeled water and 14C-labeled organic acids across isolated plant cuticles. Plant Physiology Rockville 116(1): 117-123.

Penetration of 3H-labeled water (3H2O) and the 14C-labeled organic acids benzoic acid ((14C)BA), salicylic acid ((14C)SA), and 2,4-dichlorophenoxyacetic acid ((14C)2,4-D) were measured simultaneously in isolated cuticular membranes of Prunus laurocerasus L., Ginkgo biloba L., and Juglans regia L. For each of the three pairs of compounds (3H2O/(14C)BA, 3H2O/(14C)SA, and 3H2O/(14C)2,4D) rates of cuticular water penetration were highly correlated with the rates of penetration of the organic acids. Therefore, water and organic acids penetrated the cuticles by the same routes. With the combination 3H2O/(14C)BA, co-permeability was measured with isolated cuticles of nine other plant species. Permeances of 3H2O of all 12 investigated species were highly correlated with the permeances of (14C)BA (r2 = 0.95). Thus, cuticular transpiration can be predicted from BA permeance. The application of this experimental method, together with the established prediction equation, offers the opportunity to answer several important questions about cuticular transport physiology in future investigations.

Garcia, G. A., F. Dubois, et al. (1998). Two different modes of early development and nitrogen assimilation of gymnosperm seedlings. Plant Journal 13(2): 187-199.

Light-independent chloroplast development and expression of genes encoding chloroplast proteins occur in many but not all species of gymnosperms. Early development in maritime pine (Pinus pinaster) seedlings was strongly light-independent, whereas Ginkgo biloba seedlings exhibited a typical angiosperm-like morphogenesis with differentiated patterns in light and dark. In pine, chloroplast polypeptides were undetectable in the seed embryo and accumulated in cotyledons of both light- and dark-grown plants in good correlation with light-independent chlorophyll synthesis. In contrast, chlorophyll and chloroplast proteins were only detected in light-grown ginkgo. Pine cytosolic glutamine synthetase (GS) and ferredoxin glutamate synthase (Fd-GOGAT) were present at low levels in the seeds and accumulated at comparable amounts in light- and dark-grown seedlings. Fd-GOGAT was also barely detectable in the seeds of ginkgo and only accumulated in green plants with mature chloroplasts. In G. biloba seeds and etiolated plants only cytosolic GS was identified, while in light-grown seedlings this molecular form was present at low abundance and choroplastic GS was the predominant isoenzyme. The above results have been confirmed by immunolocalization of GS protein in pine and ginkgo plantlets. In pine, GS was present in the peripheral cytoplasm of mesophyll cells and also in the phloem region of the vascular bundle. Immunocytochemical analysis showed that the labelling of mesophyll and phloem cells was only cytoplasmic, In developing ginkgo, GS antigens were present in the chloroplasts of mesophyll parenchyma cells of leaflets and green cotyledons. In contrast, a weak labelling of GS was observed in the parenchyma and phloem cells of non-green cotyledons enclosed in the seed coat. Taking all this into account, our data indicate the existence of two different modes of GS and GOGAT regulation in gymnosperms in close correlation with the differential response of plants to light. Furthermore, the results suggest that glutamine and glutamate biosynthesis is confined to the chloroplast of mesophyll cells in species with light-dependent chloroplast, development whereas compartmentation would be required in species with light-independent plastid development.

Hasenoehrl, R. U., B. Topic, et al. (1998). Dissociation between anxiolytic and hypomnestic effects for combined extracts of zingiber officinale and ginkgo biloba, as opposed to diazepam. Pharmacology Biochemistry and Behavior 59(2): 527-535.

Previous work has shown that Zingicomb (ZC), a combination preparation of zingiber officinale and ginkgo biloba, exerts anxiolytic-like effects in the elevated plus-maze (EPM), possibly related to 5-HT antagonistic properties of its components. The first experiment of this study was performed to gauge the specificity of the anxiolytic action of ZC with respect to the mixture ratio of the single components in the combination preparation. Two different combinations of zingiber officinale and ginkgo biloba extracts (ratio, of components: 1:1 or 1:2.5) were compared with the standard ratio adjusted for ZC (2.5:1). Each combination was administered intragastrically (IG) in five doses (0.01 to 10 mg/kg) before the rats were tested on the EPM. Zingicomb at 1 mg/kg elevated the time spent on the open arms scanning of the open arms and excursions into the ends of the open arms, whereas the two other combinations (1:1 and 1:2.5) did not influence rats' behavior on the EPM in the entire dose range tested. With regard to the memory-disrupting effects of anxiolytics, particularly of diazepam (DZP), a second experiment was performed to compare the effects of ZC (0.5, 1, 10 mg/kg, IG) and DZP (1 or 5 mg/kg, IP) on the performance of rats in two different learning tasks. Rats were treated with DZP or ZC prior to the learning trial of a one-trial step-through inhibitory avoidance task. Retention testing 24 h later showed impaired retention for rats injected with DZP at 5 mg/kg but not for animals that had received ZC prior to training. In a further experiment, rats were treated once daily with DZP or ZC prior to the training trials in a water maze. Injections of DZP at 5 mg/kg impaired place and cue learning, whereas the treatment with ZC did not influence the navigation performance in the maze. The present results indicate that the anxiolytic-like effects of ZC are specific in that only the mixture ratio of zingiber officinale and ginkgo biloba adjusted for the phytopharmacon was active in the EPM. Furthermore, ZC did not interfere negatively with the performance on an inhibitory avoidance and a water maze task, as opposed to DZP. This finding is interesting with regard to other studies that have revealed a similar dissociation between anxiolytic and memory-disrupting effects for chemically defined 5-HT antagonists, especially for those acting at 5-HT3 receptors.

Cohen, S. C., P. Venault, et al. (1997). Effects of Ginkgo biloba extract (EGb 761) on learning and possible actions on aging. Journal of Physiology Paris 91(6): 291-300.

A study of the effect of Ginkgo biloba extract (EGb 761) has shown enhancing effects on training in adult and aged Swiss mice. An analysis of inbred mice has confirmed this sensitivity to EGb 761, but depending on the strains, with different effects at different ages. The most interesting results are related to improvements in performances observed with aged mice of the DBA/2J strain. The results obtained with inbred strains in the study of the mossy fibers of the hippocampus make it possible to suggest a link between the improvements in training and the histological structure of the hippocampus. This possibility, which can be confirmed by further studies, is presented here.

Winter, J. C. (1998). The effects of an extract of Ginkgo biloba, EGb 761, on cognitive behavior and longevity in the rat. Physiology and Behavior 63(3): 425-433.

Extracts of the leaves of the Ginkgo biloba tree are widely used throughout the world for their purportedly beneficial effects on brain function. In the present investigation, a standardized extract, EGb 761, was self-administered orally by male Fischer 344 rats that were then tested in an eight-arm radial maze. The tasks employed were a) continuous learning and b) delayed nonmatching to position. Chronic postsession administration of EGb 761 at a dose of 50 mg/kg had no effect on continuous learning but the same dose given presession resulted in a trend toward fewer sessions to reach criterion performance as well as fewer errors. In addition, it was observed that rats chronically treated with EGb 761 lived significantly longer than vehicle-treated subjects. In a delayed nonmatching to position task using a 30-min delay in 20-month-old rats. EGb 761 administered presession produced a dose-related decrease in total, retroactive, and proactive errors; a repeated-measures design was used, with subjects serving as their own controls. Following the dose-response determination, the group, now 26 months of age, was divided in two with half receiving EGb 761 at a dose of 200 mg/kg presession and the other half vehicle (sweetened condensed milk). A statistically significant positive effect of treatment with EGb-761 was observed. The present data are consistent with the beneficial effects on cognitive performance which have been widely reported in human subjects. In addition, the data suggest that the methods employed, i.e., continuous learning and delayed nonmatching to position tasks in aged rats, are capable of detecting drugs of possible value in the treatment of human cognitive impairment. Finally, the present results encourage a search for the pharmacologically active principles of EGb 761 and for their mechanisms of action.

Ma, X., C. Jiang, et al. (1997). A study on the adsorption of flavonoids in Ginkgo biloba L. leaves by macroporous adsorptive resins. Zhongguo Zhongyao Zazhi 22(9): 539-542, 575-576.

This paper compares the adsorptive properties and adsorption kinetics of ten kinds of macroporous adsorptive resins, for flavonoids. The structures and properties of these resins were studied. The results showed that the AB-8 resin was a fine adsorbent.

Chen, X., S. Salwinski, et al. (1997). Extracts of Ginkgo biloba and ginsenosides exert cerebral vasorelaxation via a nitric oxide pathway. Clinical and Experimental Pharmacology and Physiology 24(12): 958-959.

1. Extracts from the leaves of Ginkgo biloba (EGb) and ginsenosides (GS) have been reported to be effective at increasing vascular relaxation. In the present study, the actions of EGb and GS on the vascular functions of porcine basilar arteries were investigated in vitro using tissue bath techniques. 2. Both EGb and GS relaxed the basilar artery in a concentration-dependent and partly endothelium-dependent manner. However, EGb appeared to be more potent than GS. Relaxation induced by transmural nerve stimulation (TNS) was significantly enhanced by EGb (7.5, 15 and 30 mug/mL) and GS (20, 40 and 80 mug/mL) in both endothelium-intact and -denuded basilar arteries. Enhanced TNS-induced relaxations were abolished by 0.3 mmol/L N-L-arginine. 3. The present study demonstrates that nitric oxide plays a primary role in TNS-induced relaxation as well as in EGb- and GS-enhanced relaxation within the cerebral vasculature. In addition, our data support the potential of these compounds as therapeutic strategies in cerebral ischaemia and other related vascular dysfunctions.

Li, C. L. and Y. Y. Wong (1997). The bioavailability of ginkgolides in Ginkgo biloba extracts. Planta Medica 63(6): 563-565.

A new Ginkgo biloba leaf extract, BioGinkgo 27/7, was prepared using a method that enriches ginkgolide B. The bioavailability of ginkgolides in these extracts was assessed in rabbits in comparison with a commercially available standardized 24/6 extract. It was found that, after a single dose, a higher concentration of ginkgolides was maintained for a longer period of time with these extracts than was found with commercial extract prepared by existing methods.

Yurina, A. L. and O. N. Putyatina (1997). Problems of classifications of some Paleozoic Ginkgo-like megaphyllous plants. Paleontologicheskii Zhurnal(4): 83-88.

Some diagnostic features (phyllotaxy, mode of leaf attachment, shape and dissection of lamina) in combination are considered to be of generic importance for the Paleozoic Ginkgo-like megaphyllous plants. The status of form-group Flabellofolia is proposed for the genera Flabellofolium, Enigmophyton, Ginkgophytopsis, Ginkgophyllum, and Gondwanophyton.

Maurer, K., R. Ihl, et al. (1997). Clinical efficacy of Ginkgo biloba special extract EGb 761 in dementia of the Alzheimer type. Journal of Psychiatric Research 31(6): 645-655.

Among the psychiatric illnesses associated with old age primary degenerative dementia of the Alzheimer type (DAT) has gained increasing importance in recent years. Even though a curative treatment of the disease is currently impossible, various drugs can be used to slow down its progression. In the present study the influence of oral treatment with 240 mg/day of Ginkgo biloba special extract EGb 761 (Tebonin forte, manufactured by Dr Willmar Schwabe, Karlsruhe) on the clinical course of DAT was investigated in a double-blind, randomized, placebo-controlled parallel-group design in 20 outpatients. The duration of treatment was 3 months. The primary outcome variable was the sum score in the SKT-test for the determination of attention and memory. Other psychometric tests (trailmaking test, ADAS, CGI) and electrophysiological investigations (EEG topography) were evaluated descriptively. Although the active-treatment group, with a mean sum score of 19.67 points in the, S.K.T., had a poorer baseline level than the placebo group (18.11 points), it experienced an improvement to 16.78 points under treatment with EGb 761 whereas the placebo group deteriorated to 18.89 points. The differences between the baseline and final values formed the basis for a statistical group comparison, which gave a result favourable to EGb 761, at a significance level of p<.013. In addition to this psychometric confirmation of efficacy, certain descriptive trends were found at the psychopathological (Clinical Global Impression) and dynamic functional (EEG findings) levels, which can be interpreted as evidence of effectiveness of Ginkgo biloba special extract EGb 761 in mild to moderate dementia and of local effects in the central nervous system. Inter-group differences in the ADAS cognitive and non-cognitive subscales did not reach statistical significance, probably because of the small sample size.

Zhou, X., S. Zhong, et al. (1997). High performance liquid chromatographic determination of quercetin in extract of Ginkgo biloba L. leaves. Zhongguo Zhongyao Zazhi 22(10): 616-617, 640.

This paper reports the HPLC determination of one of the flavones quercetin in the extract of Ginkgo biloba leaves. Quercetin was separated completely on an YWG-C18 column (0.46cm X 15cm), using a mixture of methanol, water and phosphoric acid (50:49.8:0.2) as mobile phase, with UV detection at 360nm. The results have shown the recoveries to be between 95.3% X 103.2% and RSD 1.86%.

Ihl, R. and C. Kretschmar (1997). Evaluation of Nootropika in the practice. Nervenarzt 68(11): 853-861.

Treatment with 'nootropic drugs' of patients suffering from dementia is often described as arbitrary. To define the potential usefulness of nootropic drugs, effects and side effects, economic aspects in comparison to other treatment approaches were studied. A summary of literature published concerning these criteria underlines the efficacy of nootropics in improving the symptoms at the beginning and in postponing the progress of the disease. The majority of substances does not lead to severe side effects. There are not enough studies comparing the effects of the substances or on prophylactic effects. Delayed admission to care units leads to a positive cost effect of nootropics. Thus, also for economic reasons it seems advisable to treat patients with nootropics. Better effects are gained when nootropic treatment is combined with training and changing of the structure of the environment. A proposal for a rational treatment with nootropics is derived from the data.

Kose, K., P. Dogan, et al. (1997). In vitro antioxidant effect of Ginkgo biloba extract (EGb 761) on lipoperoxidation induced by hydrogen peroxide in erythrocytes of Behcet's patients. Japanese Journal of Pharmacology 75(3): 253-258.

Excessive superoxide radical production and an impaired antioxidant mechanism in both the neutrophils and plasma of patients with Behcet's disease (BD) have been reported. To provide clinical support for the earlier data, erythrocyte membrane integrity was investigated by measuring malondialdehyde (MDA, a marker of lipid peroxidation) levels in the erythrocytes of BD patients. In addition, the antioxidant effect of Ginkgo biloba extract (EGb 761) at 25 and 250 mug/ml concentrations on lipoperoxidation induced by hydrogen peroxide (H2O2) in erythrocyte obtained from BD patients was examined in in vitro conditions. When compared to healthy controls, basal erythrocyte MDA levels were found to be higher in BD patients. In the in vitro study, there was also a significant increase in H202-induced MDA production in the medium containing no EGb 761 in the patient group, whereas significant decreases in MDA levels were observed in the mediums containing EGb 761 both in the patient and control groups. The decrease in MDA production was found to be related to EGb 761 concentration. These data indicate that an oxidative damage is present in erythrocytes obtained from Behcet's patients, and EGb 761, which may strengthen the antioxidant defense system, may contribute to the treatment of BD.

Sastre, J., A. Millan, et al. (1998). A Ginkgo biloba extract (EGb 761) prevents mitochondrial aging by protecting against oxidative stress. Free Radical Biology and Medicine 24(2): 298-304.

The effect of aging on indices of oxidative damage in rat mitochondria and the protective effect of the Ginkgo biloba extract EGb 761 was investigated. Mitochondrial DNA from brain and liver of old rats exhibited oxidative damage that is significantly higher than that from young rats. Mitochondrial glutathione is also more oxidized in old than in young rats. Peroxide formation in mitochondria from old animals was higher than in those from young ones. According to morphological parameters (size and complexity), there are two populations of mitochondria. One is composed of large, highly complex mitochondria, and the other population is smaller and less complex. Brain and liver from old animals had a higher proportion of the large, highly complex mitochondria than seen in organs from young animals. Treatment with the Ginkgo biloba extract EGb 761 partially prevented these morphological changes as well as the indices of oxidative damage observed in brain and liver mitochondria from old animals.

Scholtyssek, H., W. Damerau, et al. (1997). Antioxidative activity of ginkgolides against superoxide in an aprotic environment. Chemico Biological Interactions 106(3): 183-190.

The terpene lactones ginkgolide A. ginkgolide B, ginkgolide C, ginkgolide J and bilobalide, which are components of a standardized extract (EGb 761) from leaves of Ginkgo biloba, as well as ginkgolide M from roots of G. biloba were studied regarding their reaction against superoxide (O2-) and hydroperoxyl radicals (HO2) in dimethyl sulfoxide as an aprotic solvent. It was found that the ginkgolides B, C, J, M as well as bilobalide react with superoxide and its protonated form as demonstrated by EPR and UV/VIS spectroscopy. The initial reaction rate with these oxygen-derived radicals is in the order of 100 M-1/s and below. Ginkgolide A does not react with superoxide under these conditions. From these findings it can be suggested that the superoxide scavenging effect of the ginkgolides B, C, J, M and bilobalide contributes to the antioxidant properties of G. biloba.

Kim, S. J., M. H. Lim, et al. (1997). Effects of flavonoids of Ginkgo biloba on proliferation of human skin fibroblast. Skin Pharmacology 10(4): 200-205.

Ginkgo biloba studies have focused on the anti-inflammatory effects of the major components, ginkgolide and bilobalide, whereas little is known about their effect on fibroblasts. This study demonstrated the enhancing effects of Ginkgo L. extracts, especially the flavonoid fractions: quercetin, kaempferol, sciadopitysin, ginkgetin, isoginkgetin, on the proliferation of normal human skin fibroblast in vitro measured by MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl-tetrazolium bromide) assay and direct hemocytometer cell count. Furthermore, increased production of collagen and extracellular fibronectin were documented by radioisotope (2,3-3H-proline) incorporated collagen assay, procollagen type I C-peptide assay and by immunoturbidimetric assay. These proliferative effects suggest another useful pharmacologic application of Ginkgo L. extracts in addition to their well-known anti-inflammatory effect.

Amri, H., K. Drieu, et al. (1997). Ex vivo regulation of adrenal cortical cell steroid and protein synthesis, in response to adrenocorticotropic hormone stimulation, by the Ginkgo biloba extract EGb 761 and isolated ginkgolide B. Endocrinology 138(12): 5415-5426.

We previously demonstrated that repeated treatment of rats with the standardized extract of Ginkgo biloba leaves, EGb 761, and its bioactive component ginkgolide B (GKB), specifically reduces the ligand binding, and protein and messenger RNA expression of the adrenal mitochondrial peripheral benzodiazepine receptor (PBR), a key element in the regulation of cholesterol transport, resulting in decreased circulating corticosterone levels. Adrenocortical cells were isolated from rats treated with EGb 761 or GKB and cultured for 2 and 12 days. The effect of ACTH on normal and metabolically labeled cells was examined. Corticosterone levels were measured by RIA, and protein synthesis was analyzed by two-dimensional gel electrophoresis. Ex vivo treatment with EGb 761 and GKB resulted, respectively, in 50% and 80% reductions of ACTH-stimulated corticosterone production by adrenocortical cells cultured for 2 days compared with that by cells isolated from saline-treated rats. Two-dimensional gel electrophoresis analysis revealed that in cells from both control and drug-treated animals, ACTH induced the synthesis, at the same level, of a 29-kDa and pI 6.4-6.7 protein identified as the adrenal steroidogenic acute regulatory protein (StAR). In addition, treatment with EGb 761 and GKB specifically altered the synthesis of seven proteins, including inhibition of synthesis of a 17-kDa, identified as PBR. After 12 days in culture, ACTH-stimulated adrenocortical cell steroid synthesis was maintained, and it was identical among the cells isolated from animals treated with GKB or saline. Under the same conditions, the expression of PBR was recovered, whereas no effect of ACTH on the 29-kDa and 6.4-6.7 pI protein (StAR) or other protein synthesis could be seen. A comparative analysis of the effects of GKB and EGb 761 on adrenocortical steroidogenesis and protein synthesis identified, in addition to the 17-kDa PBR, target proteins of 32 kDa (pI 6.7) and 40 kDa (pI 5.7-6.0) as potential mediators of the effect of EGb 761 and GKB on ACTH-stimulated glucocorticoid synthesis. In conclusion, these results 1) validate and extend our previous in vivo findings on the effect of EGb 761 and GKB on ACTH-stimulated adrenocortical steroidogenesis, 2) demonstrate the specificity and reversibility of EGb 761 and GKB treatment, 3) question the role of the 29-kDa, 6.4-6.7 pI protein (mature StAR) as the sole mediator of ACTH-stimulated steroid production, and 4) demonstrate the obligatory role of PBR in hormone-regulated steroidogenesis.

Neau, E., A. Cartayrade, et al. (1997). Ginkgolide and bilobalide biosynthesis in Ginkgo biloba. II: Identification of a possible intermediate compound by using inhibitors of cytochrome P-450-dependent oxygenases. Plant Physiology and Biochemistry Paris 35(11): 869-879.

The presence of diterpene hydrocarbons as biosynthetic intermediates in the formation of ginkgolides and bilobalide has been investigated in Ginkgo biloba seedlings. Diterpene hydrocarbons are present only in roots, as trace amounts (1-3 mug g-1 FW). Dehydroabietane is the main hydrocarbon compound. Two inhibitors of cytochrome P-450-dependent oxygenases, tetcyclacis and clotrimazole, were supplied to the seedlings via the roots in order to deregulate the terpene pathway. As a consequence of the treatment with inhibitors, the ginkgolide and bilobalide content was lowered, both in roots and leaves. A treatment with 10 mM tetcyclacis was more effective than a 100 mM clotrimazole treatment and resulted in a strong increase (up to 41 times) of diterpene hydrocarbons in roots. This increase concerned primarily dehydroabietane. 14CO2 feeding experiments, following 10 muM tetcyclacis treatment, showed that only dehydroabietane was highly labelled. The absence of labelling in both ginkgolides and bilobalide indicates that the oxygenation reactions leading to the end-products are fully inhibited. All together, these results support the existence of a precursor-product relationship between dehydroabietane and ginkgolides plus bilobalides. The biosynthesis of oxygenated terpenes in G. biloba proceeds via a hydrocarbon intermediate.

Cartayrade, A., E. Neau, et al. (1997). Ginkgolide and bilobalide biosynthesis in Ginkgo biloba: I: Sites of synthesis, translocation and accumulation of ginkgolides and bilobalide. Plant Physiology and Biochemistry Paris 35(11): 859-868.

Ginkgo biloba trees contain specific terpene compounds, ginkgolides (diterpene) and bilobalide (pentanorditerpene). Ginkgolide A (GA) and ginkgolide B (GB) are the main molecular forms of ginkgolides. These compounds are present in young seedlings and accumulate within roots and leaves, but not in stems. In vitro experiments showed a correlation between accumulation of terpenes and rhizogenesis. Ginkgolides and bilobalide could easily be formed from 14CO2 when the photosynthesis conditions were optimized. Ginkgolide A was first labelled, as early as 8 h after application of 14CO2. The ginkgolide labelling reached a maximum at day 3 followed by a steady state around day 10. Bilobalide labelling, occurred later and showed a maximum at day 6. The chronology of ginkgolide labelling indicated a possible in situ bioconversion of ginkgolides from GA to GC, by successive additions of hydroxyl group. With both 14CO2 and (U-14C) glucose, the labelled terpenes were first detected in roots, and subsequently in stems and leaves. These complementary experiments indicate that all the enzymic steps leading to the Ginkgo diterpene end products take place in the roots but not in the leaves. Ginkgo roots are, at the same time, a site of biosynthesis and accumulation of ginkgolides and bilobalide, whereas leaves seem to act only as a sink. The balance of 14C-labelled terpenes in the whole plant during the chase period (27 days) indicates that terpenes seem to be translocated from the roots to the leaves in a source-sink manner. However, the possible involvement of modified terpene molecules in the transport process as well as the localization of the translocation pathway are not known.

Lin, S. Y. and H. P. Chang (1997). Induction of superoxide dismutase and catalase activity in different rat tissues and protection from UVB irradiation after topical application of Ginkgo biloba extracts. Methods and Findings in Experimental and Clinical Pharmacology 19(6): 367-371.

Ginkgo biloba extract (GBE) prepared from the leaves of Ginkgo biloba with 50% diluted alcohol was found to locally induce superoxide dismutase (SOD) and catalase (CAT) enzyme activity in epidermis after topical application, and also to systemically increase the activity of both enzymes in the liver heart and kidney of Sprague Dawley rats. Skin pretreated with 50% diluted alcohol-extracted liquid formulation was protected from exacerbation of UVB damage. Changes in the lipid structure of the skin of rats determined by ATR/FT-IR spectroscopy demonstrated penetration of active components from GBE dosage formulations.

Ichihashi, M., Y. Miyachi, et al. (1997). Clinical evaluation of Roc CREME ECRAN TOTAL + in photosensitive diseases. Hifu 39(5): 523-529.

CREME ECRAN TOTAL + (CRT), a sunscreen product of Roc with SPF25, was used for 21 patients with photosensitive diseases in 5 University hospitals in Japan. Clinical efficacy and safety of CRT sunscreen were evaluated after 4 and/or 8 weeks use. CRT sunscreen contained methoxycinnamate ester and dibenzoylmethane as ultraviolet (UV) absorber, titanium dioxide for UV scattering, and tocopheryl acetate and ginkgo extract for moisturing. 3 excellently- and 13 well-controlled cases were obtained among 21 photosensitive diseases. Further, no side effects were observed in these cases. These results indicate that CRT sunscreen with high efficacy and excellent safety for photosensitive diseases is also recommended for healthy persons to protect their skin from sun damage.

Chi, J. D., X. F. He, et al. (1997). HPLC determination of six flavonoid constituents in Ginkgo biloba leaves. Yaoxue Xuebao 32(8): 625-628.

Six flavonoid constituents (quercetin, isorhamnetin, kaempferol, bilobetin, ginkgetin and sciadopitysin) were isolated from Ginkgo biloba leaves and determined by reversed phase HPLC using salvianolic and B as internal standard. The column employed was Zorbax ODS (150 mm X 4 mm ID, 5 mum). The mobile phase consisted of solvent A (methanol) and solvent B (tetrahydrofuran-water-formic acid (34:65:1)) for gradient elution. The flow rate was 1 ml cntdot min-1 and detection was effected at 350 nm. This method is accurate, rapid and reproducible. Analytical data for various samples were given.

Akama, K., A. Nass, et al. (1997). Characterization of nuclear tRNATyr introns: Their evolution from red algae to higher plants. FEBS Letters 417(2): 213-218.

We have previously isolated numerous intron-containing nuclear tRNATyr genes derived from either monocotyledonous (Triticum) or dicotyledonous (Arabidopsis, Nicotiana) plants by screening the corresponding genomic phage libraries with a synthetic tRNATyr-specific oligonucleotide. Here we have characterized additional tRNATyr genes from phylogenetically divergent plant species representing red algae (Champia), brown algae (Cystophyllum), green algae (Ulva), stonewort (Chara), liverwort (Marchantia), moss (Polytrichum), fern (Rumohra) and gymnosperms (Ginkgo) using amplification of the coding sequences from the corresponding genomic DNAs by polymerase chain reaction (PCR). All novel tRNATyr genes contain intervening sequences of variable sequence and length ranging in size from 11 to 21 bp. However, two features are conserved in all plant pre-tRNATyr introns: they possess a uridine and less frequently an adenosine at the 5' boundary and can adopt similar intron secondary structures in which an extended anticodon helix of 4-5 bp is formed by base-pairing between nucleotides of the intron and the anticodon loop. In order to elucidate the potential role of the highly conserved uridine at the first intron position, we have replaced it by all other nucleosides in an Arabidopsis pretRNATyr and have studied in wheat germ extract its effect on splicing and on conversion of U to PSI in the GPSIA anticodon. Furthermore, we discuss the putative acquisition of tRNATyr introns at an early step of evolution after the separation of Archaea and Eucarya.

Jaggy, H. and E. Koch (1997). Chemistry and biology of alkylphenols from Ginkgo biloba L. Pharmazie 52(10): 735-738.

Ginkgolic acid and related alkylphenols constitute major components of the lipid fraction of the fruit pods of Ginkgo biloba L. In addition, this class of substances is present in Ginkgo leaves which are widely used to prepare extracts for the treatment of peripheral or cerebral circulatory disorders, as well as vascular and Alzheimer type dementia. The present paper reviews the literature on chemical and biological aspects of alkylphenols from Ginkgo with special reference to their allergic and other undesired properties. As these compounds are present in crude leaf extracts, their completest possible removal has therefore to be guaranteed for therapeutically used extracts by the production process. Technically this does not imply any problem and most preparations available on the market fulfil the requirements of the Monograph of the Commission E of the former Federal German Health Authority (Bundesgesundheitsamt, BGA) requesting a maximal concentration of 5 ppm ginkgolic acids.

Southworth, D. and M. Cresti (1997). Comparison of flagellated and nonflagellated sperm in plants. American Journal of Botany 84(9): 1301-1311.

Differences among flagellated and nonflagellated sperm in land plants are striking, but close examination reveals similarities in pattern of cytoskeleton and in nuclear structure. The microtubular cytoskeleton of flowering plant sperm consists of microtubule bundles arranged obliquely around the nucleus, terminating in cellular extensions. Microtubules are linked into bundles that branch and rejoin along the axis of the sperm cell, forming a cytoskeleton that determines cell shape but does not actively participate in cell movement. Generative cells and sperm share a pattern of microtubules not found in somatic cells. This pattern is initiated in the generative cell, one division before sperm formation, a situation parallel to spermatogenous cell development in vascular plants with flagellated sperm. Chromatin in flagellated and nonflagellated sperm is condensed by specialized histones.

Wolff, R. L., W. W. Christie, et al. (1997). The unusual occurrence of 14-methylhexadecanoic acid in pinaceae seed oils among plants. Lipids 32(9): 971-973.

14-Methylhexadecanoic (14-MHD) acid has been identified in a sample of pine seed oil (Pinus contorta) by gas-liquid chromatography-mass spectrometry of its picolinyl ester derivative. Its identification (through its equivalent chain length) and its distribution in four conifer families have been checked. It occurred only in Pinaceae, where it was found in 72 species belonging to the genera Pinus, Abies, Cedrus, Tsuga, Pseudotsuga, Larix, and Picea, in the range 0.02-1.15%. 14-MHD acid could not be detected in the lipids of Taxaceae (Taxus baccata), Cupressaceae Juniperus communis), or Taxodiaceae (Sciadopytis verticillata), even after a 10-fold concentration of the saturated acid fraction isolated by argentation thin-layer chromatography. it is concluded that Pinaceae, along with Ginkgo biloba seed lipids, are major exceptions in the plant kingdom with regard to 14-MHD acid, which otherwise occurs almost exclusively in lipids of animals and microorganisms. The biosynthesis and metabolic role of 14-MHD acid, which otherwise also occur in wood and leaf lipids, remain unknown.

Laurain, D., G. J. Tremouillaux, et al. (1997). Production of ginkgolide and bilobalide in transformed and gametophyte derived cultures of Ginkgo biloba. Phytochemistry Oxford 46(1): 127-130.

Ginkgolide and bilobalide were detected by HPLC analysis in cell cultures established from various G. biloba explants. These secondary metabolites of pharmacological interest were found to occur in concentrations of 0.065 and 0.087% (dry weight) in two cell suspensions. One was derived from a female prothallus and the other one from putatively transformed embryos, by transfection via Agrobacterium rhizogenes agropine type strain CFBP 2409 (A4).

Zhang, H., G. Liu, et al. (1997). Purification and characterization of tubulin from ginkgo pollen. Sexual Plant Reproduction 10(3): 136-141.

Tubulin was purified by a combination of acetone powder preparation, DEAE Sephadex A-50 chromatography, Sephacryl S-300 gel filtration, and Mono Q anion exchange chromatography from the pollen of ginkgo (Ginkgo biloba L.), a typical gymnosperm. The average yield of tubulin is 2 mg per 100 g of pollen grain. The purified tubulin is electrophoretically homogeneous. It seems to be composed of two subunits on SDS-PAGE and is resolved as two major spots on two-dimensional electrophoresis, preliminarily indicating that there are no obvious tubulin isotypes in ginkgo pollen. The apparent molecular weights of the two subunits are about 54 kDa and 52 kDa respectively, estimated from the SDS-PAGE. It was also demonstrated that tubulin from ginkgo pollen is immunochemically related to animal brain tubulin, and the purified tubulin was polymerized to microtubular aggregates in the presence of taxol and GTP in vitro.

Brailowsky, S. and T. Montiel (1997). Motor function in young and aged hemiplegic rats: Effects of a Ginkgo biloba extract. Neurobiology of Aging 18(2): 219-227.

We have previously shown beneficial effects of a Ginkgo biloba extract (EGb761-IPSEN) in accelerating functional recovery from hemiplegia induced by unilateral motor cortex ablation. Here, we report the behavioral and histological effects of various dose regimes of EGb761. In young rats (3 months), 10 mg/kg/day for 7 days produced an improvement in motor performance, relative to untreated controls, on the last day of treatment. Applying a priming (P)-maintenance (M) dose regime (P-7 = 7 days, M-21 = 21 days), a P-7 of 50 (all doses expressed in mg/kg/day) and a M-21 of 10 promoted recovery from the second day after surgery. However, in aged rats (26-28 months old) this treatment ameliorated motor performance only after the 10th day of treatment. A P-7 of 100 or 200 and a M-21 of 50 or 100 produced an acceleration of behavioral recovery in aged animals. Improvement was evident by the fifth day of treatment and was maintained after the treatment regimen. These two groups also demonstrated reduced glial fibrillary acid protein (GFAP) immunostaining and ex vacuo hydrocephalus. Thus, the confirmed efficacy of EGb in hemiplegic rats can be enhanced by an appropriate posology.

Yoon, S. Y., W. J. Choi, et al. (1997). Selective adsorption of flavonoid compounds from the leaf extract of Ginkgo biloba L. Biotechnology Techniques 11(8): 553-556.

A simple purification method has been developed in which flavonoid compounds are selectively adsorbed onto a polycarboxyl ester resin (XAD-7) from methanol extract of ginkgo leaves. When 1.0g dried gingko leaves was extracted with 100 ml of methanol, about 98% of total flavonoid compounds was recovered by selective adsorption. The pH did not affect the adsorption of flavonoids but at high pH the chemical structure of flavonoids was changed and the adsorption decreased to almost zero. As the solution polarity played a key role in the selective adsorption, the amount of water added to the methanol extract was critical for the recovery and loading of flavonoids. Using standard flavonoids, kaempferol and quercetin, the optimal water content was 80% and the recovery was 80% with 10 g of resin dosage/l.

Murata, M., J. Irie, et al. (1997). Inhibition of lipid synthesis of bacteria, yeast and animal cells by anacardic acids, glycerol-3-phosphate dehydrogenase inhibitors from ginkgo. Lebensmittel Wissenschaft and Technologie 30(5): 458-463.

The effects of anacardic acids (Ana), glycerol-3-phosphate dehydrogenase (GPDH) inhibitors from ginkgo, on growth and lipid synthesis of Bacillus subtilis, Lipomyces starkeyi and 3T3-L1 cells were examined Ana inhibited growth of B. subtilis, and the inhibition was reversed by phosphatidic acid or monoacylglycerol Ana-a (100 mu-g/mL) inhibited lipid accumulation in L. starkeyi, but not growth, when it was added after 40 h of incubation. Ana did not inhibit the adipose conversion of 3T3-L1 cells, as their inhibitory activity against GPDH of the cells was weak.

Zhu, L. W. J., H. Liao, et al. (1997). Antagonistic effects of extract from leaves of Ginkgo biloba on glutamate neurotoxicity. Acta Pharmacologica Sinica 18(4): 344-347.

AIM: To determine whether the extract of leaves of Ginkgo biloba L. (EGb) and several active constituents of EGb have protective effects against glutamate (Glu)-induced neuronal damage. METHODS: Microscopy and image analysis of nucleus areas in the arcuate nuclei (AN) of mice were made. The neuronal viability in primary cultures from mouse cerebral cortex was assessed using MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide) staining and the intracellular free calcium concentration ((Ca-2+)-i) of single neuron was measured using Fura 2. RESULTS: EGb (2.5 mg cntdot L-1) and its constituent ginkgolide B (Gin B, 2 mg cntdot -L-1) protected the neuronal viability against Glu-induced injury, and prevented the Glu-induced elevation in (Ca-2+)-i. EGb (3-10 mg cntdot kg-1) attenuated the decrease of nucleus areas in arcuate nuclei induced by Glu (1 g cntdot kg-1, sc). CONCLUSION: EGb and Gin B prevent neurons from Glu neurotoxicity through reduction of the rise in (Ca-2+)-i.

Stucker, O., C. Pons, et al. (1997). Effect of Ginkgo biloba extract (EGb 761) on the vasospastic response of mouse cutaneous arterioles to platelet activation. International Journal of Microcirculation Clinical and Experimental 17(2): 61-66.

The effect of intravenously administered Ginkbo biloba extract (EGb 761) on the vasospastic response to platelet activation has been assessed using a cutaneous flap preparation in anaesthetized mice. Arterioles of the axillary artery were observed by intravital microscopy, and platelets were activated by topical application of ADP under two steady state conditions: normothermia (37 degree C) and hypothermia (24 degree C). Responses of the cutaneous arterioles to stimulation by topical application of a thromboxane agonist (U46619) were also compared in animals treated intravenously with EGb 761 or with a thromboxane synthesis inhibitor (U63557). ADP induced a 34% constriction of the arterioles in control animals. However, no arteriolar constriction occurred in response to ADP in platelet-depleted animals (collagen-induced thrombocytopenia) or in animals treated with EGb 761 (60 mg/kg, i.v.). Exposure of the arterioles to hypothermia (24 degree C) for 10 min induced constriction of 7-12% in all experimental groups of animals. Under these hypothermic conditions, either EGb 761 or thrombocytopenia abolished ADP-induced arteriolar constriction which was substituted by arteriolar dilation, indicating that EGb 761 can inhibit the vasospasm that is produced by platelet activation. As topically applied U46619 (10-5 M) induced arterioles constriction (about 22 %) that was abolished by intravenous treatment with EGb 761, the extract appears to act directly rather than as a thromboxane synthase inhibitor. Collectively, these findings indicate that platelet factors can play a significant role in cutaneous vasospasm, and that EGb 761, via an action on the thromboxane pathway, could be useful in treating Raynaud's phenomenon and other vascular disorders which involve increased thromboxane production.

Mosle, B., P. Finch, et al. (1997). Comparison of modern and fossil plant cuticles by selective chemical extraction monitored by flash pyrolysis-gas chromatography-mass spectrometry and electron microscopy. Journal of Analytical and Applied Pyrolysis 40-41: 585-597.

In order to investigate the preservation processes influencing the occurrence of plant cuticles (and hence leaves etc.) in the fossil record we have under-taken a comparative study of modern and fossil Ginkgo cuticles by chemical and microscopical methods. Cuticles are stripped or released from modem leaf tissue with hydrogen peroxide in aqueous acetic acid. The polysaccharide component and lignin can be selectively removed by acetyl bromide in acetic acid, and the cutin (polyester) by saponification. These treatments reveal the presence of a non-saponifiable residue of a resistant biomacromolecule with a characteristic dominantly aliphatic pyrolysis pattern as demonstrated and named cutan in the prototypical Agave americana cuticle. However, the same chemical treatments of recent Ginkgo biloba, the untreated cuticle of which shows an aliphatic signature upon pyrolysis, results in complete solubilisation of the sample with no resistant residue. The pyrolysis patterns can be clearly related to electron microscopic observations of the cuticles at different stages of chemical treatment. In particular the initial presence and extent of extracuticular cellular material, and its subsequent removal by the acetylation treatment can be visualised and explained. The saponifiable cutin polyester has a structural function even when associated with a resistant biomacromolecule in the Agave americana cuticle because electron microscopy shows that the resistant residue consists only of cuticle fragments. Fossil cuticles of Ginkgo huttonii were examined by Py-GC-MS and electron microscopy. These consist of extensive cuticle sheets on which SEM reveals gross morphology closely comparable to that in the modern cuticle whilst TEM shows that extra cuticular cellular material is lacking but that the outermost amorphous cuticle zone is preserved. An aliphatic pattern of alkene/alkane doublets has been identified in all of the samples. In addition, phenolic compounds have been found in the modern and fossil Ginkgo cuticle. The presence of a series of alkene/alkane doublets and some phenolic compounds in the fossil sample, combined with preservation of outer cuticle morphology and ultrastructure suggests that a less resistant, saponifiable polymer like that in modern Ginkgo cuticle is one possible source of the morphologically-preserved organic matter in the fossil. A highly resistant macromolecule is not responsible for the preservation of fossil Ginkgo cuticles.

Kirsch, T., F. Kaffarnik, et al. (1997). Cuticular permeability of the three tree species Prunus laurocerasus L., Ginkgo biloba L. and Juglans regia L.: Comparative investigation of the transport properties of intact leaves, isolated cuticles and reconstituted cuticular waxes. Journal of Experimental Botany 48(310): 1035-1045.

Cuticular transport properties of intact leaves, isolated cuticular membranes and reconstituted cuticular waxes of the three tree species Prunus laurocerasus L., Ginkgo biloba L. and Juglans regia L. were measured using six different 14C-labelled compounds, benzoic acid, salicylic acid, 2,4-dichlorophenoxy acid, metribuzin, 4-nitrophenol, and atrazine. For the same compound and the same species, the permeance of the intact leaf and the isolated cuticle was equal. This provides strong evidence demonstrating that transport properties of cuticles are not altered during isolation. Additionally, diffusion coefficients of the 14C-labelled compounds in isolated and subsequently reconstituted cuticular wax of the three tree species were measured. Permeances of intact leaves and isolated cuticles could be predicted from diffusion coefficients, wax/water partition coefficients and the thickness of the transport-limiting wax layer with a mean deviation of about 1.7. This provides evidence that transport properties of recrystallized cuticular waxes do indeed reflect barrier properties of isolated cuticular membranes and intact leaves with in situ waxes. Thus, it can be concluded that the investigation of cuticular permeability using the three independent experimental systems of different complexity give comparable results. Finally, it was observed that permeances and diffusion coefficients measured with P. laurocerasus were always significantly lower than those measured with G. biloba and J. regia. This is interpreted as an ecological adaptation of the respective species. The evergreen species P. laurocerasus must be more adapted to environmental stress such as drought and frost injury compared to the two deciduous species G. biloba and J. regia.

Holt, B. F. and G. W. Rothwell (1997). Is Ginkgo biloba (Ginkgoaceae) really an oviparous plant? American Journal of Botany 84(6): 870-872.

Germination of Ginkgo biloba seeds with intact and removed sarcotesta was compared to test the role of the seed coat in germination biology. The presence of an intact sarcotesta significantly reduced total germination percentage when compared to seeds with the sarcotesta removed. Some seeds were also cold stratified. This treatment was not necessary for germination, but it did improve total germination percentage. The seeds were collected during the period of natural abscission. Contrary to the accepted literature, we found that Ginkgo seeds contain well-developed embryos at the time of dispersal. These data demonstrate that the seed coat contributes to winter dormancy of G. biloba, and that the phenology of this species is less primitive than popularly believed.

Manocha, A., K. K. Pillai, et al. (1997). Effect of Ginkgo biloba on chemoshock in mice. Indian Journal of Pharmacology 29(3): 198-200.

Objective: The present study was designed to evaluate the effect of Ginkgo biloba (a PAF antagonist) on chemoshock in mice. Methods: Picrotoxin and strychnine were used for inducing chemoconvulsions in mice. The onset, duration, nature, severity of convulsions and mortality were observed. The severity of convulsions was assessed by scoring method. Results: Picrotoxin and strychnine produced convulsions in higher doses but not in lower doses. Prior administration of G. biloba extract potentiated the action of picrotoxin and strychnine respectively. Conclusion: The potentiation of picrotoxin action by G. biloba indicates the involvement of GABAergic system and chloride channel. Facilitation of strychnine action by G. biloba indicates the modulating effect of the extract on glycine.

Zhang, Z. M. S. and Z. L. Li (1997). Micronucleus formation in microspores of Ginkgo biloba and its significance in evolution. Acta Botanica Sinica 39(2): 97-101.

During the study on microspore formation and its development in Ginkgo biloba L. the authors have noticed in DAPI stained squashed specimen, some abnormal chromosome arrangements appeared in metaphase I and metaphase II. There were also some chromosomal bridges in telophase I and II and some micronuclei in tetrads too. One of the five observed trees even has abnormality frequency as high as 6.5%. These micronucleus-contained cells could subsequently become sterile. Study of such diversities, when referred to that in paleobotany may provide insight into the evolution trends of this species.

Camper, N. D., P. S. Coker, et al. (1997). In vitro culture of Ginkgo. In Vitro Cellular and Developmental Biology Plant 33(2): 125-127.

Ginkgo biloba L. is an important landscape tree, is resistant to insect, fungi and other pests, and produces a number of chemicals that have pharmaceutical properties (termed ginkgolides). Studies were initiated to establish an in vitro culture protocol for Ginkgo. Explants (intact embryos, embryos with cotyledons removed, and cotyledon tissue) were removed from disinfested seeds and cultured on Murashige and Skoog minimal organics medium with various combinations of either 2,4-dichlorophenoxyacetic acid (2,4-D) or naphthaleneacetic acid (NAA) and either kinetin or benzyladenine (BA). Cultures were incubated in the light and morphological development was recorded. Both embryo and cotyledon explants produced callus (cotyledon tissue produced the most callus). Ginkgolides A and B were detected in callus tissue extracts. Intact embryo cultures initiated on media with 2,4-D plus NAA for 5 wk produced shoots and roots when transferred to media with 4.5 mu-M 2,4-D alone for an additional 5 wk. Plants were transferred from the 2,4-D media to pots and maintained in the greenhouse.

Satyan, K. S., A. K. Jaiswal, et al. (1997). Effect of ginkgolic acid conjugates on the brain monoamines and metabolites in rodents. Biogenic Amines 13(2): 143-151.

The effect of acute administration of Ginkgo biloba leaf extract of Indian origin (IGb) mainly constituting ginkgolic acid conjugates (1a-e). (and their equivalents) have been evaluated on the concentrations of catecholamines, serotonin and their major metabolites in five different regions of the rodent brain namely, hypothalamus, hippocampus, striatum, pons medulla and frontal cortex. IGb extract in the doses 50 and 100 mg/kg., p.o. (equivalent to 0.3 and 0.6 mg/kg ginkgolic acid conjugates) significantly decreased the levels of serotonin (5HT) and its metabolite 5-hydroxyindole acetic acid (5-HIAA) in all the regions of the brain assayed except the pons medulla. The treatments also augmented the levels of norepinephrine (NE) and its metabolite methylhydroxyphenyl glycol (MHPG), dose dependently in various regions of the brain. Concomitantly, the levels of dopamine (DA) and its metabolite dihydroxyphenyl acetic acid (DOPAC) were augmented significantly in the striatum. However, the turnover rate of the monoamines was not influenced by the drug treatment except that of 5HIAA/5HT in frontal cortex. The neurochemical effects of the ginkgolic acid conjugates can explain some of the behavioural actions induced by them, namely, anxiolytic, antidepressant and cognition facilitatory effects.

Wang, X. D. X. (1997). Recent status of the development and strategies of exploitation of non-wood forest products in China. Forest Research 10(2): 199-205.

The article comprehensively introduced the present state of development and the strategies of exploitation of non-wood forest products in China. Some products, such as Camellia oleifera Abel., Vernicia fordii (Hemsl.) Airy-shaw, Toxidendron vernicifluum (Stokes) P. A. Barkl, Castanea mollissima Blume, Eucmmia ulmoides Oliv, Gingo biloba L. etc., have been cultivated for a long time, and their output is the biggest in the world. Some products, such as tung oil, walnut kernel, Chinese chestnut, apricot fruit, Chinese gall and Chinese lacquer, are famous for their quality in the world. A great many of development have been achieved in the exploiting of some products in recent years. For example, the rate of gotten oil by heating interfusion and pressaring squeeze is 14.07% higher than that by usual method; the problem of precipitation has been solved in processing Chinese chestnut can; it has been discovered that there exists SOD in fruits of Hippophae rhamnoides L.; elastroplast and thermoplastic have been made with gutta percha; a kind of endo-fungi has been isolated from the bark of taxus, and it has been confirmed that this kind of endo-fungi can synthesize taxol etc. However, due to the appearance of large quantity of synthetic products, the market of the products of economical forest has been impacked. The lower level of researches has affected the processing quality and economical value. To promote the profit, we should take the following strategies: first, advanced techniques and facilities should be introduced to enforce the researches of chemical ingredients analysis, to exploit and synthesize high-value products; second, we should exploit the resources of edible vegetable oil; third, we should make use of the experience of other countries in exploiting wild plants resources and stride forward to do better research and produce better products.

Sasaki, K., K. Wada, et al. (1997). Bilobalide, a constituent of Ginkgo biloba L., potentiates drug-metabolizing enzyme activities in mice: Possible mechanism for anticonvulsant activity against 4-O-methylpyridoxine-induced convulsions. Research Communications in Molecular Pathology and Pharmacology 96(1): 45-56.

Anticonvulsant effects of bilobalide, one of the constituents of Ginkgo biloba L., on the convulsions induced by 4-O-methylpyridoxine (MPN) were investigated in mice. Bilobalide reduced the duration and incidence of MPN-induced convulsions depending on its dose and the period of treatment. In addition, the anticonvulsant effect was manifested more than 24 hours after treatment and the effect lasted for 7 days after its withdrawal. In mice treated with bilobalide (30 mg/kg, p.o., once a day for 4 days), hepatic 7-methoxycoumarin O-demethylase activity was potentiated, and the disappearance of MPN in blood after MPN injection was faster than in controls. From these results, it is assumed that the anticonvulsant effect of bilobalide against convulsions induced by MPN partly involves modulation of hepatic drug-metabolizing enzyme activity, which leads to accelerated elimination of MPN.

Grant, R. H. (1997). Biologically active radiation in the vicinity of a single tree. Photochemistry and Photobiology 65(6): 974-982.

The horizontal photon flux density of photosynthetically active radiation (PAR) and flux density of ultraviolet A (UVA) and ultraviolet B (UVB) radiation were measured in the vicinity of isolated single trees during the summer of 1996. Measurements were made under shade and sunlit conditions along a transect aligned with the solar disk and the tree trunk. Flux density measurements were normalized by the flux density at a reference location away from the tree. Results showed (1) a more rapid decline in the flux density of UVA and UVB radiation than PAR with decreasing distance to the tree trunk on both the sunlit and shaded side of a tree and (2) more rapid changes in the flux density of UVB radiation UVA radiation, and PAR with distance from the tree on the sunlit side of the tree than the shaded side of the tree. The UVB/PAR ratio was found to increase in the shadow of a tree with increasing distance from the tree to between 4 and 6 for the conditions of the study. The potential for detrimental effects by UVB flux density under conditions of the high ratio may be mitigated by sunflecks at a given location over the course of a day.

Noda, Y., K. Anzai, et al. (1997). Hydroxyl and superoxide anion radical scavenging activities of natural source antioxidants using the computerized JES-FR30 ESR spectrometer system. Biochemistry and Molecular Biology International 42(1): 35-44.

Free radical scavenging activities of water-soluble extracts from some natural sources, health foods, and antioxidant substances were measured using the JES-FR30 JEOL spectrometer. The objective was to develop a standardized method whereby comparison could be made between the radical scavenging activities of complex mixtures. Scavenging of hydroxyl radical was determined using DMPO. Activity was calibrated using a standard material, L-ascorbic acid 2-(3,4-dihydro-2,5,7,8-tetramethyl-2(4,8,12-trimethyltridecyl)-2H-1-benzopyran-6-yl-hydrogen phosphate) potassium salt (EPC-K-1), an analog of vitamin C and vitamin E which is water soluble and stable at room temperature. The order of greatest hydroxyl radical scavenging activity was green tea extract, pine bark extract (Pycnogenol), Ginkgo Biloba extract (EGb 761), a flavonoid blend of several fruit and vegetable extracts (GNLD), and Bio-Normalizer (Sun-0 Corp). Activity was determined after treatment of samples with ascorbic acid oxidase. This treatment revealed the presence of ascorbate in some natural extracts and commercial preparations. The pine bark extract was the most heat resistant and had ascorbate-like activity in the preparations. Scavenging of superoxide anion was determined using the spin trap, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), and analyzed by comparison with a standard curve made with superoxide dismutase. Comparison of the water solubilized components of natural source antioxidants showed that filtrates fractionated using centrifuge type Millipore filter tubes (M.W. lt 100,000; M.W. lt 10,000) also had almost the same SOD-like activity. Samples were also treated with ascorbate oxidase or by heating (100 degree C for 10min). The order of activity, from greatest to least, was Ginkgo biloba extract EGb 761, pycnogenol, beta-catechin, tea and BioNormalizer.

Pietta, P. G., C. Gardana, et al. (1997). Identification of Gingko biloba flavonol metabolites after oral administration to humans. Journal of Chromatography B 693(1): 249-255.

An extract of Ginkgo biloba leaves (EGb) was given to healthy volunteers. Urine samples were collected for 3 days, and blood samples were withdrawn every 30 min for 5 h. The samples were purified through SPE C-18 cartridges and analyzed by reversed-phase LC-diode array detection for the presence of EGb metabolites. Only urine samples contained detectable amounts of substituted benzoic acids, i.e., 4-hydroxybenzoic acid conjugate, 4-hydroxyhippuric acid, 3-methoxy-4-hydroxyhippuric acid, 3,4-dihydroxybenzoic acid, 4-hydroxybenzoic acid, hippuric acid and 3-methoxy-4-hydroxybenzoic acid (vanillic acid). In contrast to rats no phenylacetic acid or phenylpropionic acid derivatives were found in urine, thus indicating that in humans a more extensive metabolism takes place. As for rats the metabolites found in human urines accounted for less than 30% of the flavonoids given. The same procedure was applied to blood samples, and no metabolites could be detected.

Klein, J., S. S. Chatterjee, et al. (1997). Phospholipid breakdown and choline release under hypoxic conditions: Inhibition by bilobalide, a constituent of Ginkgo biloba. Brain Research 755(2): 347-350.

A marked increase of choline release from rat hippocampal slices was observed when the slices were superfused with oxygen-free buffer, indicating hypoxia-induced hydrolysis of choline-containing phospholipids. This increase of choline release was suppressed by bilobalide, an ingredient of Ginkgo biloba, but not by a mixture of ginkgolides. The EC-50 value for bilobalide was 0.38 mu-M. In ex vivo experiments, bilobalide also inhibited hypoxia-induced choline release when given p.o. in doses of 2-20 mg/kg 1 h prior to slice preparation. The half-maximum effect was observed with 6 mg/kg bilobalide. A similar effect was noted after p.o. administration of 200 mg/kg EGb 761, a ginkgo extract containing approximately 3% of bilobalide. We conclude that ginkgo extracts can suppress hypoxia-induced membrane breakdown in the brain, and that bilobalide is the active constituent for this effect.

Dietl, G., M. Kapitzke, et al. (1996). The Nusplingen plattenkalk (White Jurassic zeta): 1995 excavation campaign. Jahreshefte der Gesellschaft fuer Naturkunde in Wuerttemberg 152: 25-40.

The excavations carried out in 1995 in the Nusplingen plattenkalk (White Jurassic zeta, Upper Kimmeridgian) of southern Germany were very successful. Plant specimens found included well preserved Cycadopteris fronds. A Ginko specimen and Baiera were found for the first time. Among the Crustacea, the discovery of a stomatopod of the genus Sculda is particularly noteworthy. A special stratum yielded numerous echinoderms of what is probably a new species and many small bony fish, predominantly of the genera Anaethalion and Tharsis, in an excellent state of preservation. The outstanding discoveries of the 1995 excavation were a large, very well preserved Squatina ("angel shark") and three crossopterygians (lobe-finned fish).

Wolff, R. L. (1997). Discussion of the term "unusual" when discussing DELTA-5-olefinic acids in plant lipids. Journal of the American Oil Chemists' Society 74(5): 619.

Rapin, J. R., R. G. Yoa, et al. (1997). Effects of repeated treatments with an extract of Ginkgo biloba (EGb 761) and bilobalide on liver and muscle glycogen contents in the non-insulin-dependent diabetic rat. Drug Development Research 40(1): 68-74.

The effects of repeated (15-day) oral treatments with an extract of Ginkgo biloba (EGb 761; 50 mg/kg/day) or with its terpenoid constituent, bilobalide (2 mg/kg/day), were assessed in normal rats and in rats that had been previously injected with streptozotocin (50 mg/kg, i.p. in saline solution), a dose which provided a model of non-insulin-dependent diabetes mellitus (NIDDM). In this model of diabetes, blood glucose is significantly increased while the circulating insulin level remains unchanged. Glucose penetrates cells because of decreased glycogen turnover, a metabolic abnormality that can be revealed by using an oral glucose tolerance test (OGTT). In control rats, hyperglycemia was accompanied by increased glycogen synthesis, as evidenced by increased concentrations of this storage substance in liver and skeletal muscle. Repeated treatment with EGb 761 or bilobalide increased the glycogen contents of both liver and muscle. This effect of bilobalide was additive to that of hyperglycemia in muscle. In diabetic rats, hyperglycemia did not modify glycogen synthesis, indicating impaired glucose utilization. Repeated treatment with EGb 761 or bilobalide partially prevented this impairment and led to increased in glycogen content in both liver and muscle under control conditions an during OGTT with 2 g/kg glucose. The molecular mechanism underlying these actions of EGb 761 could be related to an antioxidant effect (i.e., suppression of free radical formation) or to free radical-scavenging, since EGb 761 is known to have such effects and since free radicals have been implicated in the cytotoxic activity of streptozotocin. However, the increase in glucose uptake induced by bilobalide may have been related to increased glycogen synthesis.

Pietri, S., J. R. Seguin, et al. (1997). Ginkgo biloba extract (EGb 761) pretreatment limits free radical-induced oxidative stress in patients undergoing coronary bypass surgery. Cardiovascular Drugs and Therapy 11(2): 121-131.

A growing body of evidence supports the trigger role of free radicals in the delayed functional and metabolic myocardial recovery following cardiopulmonary bypass (CPB) in humans, thus opening the field to specific therapies. This clinical study was designed to evaluate, in 15 patients undergoing aortic valve replacement, whether the extent of CPB- and reperfusion-induced lipid peroxidation, ascorbate depletion, tissue necrosis, and cardiac dysfunction is reduced by orally administered EGb 761, a Ginkgo biloba extract with potent in vitro antiradical properties. Patients received either EGb 761 (Tanakan, 320 mg/day, n = 8) or a matching placebo (n = 7) for 5 days before surgical intervention. Plasma samples were obtained from the peripheral circulation and the coronary sinus at crucial stages of the operation (i.e., before incision, during ischemia, and within the first 30 minutes post-unclamping), and up to 8 days postoperatively. Upon aortic unclamping, EGb 761 inhibited the transcardiac release of thiobarbituric acid-reactive species (p lt 0.05), as assessed by high-performance liquid chromatography, and attenuated the early (5-10 minute) decrease in dimethylsulfoxide/ascorbyl free radical levels, an electron spin resonance index of the plasma ascorbate pool (p lt 0.05). EGb 761 also significantly reduced the more delayed leakage of myoglobin (p = 0.007) and had an almost significant effect on ventricular myosin leakage (p = 0.053, 6 days postoperatively). The clinical outcome of recovery of treated patients was improved, but not significantly, compared with untreated patients. Our results demonstrate the usefulness of adjuvant EGb 761 therapy in limiting oxidative stress in cardiovascular surgery and suggest the possible role of highly bioavailable terpene constituents of the drug.

Pietri, S., E. Maurelli, et al. (1997). Cardioprotective and anti-oxidant effects of the terpenoid constituents of Ginkgo biloba extract (EGb 761). Journal of Molecular and Cellular Cardiology 29(2): 733-742.

Hemodynamic and electron spin resonance analyses were used to assess the in vivo and in vitro cardioprotective and antioxidant effects of therapeutically relevant doses of Ginkgo biloba extract (EGb 761) and its terpenoid constituents (ginkgolides A and B, bilobalide) in the rat. Significant anti-ischemic effects, indicating improved, myocardial functional recovery, were observed after repeated (15-day) oral treatments with both EGb 761 (60 mg/kg/day) and ginkgolide A (4 mg/kg/day), as compared to placebo. In vitro pre- and post-ischemic perfusion of hearts in the presence of the ginkgolides A and B (both at 0.05 mg/ml) or bilobalide (0.15/mu-g/ml), but not EGb 761 (5 mu-g/ml), significantly improved all hemodynamic parameters. Post-ischemic levels of the 5,5-dimethyl-1-pyrroline N-oxide (DMPO)/hydroxyl radical spin-adduct (DMPO-OH) in coronary effluents were significantly decreased after in vivo oral treatments or after in vitro perfusion with EGb 761 or the terpenes, the most effective compound being ginkgolide A. As the presence of the terpenes did not influence the formation of the superoxide/DMPO adduct or DMPO-OH in acellular tests with superoxide and hydroxyl radical generators, their cardioprotective effects appear to involve an inhibition of free radical formation rather than direct free radical scavenging.

Yan, Y. X. P., H. Qian, et al. (1997). Study of assay of terpenes in the leaves of Ginkgo biloba extract and its preparations by in situ fluorometric TLC. Zhongguo Zhongyao Zazhi 22(3): 159-162, 191.

A new TLC method for the assay of terpene lactones in Ginkgo biloba extract and its preparations has been established by means of optimized development condition and post-chromatographic thermal fluorescence derivatization. Satisfactory results can be obtained through polynomial regression calibration. The data obtained by this method have been proved ten times higher in sensitivity than those obtained by HPLC-refracto-detector.

Chi, J. X. L., C. Ma, et al. (1997). Studies on the chemical constituents of the leaves of Ginkgo biloba. Zhongguo Zhongyao Zazhi 22(2): 106-107, 128.

Four compounds were isolated from ethyl acetate extract of the leaves of Ginkgo biloba. Compounds II, III, IV were identified as ginkgolides A, B and C respectively. Compound I, which was obtained from the leaves of G. biloba for the first time, was identified as 3,3'-dimethoxy-4,4'-dihydroxy-stilbene by spectroscopic methods.

Kim, S. R., Y. P. Jang, et al. (1997). Bilobalide attenuates glutamate-induced neurotoxicity in primary cultures of rat cortical cells. Yakhak Hoeji 41(1): 111-116.

The neurotoxicity induced by L-glutamate in primary cultures of rat cortical cells could be attenuated by sesquiterpene constituent of Ginkgo biloba leaves, bilobalide. At the concentration of 100 nM. Bilobalide elevated the combined levels of reduced/oxidized glutathione in rat cortical cells exposed to 100 mu-M glutamate. Furthermore, bilobalide promoted a reduction in superoxide dismutase activity in glutamate-treated cells. Finally, bilobalide markedly inhibited the production of malondialdehyde, a measure of lipid peroxidation, in glutamate-treated rat cortical cells.

Kobuchi, H., L. M. T. Droy, et al. (1997). Ginkgo biloba extract (EGb 761): Inhibitory effect on nitric oxide production in the macrophage cell line RAW 264.7. Biochemical Pharmacology 53(6): 897-903.

The present study was conducted to evaluate the effect of Ginkgo biloba extract (EGb 761) on the synthesis of nitric oxide (NO) induced by lipopolysaccharide (LPS) plus interferon-gamma (IFN-gamma) in the mouse macrophage cell line RAW 264.7. EGb 761 inhibited nitrite and nitrate production, taken as an index for NO, in a concentration-dependent fashion. The IC-50 for inhibition of nitrite production by activated macrophages was about 100 mu-g/mL EGb 761. The inducible NO synthase (iNOS) enzyme activity of cytosolic preparations from activated RAW 264.7 cells was inhibited by treatment with EGb 761. In addition, reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that the expression of iNOS mRNA in activated macrophages was suppressed by high concentrations of EGb 761. However, NF-kappa-B DNA binding activity induced by activation with LPS/IFN-gamma was not inhibited by EGb 761. These findings indicate that not only does EGb 761 directly act as an NO scavenger but also that it inhibits NO production in LPS/IFN-gamma-activated macrophages by concomitant inhibition of induction of iNOS mRNA and the enzyme activity of iNOS. Thus, EGb 761 may act as a potent inhibitor of NO production under tissue-damaging inflammatory conditions.

Lok, C. (1997). Venous leg ulcers. Annales de Dermatologie et de Venereologie 124(1): 112-121.

Burger, D. W., G. W. Forister, et al. (1997). Short and long-term effects of treeshelters on the root and stem growth of ornamental trees. Journal of Arboriculture 23(2): 49-56.

Short-term (aerated solution culture and container nursery) and long-term (landscape) experiments were conducted to study the effect of treeshelters on the root and shoot growth of several ornamental trees (Sequoia sempervirens (D. Don) Endl., Quercus lobata Nee, Quercus agrifolia Nee, Lagerstroemia indica L. 'Watermelon Red', Ginkgo biloba L., Platanus racemosa Nutt., Fraxinus latifolia Benth, and Populus euamericana cv. Giacometti). In general, plants grown in treeshelters were taller and some had reduced caliper growth. Treeshelters reduced top dry mass of F. latifolia, P. racemosa, Q. agrifolia, Q. lobata and P. euamericana and also reduced root dry mass, root:shoot ratio, total root length and total root area for all species/cultivars except Q. agrifolia. The results are explained on the basis of the microenvironment in/around treeshelters, photosynthetic partitioning and immobilization of plants growing in shelters. Management challenges and potential usefulness of treeshelters in landscape transplanting are also discussed.

Markova, T. A. and K. Z. Gamburg (1997). Stereoconfiguration of endogenous N-malonyltryptophan in plants. Plant Science Shannon 122(2): 119-124.

N-malonyltryptophan (MTry) isolated from soybean and ginkgo cell cultures, etiolated tomato, wheat and rye seedlings, turgescent and wilted tomato green leaves and from apple fruits was separated on 'Chiralplates'. In all cases the spots corresponding to M-L-Try were observed. Some amount of M-D-Try was also found in wheat and rye seedlings. Try released from endogenous MTry of soybean cell culture, wilted tomato leaves and apple fruits by alkaline hydrolysis corresponded to L-Try on Chiralplates and was deaminated by L-amino acid oxidase. The treatment of soybean cells and tomato leaves with D-Try resulted in the appearance of M-D-Try which became the predominant Try conjugate. It was postulated that malonylation was a significant part of endogenous L-Try metabolism in plants whereas M-D-Try was in most cases the result of exogenous D-Try malonylation.

Chermat, R., D. Brochet, et al. (1997). Interactions of Ginkgo biloba extract (EGb 761), diazepam and ethyl beta-carboline-3-carboxylate on social behavior of the rat. Pharmacology Biochemistry and Behavior 56(2): 333-339.

The social interaction test was used to examine the effects of an extract of Ginkgo biloba (EGb 761) and its possible interactions with diazepam and ethyl beta-carboline-3-carboxylate (beta-CCE). Pairs of naive (unfamiliar) mate Wistar AF rats subjected to the same treatment were placed in a novel test arena that was brightly illuminated, and the duration (in s) of social contact was observed over a 10 min period. Single injections of EGb 761 (8-16 mg/kg, IP), given 30 min prior to testing, or repeated oral administration of the extract (48 or 96 mg/kg/day) for 8 days, significantly decreased social contact under conditions that did not influence locomotor activity. Injection of diazepam (I mg/kg, IP), 30 min before testing, significantly increased social contact. Injection of diazepam to animals that had received repeated oral treatment with EGb 761 (96 mg/kg/day) increased social interaction to an extent greater than observed with diazepam alone. Injection of beta-CCE (2-16 mg/kg, IP), 15 min before testing, significantly decreased social contact. When the animals were treated with EGb 761 (48 or 96 mg/kg/day, p.o. for 8 days) and beta-CCE (4 mg/kg), both of which decreased social interaction when administered alone, the resulting level of social contact was similar to that of control animals. Interactions with certain sites of central GABA-A/ benzodiazepine/Cl- channel receptor complexes could be involved in mediating these effects of EGb 761, diazepam and beta-CCE.

Husstedt, I. W., K. H. Grotemeyer, et al. (1997). Progression of distal symmetric polyneuropathy during diabetes mellitus: Clinical, neurophysiological, haemorheological changes and self-rating scales of patients. European Neurology 37(2): 90-94.

The complex interrelationships between progression of distal symmetric polyneuropathy (DSP) induced by diabetes mellitus and haemorheological alterations in correlation with the patients' self-rating scales about the progression of DSP were investigated. The study included 42 patients suffering from diabetes mellitus for 15 +- 10 years. Clinical, neurophysiological and haemorheological follow-ups (platelet reactivity, erythrocyte aggregation, viscosity) were performed initially (A) and repeated 42 +- 10 months later (B). At point B, clinical signs of DSP were found in 90.2% in the lower extremities, and 41.5% of the patients exhibited for the first time new symptoms and signs of DSP in the upper extremities. Besides conventional neurophysiological investigations (conduction velocity, amplitude) in the sural nerve, paired stimulation (LPSS) was applied. In peroneal nerve, conduction velocity, distal latency and F wave were estimated. These results confirmed the clinical progression of DSP (LPSS; p lt 0.05). Platelet reactivity was statistically improved (p lt 0.05) at point B predominantly as an effect of treatment (acetylsalicylic acid, Ginkgo biloba), whereas erythrocyte aggregation was increased at point B with and without treatment (p lt 0.05). Blood glucose levels were abnormal at both points. Analogue self-rating scales showed that only 27% of the patients realized their progression of DSP. In conclusion, the results prove the clinical and neurophysiological progression of DSP and highlight that haemorheological changes may play a part in the conjectural pathogenesis of DSP. As patients to not realize the dramatic progression of DSP, information of the patients about the correlation between hyperglycaemia and progressive DSP should be reinforced.

Menerath, J. M., J. Cluzel, et al. (1997). Experimental electroretinographic exploration of retinal ischemia: Preventive use of free radical scavengers and anti-PAF agents. Journal of Ocular Pharmacology and Therapeutics 13(1): 81-88.

Electroretinographic exploration is an effective approach to evaluate retinal function. In order to investigate physiopathological mechanisms and evaluate potentially protective therapies for retinal ischemia, we developed three experimental models: the first two on isolated retina, with ischemia induced by either stopping perfusion or clamping the ophthalmic artery, and the third, in vivo, with ischemia induced by ocular hypertonia. Since free radicals are implicated in the formation of post-ischemic lesions, we evaluated the protective effects of drugs known to be free radical scavengers and of an immunomediator antagonist, an anti-PAF (platelet activating factor) agent.

Stalleicken, D. and P. Ihm (1996). Using tanacan to treat cognitive deficit (Reprint from "Neurologie Psychiatrie", 1988, Sonderheft 2. 56-61). Zdravookhranenie Minsk(4): 55-57, 59.

Therapeutic effectiveness and tolerability of liquid form of tanacan (extract of Ginkgo biloba) were studied in 8505 patients (males, females, average age 69.2 years) with symptoms of cerebral insufficiency. Tests of numeral repetition and numeral combinations were used. The extract was given to the patients for 6 months. Significant improvement was observed in such clinical symptoms as perception disorders, memory loss, attention deficit, emotional disturbances, dizziness, headache and noise in the ears. Time necessary for performing the numeral combination test decreased. Reversible side effects were observed in 0.39% of cases. Therapy was discontinued in).1% of cases. The effectiveness of the preparation was graded as "good" and "very good" by approximately 80% of patients and physicians. Tolerability was found to be "good" and "very good" by more than 95% of physicians.

Han, N. Z. W. (1996). The effect of cutting top-bud from ginkgo seedlings on different date. Forest Research 9(6): 661-663.

The top-bud of young ginkgo seedlings (Ginkgo biloba L.) was cut down to promote branching on the 3rd April, 4th June, 28th August, respectively. it shows that this treatment can make seedings produce more branches, but could reduce is growth after treatment on 3rd April. According to the test, this treatment could be adopted from early to middle June.

Kim, S. R., M. H. Jeon, et al. (1996). Ginkgolides attenuate glutamate-induced neurotoxicity in primary cultures of rat cortical cells. Yakhak Hoeji 40(6): 720-726.

The neurotoxicity induced by L-glutamate in primary cultures of rat cortical cells could be attenuated by diterpene constituents of Ginkgo biloba leaves, ginkgolides A, B and C. At the concentration of 100 nM, ginkgolides up-regulated the activity of glutathione reductase in primary cultures of rat cortical cells exposed to 100 mu-M glutamate. Furthermore, ginkgolides increased the content of reduced glutathione in glutamate-treated cortical cells. However, gankgolides showed little effect in reducing superoxide dismutase activity. Ginkgolides did, however, markedly blocked the production of malondialdehyde, a byproduct of lipid peroxidation in glutamate-treated rat cortical cells.

Mo, K., C. O. Lora, et al. (1997). Biodegradation of methyl t-butyl ether by pure bacterial cultures. Applied Microbiology and Biotechnology 47(1): 69-72.

Three pure bacterial cultures degrading methyl t-butyl ether (MTBE) were isolated from activated sludge and fruit of the Gingko tree. They have been classified as belonging to the genuses Methylobacterium, Rhodococcus, and Arthrobacter. These cultures degraded 60 ppm MTBE in 1-2 weeks of incubation at 23-25 degree C. The growth of the isolates on MTBE as sole carbon source is very slow compared with growth on nutrient-rich medium. Uniformly-labeled (14C)MTBE was used to determine 14CO-2 evolution. Within 7 days of incubation, about 8% of the initial radioactivity was evolved as 14CO-2. These strains also grow on t-butanol, butyl formate, isopropanol, acetone and pyruvate as carbon sources. The presence of these compounds in combination with MTBE decreased the degradation of MTBE. The cultures pregrown on pyruvate resulted in a reduction in CO-2 evolution from (14C)MTBE. The availability of pure cultures will allow the determination of the pathway intermediates and the rate-limiting steps in the degradation of MTBE.

Carlquist, S. (1996). Wood, bark, and stem anatomy of Gnetales: A summary. International Journal of Plant Sciences 157(6 Suppl.): S58-S76.

Data from a series of eight papers, representing a survey of Gnetales at the species level, are summarized in order to develop concepts on the relationship between the anatomical data and ecology, phylogeny, and systematics. Most of the characters and character states newly reported have phylogenetic and ecological correlations for Gnetales as a whole rather than systematic significance within the genera. Wood features are sensitively related to habit, although strategies in lianoid species of Ephedra differ from those in lianoid Gnetum species. Data also bear close relationships to organography. Vessel details are given special attention because workers have questioned whether vessels originated in Gnetales independently of those in angiosperms, and thus whether or not vessel origin in the two groups is a synapomorphy. The evidence cited here favors origin of vessels in Gnetales independent of vessel origins in angiosperms. Hitherto unappreciated contrasts between vessels of Gnetales and those of angiosperms are detailed: the torus-margo structure of pits in Gnetales (both Ephedra and Gnetum), and the aspiration ability of gnetalean pits represent modes of conduction and promotion of conductive safety different from those in angiosperms, and the shape difference (circular vs. scalariform), cited in data matrices of cladograms, is secondary to the different functional syndromes. The intercalation of circular bordered pits into helical secondary wall thickenings of primary xylem tracheary elements of Ephedra and Gnetum (a feature found also in conifers and Ginkgo but not in angiosperms) is given new functional interpretations. Ephedra and Gnetum contain both tracheids and fiber-tracheids that co-occur in a mode different from that in angiosperms which contain both cell types together. Ray structure like that of Gnetales occurs widely within seed plants and likely offers little conclusive information about relationships. Wood data on Gnetales are compatible with the hypothesis that a vesselless group of gymnosperms, such as Pentoxylales or Bennettitales, is the closest sister group of angiosperms. Formation of successive cambia in Gnetum differs from that in Welwitschia: the latter has phellem but no other bark. Because Welwitschia has only phellem, there are more numerous bark features in common between Ephedra and Gnetum than one might have expected. The three genera appear monophyletic on the basis of wood and bark. Infrageneric anatomical features of systematic importance are few, although the arboreal Gnetum gnemon differs from the lianoid Gnetum species in significant ways.

Arenz, A., M. Klein, et al. (1996). Occurrence of neurotoxic 4'-O-methylpyridoxine in Ginkgo biloba leaves, Ginkgo medications and Japanese Ginkgo food. Planta Medica 62(6): 548-551.

4'-O-Methylpyridoxine (ginkgotoxin) is a neurotoxic antivitamin B6 which occurs in Ginkgo biloba L. seeds. Contrary to a previous report by Wada et al. (15), the toxin was also detected in Ginkgo biloba leaves. The leaves are a source of extracts (e.g. EGb761) employed in the preparation of Ginkgo medications. Consequently the toxin is also present in Ginkgo medications and is even detectable in homoeopathic preparations. The toxin occurs also in boiled Japanese Ginkgo food. However, the amount of the toxin is likely to be too low to exert a detrimental effect after administration of the medication or ingestion of food.

Cheng, D. C. W., X. Yang, et al. (1996). Effects of Ginkgo Plus on hypoxic pulmonary hypertension in rats. Journal of West China University of Medical Sciences 27(4): 415-417.

We examined the effects of Ginkgo Plus on the pulmonary hemodynamics and right ventricular hypertrophy in rats exposed to isobaric chronic hypoxia. The rats treated with chronic hypoxia developed pulmonary hypertension and right ventricular hypertrophy. Ginkgo Plus reduced significantly the hypoxia-induced increase of mean pulmonary arterial pressure and pulmonary vascular resistance as well as the ratio of right ventricular weight vs left ventricular plus septal weights. The results suggested that Ginkgo Plus could relieve the hypoxic pulmonary hypertension.

Ferreira, M. G. and M. C. Fonteles (1996). Different classes of PAF-antagonists block norepinephrine-induced vascular escape and tachyphylaxis in the isolated rabbit kidney. Research Communications in Molecular Pathology and Pharmacology 94(2): 147-155.

In order to study the role of platelet activating factor (PAF) on norepinephrine induced vascular escape and tachyphylaxis, compounds from different pharmacological families sharing PAF-antagonistic activity, were infused in the isolated rabbit kidney perfused with Krebs-Henseleit solution. A natural compound derived from Ginkgo biloba (BN 52020, 1.1 times 10-6 M), a triazolobenzodiazepine substance (WEB 2170, 1.1 times 10-6M) and a dihydropyridine derivative lacking cardiovascular effects (PCA 4248, 2.7 times 10-6M), were analysed. The vascular reactivity to three cycles of norepinephrine (1.3 times 10-6M), infused in the kidneys treated with each of the PAF- antagonists, were evaluated for vascular escape and tachyphylaxis. The results demonstrated a significant reduction of both regulatory phenomena. A fall in renal vascular escape promoted by PAF antagonists, from a control level of 50.32 +- 4.61 to 27.64 +- 8.01% (p lt 0.05), suggests a role for PAF-acether in the vascular adjustment of the mammalian kidney.

Dawe, R. A., J. S. Kerr, et al. (1996). Ginkgo Biloba extract: Validation of a test battery. Human Psychopharmacology 11(6): 523-524.

Teng, J. L. Z. Z. H. (1996). Ultrastructure of blepharoplast and other organelles of the spermatid in Ginkgo biloba. Acta Botanica Sinica 38(6): 421-425.

Both blepharoplast and osmiophilic globule were characteristic structures to the spermatid of Ginkgo biloba. The blepharoplast of Ginkgo biloba ranged from 3 apprx 4 mu-m in diameter and consisted of a number of basal centrioles radiating from an electron dense core that contained electron-lucent areas with microtubule structure. Microtubules extended radially from the blepharoplast into the cytoplasm. A large round osmiophilic globule with a diameter of about 10 apprx 20 mu-m, was located between the blepharoplast and the nucleus, while a filbrillogranular body in the cytoplasm was opposite to the osmiophilic globule. There were numerous mitochondria, plastids, endoplasmic reticulia and dictiosomes in the cytoplasm, particularly around the blepharoplast and the osmiophilic globule of sperm cells. The nucleus of spermatid in Ginkgo biloba was large and roundly elliptical in shape. The large spheroidal nucleolus was the most obvious structure in the nucleus. There were two regions in the nucleolus distinguished by TEM: A ring-shaped granular component, which contained maturing ribosomal precursor particles; and a centrally placed fibrillar component. The nuclear pore complexes in the nuclear envelope were plentiful but not evenly distributed.

Wang, J. Y. C. and Z. Zhai (1996). Nuclear lamina in plant cells. Science in China Series C Life Sciences 39(5): 449-457.

By using selective extraction and diethylene glycol distearate (DGD) embedment and embedment-free electron microscopy, the nuclear lamina was demonstrated in carrot and Ginkgo male generative cells. Western blotting revealed that the nuclear lamina was composed of A-type and B-type lamins which contained at least 66-ku and 84-ku or 66-ku and 86-ku polypeptides, respectively. These lamin proteins were localized at the nuclear periphery as shown by immunogold-labelling. In situ hybridization for light microscope and electron microscope showed that plant cells have the homologous sequences of animal lamin cDNA. The sorting site of lamin mRNA is mainly distributed in the cytoplasm near the nuclear envelope. The data have verified that there indeed exists nuclear lamina in plant cells.

Chaw, S. M., A. Zharkikh, et al. (1997). Molecular phylogeny of extant gymnosperms and seed plant evolution: Analysis of nuclear 18S rRNA sequences. Molecular Biology and Evolution 14(1): 56-68.

To study the evolutionary relationships among the four living gymnosperm orders and the interfamilial relationships in each order, a set of 65 nuclear 18S rRNA sequences from ferns, gymnosperms, and angiosperms was analyzed using the neighbor-joining and maximum-parsimony methods. With Selaginella as the outgroup, the analysis strongly indicates that the seed plants form a monophyletic group with the ferns as a sister group. Within the seed plants the angiosperms are clearly a monophyletic group. Although the bootstrap support for the monophyly of the gymnosperm clade is moderate, the monophyly is further supported by its lack of angiosperm-specific indels. Within the gymnosperms there appear to be three monophyletic clades: Cycadales-Ginkgoales, Gnetales and Coniferales. The cycad-ginkgo clade is the earliest gymnosperm lineage. Given the strong support for the sister group relationship between Gnetales and Coniferales, it is unlikely that Gnetales is a sister group of the angiosperms, contrary to the view of many plant taxonomists. Within Coniferales, Pinaceae is monophyletic and basal to the remaining conifer families, among which there are three monophyletic clades: Phyllocladaceae-Podocarpaceae, Araucariaceae, and Sciadopityaceae-Taxaceae-Cephalotaxaceae-Taxodiaceae-Cupressaceae. Within the latter clade, Sciadopityaceae may be an outgroup to the other four families. Among the angiosperms, no significant cluster at the level of subclass was found, but there was evidence that Nymphaeaceae branched off first. Within the remaining angiosperms, the monocots included in this study are nested and form a monophyletic group. This study attests to the utility of nuclear 18S rRNA sequences in addressing relationships among living gymnosperms. Considerable variation in substitution was observed among the ferns and seed plants.

Wojcicki, J., S. B. Gawronska, et al. (1995). Comparative pharmacokinetics and bioavailability of Flavonoid glycosides of Ginkgo biloba after a single oral administration of three formulations to healthy volunteers. Materia Medica Polona 27(4): 141-146.

Eighteen healthy volunteers received three different formulations of Ginkgo biloba: capsules (A) and drops (B) (delivered by Agon Pharma), and tablets (C) (Tebonin - Dr. W. Schwabe) in equal an quantity, orally as a single dose, at an interval of at least five days. The pharmacokinetic parameters of the most important flavonoid glycosides: quercelin, kaempferol and isorhamnetin were established. The bioavailability was estimated using capsules as a standard formulation. Only the time to reach the peak concentration (tmax) of quercetin, kaempforol and isorhamnelin administered in the form of capsules, was significantly prolonged as compared with drops and tablets. Area under the curve (AUC) was the largest for formulation B for all the evaluated flavonoidglycosides, however the differences were not statistically significant. It is concluded that the three formulations of Ginkgo biloba extract are bioequivalent.

Ha, S. W., C. J. Yi, et al. (1996). Enhancement of radiation effect by Ginkgo biloba extract in C3H mouse fibrosarcoma. Radiotherapy and Oncology 41(2): 163-167.

Background and purpose: Ginkgo biloba leaf extract (GBE) is known to increase peripheral blood circulation. The hypothesis that GBE may be able to enhance radiosensitivity of tumor by improving tumor blood flow and thus decreasing hypoxic fraction was tested. Materials and methods: Fibrosarcoma (FSaII) growing in C3H mouse leg muscle was used as a tumor model. GBE was given i.p. 1 h before irradiation with or without priming dose given 1 day earlier. Effect on tumor and normal tissue radiation reaction was investigated. Results: Tumor growth delay by radiation was more elongated after two doses (1-day interval) of GBE than after a single dose. Radiation dose for 3-day tumor growth delay was decreased from 12.45 (10.97-13.93) Gy to 6.06 (3.89-8.22) Gy by two doses of GBE (enhancement ratio=2.06 (1.32-2.79)1. Hypoxic cell fraction was 10.6% (6.3-18.2%) for control, 7.2% (3.8-14.0%) after a single dose (P=0.18) and 2.7% (1.5-5.0%) after two doses (P lt 0.001). Radiation effect on normal tissue, estimated by acute skin reaction and jejunal crypt assay, was not affected by GBE. Conclusion: Ginkgo biloba extract enhances radiation effect on tumor without increasing acute normal tissue radiation damage in this model system probably by increasing tumor blood flow and further investigation for this possible radiosensitizer is needed.

Moscatelli, A., G. Cai, et al. (1996). Dynein-related polypeptides in pollen and pollen tubes. Sexual Plant Reproduction 9(6): 312-317.

Microtubules in pollen tubes are evident within the vegetative and generative cell cytoplasm. This observation led to the formulation of several hypotheses regarding the role of microtubules in cytoplasmic movement and the migration of the vegetative nucleus/generative cell along the pollen tube. The study of microtubular motor proteins in pollen tubes followed the discovery and characterization of an immunoreactive homolog of mammalian kinesin in tobacco pollen tubes. Recent identification of dynein-related polypeptides in pollen tubes of Nicotiana tabacum and pollen of Ginkgo biloba is a significant step in the definition of the role of microtubule function within pollen and pollen tubes.

Qiu, G. H. Q., H. Li, et al. (1996). A improved method for extracting flavone glycosides from Ginkgo leaves. Acta Academiae Medicinae Hubei 17(3): 205-206.

The thesis described a improved method for extracting flavones glycosides from Ginkgo leaves. The method was used to remove chlorophyll and other aliphatics soluble impurity by using absorbent cotton absorption then cellulose pulp codeposition. The experimental result indicated the method was very effective, and the yield of flavone glycosides was 73%.

Amri, H., S. O. Ogwuegbu, et al. (1996). In vivo regulation of peripheral-type benzodiazepine receptor and glucocorticoid synthesis by Ginkgo biloba extract EGb 761 and isolated ginkgolides. Endocrinology 137(12): 5707-5718.

Glucocorticoid excess has broad pathogenic potential including neurotoxicity, neuroendangerment, and immunosuppression. Glucocorticoid synthesis is regulated by ACTH, which acts by accelerating the transport of the precursor cholesterol to the mitochondria where steroidogenesis begins. Ginkgo biloba is one of the most ancient trees, and extracts from its leaves have been used in traditional medicine. A standardized extract of Ginkgo biloba leaves, termed EGb 761 (EGb), has been shown to have neuroprotective and antistress effects. In vivo treatment of rats with EGb, and its bioactive components ginkgolide A and B, specifically reduces the ligand binding capacity, protein, and messenger RNA expression of the adrenocortical mitochondrial peripheral-type benzodiazepine receptor (PBR), a key element in the regulation of cholesterol transport, resulting in decreased corticosteroid synthesis. As expected, the ginkgolide-induced decrease in glucocorticoid levels resulted in increased ACTH release, which in turn induced the expression of the steroidogenic acute regulatory protein. Because ginkgolides reduced the adrenal PBR expression and corticosterone synthesis despite the presence of high levels of steroidogenic acute regulatory protein, these data demonstrate that PBR is indispensable for normal adrenal function. In addition, these results suggest that manipulation of PBR expression could control circulating glucocorticoid levels, and that the antistress and neuroprotective effects of EGb are caused by its effect on glucocorticoid biosynthesis.

Rong, Y., Z. Geng, et al. (1996). Ginkgo biloba modulates glutathione redox cycle in vascular endothelial cells. Nutrition Research 16(11-12): 1913-1923.

We recently reported that Ginkgo biloba extract (GBE) suppressed oxidative burst in macrophages and protected bovine pulmonary artery endothelial cells (PAEC) from oxidant injury. In this study the effects of GBE on glutathione (GSH) redox cycle and activity of antioxidant enzymes were investigated. Confluent monolayers of PAEC were incubated with GBE for 8-48 h, washed, and then lysed with Triton X-100. Biochemical assays were performed with the lysate. GBE caused both dose- and time-dependent increase in GSH level and glutathione disulfide (GSSG) reductase activity while GSH peroxidase and superoxide dismutase activity remained unaffected. Exposure of PAEC to an organic oxidant tert-butyl hydroperoxide (tBHP) resulted in decreased GSH level, increased lipid peroxidation, and elevated leakage of intracellular lactate dehydrogenase. Preincubation or simultaneous treatment of PAEC with GBE prevented these changes induced by tBHP. Our data suggest that the antioxidant effect of GBE may be due to its modulation of the GSH redox cycle in PAEC as well as direct scavenging of the oxidant.

Tosaki, A., T. Pali, et al. (1996). Effects of Ginkgo biloba extract and preconditioning on the diabetic rat myocardium. Diabetologia 39(11): 1255-1262.

Effects of preconditioning and Ginkgo biloba extract (EGb 761) were studied in isolated nondiabetic and diabetic ischaemic and reperfused rat hearts. Hearts were randomly divided into five groups in both the age-matched non-diabetic and the 8-week streptozotocin-induced diabetic groups: Group I, hearts were subjected to 30 min of global ischaemia followed by 30 min of reperfusion; Group II, one cycle of preconditioning consisting of 5 min ischaemia and 10 min re-perfusion before the induction of 30 min of ischaemia and 30 min of re-perfusion; Group III, two cycles of preconditioning; Group IV, three cycles; and Group V, four cycles before the onset of 30 min ischaemia followed by 30 min of reperfusion. Four cycles of ischaemic preconditioning resulted in a reduction of arrhythmias in non-diabetic rats. Thus, in non-diabetics, the incidence of ventricular fibrillation and tachycardia fell from 92% and 100% (no preconditioning) to 33% (p lt 0.05) and 42% (p lt 0.05), respectively. Four cycles of preconditioning failed to reduce the incidence of reperfusion arrhythmias in diabetic subjects. Preconditioning reduced the formation of oxygen free radicals measured by electron spin resonance spectroscopy, but the recovery of cardiac function was low in all non-diabetic and diabetic preconditioned groups. EGb 761 at 25 and 50 mg/kg improved cardiac function in non-preconditioned and preconditioned non-diabetic and diabetic hearts. During reperfusion in the four-cycle preconditioned non-diabetic and diabetic groups, the amount of free radicals was reduced approximately by 50 and 70% using 25 and 50 mg/kg of EGb 761, respectively. EGb 761 improved cardiac function after ischaemia in both non-preconditioned and preconditioned non-diabetic and diabetic rats. Our data suggest that diabetes could abolish the precondition-induced protection.

McElwain, J. C. and W. G. Chaloner (1996). The fossil cuticle as a skeletal record of environmental change. Palaios 11(4): 376-388.

The plant cuticle with its stomatal pores represents an important interface between the plant and its surrounding environment. The potential of cuticular features such as cuticle thickness, stomatal density, stomatal index and stomatal ratio to signal the environment in which they grew and developed have been reviewed. In particular, new stomatal data from three Yorkshire Middle Jurassic species, Brachyphyllum cruds Kendall, Brachyphyllum mamillare Lindley and Hutton and Ginkgo huttonii (Sternberg) Heer, have been compared with those of two selected nearest living equivalent (IVLE) species Athrotaxids cupressoides and Ginkgo biloba, in an attempt to deduce the atmospheric carbon dioxide concentration from that time. It appears that the development of a thick cuticle can represent an adaptation to more than one kind of environmental constraint and evidently is a feature of certain taxonomic groups. It was concluded therefore that cuticle thickness, taken on its own, was not a suitable palaeo-ecological indicator In contrast however stomatal parameters of fossil plants seem to have great potential as palaeo-atmospheric indicators of carbon dioxide and in this sense as "skeletal evidence of palaeo-ecological change The stomatal density and index results ofthe Jurassic species were significantly lower (P lt 0.0001) than those of their selected NLE species, therefore indicating elevated atmospheric CO-2 concentrations for the Middle Jurassic. In addition the stomatal rats of the Jurassic species were in agreement with those of previous Devonian and Carboniferous stomatal ratio results. These results are consistent with the evidence from carbon cycle modelling and carbon isotopic data which infer elevated atmospheric CO, concentrations during the Middle Jurassic of 4 to 5 times and 6 to 10 times the present atmospheric level respectively.

Lang, F. and E. Wilhelm (1996). Quantitative determination of proanthocyanidins in Ginkgo biloba special extracts. Pharmazie 51(10): 734-737.

Paick, J. S. and J. H. Lee (1996). An experimental study of the effect of ginkgo biloba extract on the human and rabbit corpus cavernosum tissue. Journal of Urology 156(5): 1876-1880.

Purpose: To investigate the effect of subfractions of extract from the ginkgo on human and rabbit corpus cavemosal tissue and their possible use for the treatment of impotence. Materials and Methods: Among the fractions of ginkgo biloba extract (GBE), nonginkgolide nonflavonoid fraction (NGF) has the most potent relaxing effect on vascular smooth muscle. We subfractionated NGF and speculated that some of the subfractions might have a very potent relaxing effect on corpus cavernosal tissue. Thereafter we have studied their effect on human and rabbit corpus cavernosum using organ bath and electrical field stimulation experiments. Results: In the tissue precontracted by norepinephrine (10-5 M.), corpus cavernosal tissue of human and rabbit showed relaxation in response to subfractions of NGF in a dose-dependent manner. 304U-1 showed the most potent relaxing effect (ED-50 = 0.74 mg./ml. in human, ED-50 = 0.66 mg./ml. in rabbit). 304U-1 elicits pharmacological actions on corpus cavernosum smooth muscle via the signal transduction pathway whereby relaxation induced by 304U-1 is mediated by intracellular cAMP and perhaps partially by antagonizing of the adrenergic nervous system. A hyperpolarizing effect via potassium channel opening might also be related to this relaxing effect. Conclusion: The subfractions of NGF, especially 304U-1, have a relaxing effect on corpus cavernosum tissue. 304U-1, which showed the most potent relaxing effect, can possibly be used as a drug for intracavernosal injection therapy. Considering the fact that the value of ED-50 is too high, further fractionation and in vivo study are needed before clinical use in an oral form.

Poort, R. J., H. Visscher, et al. (1996). Zoidogamy in fossil gymnosperms: The centenary of a concept, with special reference to prepollen of late Paleozoic conifers. Proceedings of the National Academy of Sciences of the United States of America 93(21): 11713-11717.

This year is the centenary of the surprising discovery in 1896 of zoidogamy in extant cycadophytes and Ginkgo. But by coincidence, also in the same year, the concept of prepollen was introduced. The morphology of prepollen was considered justification for the probable production of motile antherozoids in extinct gymnosperms. In this paper, the history of the prepollen concept is briefly outlined. It is emphasized that, in addition to well-known examples in pteridosperms and cordaitaleans, a prepollen condition also occurred among late Paleozoic conifers.

Palacios, D. M. (1995). Re-identification of three dolphin skulls in the museum of the Charles Darwin Research Station. Noticias de Galapagos(55): 6-8.

Burger, D. W., G. W. Forister, et al. (1996). Height, caliper growth, and biomass response of ten shade tree species to treeshelters. Journal of Arboriculture 22(4): 161-166.

Carrier, D. J., J. Archambault, et al. (1996). Formation of terpenoid products in Ginkgo biloba L. cultivated cells. Plant Cell Reports 15(12): 888-891.

Ginkgolides are diterpenes arising from the terpenoid precursor: geranylgeranyl pyrophosphate (GGPP). Incorporation of (1-14C) isopentenylpyrophosphate ((1-14C)IPP) into GGPP was monitored throughout the cultivation cycle of G. biloba L. cultivated cells. Because incorporation of (1-14C)IPP into GGPP had never been monitored in G. biloba, in either the whole plant or cultivated cell system, modifications to existing protocols were necessary. Modifications consisted of extracting the cells with an extraction buffer supplemented with Triton-X-100. Farnesylpyrophosphate (FPP) was the major product formed. The amount of GGPP detected was about one tenth that of FPP.

Letzel, H., J. Haan, et al. (1996). Nootropics: Efficacy and tolerability of products from three active substance classes. Journal of Drug Development and Clinical Practice 8(2): 77-94.

This paper reviews and evaluates all the currently available clinical trials on the efficacy of three nootropics. Only randomized, double-blind, placebo-controlled clinical trials were taken into account, which produced 44 studies allowing comparison of the patient populations, efficacy and tolerability of Ginkgo biloba special extracts, nimodipine and tacrine. Taking all the studies together, statistically significant results were obtained at three relevant levels of efficacy (psychopathological, psychometric, behavioural) for all three substances. Nine studies produced significant results at all three efficacy levels. One study on Ginkgo biloba and one on tacrine also produced significant results according to the latest measures now demanded (operotionalised diagnosis of dementia, inclusion of mild-to-moderate cases, statistical proof at all three levels of efficacy and global clinical evaluation). The clinical efficacy of all three substances has thus been demonstrated.

Haase, J., P. Halama, et al. (1996). Efficacy of short-term treatment with intravenously administered Ginkgo biloba special extract EGb 761 in Alzheimer type and vascular dementia. Zeitschrift fuer Gerontologie und Geriatrie 29(4): 302-309.

Van, H. H. A., R. H. Busson, et al. (1996). Synthesis of (1-14) nordolichoic acid. Chemistry and Physics of Lipids 82(1): 79-83.

We describe the synthesis of nordolichoic acid and (1-14C)nordolichoic acid starting from polyprenol isolated from the leaves of Ginkgo biloba. Coupling of polyprenol with ethyl acetoacetate, using 1,1'-(azodicarbonyl)dipiperidine/tributylphosphine, followed by hydrolysis, decarboxylation and reduction, yielded the 2-polyprenyl-1-methylethanol. This alcohol was converted into a mesylate, subjected to one-carbon elongation with KCN, and finally converted to the acid by hydrolysis of the nitrile.

Van, S. J. (1996). Cytokinin-like compounds in bark and shoot tissue of Salix babylonica and bark tissue of Ginkgo biloba after leaf abscission and during bud burst. South African Journal of Botany 62(4): 178-182.

It appears that putative cytokinin O-glucosides are stored in both root and bark tissue of Salix babylonica and in bark tissue of Ginkgo biloba. The levels of cytokinins were high in these plant parts after leaf abscission, but decreased markedly after bud burst. It is possible that cytokinins are stored in the bark and root tissue after export, and are possibly re-utilized during renewed shoot growth at the beginning of the new growing season.

Blume, J., M. Kieser, et al. (1996). Placebo-controlled double blind study on the efficacy of Ginkgo biloba extract EGb 761 in trained patients suffering from intermittent claudication. Vasa 25(3): 265-274.

This monocenter, randomized, placebo-controlled double-blind study with parallel-group comparison was carried out in order to demonstrate the efficacy of Ginkgo biloba special extract EGb 761 on objective and subjective parameters of the walking performance in trained patients suffering from peripheral arterial occlusive disease in Fontaine stage IIb. In total 60 patients were recruited (42 men; aged 47-82 years) with angiographically proven peripheral arterial occlusive disease of the lower extremities and an intermittent claudication existing for at least 6 months. No improvement had been shown despite consistent walking training and a maximum pain-free walking distance on the treadmill of less than 150 m was recorded at the beginning of the study. The therapeutic groups were treated with either Ginkgo biloba special extract EGb 761 at a dose of 3 times 1 film-coated tablet of 40 mg per day by oral route or placebo over a duration of 24 weeks following a two-week placebo run-in phase. The main outcome measure was the difference of the walking distance between the start of treatment and after 8, 16 and 24 weeks of treatment as measured on the treadmill (walking speed 3 km/h and slope of 12%). As secondary parameters the corresponding differences for the maximum walking distance, the relative increase of the pain-free walking distance, the Doppler index and the subjective evaluation of the patients were analyzed. The absolute changes in the pain-free walking distance in treatment weeks 8, 16 and 24 as against the treatment beginning (median values with 95% confidence interval) led to the following values for the patients treated with Ginkgo biloba special extract EGb 761: 19 m (14, 33), 34 m (18, 50) and 41 m (26, 64). The corresponding values in the placebo group were as follows: 7 m (-4, 12), 12 m (5, 22) and 8 m (-1, 21). The advantage of the EGb 761-treated group as compared to the placebo group could be verified statistically at the 3 time points with p lt 0.0001, p = 0.0003 and p lt 0.0001. The test for the presence of a clinically relevant difference of 20% between EGb 761 and placebo also produced a statistically significant result (p = 0.008). The Doppler index remained unchanged in both therapeutic groups: A corresponding statistically significant advantage for the EGb 761 group was observed on a descriptive level for the other parameters tested. The tolerance of the treatment was very good. The results of this placebo-controlled study show that treatment with Ginkgo biloba special extract EGb 761 produces a statistically highly significant and clinically relevant improvement of the walking performance in trained patients suffering from intermittent claudication with very good tolerance of the study preparation.

Pandey, N. K., G. C. Joshi, et al. (1996). Ginkgo biloba Linn.-a living plant fossil of Jurassic period. Indian Forester 122(2): 184.

Stoppe, G., H. Sandholzer, et al. (1996). Prescribing practice with cognition enhancers in outpatient care: Are there differences regarding type of dementia? Results of a representative survey in Lower Saxony, Germany. Pharmacopsychiatry 29(4): 150-155.

Previous studies of cognition enhancers have mainly focused on insufficiently defined groups of cognition disorders, e.g., "cerebral insufficiency'. With regard to the various biological changes in senile dementia of Alzheimer's type (SDAT) and in vascular dementia (VD), which together make up the great majority of senile dementias. many authors have encouraged different studies of these types of dementias, especially since both can be diagnosed clinically with satisfying certainty. Since primary care physicians treat the majority of elderly and demented patients, they have their own experience with cognition enhancers. We were therefore interested to know. how far these physicians differ in their treatment of SDAT and VD. We performed a representative survey (response rate 83.2%; 145 family physicians and 14 neuropsychiatrists) in the Goettingen area. A written case vignette described a 70-year-old widow with moderate dementia and vascular risk factors which are easily treated with drugs. Two versions were randomly assigned, in which (version A) either a "typical" VD history or a typical SDAT history (version B) were described. After perusal. the physician was asked whether and which drugs he would choose to treat the cognitive disorders in this patient. Most frequently, piracetam (A/B: 25.6%/30.9%), ginkgo biloba (24.4%/28.4%), and nimodipine (14.1%/25.9%) were considered. Aspirin was cited by 29.5% (A) and 17.3% (B) of the physicians respectively. As far as the type of dementia was concerned, significant differences were found only for co-dergocrine, which was preferred in SDAT. The following inter-group trends were observed: family physicians considered ginkgo biloba more often than nimodipine or co-dergocrine. The results show the apparent importance of cost- and safety aspects, while the type of dementia has hardly any impact. The latter impression corresponds to the results of drug trials demonstrating no different efficacy. In our opinion, aspirin was not sufficiently taken into consideration.

Wang, J., C. Yang, et al. (1996). The nuclear lamina in male generative cells of Ginkgo biloba. Sexual Plant Reproduction 9(4): 238-242.

Using selective extraction and diethylene glycol distearate embedment and embedment-free electron microscopy, we demonstrated nuclear lamina-like structures in sperm cells of Ginkgo biloba. A well-organized nuclear matrix network was also observed. Further studies were undertaken to determine whether or not lamin-like components exist in the pollen and sperm cells. Immunofluorescence staining using monoclonal antibodies against different animal lamins revealed lamins localized in the nuclear compartment of the sperm cells. Western blotting showed that in pollen grains there are two positive crossreaction bands at 66 kDa and 86 kDa, recognized by antibodies specific to animal lamins; in sperm cells there was only one at 66 kDa. These results indicate that nuclear lamina containing both A-type and B-type lamins was present in male generative cells of G. biloba. The data imply that plant lamins share some homology with animal lamins and may be conserved during evolution.

Stoll, S., K. Scheuer, et al. (1996). Ginkgo biloba extract (EGb 761) independently improves changes in passive avoidance learning and brain membrane fluidity in the aging mouse. Pharmacopsychiatry 29(4): 144-149.

Decreases in cell membrane fluidity may be a major mechanism of age-related functional decline. A prime cause for the decline of membrane fluidity may be the presence of free radicals. Gingko biloba extract EGb 761 protects neuronal cell membranes from free radical damage in vitro. Further, EGb 761 has repeatedly been shown to improve cognitive functions in man and in laboratory animals. To test if there is a link between these two actions we assessed the effects of EGb 761 on passive avoidance learning and on neuronal membrane fluidity in vivo in young (three-month-old), middle-aged (12-month-old) and aged (22 to 24-month-old) female NMRI mice. The animals were treated daily with 100 mg/kg EGb 761 for three weeks. There was a significant improvement in short-term memory, measured by the avoidance latency 60 seconds after the aversive stimulus (p lt 0.0311), and of membrane fluidity (p lt 0.01) in the aged animals. but no improvement in long-term memory as measured by the avoidance latency 24 hours after shock. However, no significant correlation between membrane fluidity and short-term memory performance was found. Taken together, these results indicate that EGb 761 independently improves changes in passive avoidance learning and brain membrane fluidity.

Srivastava, K. K. (1995). Adaptogens in high mountains. Indian Journal of Natural Products 11(Spec. Number): 13-19.

Ni, Y., B. Zhao, et al. (1996). Preventive effect of Ginkgo biloba extract on apoptosis in rat cerebellar neuronal cells induced by hydroxyl radicals. Neuroscience Letters 214(2-3): 115-118.

The ability of oxidative stress to induce apoptosis, and the effect of Ginkgo biloba extract (EGb761) on this induction were studied in primary cultured rat cerebellar neuronal cells. Cells were exposed to hydroxyl radicals by treating them with 20-50 mu-M hydrogen peroxide (H-2O-2) and 100 mu-M ferrous sulfate. Hydroxyl radical treatment fragmented the DNA in a manner typical of apoptosis cells, producing a ladder pattern of 200 base pair increments on 1% agarose gel electrophoresis. Pretreatment of cells with 100 mu-g/ml EGb reduced hydroxyl radical induced cells apoptosis (determined by flow cytometry) and DNA fragmentation. The results indicate that hydroxyl radicals induce apoptosis in rat cerebellar neuronal cells, and this induction can be prevented by EGb.

Bombardelli, E., A. Cristoni, et al. (1996). Activity of phospholipid-complex of Ginkgo biloba dimeric flavonoids on the skin microcirculation. Fitoterapia 67(3): 265-273.

Ginkgo biloba dimeric flavonoids (GBDF) form a stoichiometrically defined complex (Phytosome) with phospholipids. The effects of GBDF in Phytosome form on the vasomotor activity and skin microvirculation of the cheeks, hands, limbs and female breast was studied in human subjects by Infrared-Photo-Pulse-Plethysmography, Laser Doppler Flowmetry, High Performance Contact Thermography, Computerized Videother