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[an experimental model of cerebral ischemia induced by microspheres in the rat. effect of 2 ginkgo biloba extracts and of naftidrofuryl]. 1978741425
[adaptational behaviour of peripheral and central acoustic responses in guinea pigs under the influence of various fractions of an extract from gingko biloba (author's transl)].experimental studies on 114 guinea pigs proved definitely the influence of an extract from ginkgo biloba batch no. 02 on the acoustic system. experiments with animals ensured that the adaptation of excitation of the organ of corti is significantly influenced. this result is shown by registrations of the acoustic nerve potentials in the adapted and nonadapted state. the relation of excitation to adaptation is significantly changed. under adaptation of excitation an influence on the metabolism of ...1976989328
[the influence on sound damages by an extract of ginkgo biloba (author's transl)].a fraction of ginkgo biloba, used in experiments with animals ensured significantly the diminution of sound damages caused by white noise or by a pure tone of 4.5 khz. higher amplitudes of the acoustic nerve potentials show the protective effect of this fraction of ginkgo biloba at acute sound damages. it is moreover possible to hold physiologically the adaptation of excitation of the hair cells of the organ of corti by the fraction of ginkgo biloba before and after sound damage caused by white ...19751242647
effect of gingko biloba extract (egb 761) on chloroquine induced retinal alterations.electroretinography was used to investigate the preventive action of ginkgo biloba extract (egb 761) in experimental chloroquine-induced retinopathy in rats. egb 761 contains flavones and anthocyanosides known for their oxygenated radical scavenging properties. chronic administration of chloroquine (20 days) caused an overall lengthening of the duration of the erg b-wave, together with delayed peaking. these anomalies became more marked with increased duration of treatment. in rats treated simul ...19921301800
oxidative stress in diabetic retina.the authors describe the alterations usually associated with diabetic retinopathy. they concern the classical thickening of the basal membrane of retinal capillaries and the associated modification of retinal vessel permeability. these alterations correspond to the blood-retinal barrier disruption. the authors then discuss the participation of oxygenated free radicals in the pathogenesis of diabetic retinopathy. they report several experimental studies establishing such a participation and final ...19921450593
the pharmacology of extinction.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 ...19921453701
effects of methanol extract of ginkgo biloba (egb), its ethylacetate fraction (eaf) and butanol fraction (bf) on the isolated aorta. 19921507615
the inhibitory effect of plant extracts on the collagenolytic activity and cytotoxicity of human gingival fibroblasts by porphyromonas gingivalis crude enzyme.it is well known that plant extracts inhibit some enzymatic activities. the present study examined the inhibitory effects of natural plant extracts against the collagenolytic activity of porphyromonas gingivalis. the enzyme was isolated from a culture supernatant of p. gingivalis 381. the aqueous and 50% ethanolic extracts of ginkgo biloba, mosla chinensis, salvia officinalis, cinnamomum cassia, and a catechin extract of camellia sinensis exhibited strong inhibitory effects on collagenolytic act ...19911668071
[progression of multiple innervation of reinnervated rat muscle treated with bilobalide].during motor nerve regeneration a transitory polyinnervation of muscle cells occurs, which represents a phase of rearrangement of the recovered innervation. bilobalide, a terpene extrated from ginkgo biloba leaves, was proposed to affect some aspects of nervous system development and regeneration. in this work, influence of bilobalide on polyinnervation in reinnervated extensor digitorum longus muscle was studied, through electrophysiological and histological techniques. the muscle was denervate ...19911818595
protective effect of ginkgo biloba extract (egb 761) on free radical-induced changes in the electroretinogram of isolated rat retina.the retina is a tissue particularly rich in polyunsaturated fatty acids and thus highly sensitive to lipid peroxidation initiated by oxygenated free radicals. by recording the electroretinogram (erg) b wave amplitude on isolated rat retina, the authors have investigated the anti-oxidant properties of ginkgo biloba extract (egb 761). two groups of rats were used: one group was treated with egb 761 at a dose of 100 mg/kg/day per os for 10 days; the other one of untreated animals served as a contro ...19911841050
free radical-mediated effects in reperfusion injury: a histologic study with superoxide dismutase and egb 761 in rat retina.in sprague-dawley rats, retinal ischemia was induced by occlusion of the central retinal artery, while reperfusion was initiated by unclamping and removing the occluder. ninety minutes of regional ischemia followed by 24 h of reperfusion resulted in a development of retinal edema in the inner plexiform layer and a migration of neutrophils into the retinal tissue. oxygen free radicals have been implicated as inducers of cell damage in different tissues. this finding has led us to speculate that, ...19911945294
prevention by a ginkgo biloba extract (gbe 761) of the dopaminergic neurotoxicity of mptp.in mice implanted subcutaneously with osmotic minipumps releasing the neurotoxic agent n-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (mptp) for 7 days (105 micrograms h-1/mouse) (approximately 100 mg kg-1 day-1) a significant reduction (approximately 25%) in the striatal dopaminergic nerve endings was observed. this neurotoxic effect was prevented by the semi-chronic ingestion of a ginkgo biloba extract for 17 days (gbe 761, approximately 100 mg kg-1 day-1). the high concentrations (approximately ...19901982302
[anti-anaphylactic pharmacological action of water-soluble constituents of ginkgo biloba l. episperm].water-soluble constituents of ginkgo biloba episperm 100 or 200 mg/kg po given to mice inhibited passive cutaneous allergic response and the same dose given to rats ip inhibited mast cell degranulation. it antagonized the contractile effect of isolated guinea pig ileum smooth muscles induced by the antigen. it inhibited the deliverance of srs-a from anaphylactic lung of guinea pig.19902093326
[the effect of various extracts of ginkgo biloba on the response of lysosomes to free radicals and to osmotic shock]. 19902093934
superoxide anion scavenging effect and superoxide dismutase activity of ginkgo biloba extract.ginkgo biloba extract is known to be efficient in diseases associated with free radical generation. the purpose of this work was to study, under in vitro conditions, the action of ginkgo biloba extract (gbe) against superoxide anion (o2-.), which is directly or indirectly implicated in cell damage. gbe appears to have both an o2-. scavenging effect and also a superoxide dismutase activity. its antiradical effect was demonstrated by low temperature electron spin resonance and in a non-enzymatic s ...19892547645
ginkgo biloba extract prevents mucosal damage associated with small-intestinal ischaemia.we have examined how a ginkgo biloba extract influences the damaging effects of ischaemia in the small-intestinal mucosa. we used a rat experimental model in which a ligated loop of the distal ileum was subjected to ischaemia and revascularization, and the ensuing mucosal damage assessed by lysosomal enzyme release and intestinal permeability measurements. we also determined the mucosal content of malondialdehyde, a lipid peroxidation product, and the mucosal activity of myeloperoxidase, a neutr ...19892554486
[the effect of ginkgo biloba extract on the stabilization of lysosomes]. 19892626486
effects of ginkgo biloba extract on glucose transport and glycogen synthesis of cultured smooth muscle cells from pig aorta.we have examined the effect of an extract of ginkgo biloba (gbe) on glucose uptake and on glycogen synthesis in cultured smooth muscle cells (smc) from pig aorta. initial rates of glucose transport were determined by measurements of 2-deoxy-d-glucose (2-dg) uptake. from kinetic analyses apparent km and vmax values of facilitated glucose transport in cultured smc were evaluated at 2.2 mm and 9.1 nmol/min/10(6) cells respectively. gbe stimulated glucose transport in a dose-dependent manner; the ma ...19892771861
inhibition of the metabolism of platelet activating factor (paf-acether) by three specific antagonists from ginkgo biloba.washed rabbit platelet suspensions were incubated in the presence of 1-[3h]o-alkyl-2-acetyl-sn-glycero-3-phosphocholine ([3h] paf-acether), which was metabolized into 1-[3h]o-alkyl-2-acyl-sn-glycero-3-phosphocholine (alkylacyl-gpc) through the sequential action of cytosolic acetylhydrolase and membrane transacylase. within 60 min at 37 degrees, percentage of [3h] paf-acether metabolized was 50.3 +/- 5.2% (9 experiments). this conversion was inhibited in a dose-dependent manner by various concent ...19872820421
modulation of leucocyte activation in the early phase of the rabbit burn injury.previous studies in burned patients have shown an early enhanced polymorphonuclear leucocyte (pmn) generating capacity for superoxide radical (o2.-), for the arachidonic acid (aa) lipoxygenase metabolite leukotriene b4 (ltb4) and for platelet activating factor-acether (paf). these findings have been confirmed on a burn injury rabbit model. as we have suggested a pivotal role for an exaggerated initial (less than 36-48 h) neutrophil stimulation leading to a later (greater than 72 h) immuno-depres ...19882836040
comparison of the contractile effects of an extract of ginkgo biloba and some neurotransmitters on rabbit isolated vena cava.dose-related contractions were elicited in strips of rabbit isolated vena cava by norepinephrine (ne, ic50 approximately equal to 2.3 x 10(-7) m), dopamine (ic50 approximately equal to 6.9 x 10(-6) m), histamine (ic50 approximately equal to 2.1 x 10(-6) m) and extract of ginkgo biloba (gb, ic50 approximately equal to 86 micrograms/ml). serotonin and tyramine elicited very weak contractile effects in this preparation. phenoxybenzamine (10(-7) m) abolished the contractions elicited by ne, and bloc ...19852860046
[neuromediator binding to receptors in the rat brain. the effect of chronic administration of ginkgo biloba extract].the present data confirm the results of others that post-synaptic receptor changes may contribute to the decline in brain cholinergic function in ageing and dementia. we have also shown that chronic oral treatment with an extract of gingko biloba increases the apparent muscarinic receptor population in the hippocampus of the aged fisher 344 rat. the possible effect on (3h) kainic acid binding to the kainate-excitatory amino acid site is also interesting because of the proposed association of neu ...19862878427
analogues of poison ivy urushiol. synthesis and biological activity of disubstituted n-alkylbenzenes.the total synthesis of different isomers and analogues of poison ivy urushiol is described. these include the positional isomers 1-5 and the nitrogen-containing analogues 6 and 8 and their mesylamino derivatives 7 and 9. 3,4-dimethoxybenzaldehyde, m-dimethoxybenzene, resorcinol, and p-dimethoxybenzene were used as starting materials for compounds 1, 2, 3, and 4, respectively. compound 5 is prepared by catalytic hydrogenation of bilobol isolated from ginkgo biloba. compounds 6 and 7 were prepared ...19862939241
[cerebral glucose consumption. the effect of ginkgo biloba extract].deoxyglucose is transported under the same conditions as glucose from blood to cerebral tissue. deoxyglucose-6-phosphate, which cannot be neither metabolized nor eliminated, accumulates in cells. this accumulation is correlated with glucose consumption. in this study, two parameters, transfer rate of deoxyglucose and glucose consumption were measured by means of quantitative autoradiography in two experimental models: normobaric hypoxia and carotid clamping in rats. normobaric hypoxia induced a ...19862947087
[protective effects of ginkgo biloba extract on the early rupture of the hemato-encephalic barrier in the rat].during the hours immediately following an hypertensive burst or a cerebral ischemia induced by the intracarotid administration of microspheres, damage to the blood brain barrier can be observed with molecules of low molecular weight, such as angiotensin, whereas albumin or large proteins will not yet have been able to cross over and there is virtually no edema. gingko biloba extract causes the brain uptake index of angiotensin hypertensive animals. this effect is proportional to the dose of extr ...19862947088
[mechanism of action of ginkgo biloba extract in experimental cerebral edema].oedema is one of the major complication of cerebral ischaemia being at the same time a consequence and an aggravating factor. its first phase is intracellular and cytotoxic, with breakdown of ionic pumps through loss of energy, resulting in a whole sequence of ionic perturbations characterized by loss of intracellular k+ and accumulation of water and na+, cl-, and ca2+ ions in the cells of the ischaemic zone. the second phase, termed vasogenic, applies to the accumulation of lactates, inorganic ...19862947089
[effects of ginkgo biloba extract on a cerebral ischemia model in gerbils].certain anatomical characteristics peculiar to the gerbil make it the animal model best adapted to experimental pathology studies of acute ischaemia. in this animal species, devoid of any substitute vertebro-basilar vascular tissue, unilateral ligature of the carotid artery produces a cerebral ischaemia with neurological signs (well quantifiable), metabolic perturbations (especially mitochondrial) and cerebral oedema development closely resembling the symptoms revealed by physiopathology in huma ...19862947090
[effects of ginkgo biloba extract on 2 models of experimental myocardial ischemia].ginkgo biloba extract, a free radical scavenger containing kaempferol and quercetin esters, which are potent radical scavengers, was studied on various models of cardiac ischaemia, both in vitro and in vivo. on the two in vitro models of ischaemia-reperfusion described (rat and guinea-pig hearts) ginkgo biloba extract was without effect on cardiac functional parameters. however, it induced a significant decrease in the intensity of ventricular fibrillation during the reperfusion stage. on normal ...19862947091
[effect of ginkgo biloba extract on arteriolar spasm in rabbits].injectable ginkgo biloba extract, administered intravenously to rabbits, suppressed the vasospasm induced by the topic application of autologous serum on brain surface. this effect was dose-dependent as for as the normalization of the arterial diameter and duration of spasm were concerned. in animals previously treated with oral ginkgo biloba extract, the almost complete disappearance of spasm was observed at intervals of time similar to those observed after intravenous injection.19862947092
[pharmacological bases of the vascular impact of ginkgo biloba extract].the preferential tissue irrigatory effect of ginkgo biloba extract in ischaemic areas is largely explained by the direct impact of this product on both arteries and veins. the adrenergic vasoregulatory system and the vascular endothelium are the preferential targets for arterial impact. ginkgo biloba extract reinforces the physiological vasoregulation of the sympathetic nervous system directly, by acting on neuromediator release, and indirectly, by inhibiting their extraneuronal degradation by c ...19862947093
[effects of ginkgo biloba extract on functional brain activity.. an assessment of clinical and experimental studies].electroencephalography is the only convenient method for functional exploration of the brain. the recent introduction of signal analysis techniques has given it a quantitative dimension and has resulted in pharmacological studies of electoencephalograms. in four studies of this kind the effects of ginkgo biloba extract were investigated on three pathological animal models, in young healthy volunteers and in elderly people with dementia disorders. in man, the eeg tracings could be analyzed in rel ...19862947107
effect of ginkgolide paf-acether antagonists on arterial thrombosis.topical superfusion by paf-acether over a branch of the mesenteric artery of the guinea pig invariably results in the formation of a platelet thrombus, adhering onto a denuded area of the vessel wall, or at sites where local retraction of the endothelial cells has occurred. it is demonstrated that the application of exogenous paf-acether triggers a process of local autogeneration and release of endogenous paf-acether (or paf-like substances), maintaining a long phase of sequential regrowth and e ...19872960196
[implication of lipid peroxidation in triethyltin poisoning in the rat].triethyltin intoxication induces, in vivo, a significant increase of malondialdehyde concentration in rat brain. after treatment with a ginkgo biloba extract, an extract known to possess antiedematous and radical scavenging properties, the malondialdehyde level in the brain is significantly decreased. this suggests that a lipid peroxidation process is associated with cerebral oedema induced by triethyltin.19882973827
effects of an extract of ginkgo biloba on noradrenergic systems of rat cerebral cortex.oral treatment of rats with ginkgo biloba extract (gb) elicited a biphasic effect on normetanephrine (nmn) content of cerebral cortex; an initial decrease was evident after 45 minutes, followed by a marked increase that was evident after 14 days. chronic treatment with gb led to decreases in the density of 3h-dihydroalprenolol binding (after 27 days or 2 months) and in isoproterenol-stimulated adenylate cyclase activity (after 2 months) of the cerebral cortex. taken together, these results indic ...19853003764
ginkgo biloba extract inhibits oxygen species production generated by phorbol myristate acetate stimulated human leukocytes.a ginkgo biloba extract (gbe) containing flavonoids, among other compounds, was tested for the release of activated oxygen species (o-2, h2o2, oh.) during the stimulation of human neutrophils (pmns) by a soluble agonist. the extract slows down o2 consumption (respiratory burst) of stimulated cells by its inhibitory action on nadph-oxidase, the enzyme responsible for the reduction of o2 to o-2. consequently, superoxide anion (o-.2) and hydrogen peroxide (h2o2) production is significantly decrease ...19873028858
pharmacology of natural compounds. i. smooth muscle relaxant activity induced by a ginkgo biloba l. extract on guinea-pig trachea.a standardized ginkgo biloba l. extract containing flavonol glycosides induces a concentration-dependent relaxation of guinea-pig trachea in vitro and antagonizes in vivo bronchoconstriction induced by various agonists. the action of the extract appears to be mediated partially by an interaction with the eicosanoid system particularly through specific stimulation of the pge2 biosynthesis and partially by beta-adrenoceptor activation. the relaxation of guinea-pig trachea induced by the extract is ...19883174791
studies on the constitution of edible and medicinal plants. i. isolation and identification of 4-o-methylpyridoxine, toxic principle from the seed of ginkgo biloba l. 19883203417
effects of ginkgo biloba constituents related to protection against brain damage caused by hypoxia.the purpose of the present study was to approach the compound(s) responsible for the beneficial effects of an extract of ginkgo biloba leaves (egb) on animals subjected to hypoxia. in this first approach we compared the effects of the flavone and the non-flavone fraction of egb with those of the whole extract on mice in lethal hypoxia (3.5% o2), on brain energy metabolism of artificially ventilated rats inspiring 7% o2, and on local cerebral blood flow (lcbf) of normoxic rats. the latter two exp ...19883420139
effect of bn 52021, a specific antagonist of platelet activating factor (paf-acether), on calcium movements and phosphatidic acid production induced by paf-acether in human platelets.32p-labelled human platelets loaded with quin 2 and pretreated with aspirin were stimulated with 1-100 nm platelet activating factor (paf-acether or 1-0-alkyl-2-acetyl-sn-glycero-3-phosphocholine) in a medium containing the adp-scavenging system creatine phosphate/creatine phosphokinase. under these conditions, paf-acether evoked a characteristic fluorescence change allowing to quantify elevations in cytoplasmic free ca2+ from internal stores (ca2+ mobilization) or from external medium (ca2+ inf ...19873576518
effects of paf-acether on electrophysiological response of isolated retina.results of experiments performed on rat isolated retina indicate that platelet-activating factor (paf) is able to inhibit the functional response of the retina electroretinogram (erg) recorded in response to a brief light flash. in the presence of paf, the erg b-wave amplitude decreases according to a dose-dependent (2.10(-11) m; 2.10(-9) m; 2.10(-7) m) process. this effect is partially inhibited by the simultaneous administration of a ginkgo biloba extract (gbe, 10 mg/l) or ginkgolide b (bn 520 ...19873596955
antitumor principles from ginkgo biloba l. 19873677249
inhibition of antigen-induced lung anaphylaxis in the guinea-pig by bn 52021 a new specific paf-acether receptor antagonist isolated from ginkgo biloba.paf-acether appears to be a potent mediator released in response to allergen exposure in sensitized animals and it could contribute to clinical manifestations of allergic asthma. in order to ascertain this assumption the inhibition of antigen-induced lung anaphylaxis in guinea-pig by bn 52021, a new highly specific paf-acether antagonist, was studied. ovalbumin injected into passively sensitized guinea-pig induced a large bronchoconstriction which was accompanied by thrombocytopenia and leukopen ...19863754380
determination of arrangement of isoprene units in pig liver dolichol by 13c-n.m.r. spectroscopy.the arrangement of isoprene units in pig liver dolichol-18, -19 and -20 was determined by 1h- and 13c-n.m.r. spectroscopies. the alignment of trans and cis isoprene units was found to be in the order: dimethylallyl unit, two trans units, a sequence of 14-16 cis units, and a saturated isoprene unit terminated with a hydroxyl group, which verified the presumed chemical structure of dolichol. the absence of geometric isomers was confirmed. a slight amount of impurity was detected in each reversed-p ...19873632632
in vivo inhibition of plasma protein leakage and salmonella enteritidis-induced mortality in the rat by a specific paf-acether antagonist: bn 52021.the effects of bn 52021, a new specific paf-acether receptor antagonist and the total ginkgo biloba extract (gbe 761) from which this product was isolated, were studied in the rat on paf-acether-induced permeability and cell number changes and on endotoxin-induced lethality. their activities were compared to those of cyclooxygenase, 5-lipoxygenase and phospholipase a2 inhibitors. bn 52021 given s.c. or orally exerted a dose-related inhibition of paf-acether deleterious effects as well as of endo ...19863515870
inhibitory effects of a novel platelet activating factor (paf) antagonist (bn 52021) on antigen-induced prostaglandin and thromboxane formation by the guinea pig lung.the effects of a new platelet-activating factor (paf-acether) antagonist (bn 52021) extracted from ginkgo biloba leaves have been studied on the release of metabolites of arachidonic acid in igg-dependent guinea pig pulmonary anaphylaxis in vitro. prostaglandin e2 (pge2) and thromboxane b2 (txb2) were assayed using a novel elisa technique. the release of pge2 and txb2 from anaphylactic lungs reached a maximum 4-5 min following the antigen challenge (about 3.2 and 31.0 ng/ml respectively) and dec ...19863095849
specific inhibition of paf-acether-induced platelet activation by bn 52021 and comparison with the paf-acether inhibitors kadsurenone and cv 3988.bn 52021 is a chemically defined substance extracted from ginkgo biloba leaves. its inhibitory potency was tested on washed human platelets prepared so as to render them specifically sensitivity either to adenosine 5'-diphosphate (adp), arachidonic acid (aa) or paf-acether. its activity and specificity were compared with those of two other reported inhibitors of paf-acether effects: kadsurenone and cv 3988. paf-acether-induced aggregation of washed human platelets was concentration dependently i ...19863086108
purification and characterization of an iron-containing superoxide dismutase from a eucaryote, ginkgo biloba.a cyanide-insensitive superoxide dismutase was purified to electrophoretic homogeneity from leaves of the eucaryote, ginkgo biloba l. a molecular mass of 47,000 was determined for the enzyme, which consisted of two subunits of equal size. the enzyme preparation contained two isoenzymes with isoelectric points of 5.25 and 5.15. metal analysis after dialysis against edta revealed the presence of 1.4 gram atoms of iron per molecule. approximately 2 gram atoms each of copper and zinc per enzyme mole ...19853933430
effects of an extract of ginkgo biloba on the 3',5'-cyclic amp phosphodiesterase activity of the brain of normal and triethyltin-intoxicated rats.for clarification of the beneficial effects of the extract of ginkgo biloba (egb) on triethyltin (tet) toxicity in rats, the phosphodiesterase (pde) activities of the cerebral tissue were measured under in vitro and ex vivo conditions. under in vitro conditions, low concentrations of egb (0.25-4.0 mg/l) activated the enzyme, whereas after higher concentrations (5-250 mg/l), dose-dependent inhibition of the enzyme activity was observed. in the lower concentration range, the extract also partially ...19873035090
[effects of oxygenated free radicals on the electrophysiological activity of the isolated retina of the rat].particularly rich in polyunsaturated fatty acids, the retina constitutes an excellent model for testing the functional consequences of membrane lipoperoxidation. the effects could be quantified by measuring the amplitude of the electroretinogram which represents the characteristic response of the retina to its physiological stimulus (light photons). the authors report results obtained on isolated rat retina maintained in survival by perfusion. the membrane lipid peroxidation is induced by the no ...19854056320
an antivitamin b6, 4'-methoxypyridoxine, from the seed of ginkgo biloba l. 19854085085
[experimental pharmacology of ginkgo-biloba]. 19734798569
the ginkgo, the most ancient living tree. the resistance of ginkgo biloba l. to pests accounts in part for the longevity of this species.fossil records clearly demonstrate that the group of trees known as ginkgoales, of which today ginkgo biloba is the sole living member, date back over 200 million years. ginkgo bilboa itself is one of the oldest of living plants (4). it appears that the longevity of this tree and its long reproductive period are at least partially responsible for the persistence of the species. the resistance of these trees to pests such as insects, bacteria, viruses, and fungi has been studied. it is believed t ...19675341600
[on the pharmacology of the active ingredients of ginkgo biloba]. 19666014582
effects of ginkgo biloba on arterial smooth muscle responses to vasoactive stimuli.1. an extract of ginkgo biloba (gb), at a concentration (100 microgram/ml) that did not provoke isometrically-recorded contractions of rabbit aorta, was tested on the contractile effects of norepinephrine (ne), serotonin (5-ht) and dopamine (da). 2. gb potentiated the contractile effect of ne (reduced the ec50 from 75 to 36 nm), but had no obvious action on the contractile effects of 5-ht or da. 3. these results indicate that low concentrations of gb might influence catecholaminergic systems by ...19826124480
[researches on the antiaggregative activity of ginkgo biloba extract (author's transl)].sodium lactate applied on the pia-mater of the rabbit induces the appearance of venous platelets thrombi. the same phenomenon occurs in the arteries after electric stimulation of the arterial wall. gingo biloba extract, i.v. and per os, has been shown capable to partially antagonize these effects, particularly in the venous microcirculation. the ratio between the activity following the two modes of administration is about 1 to 5.19806246639
[cerebral ischemia after ligature of both carotid arteries in rats: effect of ginkgo biloba extracts (author's transl)].simultaneous ligature of both carotid arteries in long evans rats results in death for all animals. 50% of the animals survive if the ligatures are separated by a four-day interval. studies of variations in cerebral blood flow according to the time interval between the two ligatures show that alternative vascularization develops and that the balance between both hemibrains is restored. after giving l-dopa3h to animals with ligature of both carotids, increased synthesis of cerebral dopamine 3h an ...19826280311
[effect of ginkgo biloba extract on the electrophysiology of the isolated retina from a diabetic rat].the purposes of the experimental work presented here were to ascertain that diabetes causes impairment of the visual function and to test the protective properties of ginkgo biloba extract against this impairment. the experimental method selected was the isolated albino rat retina maintained in survival by perfusion. retinal function was evaluated by electroretinographic recording in response to a light stimulus. the rats were made diabetics by injection of alloxan. after one month of diabetes t ...19862947085
[antiradical properties of ginkgo biloba extract].the anti-radical properties of ginkgo biloba extract have been determined on several in vitro models. the products is as effective as uric acid, an anti-radical agent known to entrap the hydroxyl and diphenylpicrylhydrazyl radicals. in addition, it inactivates the formation of radicals, such as adriamycyl, which escape uric acid activity. it also inhibits membrane lipid peroxidation and owes to its anti-radical activity exerts a stimulant effect on the biosynthesis of prostanoids.19862947084
endothelium-dependent relaxations of rabbit isolated aorta produced by carbachol and by ginkgo biloba extract.spirally-cut strips of rabbit aorta were used to examine the relaxations produced by carbachol and extract of ginkgo biloba (gb) under isometric conditions. after precontracting the strips with phenylephrine (10(-7) m), carbachol produced a dose-related relaxation (pd2 congruent to 6.2 +/- 0.1) and this effect was antagonized competitively by atropine (pa2 congruent to 9.4 +/- 0.1). gb (0.2 or 0.3 mg/ml) also relaxed the strips. removal of the endothelium or a 30-min pre-treatment of the strips ...19846517898
the effect of intravenous infusion of tebonin (ginkgo biloba) on pial arteries in cats.the dilatory effect of intravenously infused tebonin (extract of ginkgo biloba) on pial arterial vessels (less than 100 micron diameter), has been measured using a multichannel videoangiometer through a closed cranial window in cats. after 20 minutes there was a significant dilatation of 7% which increased to 21% by one hour. results from 6 cats treated with 0.3 mg/kg/min. tebonin were compared with a group of 6 control cats; the same blood gas "steady state" situation applying to both groups. r ...19836674418
effects of an extract of ginkgo biloba and diverse substances on the phasic and tonic components of the contraction of an isolated rabbit aorta.1. the effects of phentolamine, propranolol, d 600, theophylline, papaverine and an extract of ginkgo biloba were studied with respect to the two phases of the contractile response induced by norepinephrine in an isolated rabbit aorta. 2. phentolamine (3 x 10(-6) m) inhibits the rapid phase of the contraction of the rabbit aorta brought on by norepinephrine (ne) 10(-5) m more strongly than the tonic phase. propranolol (10(-6) m) potentiates this rapid phase. 3. d 600 inhibits the slow phase with ...19836840510
effects of an extract of ginkgo biloba on rabbit isolated aorta.1. extract of ginkgo biloba (gb) provoked a dose-dependent contraction of spirally-cut rabbit aortic strips (ec50 congruent to 1.0 mg/ml) by an action that was antagonized by phentolamine (10(-7) m). 2. inhibitors of catecholamine re-uptake, cocaine (10(-5) m) and desipramine (10(-7) m) potentiated the contractile effect of norepinephrine (ne), but inhibited the contractile effects of gb and tyramine. 3. a comparison of the actions of gb, ne and tyramine using aortic strips prepared from control ...19827095401
[absorption, distribution and elimination of a labelled extract of ginkgo biloba leaves in the rat].the absorption, distribution and elimination of a radiolabelled 14c extract prepared from ginkgo biloba leaves have been studied in rats. following oral administration, expired 14c-co2 represented 16% of the administered dose excreted within the first 3 hours post-dose out of a total of 38% after 72 hours. an additional 21% of the administered dose was eliminated in the urine. the absorption of the radiolabelled ginkgo biloba extract was at least 60%. the pharmacokinetics of the drug, based on b ...19862947082
effects of ginkgo biloba on changes induced by quantitative cerebral microembolization in rats.unilateral embolization of the brain was performed in rats by the intracarotid injection of 4000 radioactive microspheres (50 micron). the local blood flow was determined using the iodoantipyrine technique in the hippocampus, hypothalamus, striatum and remainder of the brain. embolization resulted in a decrease in the blood flow and a modification of the distribution of microflow. besides, the embolization produced changes in energy metabolism, specially a fall in atp and glucose levels and an i ...19807377897
modification of cisplatin-induced renal p-aminohippurate uptake alteration and lipid peroxidation by thiols, ginkgo biloba extract, deferoxamine and torbafylline.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 ...19957477647
[factors influencing the prescribing of nootropic drugs. results of a representative inquiry in lower saxony].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.19957493562
protection of hypoxia-induced atp decrease in endothelial cells by ginkgo biloba extract and bilobalide.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 ...19957575684
effects of repeated treatments with an extract of ginkgo biloba (egb 761) on cerebral glucose utilization in the rat: an autoradiographic study.1. the autoradiographic method based on 2-deoxy-d[1-14c]glucose ([14c]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 ...19957590134
allergic contact dermatitis to ginkgo biloba l.: relationship with urushiol.a ginkgo biloba l. fruit extract was prepared and purified. three groups of guinea pigs were sensitized to the crude extract, anacardic acids 1, and cardanols 2 respectively, using the fcat method, and the fourth group to urushiol using the epicutaneous route. each group was tested for reaction to the primary sensitizer and to the different main aromatic compounds isolated from ginkgo fruits. anacardic acids were found to be good sensitizers, while cardanols failed to induce allergic contact der ...19892774654
ginkgo biloba extract facilitates recovery from penetrating brain injury in adult male rats.adult, male sprague-dawley rats received 100 mg/kg ginkgo biloba extract (gbe) intraperitoneally for 30 days. gbe reduced overall activity and decreased sensitivity to light in the open field maze. the rats were also less responsive to noxious stimuli after 13 days of treatment with gbe. after the last injection, all subjects were trained on a delayed-spatial alternation task. subsequent to acquisition of the spatial task, the rats received either sham operations and saline or bilateral frontal ...19892744128
inhibition of platelet-activating factor (paf)-induced chemotaxis and paf binding to human eosinophils and neutrophils by the specific ginkgolide-derived paf antagonist, bn 52021.we have investigated the effects of bn 52021 (a specific paf antagonist derived from ginkgo biloba) on paf-induced human eosinophil and neutrophil chemotaxis. in response to an optimal concentration of paf (10(-6) mol/l), the drug was significantly more potent (p less than 0.001) in inhibiting eosinophil as compared to neutrophil locomotion. these inhibitory effects were observed in a dose-dependent manner with a concentration of drug required to produce 50% inhibition of 7.0 (+/- 2.2) x 10(-6) ...19892536413
effects of an extract of ginkgo biloba (egb 761) on "learned helplessness" and other models of stress in rodents.the effects of repeated oral administration of an extract of ginkgo biloba (egb 761) on various behavioral models of stress in rodents were investigated. the models in rats included "learned helplessness," shock-suppressed licking (vogel conflict test) and forced swimming-induced immobility ("behavioral despair"). the models in mice included shock-suppressed exploration (four plates test), spontaneous exploration (staircase test) and food consumption in a novel situation (emotional hypophagia). ...19902217527
new experimental model for the evaluation of adaptogenic products.a new animal model for evaluating improvement in physical work performance and endurance in an adverse environment is described. in this model, rats in restraint were exposed to 5 degrees c at 480 mmhg atmospheric pressure. results were compared to an animal forced to swim in water at 23 degrees c. in both the models, colonic temperature (tr) of the rats was continually monitored during exposure to adverse environment and during recovery at 32 degrees c and normal atmospheric pressure. the time ...19902214813
influences of ginkgo biloba on cyclosporin a induced lipid peroxidation in human liver microsomes in comparison to vitamin e, glutathione and n-acetylcysteine.the in vitro effect of cyclosporin a (csa) on lipid peroxidation in human liver microsomes was investigated, and efforts were made to prevent the resulting toxic effect of csa. microsomes were prepared from human liver resection material and incubated with csa (0, 10, 30, 100, 300, 1000 micrograms/ml) for one hour (ph 7.4, 37 degrees, 95% o2, 5% co2). subsequently the resulting concentrations of malondialdehyde equivalents (mda) were determined, a breakdown product of lipid peroxidation. further ...19912018556
inhibition of preretinal proliferation by free radical scavengers in an experimental model of tractional retinal detachment.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 ...19947698262
efficiency of ginkgo biloba extract (egb 761) in antioxidant protection against myocardial ischemia and reperfusion injury.the cardio-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 ...19957735127
expression of glial fibrillary acidic protein (gfap), glutamine synthetase (gs), and bcl-2 protooncogene protein by müller (glial) cells in retinal light damage of rats.in retinal light damage, degeneration of photoreceptors may cause alterations of glial (müller) cells. we performed immunocytochemical studies on müller 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 fou ...19957746501
ethnopharmacology and the development of natural paf antagonists as therapeutic agents.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, anap ...19911881152
changes of enzyme activities in the rat myocardium caused by experimental hypoxia with and without ginkgo biloba extract egb 761 pretreatment. a cytophotometrical study.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 su ...19957771185
lipoperoxidation induced by hydrogen peroxide in human erythrocyte membranes. 1. protective effect of ginkgo biloba extract (egb 761).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 micrograms/ml suggest that the antioxidant potential of egb 761 in erythroc ...19957774754
plasticity mechanisms in vestibular compensation in the cat are improved by an extract of ginkgo biloba (egb 761).the effects of administration of an extract of ginkgo biloba (egb 761) on vestibular compensation was studied in unilateral vestibular neurectomized cats. this experimental model of cns plasticity was investigated by using behavioral tests (postural disorders compensation, locomotor balance recovery), electrophysiological (spontaneous and evoked neck muscle activity) and neurophysiological (spontaneous firing rate recovery of deafferented vestibular cells) recordings, and immunocytochemical meth ...19911805241
ginkgo biloba extract egb 761 is not active against mycobacterium avium infection in c57bl/6 mice. 19957785973
peroxyl radical scavenging activity of ginkgo biloba extract egb 761.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 i ...19957786306
effect of long-term treatment with egb 761 on age-dependent structural changes in the hippocampi of three inbred mouse strains.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 mossy fibers which appear to decrease as a function of ageing. experim ...19957823780
effects of four non-cholinergic cognitive enhancers in comparison with tacrine and galanthamine on scopolamine-induced amnesia in rats.amnesia can be induced in rats in the passive avoidance paradigm by administration of scopolamine, a central muscarinic receptor antagonist. tacrine or galanthamine, inhibitors of acetylcholinesterase, given in conjunction with scopolamine partially reversed the scopolamine-induced deficit in passive avoidance performance. four so-called cognitive enhancers, all widely used for the treatment of the symptoms associated with mental aging, cerebral insufficiency and senile memory disorder, were inv ...19921738791
effect of egb 761, a ginkgo biloba extract, on early arrhythmia induced by coronary occlusion and reperfusion in dogs.egb 761 is a preparation of ginkgo biloba extract, which has complex biologic actions including free radical scavenging activity. to examine the anti-arrhythmic effect of egb 761, a canine preparation of coronary artery occlusion-reperfusion was tested. under intravenous anesthesia and open chest conditions, 32 dogs were subjected to 30 min of coronary occlusion, followed by reperfusion. twelve received egb 761 by intravenous injection, 1 mg/kg five minutes before coronary occlusion, followed by ...19947866057
ginkgo biloba extract (egb 761) improves postischemic function in isolated preconditioned working rat hearts.we studied the effect of preconditioning and gikgo biloba extract (egb 761) in relation to the recovery of contractile function after global ischemia in the isolated working rat heart.19947921376
effects of ginkgo biloba extract (egb 761) on the guinea pig vestibular system.previous studies have demonstrated that the administration of ginkgo biloba extract (egb 761) improves the compensation of the vestibular syndrome induced by transection of the viiith nerve. to investigate the mechanisms at play, the vestibular nuclei of alert guinea pigs were perfused with egb 761. this perfusion always induced a stereotyped reversible postural syndrome that was the mirror image of the syndrome provoked by the unilateral lesion of the otolithical receptors. this result supports ...19921513841
chloroplastic genomes of ginkgo biloba and chlamydomonas moewusii contain a chlb gene encoding one subunit of a light-independent protochlorophyllide reductase.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. polymorphia 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-pro ...19948001171
the nitric oxide-scavenging properties of ginkgo biloba extract egb 761.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 potenti ...19948003011
hemorrheological and circulatory effects of gincosan.gincosan is a combined preparation containing 60 mg ginkgo biloba and 100 mg ginseng, standardized of 24% ginkgo flavone glycosides and 4% ginsenosides. hemorrheological and circulatory effect as well as blood pressure behavior after the administration of gincosan were studied in an acute trial on 10 voluntary subjects with a mean age of 26 years. systolic blood pressure decreased significantly both for the large-dose (120 mg ginkgo biloba +200 mg ginseng) and low-dose administration (60 mg gink ...19921506124
ginkgo 11s seed storage protein family mrna: unusual asn-asn linkage as post-translational cleavage site.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). th ...19948061314
uv-c irradiation-induced peroxidative degradation of microsomal fatty acids and proteins: protection by an extract of ginkgo biloba (egb 761).after exposure of rat liver microsomes to uv-c irradiation, analysis of membrane fatty acids by gas chromatography confirmed that egb 761, a drug containing a dosed and standardized extract of ginkgo biloba, provides effective protection against free radical attack in vitro. this analysis, coupled with thiobarbituric acid (tba) reaction, permitted qualitative and overall quantitative evaluation of radical-induced damage to polyunsaturated fatty acids (pufa), as well as evidence of the antioxidan ...19921505777
alpha 2-adrenoceptor changes during cerebral ageing. the effect of ginkgo biloba extract.[3h]rauwolscine binding to alpha 2-adrenoceptors in cerebral cortex and hippocampus membranes of young (4 months) and aged (24 months) wistar rats has been investigated. in aged rats, bmax values of [3h]rauwolscine binding were significantly reduced (25-32%) in the cerebral cortex and hippocampus, as compared with the number of alpha 2-adrenoceptors found in young rats. chronic treatment with ginkgo biloba extract did not alter [3h]rauwolscine binding in the hippocampus of young rats, but signif ...19921350623
flow cytometric estimation of the effect of ginkgo biloba extract on the content of hydrogen peroxide in dissociated mammalian brain neurons.the effect of ginkgo biloba extract (gbe) on the content of hydrogen peroxide was estimated in cerebellar neurons dissociated from rats, by means of a flow-cytometer and 2',7'-dichlorofluorescein (dcf) diacetate, a fluorescent dye for intracellular hydrogen peroxide. the gbe started to reduce the dcf fluorescence of the neuron at 0.1 microgram/ml to 0.3 microgram/ml. further increases in the gbe concentration (up to 3 micrograms/ml) produced a dose-dependent decrease in the dcf fluorescence, sug ...19921287275
[experimental model of cerebral ischemia preventive activity of ginkgo biloba extract (author's transl)].unilateral embolization of the brain was performed in rats by intracarotid injection of 4 000 radioactive microspheres (50 mu). local blood flow in hippocampus, striatum, hypothalamus and remainder of the brain were determined using the iodoantipyrine technique. embolization resulted in a decreases in blood flow and modificationof the distribution of microflow. furthermore, embolization produces changes in energy metabolism : particularly a fall in atp and glucose levels and an increase in lacta ...1979233452
ischaemia and reperfusion-induced injury in rat retina obtained from normotensive and spontaneously hypertensive rats: effects of free radical scavengers.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 ...19938144317
composition of the neutral and phospholipid fractions from ginkgo nuts (ginkgo biloba) and fatty acid composition of individual lipid classes. 19768476
effect of in vivo application of the ginkgo biloba extract egb 761 (rökan) on the susceptibility of mammalian retinal cells to proteolytic enzymes.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. ...19948196936
[effect of leaves of ginkgo biloba on hair regrowth in c3h strain mice].effects of 70% ethanolic extract from leaves of ginkgo biloba (gbe) on the hair regrowth in normal and high butter diet-pretreated c3h strain mice which posterior hair we shaved were investigated. gbe showed a promoting effect on the hair regrowth. gbe had the inhibitory effects on blood platelet aggregation, thrombin activity and fibrinolysis. gbe inhibited the increase of serum the triglyceride level in high cholesterol diet-treated rats. these results suggested that gbe promotes the hair regr ...19938254481
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