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At least 19 recordsLinked to original sources

PubMed2000

Protective effect of ginkgo extract on rat brain with transient middle cerebral artery occlusion.

It has been empirically known that Ginkgo extract is useful for reducing many symptoms associated with cerebral blood flow (CBF) insufficiency, but its mechanisms have been uncertain. In the present study, therefore, we gave Ginkgo extract to rats with per os digestion, and investigated its effect on CBF and ischemic brain damage with middle cerebral artery occlusion (MCAO). The treatment with Ginkgo extract (10 mg 100 g-1 rat) increased CBF in the normal condition, but the degree of increase in CBF was lesser during and after MCAO. TTC staining showed that infarct volume was reduced with Ginkgo treatment. TUNEL and HSP72 immunostaining confirmed the protective effect of Ginkgo treatment reducing numbers of TUNEL and HSP72 positive cells. Immunohistochemical analysis showed that caspase-3 expression was less abundant in Ginkgo treated rats. The present results suggest that Ginkgo extract contains a substance which increases normal CBF and reduces ischemic brain damage.

Animals↗

PubMed2001

Evaluation of the allergenic potential of Ginkgo biloba extracts.

Ginkgo biloba extracts are used for the treatment of central and peripheral malperfusion, cerebral insufficiency and dementia. Between 1996 and 1998, several patients in Austria who had received parenteral Ginkgo extracts were reported to have developed allergy-like symptoms. The aim of the present study was to determine whether Ginkgo biloba extracts contain type I allergens. The protein content of Ginkgo biloba extracts was determined by BCA protein determination and SDS-PAGE. We used sera from 95 polysensitized plant-allergic patients (the sera contained IgE antibodies against most plant allergens), and rabbit antisera raised against defined recombinant plant allergens. The presence of allergens in Ginkgo extracts was determined by dot-blotting and Wester blot. Neither rabbit antisera nor IgE antibodies of patients reacted to the Ginkgo extracts. In addition, it was shown that prick testing of the skin could be conveniently used to study Gingko extracts for allergenic activity. In conclusion, no evidence for the presence of type I allergens in Ginkgo extracts was found. We recommend serological and/or skin testing to exclude sensitisation to components of Ginkgo biloba extracts.

Adult↗

PubMed2001

[A comparison of cholinesterase inhibitors and ginkgo extract in treatment of Alzheimer dementia].

AIM: To compare the effectiveness of second-generation cholinesterase inhibitors (donepezil, rivastigmine, metrifonate) with that of the special ginkgo extract EGb 761R in Alzheimer's disease. METHOD: Analysis of the effect on cognition with the aid of the ADAS-cog.scale, placebo-adjusted, within six months; statistical evaluation of the effect using the confidence interval for the potential mean improvement. RESULTS: All medications are statistically significantly superior to placebo. The mean improvement is larger for the cholinesterase inhibitors than for the ginkgo extract. In the statistically unfavorable case, the effect of the cholinesterase inhibitors is still appreciable, but not for the ginkgo extract. CONCLUSION: Until the results of direct comparative studies are available, the present results indicate a superior effect of cholinesterase inhibitors over the ginkgo extract in the treatment of mild to moderate Alzheimer's disease.

Aged↗

PubMed2005

Influence of the Ginkgo extract EGb 761 on rat liver cytochrome P450 and steroid metabolism and excretion in rats and man.

Extracts from leaves of Ginkgo biloba L. are among the most used herbal medicinal products worldwide. Based on in-vitro tests and studies in rats, concern has been expressed that intake of Ginkgo extracts may affect hepatic metabolism of xenobiotics and cause drug interactions, although no evidence for modulation of cytochrome P450 (CYP450) enzyme activity was obtained in human trials. Because of these contradictory findings, we investigated the effects of the standardised extract EGb 761 on hepatic CYP450 in rats. EGb 761 (100 mg kg-1 daily, p.o., for 4 days) strongly increased liver CYP450 content and altered the ex-vivo biotransformation of androstendione, as well as metabolism of endogenous steroids. However, in human subjects no effect on the urinary steroid profile was observed after intake of EGb 761 for 28 days (240 mg daily). These results indicate that the effects of EGb 761 on drug metabolising enzymes are specific for rats and may not be extrapolated to man.

Administration, Oral↗

PubMed2005

[Clinical study on treatment of pulmonary interstitial fibrosis with ginkgo extract].

OBJECTIVE: To observe the effect of ginkgo extract on pulmonary interstitial fibrosis. METHODS: Forty-five patients with pulmonary interstitial fibrosis were randomly divided into two groups, the treated group (n = 30) received ginkgo biloba extract 1 g, three times a day; the control group received prednisone 30 mg, once a day, the therapeutic course for both groups was 3 months. Changes of clinical symptoms, pulmonary function, arterial partial pressure of oxygen, computerized tomography (CT), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor-alpha(TNF-alpha) in the two groups were observed before and after treatment. RESULTS: The efficacy of treatment in the two groups showed insignificant difference, clinical symptoms, pulmonary function, arterial partial pressure of oxygen were improved after treatment (P < 0.05), and the levels of IL-6, IL-8 and TNF-alpha significantly decreased after treatment as compared with those before treatment in the two groups. The occurrence of pulmonary infection was less in the treated group than that in the control group (P <0.05). CONCLUSION: Ginkgo is effective in treating pulmonary interstitial fibrosis.

Aged↗

PubMed2000

[Experimental study on suppressive effect of ginkgo extract on adhesion of vascular endothelial cell to monocyte induced by minimally modified low density lipoprotein].

OBJECTIVE: To observe the effect of Ginkgo extract on the interaction between minimally modified low density lipoprotein (MM-LDL) induced human umbilical vein endothelial cell (HUVEC) and U937 monocyte-like cell line. METHODS: The adhesive percentage between HUVEC and U937 by counting and the expression of VCAM-1, ICAM-1, P-selectin by ELISA. RESULTS: Treatment of HUVEC with MM-LDL (75 micrograms/ml) for 4 hrs could significantly increase the adhesion of U937 to HUVEC (P < 0.01) and Ginkgo extract could suppress the adhesion in dose-dependent manner. The surface expression of VCAM-1, ICAM-1, P-selectin was not induced by MM-LDL, while recombination tumor necrosis factor-alpha 5.0 ng/ml, as a positive control, could do. CONCLUSION: Ginkgo extract afforded protection against HUVEC damage induced by MM-LDL and the adhesion of monocytes to endothelial cells induced by MM-LDL is not mediated by VCAM-1, ICAM-1 and P-selectin.

Cell Adhesion↗

PubMed1998

[Protective effects of folium Ginkgo extract on experimental cerebral ischemia of mice].

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 GSH-Px 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.

Animals↗

PubMed2003

Neuroprotective effects of Ginkgo biloba extract.

Ginkgo biloba extract has been therapeutically used for several decades to increase peripheral and cerebral blood flow as well as for the treatment of dementia. The extract contains multiple compounds such as flavonoids and terpenoids that are thought to contribute to its neuroprotective and vasotropic effects. In this review, we summarize the experimental results on the mechanism of neuroprotection induced by standardized extract of Ginkgo biloba leaves (EGb 761) and its constituents. The effects described mostly in animals include those on cerebral blood flow, neurotransmitter systems, cellular redox state and nitric oxide level. Furthermore, we discuss the current status of clinical trials as well as undesired side effects of EGb 761.

Animals↗

PubMed1993

[Biological standardization of Ginkgo extracts].

The determination of the inhibition of PAF (platelet-activating factor)-induced platelet aggregation has been proposed as a biological standardization method for commercially available Ginkgo biloba extracts by measuring the characteristic pharmacological effect of ginkgolides in vitro. The determination is specific for ginkgolides A, B, C, and J and is not influenced by other constituents present in Ginkgo biloba extracts. IC50 values of ginkgolide B can be used to standardize various Ginkgo extracts produced by special extraction methods with respect to equi-effective ginkgolide B contents. In order to compare values obtained by a chemical-analytical procedure with those obtained by the biological assay, the equi-effective total ginkgolide content of each Ginkgo extract had to be calculated. Accordingly, the concentrations of the individual ginkgolides in the various Ginkgo extracts were determined chromatographically by assaying ginkgolides as trime-thylsilyl derivatives. Their individual contributions towards the measured in vitro effects were derived from their respective IC50 values. The calculated equi-effective total ginkgolide contents of the Ginkgo extracts were in good agreement with those obtained by gas chromatography. The results demonstrate that, in addition to a chemical standardization, the biological standardization of Ginkgo extract preparations is also feasible.

Lactones↗

PubMed1986

[Preparation and definition of Ginkgo biloba extract].

Ginkgo biloba extract is a well-defined and complex product prepared from green leaves of Ginkgo biloba. The leaves are harvested from trees growing in plantations in South Corea, Japan and France. The mode of culture, harvesting and extraction are perfectly standardized and controlled. Analysis of Ginkgo biloba extract makes it possible to confirm that undesirable substances have been eliminated and to measure the amount of active principles. The extract contains flavonoid substances, such as the Ginkgo-flavone glycosides and terponoids which are characteristic of Ginkgo and have a unique structure (ginkgolides, bilobalide).

Chemical Phenomena↗

PubMedDate not supplied

Induction of superoxide dismutase and catalase activity in different rat tissues and protection from UVB irradiation after topical application of Ginkgo biloba extracts.

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.

Administration, Topical↗

PubMed1989

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 system (phenazine methosulfate-NADH), and its enzymatic activity was shown by polarographic determination.

Animals↗

PubMed2004

Estrogenic activities of Ginkgo biloba extracts.

Ginkgo biloba extracts (GBE) are extracted from the leaves of Ginkgo biloba tree. GBE contains 24% of phytoestrogens, which is kaempferol, quercetin, and isorhamnetin. It has been reported that phytoestrogens could be a part of SERMs (Selective estrogen receptor modulators) and possibly the alternative HRT (Hormone replacement therapy) for postmenopausal women. The goal of this study was to investigate the potencies of GBE and its major components (quercetin, kaempferol, isorhamnetin) for estrogenic effect, which confirms the capacity as an alternative HRP. It was found that GBE and its major components exerted a dual action on ER-alpha and ER-beta in competitive binding assay. The binding affinity of these chemicals to ER-beta was higher than to ER-alpha. In the E-screen assay, these chemicals induced cell proliferation in ER-positive MCF-7 cell, but not in ER-negative MDA-MB-231 cells. The cell proliferation induced by these chemicals was blocked by tamoxifen. Also, GBE and its major components induced pS2 and PR (progesterone receptor) transcription in MCF-7 cells. Therefore these results indicated that GBE and its major components had the weak estrogenic activities through the estrogen response pathway by an interaction with the ER. In conclusion, we provided the evidence of potential estrogenic activities of GBE, which could be useful as an alternative HRP. However, further studies are required to assess the physiological significance of GBE in animals and humans.

Binding, Competitive↗

PubMed2004

The effect of Ginkgo extract EGb761 in cisplatin-induced peripheral neuropathy in mice.

Neuroprotective effect of Ginkgo biloba extract EGb761 in cisplatin (cis-diamminedi-chloroplatinum, or CDDP)-induced peripheral neuropathy was investigated. Swiss albino mice were treated with CDDP, 2 mg/kg ip twice a week for nine times. One group of the animals also received EGb761 in the drinking water at an estimated dosage of 100 mg/kg per day. Two other groups received vehicle (control) or EGb761 only. Development of neuropathy was evaluated with changes in sensory nerve conduction velocity (NCV). Following the treatments, dorsal root ganglia (DRGs) were microscopically examined and some were cultured for 3 days. EGb761 proved effective in preventing the reduction in NCV (P < 0.0001) caused by CDDP. CDDP caused a decrease in the number of migrating cells (P < 0.01) and in the length of outgrowing axons (P < 0.01) while EGb761 treatment prevented the latter. CDDP led to smaller nuclear and somatic sizes in neurons (P < 0.01), while with EGb761 co-administration, both were close to control values. Animals having EGb761 only had similar results with controls. In conclusion, EGb761 was found to be effective in preventing some functional and morphological deteriorations in CDDP-induced peripheral neuropathy.

Administration, Oral↗

PubMed1988

Influence of the specific antagonist of PAF-acether, BN 52021, and of Ginkgo extract on the rejection of murine tail skin allografts and the PAF-acether mortality in mice in particular consideration of the role of TXB2.

An oral application of 2 x 10 mg/kg daily of the PAF antagonist, BN 52021, significantly prolonged the distal allograft survival in the murine tail skin model of cell-mediated allograft rejection. BN 52021 diminished the TXB2 content in the skin at and near to the transplantation site by two thirds whereas PAF-acether significantly enhanced the TXB2 content in murine tail skin. Similar to the tail skin BN 52021 also reduced by more than 70% the TXB2 release from human granulocytes stimulated by calcium ionophore A 23187. The PAF-acether mortality (LD75) in NMRI mice was decreased to 20% by BN 52021 with a lower dose than by BN 52020. Comparing Ginkgo total extract in doses which significantly diminished the 75% mortality by PAF-acether in mice with BN 52021 and BN 52020 in doses that produced the same inhibitory effect, a potentiated effect of Ginkgo extract resulted with respect to the share of BN 52021 and BN 52020 in Ginkgo extract.

Animals↗

PubMed2004

Total phenolics and antioxidant activities of fenugreek, green tea, black tea, grape seed, ginger, rosemary, gotu kola, and ginkgo extracts, vitamin E, and tert-butylhydroquinone.

The total phenolics and antioxidant activities of fenugreek, green tea, black tea, grape seed, ginger, rosemary, gotu kola, and ginkgo extracts, vitamin E, and tert-butylhydroquinone, were determined. Grape seed and green tea were analyzed for their phenolic constituents using high-performance liquid chromatography. The total phenolics of the plant extracts, determined by the Folin-Ciocalteu method, ranged from 24.8 to 92.5 mg of chlorogenic acid equivalent/g dry material. The antioxidant activities of methanolic extracts determined by conjugated diene measurement of methyl linoleate were 3.4-86.3%. The antioxidant activity of the extracts using chicken fat by an oxidative stability instrument (4.6-10.2 h of induction time) followed a similar trend in antioxidant activity as determined by the Folin-Ciocalteu method. Seven phenolics in grape seed and green tea extracts were identified that ranged from 15.38 to 1158.49 and 18.3 to 1087.02 mg/100 g of extract, respectively. Plant extracts such as green tea and grape seed extracts can be used to retard lipid oxidation in a variety of food products.

Antioxidants↗

PubMed2007

[Special ginkgo extract in cases of vertigo: a systematic review of randomised, double-blind, placebo controlled clinical examinations].

BACKGROUND: The concept for the medical treatment of vertigo has changed over the last 30 years due to recognition of the dependence of the vertiginous sensation on vestibular compensation and the dependence of vestibular compensation on the state of vigilance. METHODS: In this systematic review, experimental studies of the influence of the special ginkgo extract EGb 761 on vestibular compensation in animals and randomized, double-blind clinical studies of EGb 761 in vestibular and non-vestibular vertigo are described and critically evaluated. RESULTS: The beneficial effect of EGb 761 on vestibular compensation has been demonstrated in preclinical and clinical studies. CONCLUSION: Evidence of the efficacy of EGb 761 for the treatment of vertiginous syndromes is presented in the available studies.

Animals↗

PubMed2003

Ginkgo extract or cholinesterase inhibitors in patients with dementia: what clinical trials and guidelines fail to consider.

Dementia of Alzheimer's type (DAT), together with vascular dementia, is the most important indication for Ginkgo biloba extract (EGb). The therapeutic efficacy of this extract is founded on neuroprotective, metabolic and rheological effects. In addition to these mechanisms--which also form the basis of the activity of the older synthetic nootropics--the hypothesis that DAT is due to a "cholinergic deficit" at central synapses has led, over the last decade, to the development of a new group of drugs for this indication, the cholinesterase (ChE) inhibitors. Thus nowadays, EGb is competing, on the synthetic side, with the ChE inhibitors tacrine, donepezil, rivastigmine and galantamine. No direct comparative trials have been undertaken, but long-term studies lasting 24-56 weeks to demonstrate efficacy have been carried out with both groups of substances in accordance with current EU guidelines. To date, only one psychometric scale has gained general acceptance as the primary criterion of efficacy, namely the cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-Cog), whose scores range from 0 to 70 (the lower the better). The initial scores of patients in the trials were between 20 and 30; the improvements after 6 months treatment (less those seen with placebo) were about 2 points under Ginkgo extract and 2 to 4 points with the ChE inhibitors. However, the relatively small differences are called into question by the occurrence of drug-specific side effects with the ChE inhibitors. Unlike the treatment with EGb, up to 90% of the patients given the ChE inhibitors developed nausea and vomiting, so there is a suspicion that methodological reasons in the sense of an "unblinding" of the treatment groups caused the apparent superiority in the intensity of the effect. In addition, the benefits of treatment were rapidly reversed after ending administration of ChE inhibitors, which did not occur to the same extent with EGb. Adverse drug reactions are more than 10 times more common with the ChE inhibitors and the treatment costs about five times higher than with EGb. Given the limited therapeutic options for DAT, treatment with EGb still appears to be the method of choice compared to the ChE inhibitors.

Cholinesterase Inhibitors↗