Ginkgo Biloba Research Today is a free monthly online journal that collates and summarizes the latest research about Ginkgo Biloba, including details on ginkgo biloba, herbal remedies, side effects, benefits.

The Ginkgo biloba extract EGb 761((R)) and its main constituent flavonoids and ginkgolides increase extracellular dopamine levels in the rat prefrontal cortex.

Yoshitake T, Yoshitake S, Kehr J

Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.

Background and purpose: Experimental and clinical data suggest that extracts of Ginkgo biloba improve cognitive function. However, the neurochemical correlates of these effects are not yet fully clarified. The purpose of this study was to examine the effects of acute and repeated oral administration of the standardized extract EGb 761((R)) on extracellular levels of dopamine, noradrenaline and serotonin (5-HT), and the dopamine metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the prefrontal cortex (PFC) and striatum of conscious rats. Experimental approach: Monoamines and their metabolites were monitored by the use of microdialysis sampling and HPLC with electrochemical or fluorescence detection. Key results: A single oral dose of EGb 761 (100 mg.kg(-1)) had no effect on monoamine levels. However, following chronic (100 mg.kg(-1)/14 days/once daily) treatment, the same dose significantly increased extracellular dopamine and noradrenaline levels, while 5-HT levels were unaffected. Chronic treatment with EGb 761 showed dose-dependent increases in frontocortical dopamine levels and, to a lesser extent, in the striatum. The extracellular levels of HVA and DOPAC were not affected by either acute or repeated doses. Treatment with the main constituents of EGb 761 revealed that the increase in dopamine levels was mostly caused by the flavonol glycosides and ginkgolide fractions, whereas bilobalide treatment was without effect. Conclusions and implications: The present results demonstrate that chronic but not acute treatment with EGb 761 increased dopaminergic transmission in the PFC. This finding may be one of the mechanisms underlying the reported effects of G. biloba in improving cognitive function.

Published 28 January 2010 in Br J Pharmacol.
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Articles on Ginkgo Biloba published 27 January 2010:

Effectiveness of Standardized Ginkgo biloba Extract on Cognitive Symptoms of Dementia with a Six-Month Treatment: A Bivariate Random Effect Meta-Analysis.   Pharmacopsychiatry.

INTRODUCTION: The objective of this study is to take into consideration the influence of baseline risk on the treatment effect and evaluate the effectiveness of standardized GINKGO BILOBA extract (GbE) on cognitive symptoms of dementia with the treatment period of approximately 6 months. METHODS: We systematically searched the literature to identify all randomized placebo-controlled clinical trials (English language) of GbE in the treatment of dementia. Data were extracted from selected trials ... [Abstract] [Full-text]

Articles on Ginkgo Biloba published 22 January 2010:

Ginkgo biloba and ginkgotoxin.   J Nat Prod, 73(1): 86-92.

Products prepared from Ginkgo biloba are top-selling phytopharmaceuticals especially in Europe and major botanical dietary supplements in the United States. In European medicine, G. biloba medications are used to improve memory, to treat neuronal disorders such as tinnitus or intermittent claudication, and to improve brain metabolism and peripheral blood flow. The whole array of indications is reflected by a number of defined natural product constituents in G. biloba. The most well-known ones ... [Abstract] [Full-text]

Articles on Ginkgo Biloba published 14 January 2010:

Optics of sunlit water drops on leaves: conditions under which sunburn is possible.   New Phytol.

Summary *It is a widespread belief that plants must not be watered in the midday sunshine, because water drops adhering to leaves can cause leaf burn as a result of the intense focused sunlight. The problem of light focusing by water drops on plants has never been thoroughly investigated. *Here, we conducted both computational and experimental studies of this phyto-optical phenomenon in order to clarify the specific environmental conditions under which sunlit water drops can cause leaf burn. ... [Abstract] [Full-text]

Articles on Ginkgo Biloba published 7 January 2010:

Supplementing cognitive aging: a selective review of the effects of ginkgo biloba and a number of everyday nutritional substances.   Exp Aging Res, 36(1): 105-22.

This review concerns a number of substances that have been receiving much attention, particularly in the media, for their potential to protect against age-related cognitive decline, and a focus is placed upon recent findings. Omega-3 fatty acids appear to play important roles in preserving neuronal structure and function and minimizing cognitive decline, whereas the antioxidant vitamins C and E appear to be particularly beneficial for combating age-related oxidative stress when administered in ... [Abstract] [Full-text]

Articles on Ginkgo Biloba published 30 December 2009:

Ginkgo biloba treating patients with attention-deficit disorder.   Phytother Res, 24(1): 26-7.

Various medications such as clonidine facilitate calming, enhance frustration tolerance and reduce aggression in attention-deficit disorder (ADD) patients. The use of Ginkgo biloba was studied as an herbal alternative. Six psychiatric outpatients diagnosed with ADD were rated at baseline and while taking Ginkgo biloba to determine its efficacy as a treatment for ADD. Comparisons of Wender Utah ratings within subject were used to measure behavioral changes in the subjects. During Ginkgo biloba ... [Abstract] [Full-text]

Pharmacokinetics of bilobalide, ginkgolide A and B after administration of three different Ginkgo biloba L. preparations in humans.   Phytother Res.

A sensitive LC-ESI-MS method with a solid-phase extraction was established for the determination of bilobalide, ginkgolide A and ginkgolide B in human plasma; bioavailability and pharmacokinetics of three different Ginkgo biloba L. preparations have been investigated. The preparations used in the present single-dose pharmacokinetic study were different formulations of Ginkgo biloba L. extracts (Geriaforce tincture, new Ginkgo fresh plant extract tablets and EGb 761) with various excipients. The ... [Abstract] [Full-text]

Ginkgo biloba for preventing cognitive decline in older adults: a randomized trial.   JAMA, 302(24): 2663-70.

CONTEXT: The herbal product Ginkgo biloba is taken frequently with the intention of improving cognitive health in aging. However, evidence from adequately powered clinical trials is lacking regarding its effect on long-term cognitive functioning. OBJECTIVE: To determine whether G. biloba slows the rates of global or domain-specific cognitive decline in older adults. DESIGN, SETTING, AND PARTICIPANTS: The Ginkgo Evaluation of Memory (GEM) study, a randomized, double-blind, placebo-controlled ... [Abstract] [Full-text]

Articles on Ginkgo Biloba published 22 December 2009:

Development of liquid chromatography/mass spectrometry methods for the quantitative analysis of herbal medicine in biological fluids: a review.   Biomed Chromatogr, 24(1): 91-103.

The development of liquid chromatography-mass spectrometry (LC-MS) and tandem MS/MS for the analysis of bioactive components and their metabolites of herbal medicines in biological fluids is reviewed with the aim of providing an overview of the current techniques and methods used. The issues and challenges associated with various stages of the analytical method development are discussed using Ginkgo biloba and Panax ginseng as case studies. LC-MS offers selectivity and specificity in both the ... [Abstract] [Full-text]

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