EGb 761: ginkgo biloba extract, Ginkor

Drugs R D. 2003;4(3):188-93

ABSTRACT

EGb 761 [Ginkgo biloba extract EGb 761, Rokan, Tanakan, Tebonin] is a standardised extract of Ginkgo biloba leaves and has antioxidant properties as a free radical scavenger. A standardised extract of Ginkgo biloba leaves is a well defined product and contains approximately 24% flavone glycosides (primarily quercetin, kaempferol and isorhamnetin) and 6% terpene lactones (2.8-3.4% ginkgolides A, B and C, and 2.6-3.2% bilobalide). Ginkgolide B and bilobalide account for about 0.8% and 3% of the total extract, respectively. Other constituents include proanthocyanadins, glucose, rhamnose, organic acids, D-glucaric and ginkgolic acids. EGb 761 promotes vasodilation and improves blood flow through arteries, veins and capillaries. It inhibits platelet aggregation and prolongs bleeding time. EGb 761, which was originated by Dr Willmar Schwabe Pharmaceuticals (Dr Willmar Schwabe Group), has been available in Europe as a herbal extract since the early 1990s. However, products containing EGb 761 are not approved for use by the US FDA. As a dietary supplement, Nature's Way in the US distributes and markets a standardised extract of Ginkgo biloba leaves (the EGb 761 Formula) under the name Gingold Nature's Way. The French company Beaufour-Ipsen and its German subsidiary Ipsen Pharma are co-developing EGb 761 with Dr Willmar Schwabe Group. Beaufour-Ipsen (France) is developing EGb 761 as Tanakan, Dr Willmar Schwabe Pharmaceuticals (Germany) as Tebonin and Ipsen Pharma (Germany) as Rokan. Intersan was formerly developing EGb 761 in Germany, but Intersan appears to have been merged into Ipsen Pharma. However, there has been no recent development for these indications. In the UK and other European countries, the cardioprotective effects of EGb 761 in myocardial ischaemia and reperfusion are being investigated in preclinical studies. The psychological and physiological benefits of ginkgo are said to be based on its primary action of regulating neurotransmitters and exerting neuroprotective effects in the brain, protecting against or retarding nerve cell degeneration. Ginkgo also benefits vascular microcirculation by improving blood flow in small vessels and has antioxidant activity. There has been conflicting evidence about the benefits of ginkgo, e.g. the ginkgo clinical trial published in August 2002 in JAMA concluded that a leading ginkgo supplement did not produce measurable benefits for memory in healthy adults over 60, although a month earlier, another study concluded that the same ginkgo extract is effective in helping normal healthy older adults in memory and concentration. However, in December 2002, the Cochrane Collaboration, the world's most respected scientific reviewer of clinical trials in medicine, concluded that the published literature strongly supports the safety and potential benefits of ginkgo in treating memory loss and cognitive disorders associated with age- related dementia. A phase II study of EGb 761 in combination with fluorouracil is in progress in Germany in patients with pancreatic cancer. German researchers are investigating the potential of EGb 761 for the treatment of sudden deafness and tinnitus in clinical studies. EGb 761 was undergoing preclinical development for the potential treatment of diabetes in France, diabetic neuropathies in Russia, and cancer in Brazil. However, there has been no recent development for these indications. Beaufour-Ipsen has expressed the intention to license out its diabetes projects that may include EGb 761.

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