EGb 761 [
Ginkgo biloba extract EGb 761, Rökan,
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 Rökan. 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.