Studies on the therapeutic effects of Ginkgo biloba

While there is still no cure for Alzheimer's Disease, Ginkgo biloba has been touted in the market for decades as an effective phytomedicine to prevent this fatal disease. This claim was considered unsupported until the studies in 1990's demonstrated that Ginkgo biloba leaf extract could indeed have therapeutic potential in slowing Alzheimer's Disease [Hofferbach, B. (1994) The efficacy of EGb 761 in patients with senile dementia of the Alzheimer type: A double blinded, placebo-controled study on different levels of investigation. Hum. Psychopharmacol. 9:215-222.], and in early stages of Alzheimer's Disease [Kanowski, S. et al. (1997) Proof of the efficacy of the Ginkgo biloba special extract EGb 761 in outpatients suffering from mild to moderate dimentia of the Alzhiemer's type or multi-infarct demnetia. Phytomedicine 4(1):3-13.]. Recent studies such as Le Bars et al., DeFeudis and Drieu, Stough et al., McKenna, Jones, and Hughes, Watanabe et al., Forstl, and Wettstein confirmed previous observations of beneficial effects of Ginkgo biloba phytochemicals on Alzheimer's Disease. Although the seeds of Ginkgo biloba have been most commonly employed in traditional Chinese medicine, in recent years standardized extracts of the leaves have been widely sold as a phytomedicine in Europe and as a dietary supplement in the United States. The primary active constituents of the leaves include flavonoid glycosides and unique diterpenes known as ginkgolides; the latter are potent inhibitors of platelet activating factor. Clinical studies have shown that ginkgo extracts exhibit therapeutic activity in a variety of disorders including Alzheimer's disease, failing memory, age-related dementias, poor cerebral and ocular blood flow, congestive symptoms of premenstrual syndrome, and the prevention of altitude sickness. Due in part to its potent antioxidant properties and ability to enhance peripheral and cerebral circulation, ginkgo's primary application lies in the treatment of cerebrovascular dysfunctions and peripheral vascular disorders [McKenna DJ, Jones K, Hughes K. (2001) Altern Ther Health Med. 7(5):70-86, 88-90.] After all, Ginkgo biloba's beneficial role in Alzheimer's Disease appear to be more than just a hype, although by no means it is a cure.