Publication: Ginkgo biloba- an appraisal
Date
2004
Journal Title
Journal ISSN
Volume Title
Publisher
Kathmandu University
Abstract
Ginkgo biloba has been used in traditional Chinese medicine for about 5000 years. A standardized preparation, EGb
761 has been recently prepared. The pharmacologically active constituents, flavonol glycosides and the terpene
lactones are standardized. The terpene lactones comprise of ginkgolides A, B, C and bilobalides. The extract
scavenges excess free radicals and pretreatment with EGb 761 reduces damage by free radicals in patients
undergoing coronary bypass surgery. The action of platelet activating factor is antagonized and platelet aggregation
is reduced. Blood flow is increased. Release of prostacyclines and nitric oxide was shown to be stimulated. Ginkgo
biloba has been found to be useful in the treatment of Alzheimer’s disease and cognitive impairment. EGB 761 has
shown beneficial effect in aging and mild cognitive impairment. Bilobalide has been shown to be protective against
glutamate-induced excitotoxic neuronal death. Early studies indicate a potential role in age-related macular
degeneration and some types of glaucoma. Anticancer action is related to antioxidant, anti-angiogenic and gene
regulatory actions. Ginkgo biloba has shown overall improvement in about 65% of patients with cerebral
impairment and a similar percentage suffering from peripheral vascular diseases. A recent study suggested that
phytoestrogens in Ginkgo biloba may have a role as alternative hormone replacement therapy. Recent trials have not
shown a beneficial effect of Ginkgo biloba in tinnitus and acute mountain sickness. Ginkgo biloba increased the
bioavailability of diltiazem. The extract has been shown to protect against doxorubicin-induced cardiotoxicity and
gentamicin-induced nephrotoxicity in animals. Ginkgo biloba inhibits microsomal enzymes and has a potential for
drug interactions. Further studies to establish the efficacy of Ginkgo biloba are required.
Key words: Dementia, Drug interactions, Ginkgo biloba extract, Neuroprotection, Peripheral vascular disease