Ginkgo BilobaLeave Extract: Biological, Medicinal, and Toxicological Effects

Abstract Ginkgo biloba leave extract is among the most widely sold herbal dietary supplements in the United States. Its purported biological effects include: scavenging free radical; lowering oxidative stress; reducing neural damages, reducing platelets aggregation; anti-inflammation; anti-tumor activities; and anti-aging. Clinically, it has been prescribed to treat CNS disorders such as Alzheimer's disease and cognitive deficits. It exerts allergy and changes in bleeding time. While its mutagenicity or carcinogenic activity has not been reported, its components, quercetin, kaempferol and rutin have been shown to be genotoxic. There are no standards or guidelines regulating the constituent components of Ginkgo biloba leave extract nor are exposure limits imposed. Safety evaluation of Ginkgo biloba leave extract is being conducted by the U.S. National Toxicology Program. Key words: Gingko Biloba leave extractbiological and toxicological effectsginkgolidcquercetin This article is not an official guidance or policy statement ofU.S. Food and Drug Administration (FDA) or National Toxicology Program (NTP). No official support or endorsement by the U.S. FDA and NTP is intended or should be inferred. Notes a The LD50of 7.73 g/kg corresponds to 2.3 g/kg of active ingredients, 1.9 g/kg of flavone glycosides, and 464 mg/kg of terpene lactones