Systemic exposure to Ginkgo biloba extract in male F344/NCrl rats: Relevance to humans.

Abstract

Ginkgo biloba extract (GBE) is a popular botanical dietary supplement used worldwide and the safety of use is a public health concern. While GBE is a complex mixture, the terpene trilactones and flavonol glycosides are believed to elicit the pharmacological and/or toxicological effects of GBE. In a National Toxicology Program (NTP) 2-year rodent bioassay with GBE, hepatotoxicity was observed in rodents (≥100\u202fmg/kg in rats, ≥ 200\u202fmg/kg in mice). Subsequently, questions arose about whether or not the GBE used in NTP studies was representative of other GBE products and how rodent doses are related to human doses. To address these, we generated systemic exposure data for terpene trilactones in male rats following oral administration of 30, 100, and 300\u202fmg/kg GBE test article from the 2-year bioassay. Dose-normalized Cmax and AUC∞ for terpene trilactones from the current study were within 5-fold of published rodent studies using a standardized GBE preparation. Comparison of our rat systemic exposure data at 100\u202fmg/kg GBE to published human data following ingestion of 240\u202fmg GBE-containing product showed that the rat/human exposure multiple was 3-22, for terpene trilactones. These data demonstrate the relevance of NTP rodent toxicity data to humans.