Effect of Ginkgo biloba extract on microsomal enzyme induction

Twenty-four healthy volunteers were divided in three groups who were randomly assigned different treatments for 13 days: group I received 400 mg/day of a defined Ginkgo biloba extract (GBE), group II 300 mg/day of phenytoin and group III a placebo. The elimination half-life of antipyrine was measured with a high performance liquid chromatographic technique initially and on the last day of the administration of the treatments. The results show that the half-life of antipyrine was not affected by GBE and placebo treatments, whereas it was significantly decreased (p less than 0.05) frm 12.2 to 6.8 h after phenytoin control treatment. This study demonstrates that GBE has no effect on the hepatic microsomal drug oxidation system.