title: Studies on interactions between functional foods or dietary supplements and medicines. III. Effects of ginkgo biloba leaf extract on the pharmacokinetics of nifedipine in rats.
abstract: The effects of Ginkgo biloba leaf extract (GBE), one of the most widely used herbal dietary supplements in Japan and the United States, on the pharmacokinetics of nifedipine (NFP), a typical probe of P450 (CYP) 3A, but not a substrate of the multidrug transporter P-glycoprotein (P-gp), were studied using rats. Simultaneous oral treatment with GBE (20 mg/kg) did not affect the pharmacokinetics after intravenous administration of NFP (2.5 mg/kg). However, the maximal plasma NFP concentration, the area under the concentration-time curve and absolute bioavailability after oral administration of NFP (5 mg/kg) were significantly increased by simultaneous oral treatment with GBE, approximately 1.6-fold, 1.6-fold and 2.1-fold, respectively. These results suggest that the concomitant oral use of GBE appeared to reduce the first-pass metabolism of orally administered NFP, by inhibiting CYP3A, possibly but not P-gp, in rats.
authors.affiliation: Department of Pharmacy, Takarazuka City Hospital, Kohama, Japan.
authors.forename: Mutsunobu
authors.initials: M
authors.lastname: Yoshioka
authors.forename: Noriaki
authors.initials: N
authors.lastname: Ohnishi
authors.forename: Noriko
authors.initials: N
authors.lastname: Sone
authors.forename: Suguru
authors.initials: S
authors.lastname: Egami
authors.forename: Koji
authors.initials: K
authors.lastname: Takara
authors.forename: Teruyoshi
authors.initials: T
authors.lastname: Yokoyama
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kuroda
mesh_terms: D000284:Administration, Oral; D000818:Animals; D019587:Dietary Supplements; D018565:Food-Drug Interactions / Q000502:physiology*; D020441:Ginkgo biloba; D008297:Male; D009543:Nifedipine / Q000008:administration & dosage / Q000493:pharmacokinetics*; D010936:Plant Extracts / Q000378:metabolism; D018515:Plant Leaves; D051381:Rats; D017208:Rats, Wistar
chemical_list: D010936:Plant Extracts; D009543:Nifedipine