title: [Effect of three herbal extracts on cytochrome P450 and possibility of interaction with drugs].
abstract: Herb-drug interactions are mainly mediated by hepatic cytochrome P450 (CYP) enzymes. Here, we examined the effect of three herbs (valerian, salacia and black cohosh) on CYP activity in vivo in mice and in liver microsomes in vitro. Extracts which showed activity in the preliminary tests were then fed to mice at various doses (0, 0.5, 1.5 and 4.5%). Valerian did not show any effect on hepatic CYPs. Black cohosh increased the liver weight, total CYP content and CYP activities (2B and 3A) in a dose-dependent manner (up to 4.5%). Salacia inhibited CYP1A2 activity in liver microsomes in vitro. Also, salacia at the dietary dose of 4.5% suppressed body weight gain, decreased hepatic total CYP content and increased CYP activities (1A1, 2B and 2C). These findings suggest that black cohosh and salacia at high dose affect the activity of hepatic CYPs, and therefore may interact with drugs that are metabolized by CYP.
authors.affiliation: Information Center, National Institute of Health and Nutrition, Shinjuku-ku, Tokyo, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Yokotani
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Chiba
authors.forename: Yoko
authors.initials: Y
authors.lastname: Sato
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nakanishi
authors.forename: Masatsune
authors.initials: M
authors.lastname: Murata
authors.forename: Keizo
authors.initials: K
authors.lastname: Umegaki
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D031885:Cimicifuga; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004347:Drug Interactions; D005260:Female; D008099:Liver / Q000201:enzymology*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008862:Microsomes, Liver / Q000201:enzymology*; D010936:Plant Extracts / Q000494:pharmacology*; D049918:Salacia; D014632:Valerian
chemical_list: D010936:Plant Extracts; D003577:Cytochrome P-450 Enzyme System