title: Inhibitory effects of fruit juices on cytochrome P450 2C9 activity in vitro.
abstract: There is limited information on the effect of fruits on human cytochrome P450 (CYP) 2C9 activity. The objective of this study was to determine the effect of fruit juice on CYP2C9-mediated drug metabolism. Nine citrus fruits and eight tropical fruits were chosen. We investigated effects of the fruits on diclofenac 4'-hydroxylation and tolbutamide hydroxylation by human liver microsomes. Among the fruits, pineapple juice showed potent inhibition of CYP2C9 activity. The addition of 25 microl (5.0% v/v) of pineapple juice resulted in almost complete inhibition. Next we examined the inhibitory effect of bromelain, a cysteine protease in pineapple. Bromelain also strongly inhibited CYP2C9 activity. In addition, E-64, a cysteine protease inhibitor, almost entirely blocked inhibition by pineapple juice and bromelain. Thus we found that pineapple juice was a potent inhibitor of CYP2C9, and that the inhibitory effect might be due to the bromelain contained in pineapple.
authors.affiliation: School of Pharmaceutical Sciences, Kyushu University of Health and Welfare, Nobeoka, Miyazaki 882-8508, Japan.
authors.forename: Muneaki
authors.initials: M
authors.lastname: Hidaka
authors.forename: Masashi
authors.initials: M
authors.lastname: Nagata
authors.forename: Yohei
authors.initials: Y
authors.lastname: Kawano
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sekiya
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Kai
authors.forename: Keishi
authors.initials: K
authors.lastname: Yamasaki
authors.forename: Manabu
authors.initials: M
authors.lastname: Okumura
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Arimori
mesh_terms: D001189:Aryl Hydrocarbon Hydroxylases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D001628:Beverages; D001963:Bromelains / Q000494:pharmacology; D065729:Cytochrome P-450 CYP2C9; D005638:Fruit; D008862:Microsomes, Liver / Q000201:enzymology; D011480:Protease Inhibitors / Q000494:pharmacology; D014462:Ultrafiltration
chemical_list: D011480:Protease Inhibitors; D001963:Bromelains; C450260:CYP2C9 protein, human; D065729:Cytochrome P-450 CYP2C9; D001189:Aryl Hydrocarbon Hydroxylases