Inhibition of Human Liver Cytochrome P450 by Star Fruit Juice

Jiang-Wei Zhang1, Yong Liu1, Jie Cheng1, Wei Li1, Hong Ma1, Hong-Tao Liu1, Jie Sun2, Li-Ming Wang2, Yu-Qi He3, Yun Wang3, Zheng-Tao Wang3, Ling Yang4

1Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road, Dalian, China
2The Second Affiliated Hospital of Dalian Medical University, Dalian, China
3University of Traditional Chinese Medicine, Shanghai, China
4Institute of Chemical Physics


Purpose. To examine the inhibitory effects of star fruit (Averrhoa carambola) juice towards seven major cytochrome P450 (CYP) isoforms and NADPH-cytochrome P450 reductase (CPR). Methods. The inhibitory effects of star fruit juice (0.5 to 5%, v/v) against the activities of seven CYP isoforms including CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2D6, CYP2E1, CYP3A4 and CPR were examined in human liver microsomes. To identify time-dependent inhibition, star fruit juice (2.5%, v/v) was preincubated with microsomes and a NADPH-generating system for 0-15 min, and then the extent of inhibition towards seven CYP isoforms were examined. Results. Star fruit juice (5.0%, v/v) was found to inhibit all the activities of CYP isoforms tested by more than 70%. Based on the half inhibition values (%, v/v), the inhibitory effects towards different CYP isoforms were in the following order: CYP2A6 (0.9) > CYP1A2 (1.4) > CYP2D6 (1.6) > CYP2E1 (2.0) > CYP2C8 (2.2) > CYP2C9 (3.0) > CYP3A4 (3.2). Time-dependent inhibition was not observed towards any of the tested CYP isoforms. In addition, star fruit juice was found not to inhibit the activity of CPR. Conclusions. Star fruit juice inhibited the seven CYP isoforms tested, with the strongest inhibitory effect against CYP2A6 and the least towards CYP3A4.

J Pharm Pharm Sci, 10 (4): 496-503, 2007

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