Abstract: AIM: To investigate the effects of Huangkui Capsule on rat activities of CYP1A2,CYP3A4 and CYP2E1. METHODS: 14 rats were randomly and equally divided into two groups: clinically-equivalent-dose group and higher-dose group. Two group rats underwent 2-cycle pharmacokinetic experiments before and after being treated with two doses of Huangkui Capsule for 14 days,in which the rats were concomitantly administered Theophylline (30 mg/kg), Chlorzoxazone (50 mg/kg) and Dapsone (20 mg/kg) by gastrogavage, followed by blood-withdrawing from orbital bleeding at different intervals within 24 hours. High-performance liquid chromatography (HPLC) was utilized to simultaneously quantitate 3 probe compounds in rat plasma, and DAS1.0 Software was used to fit plasma concentration-time curve and calculate their corresponding principal pharmacokinetic parameters,among which the statistical differences were evaluated by Paried t-test. RESULTS: In the 14-day administration period,the 2-cycle pharmacokinetic parameters of 3 probes for the clinically-equivalent-dose group rats exhibited insignificant differences(P>0.05), meanwhile ,after being treated with higher-dose Huangkui Capsule,there were no significant differences for theophylline pharmacokinetics in rats,but AUC_0-24h of chlorzoxazone after treatment was 1.75 times larger than that before treatment(P<0.05), in addition AUC_0-24h of dapsone after treatment were 0.63 times of it before treatment(P<0.05). CONCLUSION: Clinically-equivalent-dose Huangkui Capsule did not affect the activities of rat CYP1A2,CYP3A4 and CYP2E1; higher-dose Huangkui could not insignificantly change CYP1A2 activity,but could weakly inhibit activities of CYP2E1 and induce CYP3A4.

Key words: Abelmoschus moschatus Medicus, CYP450, Theophylline, Dapsone, Chlorzoxazone