Abstract: AIM: Enzymes probes were employed for the study on the effects of liver CYP450 induced by panax notoginsenoside injection (PNSi) in rats. METHODS: PNSi was intravenous administered to rats for 5 weeks at the dosage of 20 mg°kg^-1°d^-1. Then 5.0 mg/kg dosage of nimodipine or 20.0 mg/kg dosage of warfarin sodium was given to rats via intrave-nous or intragastric administration, respectively at the last time of PNSi .HPLC wasemployed for the determi-nation of nimodipine and warfarin sodium in rat plasma .Pharmacokinetic parameters which simulated by DAS software were used for the evaluation on the effects of CYP3A4, CYP2C9 and CYP1A2 induced by PNSi . Two-sides of students test was used for datum analysis. RESULTS: Sensitive, rapid and specificity HPLC method was developed and validated for the determina-tion of nimodipine and warfarin in rat plasma success-fully .There were no markedly changes of pharmacoki-netic parameters of nimodipine or warfarin in rats in-duced by PNSi .However, the AUC and clearance of nimodipine displayed the tendency of increasing or de-creasing, respectively and the t_max , t_1/2 and AUC of warfarin sodium showed the tendency of increasing after intravenous administration of PNSi for a long time. CONCLUSION: PNSi showed potential inhibitory effect on the activities of CYP3A4, CYP2C9 and CYP1A2.Potential drug-drug interaction should be more cared when PNSi was co-administered with nimo-dipine or warfarin sodium in clinic .

Key words: panax notoginsenoside injection(PN-Si), nimodipine, warfarin sodium, pharmacokinetics, drug-drug interaction