ABSTRACT
<p><b>OBJECTIVE</b>To study the effects of the water extract of Rehmannia glutionsa, Scrophularia ningpoensis, Asparagus cochinchinensis and Ophiopogon japonicas, which are the drug from Tianwang Buxin Wan from nourishing vin, on the content of cytohrome P450 (CYP450) in rat and the activities of CYP3A, CYP2E1 and CYP1A2 to investigate the role of CYP450 in the biotransformation of Tianwang Buxin Wan.</p><p><b>METHOD</b>The rats were killed after administrated with extracts once daily for consecutive 7 days, the livers were removed rapidly and weighed, liver microsomes were prepared with ultra-centrifuge method, the contents of liver microsomal CYP450, cytochrome b5 (Cytb5) and the activities of CYP3A were examined by ultraviolet spectrophotometry, the activities of CYP2E1 and CYP1A2 were determined by high performance liquid chromatography (HPLC).</p><p><b>RESULT</b>All groups had no difference in the levels of liver indexe compared with normal sodium group. The water extract of R. glutionsa obviously decreased the contents of P450 (P < 0.01) and increased the activity of CYP3A (P < 0.01) and CYP1A2 (P <0.05). The water extract of S. ningpoensis decreased the contents of P450 (P < 0.05) and significantly increased CYP3A and CYP1A2 activities (P < 0.01). A. cochinchinensis increased content of Cytb5 (P < 0.05) in rat and increased the activity of CYP2E1 (P < 0.05) and CYP1A2 (P < 0.01). O. japonicas had no significant difference on the contents of CYP450 and Cytb5 while increased the activities of CYP3A (P < 0.05), CYP2E1 (P < 0.05) and CYP1A2 (P < 0.01).</p><p><b>CONCLUSION</b>R. glutionsa and S. ningpoensis could decrease the content of CYP450 enzyme in rat liver and induct the activities of CYP3A and CYP1A2. A. cochinchinensis could induct the activities of CYP2E1 and CYP1A2. O. japonicus could induction the activities of CYP3A, CYP2E1 and CYP1A2 in Tianwang Buxin Wan. By inhibiting CYP450 activity to decrease the metabolism of other drugs, the effect of other functional groups in the compatibility of Tianwang Buxin Wan can be enhanced, and a theoretical basis on studying the compatible mechanism can be provided.</p>