Abstract:Objective: To conclude the possible interaction between gingko extract and simvastatin, by studing the effect of gingko extract on vitro metabolism of simvastatin and involving critical metabolic enzyme, which can guide the clinicians to use them rationally (propose good guideline for rational using of the two medcine mentioned above). Method: Thirty-two female SD rats were randomly separated into 4 groups, including negative control group. High dose of gingko extract. Low dose of gingko extractand positive control group. All groups were administered for 10 days with stomach tube, and then the quantity of liver microsome protein, the activity of CYP3A were determined by spectrophotograph. simvastatin was incubated with the liver microsome, and the effect of gingko extract on its metabolism was estimated by measuring the amount of simvastatin by HPLC. Result: Comparing with the negative contrast group:the quantity of liver microsome protein, the activity of CYP3A and the metabolism of simvastatin in positive control group were all increased markly (P<0.05). In high dose group, the quantity of liver microsome protein and the activity of CYP3A were both increased significantly (P<0.05), and the metabolism of simvastatin also accelerate obviously (P<0.05). But in the low dose group significant distinction of every index was not found. Conclusion: High dose of gingko extract can induce the activity of CYP3A, and promote the metabolism of simvastatin, so the medical interaction should be focused when gingko extract is coadministered with simvastatin and other substracts of CYP3A.