Abstract:Objective: To observe the effects of ginkgolides on gene expression of hepatic cytochrome P-450 in rats. Method: Sprague-Dawley rats were administered ginkgolides (100 mg·kg-1 body weight) through oral gavage once daily for four consecutive days. The level of gene expression in liver tissues was analyzed by competitive reverse transcription-polymerase chain reaction (competitive RT-PCR). Result: A single and prospective band of CYP1A1, CYP1A2, CYP2B1/B2, CYP2C11, CYP2E1, CYP4A1 and cyclophilin was observed after polymerase chain reaction (PCR) when the reactive system of reverse transcription (RT) had no target RNA, which confirmed the competi tior had a specific capacity to bind to the CYP or cyclophilin primer. CYPlAl mRNA was not dectectable in the h‘vers of untreated control rats and ginkgolides-treated rats. The levels of CYP 2C11 and CYP2E1 were not changed by ginkgolides treatment. In contrast, the levels of gene expression for CYP1A2 and CYP2B1/B2 were decreased, however, the levels of gene expression for CYP3A1 and CYP4A1 in ginkgolides group were distinctly increased compared with the control. Condusion: A specific effect of ginkgolides on cytochrome P-450 gene expression was observed in this investigation. Ginkgolides had various effects on different cytochrome P-450 isoforms.