奥美拉唑对HepG2细胞中CYP2C19酶表达及活性的影响

目的：研究奥美拉唑（omeprazole）对HepG2细胞CYP2C19酶表达及活性的影响，间接反映奥美拉唑和氯吡格雷联合用药是否存在药物的相互作用。方法通过MTT实验筛选出奥美拉唑对HepG2细胞的无毒浓度。采用实时定量PCR （Q-PCR）及Western印迹法检测奥美拉唑（浓度分别为0、0.1、1和10 mg/L）对HepG2细胞中CYP2C19在mRNA和蛋白水平上表达的影响。奥美拉唑（0、0.1、1、10和100 mg/L）与表达人CYP450同工酶和人CYP450还原酶的昆虫细胞的微粒体共同孵育，在体外水平上通过荧光强度的变化分析对CYP2C19酶活性的影响。结果奥美拉唑对HepG2细胞无毒性的浓度范围为0～10 mg/L。在mRNA及蛋白表达水平上，奥美拉唑各浓度组均抑制CYP2C19酶的表达，且具有浓度依赖性。酶活性检测表明，当奥美拉唑的浓度达到10、100 mg/L时，荧光强度明显减弱，表明高浓度奥美拉唑抑制CYP2C19酶的表达。结论奥美拉唑能降低HepG2细胞色素氧化酶CYP2C19的表达，并抑制其活性，提示奥美拉唑与其他需经过CYP2C19酶代谢才能转化为活性代谢产物的药物（氯吡格雷）联用时，有可能会出现药效抵抗现象。

Effects of Omeprazole on the expression and activity of CYP2C19 in HepG2 cells

Objective To investigate the effects of omeprazole on the expression and the activity of CYP2C19 in HepG2 cells. Methods MTT assay was performed to screen the concentration range of omeprazole which did not inhibit HepG2 cell proliferation. Real-time quantitative polymerase chain reaction(Q-PCR)were carried out to determine the effects of omeprazole(0,0.1,1 and 10 mg/L)on the expression of CYP2C19 mRNA,Western blot was carried out to determine the effect of(0,0.1,1 and 10 mg/L)on the ex?pression of CYP2C19 protein. After incubation of different concentrations of omeprazole(0,0.1,1,10 and 100 mg/L)with microsomes prepared from insect cells expressing human P450 isozyme,the fluorescence of the samples was detected in a plate reader to analyze if omeprazole inhibited the CYP2C19 activity. Results Omeprazole could down-regulate CYP2C19 mRNA and protein expressions of HepG2 cells in a dose-dependent manner. When the concentration of omeprazole reached 10 or 100 mg/L,the fluorescence intensities obviously decreased,indicating inhibited CYP2C19 activity. Conclusion Omeprazole inhibits the expression and the activity of CYP2C19 in HepG2 cell. When omeprazole is used in combination with drugs activated via CYP2C19 metabolism,their interaction should be considered carefully.