没食子酸对细胞色素P4503A4介导的硝苯地平代谢的影响

Effect of gallic acid on cytochrome P4503A4-mediated metabolism of nifedipine in vitro

目的体外研究没食子酸对细胞色素P4503A4(CYP3A4)介导的硝苯地平代谢的影响。方法将不同浓度没食子酸、人肝微粒体(HLM)与硝苯地平孵育,测定硝苯地平的减少率并计算其半抑制浓度IC_(50)值。将没食子酸与HLM预孵育0 min和30 min后作为干预1组和干预2组;将不加入没食子酸、HLM预孵育0 min设为空白组,分别将不同浓度硝苯地平加入各组启动反应,绘制米氏曲线得到酶动力学参数Km及Vmax,计算硝苯地平的代谢清除率CL(K_(m)/V_(max))。结果没食子酸对CYP3A4存在明显的浓度依赖性抑制,以硝苯地平为底物时,IC_(50)为403.9μg·mL-1。干预1组中仅有没食子酸存在,硝苯地平经CYP3A4的代谢清除率为0.37 mL·min^(-1)·mg^(-1),干预2组中没食子酸产生了代谢产物,此时硝苯地平的代谢清除率为1.5×10-2 mL·min^(-1)·mg^(-1),2组代谢清除率均显著低于空白组(0.66 mL·min^(-1)·mg^(-1))。结论没食子酸可通过抑制CYP3A4减少其对硝苯地平的代谢,具有诱导药物不良反应的风险。

Objective To investigate the inhibitory effect caused by gallic acid towards cytochrome P4503A4(CYP3A4)mediated metabolism of nifedipine in vitro.Methods Different concentrations of gallic acid were incubated with human liver microsomes(HLM)and nifedipine,the reduction rate of nifedipine was detected to obtain IC_(50).After incubation of gallic acid with HLM for 0 min and 30 min,they were divided into intervation-1 group and intervation-2 group,HLM was pre-incubated for 0 min without gallic acid in blank group.Nifedipine with different concentrations was added to start up reaction respectively.The kinetic parameters of enzyme(Km and Vmax)were obtained by plotting Michaelis-Menten curve,and the metabolic clearance rate(CL)of nifedipine was calculated.Results The gallic acid had obvious concentration-dependent inhibition effect on CYP3A4.When nifedipine was used as a substrate of CYP3 A4,the IC_(50)value was 403.9μg·mL-1.In intervation-1 group with gallic acid only,the CL of nifedipine was 0.37 mL·min^(-1)·mg^(-1).In intervation-2 group with products of gallic acid,the CL was 1.5×10-2 mL·min^(-1)·mg^(-1).Both were significantly lower than the blank group(0.66 mL·min^(-1)·mg^(-1)).Conclusion Gallic acid can reduce the metabolism of nifedipine by inhibiting the activity of CYP3A4.It has a risk of inducing drug adverse reactions.