RESUMO
This study aimed to investigate the effects of tannins extracted from Tibetan medicine Phyllanthi Fructus on cytochrome P450 enzyme of liver microsomes in rats.Cocktail probe substrates were incubated with liver microsomes in vitro.Metabolic elimination percentages of the six probe substrates,including dapsone,dextromethorphan hydrobromide,coumarin,phenacetin,chlorzoxazone and tolbutamide,were determined by HPLC.The effects of tannins extracted from Tibetan medicine Phyllanthi Fructus on the enzymatic activity of rat liver microsomal P450s was evaluated.It was found that tannins extracted from Phyllanthi Fructus did not impact P450 enzymes.The IC50 values of CYP3A4 and CYP1A2 were over 200 μg·mL-1,while the IC50 value of CYP2C9 was superior to 500 tg·mL-1.In conclusion,Tannins extracted from Tibetan medicine Phyllanthi Fructus did not significantly affect cytochrome P450 enzymes.