Study on inhibitory effect of water extract of Polygonum multiflorum on CYP1A2 and CYP2E1 enzymatic activities and mRNA expressions in rat liver / 中国中药杂志

Rats were continuously given different doses of water extract of Polygonum multiflorum (1, 10 g x kg(-1)) for 7 days to prepare liver microsomes. Cocktail in vitro incubation approach and Real-time quantitative PCR technology were used to observe the effect of water extract of P. multiflorum on CYP450 enzymatic activities and mRNA expressions in rat liver. Compared with the blank control group, both 1, 10 g x kg(-1) water extract of P. multiflorum treated groups showed significant inhibitions in CYP2E1 enzymatic activities and mRNA expressions (enzymatic activities of CYP2E1, P < 0.01; mRNA expression of CYP2E1, P < 0.05 in 1 g x kg(-1) group, P < 0.01 in 10 g x kg(-1) group). They revealed a significant increase in the enzymatic activity of CYP3A1 (P < 0.01), but without significant change in mRNA expressions. The 10 g x kg(-1) group showed a significant inhibition in CYP1A2 enzymatic activities and mRNA expressions in rat livers (P < 0.01).

Effect of comparability of Coptis chinensis and Scutellaria baicalensis on five sub-enzymatic activities of liver microsomes in rats / 中国中药杂志

To study the mechanism of metabolic interaction between Coptis chinensis and Scutellaria baicalensis. Rats were given C. chinensis and S. baicalensis for 7 days to produce hepatic microsomal enzyme. Cocktail probe substrate and liver microsome in vitro temperature incubation method were adopted. Meanwhile, the metabolic elimination percentages of the five probe substrates were detected with HPLC, in order to evaluate the effect of each administration group on the enzymatic activity of rat liver microsome CYP450. Compared with the blank group, C. chinensis obviously inhibited CYP2D6 and CYP1A2, and S. baicalensis remarkably inhibited CYP1A2, CYP2E1 and CYP2C9. The compatibility of C. chinensis and S. baicalensis with the ratio of 1:1 not only inhibited CYP1A2, but also remarkably activated CYP2D6 and CYP3A4. However, their activation effect disappeared under the ratio of 2: 1, and turned into the inhibitory effect on CYP1A2 and CYP2C9. The results showed that C. chinensis and S. baicalensis had an inhibitory effect on CYP450, but their compatibility with certain ratio resulted in double effects of activation and inhibition, which was related to their compatibility ratio. It is speculated that the inhibitory and inducing effects of C. chinensis and S. baicalensis on metabolic enzymes are among causes for their attenuation and synergistic effects.