3种中药成分对大鼠CYP3A4酶代谢的影响

Interaction between four herb compounds and a western drug by CYP3A4 enzyme metabolism in vitro

目的:探讨3种中药成分(延胡索乙素、甲基莲心碱、三七总皂苷)对CYP3A4酶代谢活性的影响,以了解中药与CYP3A4酶底物联合用药时可能产生的相互作用。方法:采用超高速离心法制备大鼠肝脏微粒体,建立体外肝脏微粒体混合酶代谢体系。以睾丸酮作为底物探针,用HPLC建立检测CYP3A4酶代谢活性的方法,分别考察体外代谢体系的最适宜底物浓度、代谢时间、pH、孵育温度以及磷酸盐浓度。在确定的条件下,将3种中药成分稀释成不同浓度,分别与睾丸酮共同孵育于肝微粒体代谢体系中,测定在有或无中药成分存在下代谢产物6β-羟基睾丸酮的产生量,以评估中药成分对CYP3A4酶代谢的影响。结果:在肝微粒体孵育体系中,睾丸酮代谢为6β-羟基睾丸酮最适宜的体外代谢条件为底物浓度200μmol.L-1,代谢时间3.5 h,pH 7.0,孵育温度37℃,磷酸盐终浓度0.1 mol.L-1。延胡索乙素和三七总皂苷均对CYP3A4酶的抑制作用较弱,IC50>100μmol.L-1,甲基莲心碱有一定的抑制作用,IC50为(47.5±2.3)μmol.L-1。结论:延胡索乙素和三七总皂苷对CYP3A4酶代谢无明显影响,提示这2种中药成分与CYP3A4酶底物之间的相互作用较低,甲基莲心碱有可能会产生微弱的药物相互作用。

Objective： To explore the interaction between herbal medicines and western drugs based on CYP3A4 enzyme metabolism by using testotesrone as a probe in liver microsome metabolism system in vitro. Method ： The mixed liver microsome enzymatic system consisting of rat liver microsomes by ultra-high-speed centrifuge was established. The substrate testosterone was added into the system and enzyme CYP3A4 metabolic activity was expressed by the output of 6,8-hydroxy-testosterone which was measured by HPLC method. The proper conditions for testotesrone metabolism in liver microsome system included substrate concentration, incubation time, pH and incubation temperature. When the conditions in vitro were determined, three kinds of Chinese herbal medicinal ingredients （ Tetrahydropalmatine, neferine, panax notoginseng saponins） were diluted into different concentrations and incubated with testotesrone in the liver microsomes incubation system, respectively. The results were measured through metabolite production with or without the presence of Chinese medicines. We assessed the Chinese herbal medicinal ingredients＇effect on the metabolism of CYP3A4 enzyme through 6β-hydroxy metabolite of testosterone production. Result： Liver microsomes were incubated in the system, the testosterone metabolited into 6,8-hydroxy testosterone. The metabolism conditions were proper at the concentration of testosterone 200 umol·L^-1 which was incubated for 3.5 hours at 37℃ in pH 7. 0, PBS 0. 1mol·L^-1. The inhibition of tetrahydropalmatine and panax notoginseng saponins on testotesrone were weak with IC50 〉 100 umol·L^-1, The neferine had a little inhibition on testotesrone metabolism, IC50 〈 100 umol·L^-1. Conclusion： Tetrahydropalmatine and panax notoginseng saponins had no obvious effect on testotesrone metabolism. Nefer- ine had a little effect on testotesrone metabolism. It prompted that drug-interaction could not be apparent between two kinds of Chinese medicines and the CYP3A4 enzyme substrate, Neferine could bring about drug-interaction.