决明子水提液对大鼠肝脏CYP450酶的影响

该文研究决明子水提液对大鼠肝脏CYP450酶酶活性、mRNA及蛋白表达水平的影响。取SD大鼠,口服灌胃受试药物后,处死,用冰冷生理盐水灌流肝脏,提取大鼠肝脏微粒体、肝脏总RNA和总蛋白,采用Cocktail体外孵育法结合液质联用(LCMS)技术对大鼠肝脏中CYP1A2,2B1,2C11,2D2,2E1,3A1各亚酶的酶活性进行测定,并应用荧光定量PCR技术和Western blot对上述亚型的mRNA和蛋白表达水平进行检测。结果表明,酶活性方面,决明子水提液组与空白组比较可明显诱导CYP1A2,2B1,2C11,2D2,2E1,3A1的酶活性,其中决明子低剂量组对CYP2D2有明显的抑制作用,中、高剂量组对CYP2D2有明显的诱导作用,且都呈剂量依赖性增加,但对CYP3A1的诱导不呈剂量依赖性;mRNA表达方面,决明子水提液对CYP1A2,2C11,2D2,2E1mRNA的表达具有显著诱导作用,其中对CYP1A2,2D2,2E1诱导作用呈剂量依赖性,与酶活性水平具有一致性,对CYP2B1,3A1没有明显作用;蛋白表达方面,决明子水提液对CYP2C11,2E1的表达也具有诱导作用,但没有统计学差异。决明子水提液对CYP450同工酶不同程度诱导或抑制作用,特别是对于CYP2C11,2E1亚型酶,酶活性与mRNA,蛋白表达水平具有一致性,提示当与这些酶底物合并用药时,尤其是与CYP2C11,2E1代谢有关的药物合用时,应充分考虑到潜在的有益和不利的药物相互作用。

Effects of aqueous extract of Cassiae Semen on activity hepatic microsomal CYP450 isozymes in rats

To study the effect of aqueous extract of Cassiae Semen on the activity, mRNA and protein expressions of cytochrome P450(CYP450) system in rat liver microsomes, microsomes of rat liver were prepared after the oral administration with aqueous extract of Cassiae Semen for 14 days. The enzyme activity was quantified by Cocktail method. Meanwhile, the mRNA and protein expressions of CYP1A2, CYP2B1, CYP2C11, CYP2D2, CYP2E1 and CYP3A1 in the livers were detected by RT-PCR and Western blot. The result of this experiment was that aqueous extract of Cassiae Semen obviously induced the enzyme activities of CYP1A2, CYP2B1, CYP2C11, CYP2D2, CYP2E1 and CYP3A1. Low dose of aqueous extract of Cassiae Semen significantly reduced the activity of CYP2D2, but the activity of CYP2D2 was significantly induced by middle dose and high dose of aqueous extract of Cassiae Semen. These subtypes were increased in a dose-dependent manner except for CYP3A1. The mRNA levels of CYP1A2, CYP2C11, CYP2D2 and CYP2E1 were also induced in rats treated with aqueous extract of Cassiae Semen, but with no significant effect in CYP2B1 and CYP3A1 mRNA expressions. The protein levels of CYP2C11 and CYP2E1 were also induced in rats treated with aqueous extract of Cassiae Semen, but with no significant difference. Since the enzyme activity, mRNA and protein expressions of CYP450, particularly CYP2C11and2E1subtypes, were induced or inhibited by aqueous extract of Cassiae Semen to varing degrees, suggesting the potential drug-drug interactions should be concerned.