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

Abstract

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.