Effects Of Shenmai Injection And Its Effective Components On Drug Metabolismenzyme

cytochrome P450(CYP450), the most important phase Idrug-metabolizing enzymes, participate in the metabolism of drugs,carcinogen and environmental pollutants.The interactions between SMIand other drugs can occur through induction or inhibition of CYP450enzymes by SMI. In the heart, the modulatived effects of SMI on CYP450enzymes may contribute to find new targets and pathway for itscardio-protective mechanism.First, we investigated the effects of Shenmai Injection(SMI) on theactivity and mRNA expression of cytochrome P450system in rat livermicrosomes. Rat liver microsome were prepared after a fourteen-daycontinuous administration of SMI. A HPLC-MS method was applied todetermine the metabolites formation of six CYP450s probe substrates inrat liver microsomal incubations. The activity of CYP450isozymes wererepresented by the formation of metabolites. A RT-PCR method wasapplied to determine the mRNA expression levels of CYP450. SMI hadincreased significantly the activity of CYP2B6and CYP2C9,and no effects on CYP1A2and CYP3A; HSI had significant induction effects onthe activity of CYP1A2、CYP2B6and CYP2C9,inhibition trend on theactivity of CYP3A,but no statistically in control; MDI had induction onthe activity of CYP2C9. At the mRNA level, SMI induced the expressionof CYP1A2、CYP2B and CYP2C，the expression of CYP2C were inducedby HSI and MDI. HSI had inhibition on the expression of CYP3A,but nostatistically in control. SMI can induction CYP2B and CYP2C on thelevels of enzyme activity and mRNA expression, HSI could inhibiteCYP3A enzyme, MDI induct CYP2C. SMI and the constituents from SMIexhibited the inhibition on rat liver microsomal CYP450isozymes to acertain extent. The possibility of interaction between SMI andcoadministrative drugs will be considered based on the levels and subtypeof CYP450involved in the drug metabolism.To investigate the influence of Shenmai Injection(SMI) on theexpression of cytochrome P450system in rat heart. Compared with thecontrol, SMI induced the expression of other CYP genes except CYP2B1、CYP4A3and CYP4F6; HSI caused a induction of CYP2E1、CYP4A3、CYP4F1and EHPX2. In addition, there was a significant induction onANP、BNP and EHPX2, a inhibition on CYP2B1and CYP2C11withtreatment of MDI. Although there was no significant change in the geneexpression of CYP2B1by treatment with SMI, and MDI caused asignificant inhibitory of CYP2B1, therefore HSI greater than MDI on the effect of CYP2B1. SMI, HIS and MDI caused a significant induction onCYP2E1、CYP4F1and EHPX2, therefore the induction of CYP2E1、CYP4F1and EHPX2were probably contributed by HongShen andMaiDong. MDI was greater than HSI on the induction of ANP and BNP.SMI is widely used for the treatment of cardiovascular diseases, theinduction of CYP2J3、ANP and BNP mRNA expression maybe themetabolism pathway of cardioprotection.For a more comprehensive study of the impact of SMI on P450enzymes, the active monomer Ophiopogonin D was selected for furtherstudy. Determination Ophiopogonin D acting on the H9c2cells, thechanges of CYP2J3mRNA levels,protein levels and the content of14-15EETs. The results showed that: Ophiopogonin D caused a significantinduction on CYP2J3mRNA expression levels and protein expressionlevels, and showed a concentration-dependent manner in the experimentaldose range. Finally ELISA experiments also confirmed that OphiopogoninD can increase the content of14-15EETs.In summary, SMI can induct or inhibit the CYP450enzyme of ratliver and heart. When SMI combined with other medicines in clinic, theincidence of drug interaction should be given close attention. Also thetherapeutical effect in cardiovascular disease of SMI, may be closelyrelated to the regulation of CYP2J3.