Abstract: To explore the effect and potential mechanism of ursolic acid(UA) in myocardial ischemia reperfusion injury(MI/R) of diabetic rats. The model of diabetic rats were induced by injecting Streptozotocin and observed for 2 weeks. Diabetic rats were randomly divided into Sham group(Sham),myocardial ischemia reperfusion injury group(MI/R),and ursolic acid(low,middle,high) pretreatment group(UA). The MI/R model was induced by ligating left anterior descending coronary artery of diabetic rats. The cardial Systolic and diastolic function,the cardial infarct size and the expression of acute cardiac injury biomarkers(CKMB,AST and LDH),AKT,p-AKT,PI3K,IL-6,IL-1β,TNF-α,BCL-2 and TUNEL were examined in the rats of all groups. Compared with the Sham group,MI/R group had higher infarct size and the expression of CK,AST,LDH,p-AKT,PI3K,IL-6,IL-1β,TNF-α,Bax and TUNEL and with lower expression of BCL-2 and the cardial Systolic and diastolic function. Compared with the MI/R group,the UA group had lower expression of infarct size and the expression of CK,AST,LDH,pAKT,PI3K,IL-6,IL-1β,TNF-α,Bax and TUNEL with higher cardial Systolic and diastolic function and BCL-2 expression. There was no difference on the expression of AKT among three groups. UA pretreatment can protect diabetic rats against myocardial ischemia reperfusion injury by attenuating inflammation and apoptosis. The mechanism of which was associaing with suppressing the activation of AKT/PI3K signal pathway.

Key words: ursolic acid, myocardial ischemia reperfusion injury, inflammation, apoptosis