Lagerstroemia speciosa L. attenuates apoptosis in isoproterenol-induced cardiotoxic mice by inhibiting oxidative stress: possible role of Nrf2/HO-1.

Myocardial oxidative stress leading to apoptosis and remodeling is the major consequence of ischemic heart disease. In the present study, we investigated the effect of Lagerstroemia speciosa L. leave (LS) extract containing 1 % corosolic acid in the context of cardiovascular disorder by using isoproterenol (ISO)-induced myocardial injury mouse model. Serum was analyzed for specific cardiac injury biomarkers. Cardiac tissue was examined for lipid peroxidation, protein carbonyl content, antioxidant (GSH, GR, GPx, GST, SOD, CAT, NQO1, and HO-1), and apoptosis (cleaved caspase-3, Bax, Bcl-2, p53, and DNA fragmentation) status. Myocardial protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2) in different experimental groups was evaluated. Pathological changes in heart tissue and activities of matrix metalloproteinases (MMPs) were also analyzed. Our results demonstrated that LS pretreatment augmented myocardial antioxidant status and attenuated myocardial oxidative stress. Myocardial apoptosis as well as MMPs activities was significantly prevented by LS pretreatment in ISO-induced mice. In addition, the immunoblot of Nrf2 revealed that LS pretreatment enhanced the nuclear protein expression of Nrf2 when compared to ISO control group. Thus, the overall results indicate that LS has cardioprotective effect and may prevent the myocardial stress by suppressing apoptosis through up-regulation of myocardial antioxidant levels.