CARDIOPROTECTIVE EFFECT OF ARBUTIN ON LIPID PEROXIDATION AND ANTIOXIDANT DEFENSE SYSTEM IN ISOPROTERENOL INDUCED MYOCARDIAL INFARCTION IN RATS

The present study was designed to investigate the cardioprotective effect of Arbutin (ARB) against isoproterenol (ISO) induced myocardial infarction (MI) in rats by studying cardiac and hepatic markers, antioxidant defense system, lipid peroxidation products and histopathological changes. Rats were pretreated with ARB (25 and 50 mg/kg BW) for 21 days. After pretreatment, ISO (60 mg/kg BW) was administered subcutaneously into the rats at an interval of 24 h for 2consecutive days to induce MI. In the present study ISO-induced myocardial damage was indicated by the increased heart weight to body weight ratio and the increased activity of marker enzymes such as CK, CK-MB, ALT, AST, LDH, and the elevated levels of troponin T and I in the serum. In addition, the levels of lipid peroxidation products such as TBARS, CDs, and LHPs were significantly increased in the plasma and heart tissue of ISO rats. Activities of enzymic antioxidants such as SOD, CAT, GPx, GST and the non-enzymic antioxidants like vitamin C, vitamin E and reduced glutathione (GSH) were decreased in the erythrocytes, plasma and heart tissues of the ISO-administered rats. Histopathological observations substantiate with the biochemical parameters. The 50 mg/kg BW of ARB was more pronounced than the 25 mg/kg BW and brought back all the above parameters to near normal. ARB ameliorates myocardial damage caused by ISO in rats and provides cardioprotective effect by scavenging the free radicals, restoring the endogenous antioxidants, preserving histopathology of the myocardium and by improving the cardiac function.