RESUMO
With a view to evaluate the cardioprotective effect of ethanolic extract of S. anacardium nut and the possible interaction with propranolol against isoproterenol induced myocardial damage in rats, female Sprague-Dawley rats were pre-treated with propranolol (10 mg/kg for 7 days), low and high doses of S. anacardium (100 and 500 mg/kg for 21 days) and their combination orally and subsequently subjected to isoproterenol administration (150 mg/kg, sc) for two consecutive days. The influence of prophylactic treatment was analysed by quantification of biomarkers and antioxidants, electocardiographic parameters and histopathological observations. The activities of lactate dehydrogenase and creatinine phosphokinase-MB were reduced in serum and raised in heart tissue with concurrent elevation in superoxide dismutase and catalase activities as well as reduction in thiobarbituric acid reactive species levels significantly in all treated groups compared to isoproterenol group. Similarly, electrocardiographic changes were restored to normalcy in all treated groups. To conclude, combination of high dose of S. anacardium with propranolol was found to be most effective in alleviating the abnormal conditions induced by isoproterenol.