methanolic extract of Syzygium cumini (Family: Myrtaceae) seeds, a medicinal herb, on isoproterenol-induced Myocardial Infarction (MI) in rats. Five groups of albino rats, each comprising six animals, were selected for this study. Group I served as a control, Group II rats were given isoproterenol (20 mg/100 g, subcutaneously), and Group III rats were given methanolic extract of Syzygium cumini seeds (SME) of 500 mg/kg. Groups IV and V rats were given SME (250 mg/kg and 500 mg/kg, respectively) and isoproterenol (20 mg/100 g subcutaneously) prior to MI induction. The transaminases (Aspartate Transaminase and Alanine Transaminase), Lactate Dehydrogenase (LDH) and Creatine Phosphokinase (CPK), were estimated in both the serum and heart tissues, and the serum uric acid level was also estimated. Isoproterenol significantly increased the activities of CPK, LDH and the transaminases in serum with a concomitant decrease in these enzymes in tissue. Pretreatment with SME at a dose of 500 mg/kg body weight for 30 days had a more significant effect on the activities of marker enzymes compared to 250 mg/kg treated group. Serum uric acid level, which increased on isoproterenol administration, registered near normal values on treatment with SME under study. The study confirms the cardioprotective potential of methanolic extract of Syzygium cumini seeds against isoproterenol-induced biochemical alterations in rats.
