Experimental myocardial necrosis in rats: Role of arjunolic acid on platelet aggregation, coagulation and antioxidant status

Arjunolic acid, a new triterpene and a potent principle from the bark of Te rminalia arjuna, has been shown to provide significant cardiac protection i n isoproterenol induced myocardial necrosis in rats. To further explore the mechanism of action of arjunolic acid, antiplatelet activity, anticoagulan t assays, electrocardiographic changes, serum marker enzymes, antioxidant s tatus, lipid peroxide and myeloperoxidase (MPO) have been measured and the results are compared with a potent cardioprotective drug, acetyl salicylic acid (ASA). Administration of isoproterenol produces electrocardiographic c hanges such as decreased R amplitude and increased ST segment elevation and has resulted in an increase in serum marker enzyme levels as well as a dec rease in enzymatic and nonenzymatic antioxidant levels. Arjunolic acid at a n effective dosage of 15 mg/kg body weight (pre and post treatment),when ad ministered intraperitoneally (i.p.), effects a decrease in serum enzyme lev els and the electrocardiographic changes get restored towards normalcy. Arj unolic acid treatment is also shown to prevent the decrease in the levels o f superoxide dismutase, catalase, glutathione peroxidase, ceruloplasmin, al pha -tocopherol, reduced glutathione (GSH), ascorbic acid, lipid peroxide, MPO and the cardioprotection is confirmed by the histopathological studies. This study shows that the cardioprotection of arjunolic acid pre and post t reatment could possibly be due to the protective effect against the damage caused by myocardial necrosis.