The objective of this study was to determine the comparative cardioprotective potential of bark and gemmomodified extract of Terminalia arjuna. Cardioprotective potential was evaluated against isoproterenol induced cardiotoxicity. Both ways of treatment, curative and preventive were studied. In preventive cardioprotective potential, rabbits were pretreated with both extracts of T. arjuna (200 mg/kg) for three weeks and then cardiotoxicity was induced with isoproterenol. In curative way of treatment isoproterenol was given for two days and then these cardio intoxicated rabbits were treated with plant extracts. The activities of cardiac marker enzymes (CK-MB, AST, ALT, and LDH) and antioxidants enzymes (SOD, CAT) were analyzed in serum and heart tissues of different groups of experimental rabbits. Isoproterenol significantly (P<0.001) increased the level of enzymes. The three week prior administration and curative treatment of T. arjuna extracts resorted the enzymes and antioxidants level equal to normal. HPLC analysis of the extracts confirmed the presence of important flavonol and phenolic acids in both extracts. It can be concluded that gemmomodified and bark extract of T. arjuna has strong cardioprotective potential.

Key words: Cardioprotective potential, Gemmomodified extract, HPLC analysis, Terminalia arjuna