The usefulness of doxorubicin, a highly effective antitumor drug, islimited by the risk of developing cardiomyopathy. Subcellular changes leadingto this toxicity are suggested to be mediated through a drug-induced increasein free radicals and lipid peroxidation. The present study was undertaken toinvestigate the possible protection that silymarin, an antioxidant drug, andtelmisartan, angiotensin receptor bloker, can offer against doxorubicin,isoproterenol - induced cardiotoxicity. Doxorubicin was administered to malealbino rats in 2.5 mg/kg interaperitoneal injections every other day over aperiod of 2 weeks (cumulative dose, 15 mg/kg). Isoproterenol wasadministered in 85 mg/kg S.C. in the 13 and 14 day. Protection fromdoxorubicin and isoproterenol- oxidative injury was investigated byadministration of silymarin (50 mg /kg orally daily), and telmisartan (10 mg/kgorally daily). At the end of the experemintal period, BP was measured, ECGwas performed, LDH and CPK were assessed and histopathologicalexamination of the heart tissue was performed. Injection of Doxorubicin,isoproterenol produced myocardial oxidative damage and decreased survivalrepresented by marked increase in LDH, CPK. Administration of silymarin ortelmisartan concurrently with doxorubicin or isoproterenol significantlyreduced the oxidative myocardial changes-induced by doxorubicin andisoproterenol injection. Histopathological observations were in correlationwith the biochemical parameters. This indicates that silymarin and telmisartanprovide protection against doxorubicin- and isoproterenol-induced cardiacinjury in terms of oxidative stress.