This study was designed to investigate the protective effect of curcumin (CUR) against isoprenaline induced myocardial ischaemia in rat myocardium. The effect of single oral dose of curcumin (15 mg kg(-1)), administered 30 min before and/or after the onset of ischaemia, was investigated by assessing oxidative stress related biochemical parameters in rat myocardium. Curcumin pre and post-treatment (PPT) was shown to decrease the levels of xanthine oxidase, superoxide anion, lipid peroxides (LPs) and myeloperoxidase while the levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) activities were significantly increased after curcumin PPT. Histopathological and transmission electron microscopical studies also confirmed the severe myocardial damage occurring as a consequence of isoprenaline induced ischaemia and they also showed the significant improvement effected by curcumin PPT. These findings provided evidence that curcumin was found to protect rat myocardium against ischaemic insult and the protective effect could be attributed to its antioxidant properties as well as its inhibitory effects on xanthine dehydrogenase/xanthine oxidase (XD/XO) conversion and resultant superoxide anion production.