The study was undertaken to evaluate the cardioprotective potential of the flavonoids osajin and pomiferin against ischemia-reperfusion induced injury in rat hearts as a model of antioxidant-based composite therapy. Studies were performed with isolated, modified Langendorff-perfused rat hearts and ischemia of the heart was initiated by stopping the coronary flow for 30 min followed by 60 min of reperfusion (14 ml.min-1). Wistar rats were divided into four groups. The treated groups received osajin or pomiferin (5 mg/kg/day in 0.5% Avicel), the placebo group received only 0.5 Avicel; the intact group was left without any applications. Biochemical indicators of oxidative damage – malondialdehyde, superoxide dismutase, glutathione peroxidase, total antioxidant activity in serum and the myocardium have been evaluated. We also examined the effect of osajin and pomiferin on cardiac function: left ventricular end-diastolic pressure, left ventricular pressure, and peak positive dP/dt. Our results demonstrate that the flavonoids osajin and pomiferin attenuate the myocardial dysfunction provoked by ischemia-reperfusion. This was confirmed by an increase in both the antioxidant enzyme values and the total antioxidant activity. The cardioprotection provided by osajin and pomiferin treatment results from the suppression of oxidative stress and correlates with the improved ventricular function.

        Key words: Maclura pomifera – flavonoids osajin and pomiferin – heart ischemia-reperfusion – free oxygen radicals