Oxygen-derived free radicals have been implicated in the pathogenesis of renal injury after ischemia-reperfusion. Caffeic acid phenethyl ester (CAPE), an active component of propolis extract, exhibits antioxidant and anti-inflammatory properties. To determine whether CAPE offers any advantage over alpha -tocopherol, we compared their effects on an in vivo model of renal ischemia-reperfusion injury in rats. CAFE at 10 mu mol/kg or alpha -tocopherol at 10 mg/kg was administered intraperitoneally before reperfusion. Acute administration of CAFE suppressed ischemia-reperfusion induced renal lipid peroxidation and tissue injury more than alpha -tocopherol. CAFE may therefore offer a therapeutic advantage in acute injury settings.