Protective role of melatonin given either before ischemia or prior to reperfusion on intestinal ischemia-reperfusion damage

: Tissue injury resulting from ischemia‐reperfusion is of fundamental importance. Experimental evidence suggests that the generation of reactive oxygen species is significantly responsible for this type of injury. In the present study, besides investigating the protective role of melatonin on tissue damage caused by intestinal ischemia‐reperfusion, the protective activity of this compound was also analyzed in both pre‐ and post ischemia melatonin‐treated rats. The activities of the main antioxidative enzymes, catalase, superoxide dismutase and glutathione peroxidase in the intestine showed significant (P