Protective effects of melatonin on acute cerebral ischemia-reperfusion injury in rats

AIM To study the protective effects of melatonin(MT) on acute cerebral ischemia reperfusion injury.METHODS The model of cerebral ishemia-2 h/reperfusion-24 h was induced by middle cerebral artery occlusion(MCAO) in SD rats. Melatonin (10,20 mg·kg -1 ip)was administered four times in an animal:At 0, 1, 2, 6 h of reperfusion. After 24 h reperfusion, the content of malondialdehyde(MDA),the activities of superoxide dismutase(SOD)and myeloperoxidase (MPO)in brain tissue, the content of thromboxane B 2(TXB 2) and 6-keto-prostaglandin F 1α(6-keto-PGF 1α)in plasma were measured. RESULTS Compared with vehicle group, MT 10, 20 mg·kg -1 protected the activity of SOD, reduced the content of MDA, MT 20 mg·kg -1 also inhibited the increase of MPO in brain tissue ,and attenuated the disequilibrium of TXB 2 /6-keto-PGF 1α.CONCLUSION The protective effects of MT on acute cerebral ischemia reperfusion injury may be related to its increasing antioxidase activities,decreasing lipid peroxidative damage and inhibiting inflammations.