The antioxidant effects of melatonin after intracerebral hemorrhage in rats

Abstract

Free radical mechanisms are involved in secondary brain injury after intracerebral hemorrhage (ICH). Since melatonin is a potent free radical scavenger and indirect antioxidant, the objective of this study was to evaluate whether melatonin administration would attenuate oxidative stress, brain edema, and neurological deficits in a rat model of ICH. Animals were assigned into groups consisting of sham (needle trauma), vehicle, and melatonin (15 or 150mg=kg). All injections occurred through the intraperitoneal route, at either 15 min or 3 h after collagenase ICH induction. Then, lipid peroxidation, neurological scoring (18-point system), and brain water content were evaluated at 24 h post-ICH. Results demonstrated dramatically increased lipid peroxidation after collagenase-induced ICH; however, melatonin treatment effectively attenuated this lipid peroxidation. Nonetheless, neurological scoring and brain water content in the right basal ganglia was without significant difference between any treatment regimens (15 or 150mg=kg of melatonin) or time points of drug administration (15 min or 3 h post-ICH). Therefore, melatonin reduced oxidative stress but did not change extent of brain edema or neurologic deficits. © 2008 Springer-Verlag.