Effects of Melatonin on Oxidative Stress and Neuronal Apoptosis in Hippocampus of Rats with Epilepsy

WU Li-na; GAN Yan-feng; SU Bing-yin

doi:10.3969/j.issn.1006-9771.2016.05.010

Abstract：Objective To investigate the effects of melatonin on oxidative stress and neuronal apoptosis in hippocampus of epileptic rats and the mechanism. Methods Seventy-two adult male Sprague-Dawley rats were equally divided into control group, model group, low dose group and high dose group. The model group was injected coriamyrtin 50μg/kg in the lateral ventricle, while the low dose group and high dose group were injected melatonin 20 mg/kg and 60 mg/kg, respectively, 30 minutes before injection of coriamyrtin. The contents of malo-ndialdehyde (MDA) and superoxide dismutase (SOD) were detected with ultraviolet spectrophotometer, the apoptosis was detected with TU-NEL, and the ultrastructural changes of neurons and mitochondria in hippocampal CA3 region were observed with electron microscopy, af-ter 60 minutes of epilepsy. Results The neurons and mitochondria in hippocampus were damaged, the number of apoptotic cells significant-ly increased (P<0.001), the content of SOD decreased (P<0.001), and the content of MDA increased (P<0.001) in the model group, com-pared with the control group. In the low dose group, the ultrastructural damage relieved, the number of apoptotic cells decreased (P<0.01), the content of SOD increased (P<0.05), and the content of MDA decreased (P<0.05);and for the high dose group, the ultrastructural damage relieved very much, the number of apoptotic cells decreased (P<0.001) and was not significantly different from the control group (P>0.05), SOD increased (P<0.001), and MDA decreased (P<0.001), compared with the model group. Conclusion Exogenous melatonin may signifi-cantly reduce neuronal apoptosis in rat hippocampal after epilepsy, and high dose is more effective, which may relate with resistance of oxi-dative stress, alleviate neuronal mitochondrial damage.