The effect of melatonin administration on ethanol-induced lipid peroxidation in rats.

This study was carried out in order to determine the role of melatonin in preventing lipid peroxidation due to acute ethanol intoxication. Male Wistar Albino rats, 2.5-3 months old, were divided into two groups. Melatonin (in 1% ethanol, 2 mg kg-1 body weight) was given intraperitoneally (i.p.) for 21 days to experimental rats whereas controls received 1% ethanol only. On day 21, 6 g kg-1 body weight ethanol was injected to half of the animals in each group and the remainder were kept as corresponding controls. Animals were killed 5 h after ethanol injection. Malondialdehyde (MDA), reduced glutathione (GSH) and the antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase and catalase) were determined in liver tissue homogenates. MDA levels were increased whereas GSH levels tend to decrease following alcohol injection. Melatonin administration prior to ethanol did not alter MDA and GSH levels of tissue and among antioxidant defence enzymes studied, only CuZn-SOD was found to be increased in animals that received melatonin + ethanol. According to the findings of this study, melatonin did not appear to have any direct effect on alcohol-induced lipid peroxidation.