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. M ale 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 intrape ritoneally (i.p.) for 21 days to experimental rats whereas controls re ceived 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 k ept as corresponding controls. Animals were killed 5 h after ethanol i njection. Malondialdehyde (MDA), reduced glutathione (GSH) and the ant ioxidant enzyme activities (superoxide dismutase, glutathione peroxida se and catalase) were determined in liver tissue homogenates. MDA leve ls were increased whereas GSH levels tend to decrease following alcoho l injection. Melatonin administration prior to ethanol did not alter M DA and GSH levels of tissue and among antioxidant defence enzymes stud ied, only CuZn-SOD was found to be increased in animals that received melatonin + ethanol. According to the findings of this study, melatoni n did not appear to have any direct effect on alcohol-induced lipid pe roxidation. (C) 1998 The Italian Pharmacological Society.