Melatonin prevents brain oxidative stress induced by obstructive jaundice in rats

The aim of the study was to analyze the impact of melatonin on brain oxidative stress in experimental biliary obstruction. Cholestasis was done by a double ligature and section of the extrahepatic biliary duct. Melatonin was injected intraperitoneally (500 mu g/kg/day). Malon-dialdehyde (MDA), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) contents were determined in the brain tissue. Biliary obstruction raised MDA and reduced GSH contents in the cortex, cerebellum, and hypothalamus areas. Moreover, the scavenger enzyme activity significantly dropped in all areas of the brain. Melatonin drastically reduced MDA concentration and enhanced GSH concentration, as well as all antioxidant enzyme activity in all brain areas obtained from the bile ductligated animals. In conclusion, the treatment with melatonin decreased lipid peroxidation and recovered the antioxidant status in the brain from cholestatic animals. (C) 2007 Wiley-Liss, Inc.