Protective effect of polysaccharide from the loach on the in vitro and in vivo peroxidative damage of hepatocyte

Misgurnus anguillicaudatus polysaccharide (MAP), a type of natural neutral polysaccharide occurring in the mucus of Misgurnus anguillicaudatus C., was studied for antioxidant bioactivity. The preliminary research showed that MAP was able to remove O-2(.) HO., H2O2 and other active compounds of oxygen and significantly protected DNA chains from being damaged by hydroxyl radicals. This antioxidant bioactivity was further evaluated using the model of peroxide-induced oxidative injury in rat primary hepatocytes and hepatotoxity in mice. The results demonstrated that MAP, at the concentrations of 0.10 similar to 0.40 mg/ml, significantly increased the activity of SOD and GSH-px, but decreased the consumption of reduced glutathione and the formation of malondialdehyde induced by a 30-min treatment of H2O2 (2.0 mmol/L). The in vivo investigation showed that oral pretreatment of MAP (100, 200 and 300 mg/kg) for 7 days before a single dose of t-BHP (0.2 mmol/kg, ip) significantly lowered the serum levels of hepatic enzyme markers (alanine and aspartate aminotransferase) and reduced oxidative liver injury. The histopathological evaluation of the liver revealed that MAP reduced the incidence of liver lesions including inflammatory, leukocyte infiltration, and necrosis induced by t-BHP in mice. Based on the results described above. a conclusion can be drown that MAP may play an important role in the prevention of oxidative damage in living systems. (C) 2002 Elsevier Science Inc. All rights reserved.