Effects of glutamine on oxidative stress and nuclear factor-κB expression in the livers of rats with nonalcoholic fatty liver disease

The aim of this study was to investigate the effects of glutamine on the histomorphology of the liver, oxidative stress and nuclear factor-kappa B (NF-kappa B) expression in the development of nonalcoholic fatty liver disease (NAFLD). NAFLD was induced in rats by a high-fat diet, and rats in the treatment group were subjected to oral administration of glutamine (1 g/kg/day). Rats from the treatment, model and normal control groups were assessed after 8 and 12 weeks (n=6 per group at each time-point). The levels of glutathione (GSH), malondialdehyde (MDA) and tumor necrosis factor-alpha (TNF-alpha) in the liver, and the liver histopathology and NF-kappa B protein 65 (p65) expression in the liver were assessed. Compared with the control group under the same experimental period, the MDA and TNF-alpha levels in the liver, the hepatic steatosis and the hepatic expression of NF-kappa B p65 were significantly higher in the model and the treatment groups (P<0.05), while the GSH levels in the liver were significantly lower (P<0.05). These indices improved significantly in the treatment group compared with the model group (P<0.05). In conclusion, glutamine reduces the degree of oxidative stress in the liver, inhibits NF-kappa B p65 expression and improves hepatic steatosis. Glutamine has a certain protective effect in NAFLD.