Berberine attenuates hepatic oxidative stress in rats with non-alcoholic fatty liver disease via the Nrf2/ARE signalling pathway

The present study investigated the effects of berberine (BBR) on hepatic oxidative stress and the nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) signalling pathway in rats in which non-alcoholic fatty liver disease (NAFLD) was induced by a high-fat diet. Rats were randomly divided into three groups: The normal control (NC), high-fat diet (HFD) and BBR groups. The NC group received a normal diet, while the other two groups were fed a high-fat diet. The rats in the BBR group were also fed BBR (100 mg/kg body weight) daily. A total of 8 weeks later, serum and liver lipid levels were measured. Hepatic histopathological changes were observed with haematoxylin and eosin and Oil Red O staining. Transmission electron microscopy was performed to observe the ultrastructural changes of the liver. The levels of superoxide dismutase (SOD), glutathione (GSH) and malondialdehyde (MDA) in the liver were measured. Quantitative polymerase chain reaction and western blotting were performed to investigate the expression of genes in the Nrf2/ARE signalling pathway in the liver. Histopathological results demonstrated that rats fed a high-fat diet for 8 weeks developed NAFLD, characterized by hepatic steatosis. BBR significantly decreased the body weight and liver weight. BBR markedly reduced hepatic steatosis, and the serum and liver lipid levels. Hepatic SOD and GSH levels were increased, while MDA levels were decreased by BBR co-administered with a high-fat diet. Additionally, the Nrf2/ARE signalling pathway was revealed to be involved in the protective effect of BBR on rats fed a high-fat diet. In conclusion, BBR may alleviate hepatic oxidative stress in rats with NAFLD, which may be partly attributed to the activation of the Nrf2/ARE signalling pathway.