Objective:To construct a rat model of non-alcoholic fatty liver disease(NAFLD)by choline-deficient high fat diet(CDHFD),and to observe the association between feeding cycle and antioxidant pathway.Methods:The study lasted 16 weeks and was divided into 4 cycles.Detection of pathological changes and expression of antioxidant enzymes in rats liver in different cycles.Results:The early stage of liver steatosis and inflammation in model rats was 2～4 weeks,non-alcoholic steatohepatitis(NASH)stage was 4～8 weeks,and liver fibrosis progression was 8～16 weeks.Mechanistic studies had shown that the expressions of antioxidant enzymes Nrf2,SOD and GSH-Px in the liver of NAFLD rats gradually decreased with the extension of the feeding cycle.Conclusion:Different modeling cycles can successfully induce the pathological changes of steatosis,inflammation and liver fibrosis in rat liver,and the pathological changes are time-dependent with the expressions of antioxidant enzymes.

Objective:To construct a rat model of non-alcoholic fatty liver disease(NAFLD)by choline-deficient high fat diet(CDHFD),and to observe the association between feeding cycle and antioxidant pathway.Methods:The study lasted 16 weeks and was divided into 4 cycles.Detection of pathological changes and expression of antioxidant enzymes in rats liver in different cycles.Results:The early stage of liver steatosis and inflammation in model rats was 2～4 weeks,non-alcoholic steatohepatitis(NASH)stage was 4～8 weeks,and liver fibrosis progression was 8～16 weeks.Mechanistic studies had shown that the expressions of antioxidant enzymes Nrf2,SOD and GSH-Px in the liver of NAFLD rats gradually decreased with the extension of the feeding cycle.Conclusion:Different modeling cycles can successfully induce the pathological changes of steatosis,inflammation and liver fibrosis in rat liver,and the pathological changes are time-dependent with the expressions of antioxidant enzymes.

Nonalcoholic steatohepatitis (NASH) is an important part of the exacerbation of nonalcoholic fatty liver disease (NAFLD), and inflammation and liver damage are important pathological features of this stage. As one of the pathogenic mechanisms of NASH, lipotoxicity can regulate liver inflammation and hepatocyte apoptosis through multiple pathways. Therefore, this article elaborates on the specific regulatory mechanism of lipotoxicity on NASH from the two aspects of inflammation and hepatocyte apoptosis, which involves a variety of liver nonparenchymal cells and various signaling pathways such as JNK, NF-κB, and caspase-mediated cell apoptosis, so as to provide new ideas for the diagnosis and treatment of NASH in clinical practice.