Effects of niacin on lipid metabolism in rat model of non-alcoholic fatty liver disease / 临床肝胆病杂志

ABSTRACT

ObjectiveTo investigate the effects of niacin on the lipid metabolism in rat model of non-alcoholic fatty liver disease (NAFLD). MethodsForty Sprague-Dawley rats were randomly divided into control group, model group, intervention group 1 (0.5% niacin), and intervention group 2 (1% niacin). Rats were fed with high-fat diet for 8 weeks to induce an NAFLD model. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase, levels of total cholesterol (TC), triglyceride, and free fatty acid in serum and liver tissue, and level of malondialdehyde (MDA) in liver tissue were measured using assay kits. The morphological and histopathological changes in the liver were observed under a microscope. Comparison of data between groups was made by univariate analysis of variance using SPSS software; moreover, least significant difference test (equal variance assumed) and Tamhane's T2 test (equal variance not assumed) were used for pairwise comparison. ResultsCompared with the model group, every intervention group had significantly lower levels of ALT, TC, AST, TG, and FFA (all P＜0.05) in serum and level of MDA in liver tissue (P＜0.05), and had significantly increased expression of PPARα mRNA (P＜0.05), DGAT2 mRNA (P＜0.05), and SREBP1c mRNA (P＜0.05). Intervention group 2 had significantly reduced expression of DGAT2 mRNA and SREBP1c mRNA compared with intervention group 1 (P＜0.05). Compared with the model group, the intervention groups had relieved fatty degeneration of hepatocytes and alleviated inflammatory cell infiltration in the centrilobular portion of the liver. ConclusionNiacin regulates lipid metabolism in NAFLD animal models, reduces lipid oxidative stress, and significantly reduces liver steatosis and fibrosis by regulating the expression of PPARα mRNA, DGAT2 mRNA, and SREBP1c mRNA, so as to realize the protective effect against NAFLD.