Improvement Effect of Mussel Polysaccharide α-D-Glucan on Non-Alcoholic Fatty Liver Apolipoprotein E Knockout Mice Induced by High Fat Diet

The aim of this study was to investigate the improvement effect of mussel polysaccharide α-D-glucan (MP-A) on non-alcoholic fatty liver disease (NAFLD) in the high-fat diet (HFD) induced apolipoprotein E knockout (ApoE^−/−) mice. 20 normal C57BL/6J mice were randomly divided into two groups: Normal group, normal+MP-A group, and 20 ApoE^−/− mice were randomly divided into two groups: Model group, model+MP-A group, 10 mice in each group. ApoE^−/− mice were fed with high fat diet to induce the NAFLD model. After MP-A were administered, serum and liver triglyceride (TG) and total cholesterol (TC) levels were detected, and the pathological morphology of liver tissue were evaluated by histopathology. The mRNA levels and protein levels of the receptors related to lipid metabolism and cholesterol metabolism were also measured simultaneously. Results showed that compared with the model group, the mice in the model+MP-A group showed significant decreases in the weight growth rate (P<0.05), serum TG level (P<0.01) as well as the liver TG and TC levels (P<0.05). Histomorphology showed that the lipid vacuoles in the mice liver were significantly reduced in the model+MP-A group. In addition, compared with the model group, model+MP-A group could significantly decreased the mRNA expression level of fatty acid synthase (FAS) in liver tissue (P<0.05), and significantly raised the cholesterol 7α-hydroxylase (CYP7A1) mRNA expression level (P<0.05). Moreover, compared with the model group, the expression of farnesoid X receptor (FXR) and CYP7A1 proteins in the liver tissue of the model+MP-A group were significantly improvements (P<0.05), while the expression of sterol regulatory element-binding protein-1C (SREBP-1C) and FAS proteins were significantly reduced (P<0.05). These results showed that MP-A significantly modulated the FXR-SREBP-1C-FAS signaling pathway and the expression of CYP7A1 receptor, which were closely related to hepatic lipid metabolism. Therefore, MP-A could significantly improve the HFD induced NAFLD and has a great development potential.