Effects of Atorvastatin on Bile Acid Metabolism in High-fat Diet-fed ApoE-/- Mice

Statins are considered as the cornerstone of the prevention and treatment of atherosclerotic cardiovascular disease, where pleiotropic effects are thought to contribute greatly in addition to the lipid-lowering effect. Bile acid metabolism has been gradually reported to be involved in the antihyperlipidemic and antiatherosclerotic effects of statins, but with inconsistent results and few studies carried out on animal models of atherosclerosis. The study aimed to examine the possible role of bile acid metabolism in the lipid-lowering and antiatherosclerotic effects of atorvastatin (ATO) in high-fat diet-fed ApoE(-/-) mice. The results showed that the levels of liver and faecal TC as well as ileal and faecal TBA were significantly increased in mice of the model group after 20 weeks of high-fat diet feeding compared with the control group, with significantly downregulated mRNA expression of liver LXR-alpha, CYP7A1, BSEP, and NTCP. ATO treatment further increased the levels of ileal and faecal TBA and faecal TC, but no obvious effect was observed on serum and liver TBA. In addition, ATO significantly reversed the mRNA levels of liver CYP7A1 and NTCP, and no obvious changes were observed in the expression of LXR-alpha and BSEP. Our study suggested that statins may enhance the synthesis of bile acids and facilitate the reabsorption of bile acids from the ileum via portal into the liver, possibly through the upregulation of the expression of CYP7A1 and NTCP. The results are helpful in enriching the theoretical basis for the clinical use of statins and have good translational value.