Effects of capsaicin on the cholesterol lithogenesis in the gallbladder of C57BL/6 mice

Objective: High-fat diet was used to induce cholesterol lithogenesis in the gallbladder of C57BL/6 mice in which the effects of capsaicin on the cholesterol lithogenesis were investigated and the potential mechanism was explored.
Methods: A total of 30 C57BL/6 mice were randomly didivded intocontrol group (mice were feed with normal food), gallbladder stone group (GS group; mice received high fat diet) and capsaicin group (CA group; mice received high fat diet containing 0.015% capsaicin).
Results: Results showed 0%, 100% and 20% of mice had gallbladder stone in control group, GS group and CA group, respectively. All the parameters became abnormal in GS group as compared to control group, but improved to different extents after simultaneous intake of capsaicin (such as total cholesterol in bile acid, and total cholesterol, triglycerides, low-density lipoprotein and high-density lipoprotein in the serum). In GS group, cholesterol saturated index (CSI) increased significantly (1.32 vs. 0.46) as compared to control group suggesting the cholesterol supersaturated bile. The CSI was reduced to 0.8 in CA group. In addition, simultaneous intake of capsaicin significantly improved the abnormal expressions of COX-2, MUC5AC and TRPV1 in the gallbladder and abnormal expressions of CYP7A1, HMG-CoA reductase and TRPV1 in the liver.
Conclusion: Capsaicin may prevent the high-fat diet induced cholesterol lithogenesis in C57BL/6 mainly via activating TRPV1 and regulating CYP7A1 and HMG-CoA reductase in the liver as well as COX-2 and MUC5AC in the gallbladder, which are key genes regulating the cholesterol metabolism.