Maslinic acid protects against obesity-induced nonalcoholic fatty liver disease in mice through regulation of the Sirt1/AMPK signaling pathway

FASEB J. 2019 Nov;33(11):11791-11803. doi: 10.1096/fj.201900413RRR. Epub 2019 Jul 30.

Abstract

Maslinic acid is a pentacyclic triterpenoid that is distributed in the peel of olives. Previous studies found that maslinic acid inhibited inflammatory response and antioxidant effects. We investigated whether maslinic acid ameliorates nonalcoholic fatty liver disease in mice with high-fat-diet (HFD)-induced obesity and evaluated the regulation of lipogenesis in hepatocytes. Male C57BL/6 mice fed a normal diet or HFD (60% fat, w/w) were tested for 16 wk. After the fourth week, mice were injected intraperitoneally with maslinic acid for 12 wk. In another experiment, HepG2 cells were treated with oleic acid to induce lipid accumulation or maslinic acid to evaluate lipogenesis. Maslinic acid significantly reduced body weight compared with HFD-fed mice. Maslinic acid reduced liver weight and liver lipid accumulation and improved hepatocyte steatosis. Furthermore, serum glucose, leptin, and free fatty acid concentrations significantly reduced, but the serum adiponectin concentration was higher, in the maslinic acid group than in the HFD group. In liver tissue, maslinic acid suppressed transcription factors involved in lipogenesis and increased adipose triglyceride lipase. In vitro, maslinic acid decreased lipogenesis by activating AMPK. These findings suggest that maslinic acid acts against hepatic steatosis by regulating enzyme activity involved in lipogenesis, lipolysis, and fatty acid oxidation in the liver.-Liou, C.-J., Dai, Y.-W., Wang, C.-L., Fang, L.-W., Huang, W.-C. Maslinic acid protects against obesity-induced nonalcoholic fatty liver disease in mice through regulation of the Sirt1/AMPK signaling pathway.

Keywords: HepG2; hepatic steatosis; lipogenesis; lipolysis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AMP-Activated Protein Kinases / drug effects
  • AMP-Activated Protein Kinases / metabolism
  • Animals
  • Diet, High-Fat / adverse effects
  • Lipid Metabolism / drug effects*
  • Liver / drug effects*
  • Liver / metabolism
  • Male
  • Mice, Inbred C57BL
  • Non-alcoholic Fatty Liver Disease / drug therapy
  • Non-alcoholic Fatty Liver Disease / metabolism
  • Obesity / complications
  • Obesity / drug therapy
  • Obesity / metabolism
  • Protective Agents / pharmacology
  • Signal Transduction / drug effects*
  • Triterpenes / pharmacology*

Substances

  • Protective Agents
  • Triterpenes
  • maslinic acid
  • AMP-Activated Protein Kinases