Corosolic acid ameliorates non-alcoholic steatohepatitis induced by high-fat diet and carbon tetrachloride by regulating TGF-β1/Smad2, NF-κB, and AMPK signaling pathways

Phytother Res. 2021 Sep;35(9):5214-5226. doi: 10.1002/ptr.7195. Epub 2021 Jul 2.

Abstract

Hawthorn (Crataegus pinnatifida Bunge. var. major) is an edible and medicinal fruit that is very common in food and traditional Chinese medicine. Corosolic acid (CA), a pentacyclic triterpenoid, which is an active component of hawthorn (Crataegus pinnatifida Bunge. var. major), has been exhibiting various pharmacological activities such as antidiabetic, antibacterial, anticancer, antiinflammatory, and antioxidant effects. The study aimed to evaluate the effect of CA on non-alcoholic steatohepatitis (NASH) in mice induced by 60 kcal% high-fat diet (HFD) and carbon tetrachloride (CCl4 ). CA lowered liver index and serum AST, ALT, TG, and TC levels compared to those in the model group. Histological analyses of the liver tissues of mice treated with CA revealed significantly decreased number of lipid droplets and alleviated inflammation and fibrosis. CA inhibited the transcripts of pro-fibrogenic markers (including α-SMA, collagen I, and TIMP-1) and the levels of pro-inflammatory cytokines (including TNF-α, IL-1β, caspase-1, and IL-6) associated with hepatic fibrosis, and NF-κB translocation and TGF-β1/Smad2 and AMPK pathways. In addition, CA reduced lipid accumulation via the regulation of AMPK and NF-κB activation in FFA-induced steatotic HepG2 cells. CA also decreased α-SMA, collagen I expressions, and Smad2 phosphorylation, which were reduced by TGF-β1 treatment in LX2 cells. Our results suggested that CA ameliorated NASH through regulating TGF-β1/Smad2, NF-κB, and AMPK signaling pathways, and CA could be developed as a potential health functional food or therapeutic agent for NASH patients.

Keywords: AMPK; NF-κB; TGF-β1/Smad2; corosolic acid; liver fibrosis.

MeSH terms

  • AMP-Activated Protein Kinases / metabolism
  • Animals
  • Carbon Tetrachloride
  • Diet, High-Fat / adverse effects
  • Liver / metabolism
  • Liver Cirrhosis
  • Mice
  • NF-kappa B / metabolism
  • Non-alcoholic Fatty Liver Disease* / drug therapy
  • Signal Transduction / drug effects*
  • Smad2 Protein
  • Transforming Growth Factor beta1 / metabolism
  • Triterpenes* / pharmacology

Substances

  • NF-kappa B
  • Smad2 Protein
  • Smad2 protein, mouse
  • Tgfb1 protein, mouse
  • Transforming Growth Factor beta1
  • Triterpenes
  • corosolic acid
  • Carbon Tetrachloride
  • AMP-Activated Protein Kinases