Effects of taraxasterol against ethanol and high-fat diet-induced liver injury by regulating TLR4/MyD88/NF-κB and Nrf2/HO-1 signaling pathways

Life Sci. 2020 Dec 1:262:118546. doi: 10.1016/j.lfs.2020.118546. Epub 2020 Oct 6.

Abstract

Studies have reported that taraxasterol (TAR) is effective in the treatment of immune liver injury and alcoholic liver injury. The mechanism of action is mainly related to the inhibition of inflammation. To determine the key molecular mechanisms for the effect of TAR on alleviating ethanol and high-fat diet-induced liver injury, pathological morphology, biochemistry, oxidative stress, inflammatory response and lipid metabolism were examined. Our results showed that TAR could inhibit ethanol-induced hepatocyte death or lipid accumulation, and suppress oxidative stress, inflammatory response and lipid metabolism disorders. More specifically, ethanol-induced TLR-4 and MyD88 inflammatory response were down-regulated, when treated with TAR. Production of CYP2E1, Nrf2 and HO-1, which produced in response to increased oxidative stress, were regulated in TAR treated, ethanol-induced hepatocytes. In summary, TAR could inhibit the inflammatory response and oxidative stress, which was related to the regulation of TAR on TLR-4/MyD88/NF-κB and Nrf2/HO-1 pathways.

Keywords: Ethanol; High-fat diet; Nrf2/HO-1; TLR4/MyD88/NF-κB; Taraxasterol.

MeSH terms

  • Animals
  • Diet, High-Fat / adverse effects
  • Ethanol / toxicity
  • Heme Oxygenase-1 / metabolism
  • Inflammation / prevention & control
  • Liver Diseases / prevention & control*
  • Liver Diseases, Alcoholic / prevention & control*
  • Male
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Myeloid Differentiation Factor 88 / metabolism
  • NF-E2-Related Factor 2 / metabolism
  • NF-kappa B / metabolism
  • Oxidative Stress / drug effects*
  • Signal Transduction / drug effects
  • Sterols / pharmacology*
  • Toll-Like Receptor 4 / metabolism
  • Triterpenes / pharmacology*

Substances

  • Membrane Proteins
  • Myd88 protein, mouse
  • Myeloid Differentiation Factor 88
  • NF-E2-Related Factor 2
  • NF-kappa B
  • Nfe2l2 protein, mouse
  • Sterols
  • Tlr4 protein, mouse
  • Toll-Like Receptor 4
  • Triterpenes
  • Ethanol
  • taraxasterol
  • Heme Oxygenase-1
  • Hmox1 protein, mouse