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

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.