Wedelolactone Mitigates Alcoholic Steatohepatitis via Modulating the TLR4/MyD88/NF- κ B Pathway

Abstract

Background. Wedelolactone (WEL) has demonstrated anti-inflammatory properties. However, the therapeutic effect and underlying mechanisms of WEL against alcoholic steatohepatitis (ASH) remain unclear. This study aimed to investigate these aspects using animal and cell models. Methods and Results. The animals were categorized into the Pair-fed, ethanol-fed, ethanol + low-dose WEL, and ethanol + high-dose WEL groups. The serum levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 in the ethanol + WEL group exhibited a dose-dependent decrease. Histopathological evaluations revealed that WEL mitigated liver injury, lipid accumulation, and macrophage infiltration provoked by alcohol consumption and a high-fat diet in mice. Network pharmacology analysis identified the toll-like receptor 4 (TLR4) pathway as the primary target of WEL in treating ASH. Molecular docking simulations demonstrated WEL's strong binding affinity with TLR4. Immunofluorescence results highlighted that WEL downregulated the heightened TLR4 expression induced by alcohol and a high-fat diet. Additionally, RAW264.7 and AML-12 cells were stimulated with ethanol to establish an in vitro model. WEL treatment resulted in reduced mRNA and protein levels of alcohol-induced inflammatory mediators, downregulation of TLR4 and myeloid differentiation factor 88 (MyD88) expression, and inhibition of nuclear translocation of NF-κB-P65. Cellular immunofluorescence analyses demonstrated WEL's ability to reduce alcohol-induced TLR4 expression. Flow cytometry and western blotting analyses confirmed WEL's protective effect against ethanol-induced hepatocyte apoptosis. Conclusion. WEL may mitigate the impact of ASH by modulating the TLR4/MyD88/NF-κB pathway.