Wogonoside alleviates metabolic dysfunction-associated steatohepatitis by modulating AMPK and xCT/GPX4 pathways to restrain lipid dysregulation and ferroptosis.

BACKGROUND: Metabolic dysfunction-associated steatohepatitis (MASH) is a progressive form of metabolic dysfunction-associated steatotic liver disease with limited pharmacological treatment options. Wogonoside (WOG), a flavonoid isolated from Scutellaria baicalensis, exhibits anti-inflammatory, antioxidant, and lipid-lowering activities; however, its effects and underlying mechanisms in MASH remain unclear.

METHODS: A high-fat and high-fructose diet (HFFD)-induced mouse model of MASH and free fatty acid (FFA)-induced HepG2 cell steatosis model were used to evaluate the hepatoprotective effects of WOG. Liver histopathology, serum biochemical parameters, glucose tolerance, lipid accumulation, oxidative stress, ferroptosis-associated indicators, transcriptomic profiling, and expression of relevant proteins were assessed. The anti-ferroptotic effects of WOG were further examined using erastin and ferrostatin-1 in HepG2 cells.

RESULTS: WOG administration ameliorated HFFD-induced obesity, hepatic steatosis, hepatocellular ballooning, liver injury, dyslipidemia, insulin resistance, oxidative stress, and inflammatory responses in mice. Transcriptomic analysis indicated that WOG-responsive genes were enriched in lipid metabolism, peroxisome proliferator-activated receptor signaling, AMPK signaling, and ferroptosis-related pathways. In liver tissues and FFA-treated HepG2 cells, WOG increased AMPK phosphorylation and upregulated the expression of PGC-1α, PPARα, and CPT-1, while reducing the expression of SREBP-1c and its downstream lipogenic proteins, including ACLY, ACACA, FASN, and SCD-1. These changes were accompanied by decreased hepatic and intracellular triglyceride accumulation. In addition, WOG reduced reactive oxygen species, restored mitochondrial membrane potential, increased Nrf2 and HO-1 expression, and attenuated inflammatory responses. WOG also decreased Fe2+ accumulation and lipid peroxidation, restored glutathione homeostasis, and increased xCT and GPX4 expression in vivo and in vitro. Moreover, WOG counteracted erastin-induced ferroptosis-related changes and exhibited effects similar to those of ferrostatin-1 in FFA-treated HepG2 cells.

CONCLUSION: WOG alleviates experimental MASH by improving hepatic lipid metabolic homeostasis and suppressing ferroptosis-associated injury. These protective effects are associated with activation of AMPK signaling and restoration of the xCT/GPX4 antioxidant defense axis. WOG may therefore represent a promising candidate for the pharmacological management of MASH.