Novel bioactive peptides alleviate Western diet-induced MAFLD in C57BL/6J mice by inhibiting NLRP3 inflammasome activation and pyroptosis via TLR4/NF-κB and Keap1/Nrf2/HO-1 signaling pathways.

Metabolic-associated fatty liver disease (MAFLD) has emerged as a leading chronic liver disease. This condition is characterized by an abnormal accumulation of fat within liver and can progress from simple steatosis to more severe stages involving chronic inflammation and oxidative stress. In this study, we investigated the potential therapeutic effects and underlying mechanism of novel bioactive peptides (EWYF and EWFY) on Western diet-induced MAFLD in C57BL/6J mice. Mice fed a normal chow diet (ND group) and Western diet (WD and treatment groups) for 8 weeks. Treatment groups received EWYF and EWFY peptides in low (10 mg/kg/day) and high (50 mg/kg/day) doses were divided into four groups: EWYF10, EWYF50, EWFY10, and EWFY50. Western diet-induced body weight gain and increased liver weight along with visceral adiposity, which were markedly reversed by bioactive peptides in a dose-dependent manner. Additionally, bioactive peptides significantly reduced hepatic steatosis, liver injury and proinflammatory response. Western diet-induced glucose tolerance and insulin resistance, whereas bioactive peptides significantly improved glucose tolerance and insulin sensitivity. Persistent intake of Western diet triggered chronic inflammation and severe oxidative stress, which were significantly alleviated by bioactive peptides treatment via inhibiting NOD-like receptor protein 3 (NLRP3) inflammasome activation and mitigated pyroptosis by modulating TLR4/NF-κB and Keap1/Nrf2/HO-1 signaling pathways. Furthermore, molecular docking studies suggest that EWYF and EWFY act as fructokinase antagonists and TLR4 inhibitors, which potentially alleviates Western diet-induced MAFLD. Collectively, these findings highlight EWYF and EWFY as promising candidates for MAFLD treatment due to their potent antioxidant and anti-inflammatory properties via specific molecular inhibition.