Silybum marianum peptide-rich fraction alleviates acute liver injury by inhibiting TRAF3/NIK/NF-κB and is associated with changes in gut microbiota composition

Acute liver injury (ALI) is a severe and prevalent condition that can progress to irreversible liver damage and failure. This study aimed to investigate the prophylactic hepatoprotective potential of Silybum marianum peptides (SMP) in ALI and elucidate its underlying mechanisms. Using a carbon tetrachloride (CCl 4 )-induced ALI mouse model, we evaluated the dose-dependent effects of SMP. Additionally, we explored the modulatory effects of SMP on the NF-κB pathway, gut microbiota composition, and metabolite profiles. The role of SMP in the TRAF3/NIK/NF-κB signaling axis was further validated in a NIK-overexpressing Hepa1-6 cell model. Our results demonstrated that 14-day SMP administration did not significantly affect body weight, fasting blood glucose levels, or liver and spleen weights, and no significant difference in serum ALT activity was observed. Notably, SMP (200 mg/kg) significantly alleviated CCl 4 -induced liver injury, as evidenced by enhanced hepatic antioxidant capacity, reduced expression of proinflammatory cytokines, and attenuated immune cell infiltration. Furthermore, SMP was associated with changes in gut microbiota composition and community structure in CCl 4 -induced ALI mice. Mechanistically, SMP suppressed the TRAF3/NIK/NF-κB pathway. These findings highlight SMP as a promising candidate for the prevention of CCl 4 -induced ALI, acting through multimodal mechanisms involving anti-inflammatory, antioxidant, and gut microbiota-associated pathways.