Rutin Attenuates Liver Fibrosis by the IRG1-Itaconate-Nrf2 Axis: Modulation of Oxidative Stress and NLRP3 Inflammasome Activation

Liver fibrosis, a common outcome of chronic liver injury, is characterized by excessive inflammation and oxidative stress. Rutin, a bioactive flavonoid with known antioxidant and anti-inflammatory properties, has not been thoroughly investigated for its potential anti-fibrotic mechanisms. This study aimed to elucidate the role of Rutin in liver fibrosis and its underlying molecular pathways. A carbon tetrachloride (CCl₄)-induced murine liver fibrosis model was employed. Liver injury, fibrotic deposition, inflammatory response, and oxidative stress were evaluated through histopathological examination, Western blotting, quantitative real-time PCR, and RNA sequence. The involvement of immune-responsive gene 1 (IRG1) was investigated using IRG1-knockout mice, while molecular docking and cellular thermal shift assay (CETSA) were performed to assess Rutin-IRG1 binding. The results showed that Rutin treatment significantly attenuated CCl₄-induced hepatic injury and collagen accumulation, accompanied by reduced markers of fibrosis. Mechanistically, Rutin activated the IRG1-itaconate axis, leading to a notable decrease in reactive oxygen species and pro-inflammatory cytokine release by Nrf2 activation and NLRP3 inflammasome containment. Molecular analyses confirmed direct binding of Rutin to IRG1, stabilizing its structure and enhancing its functional activity. The protective effects of Rutin were abolished in IRG1-deficient mice, underscoring the essential role of IRG1 in its anti-fibrotic action. In conclusion, Rutin ameliorates liver fibrosis by mitigating oxidative stress and suppressing NLRP3 inflammasome activation through targeting the IRG1/itaconate pathway, revealing a novel immunometabolic mechanism for its hepatoprotective effect.