Dapansutrile mitigates methotrexate-induced hepatotoxicity in rats: roles of inflammation, oxidative stress, pyroptosis, and autophagy.

Aims: Methotrexate (MTX) is a widely used chemotherapeutic and immunosuppressive agent; however, its clinical utility is frequently limited by dose-dependent hepatotoxicity which was mediated through oxidative stress and dysregulated inflammatory signaling. The present study investigated the protective effect of dapansutrile (DAPA), a selective NLRP3 inflammasome inhibitor, against MTX-induced hepatic injury in rats and elucidated the underlying molecular mechanisms. Methods: MTX hepatotoxicity was induced by a single intraperitoneal injection (20 mg/kg), while DAPA was administered orally at doses of 10 or 20 mg/kg for seven consecutive days. Results: MTX administration resulted in pronounced liver dysfunction, as evidenced by marked elevations in serum ALT, AST, ALP, and GGT levels, severe histopathological alterations, enhanced lipid peroxidation, depletion of endogenous antioxidants, and activation of TLR4/MyD88/NF-κB signaling. Furthermore, MTX robustly triggered NLRP3 inflammasome activation, leading to increased caspase-1 activity, elevated IL-1β and IL-18 levels, enhanced gasdermin D cleavage, and induction of pyroptotic cell death. MTX also disrupted hepatic autophagic activity, as indicated by reduced LC3-II levels and p62 accumulation. DAPA treatment significantly ameliorated these biochemical, histological, and molecular abnormalities. DAPA suppressed oxidative stress, attenuated inflammatory cytokine production, inhibited inflammasome-mediated pyroptosis, and restored autophagic balance. Conclusion: Collectively, these findings demonstrate that DAPA confers robust hepatoprotection against MTX-induced toxicity through coordinated modulation of inflammatory, oxidative, pyroptotic, and autophagic pathways.