Therapeutic potential of β-sitosterol in methotrexate-induced liver injury: association with STING and ERK-1 pathways

BACKGROUND: Methotrexate (MTX) is a commonly used drug to treat various cancers and autoimmune disorders, but its clinical utility is often limited by hepatotoxicity. β-sitosterol is a bioactive phytosterol compound that is naturally present in various plant foods and exhibits multiple antioxidant, anticancer and immunomodulatory activities. It has not been fully explored for its potential protective effects against liver injury. This study investigated whether β-sitosterol is associated with reduced hepatic injury in a short-term MTX model. METHODS: The rats were arbitrarily assigned to three groups as control, MTX and MTX + β-sitosterol groups. A single intraperitoneal dose of MTX was used to induce liver toxicity, and animals subsequently received either β-sitosterol or vehicle by oral gavage once daily for ten days. Liver tissues were evaluated using semi-quantitative histopathological scoring. Plasma alanine transaminase (ALT) and malondialdehyde (MDA), as well as liver transforming growth factor-β (TGF-β), MDA, stimulator of interferon genes (STING) and extracellular signal-regulated kinase 1 (ERK-1) levels were measured. RESULTS: β-sitosterol treatment was associated with lower plasma ALT and MDA levels compared with the MTX group. Hepatic TGF-β, MDA, STING and ERK-1 levels were also reduced in the MTX + β-sitosterol group. Histopathology showed attenuated hepatocyte necrosis, inflammatory infiltration and early fibrotic changes. CONCLUSIONS: β-sitosterol was associated with reduced oxidative stress markers and lower hepatic TGF-β, STING and ERK-1 levels in this short-term MTX injury model. These findings suggest that β-sitosterol may have potential therapeutic value in mitigating MTX-related hepatotoxicity.