Alleviation of Liver Dysfunction, Oxidative Stress and Inflammation Underlies the Protective Effect of Arbutin in Methotrexate-Induced Hepatotoxicity: An In-Depth Biochemical and Histopathological Insights

Abstract

Background: Methotrexate (MTX) is a highly employed chemotherapeutic and immunosuppressive agent, but its clinical application is often restricted by dose-dependent hepatotoxicity. Objectives: This study investigates the hepatoprotective potential of arbutin (ARB), a natural β-glucoside of hydroquinone, against MTX-induced liver damage. Methods: The experimental design involved 40 male Wistar rats, randomly allocated to five groups of 8 animals: (1) a control group receiving normal saline; (2) an MTX-only group administered an intraperitoneal MTX injection (20 mg/kg) on day 9; and (3 - 5) three MTX + ARB co-treatment groups receiving oral ARB at 25, 50, and 100 mg/kg over 10 continuous days, with MTX administered. Hepatic injury markers (ALT, AST, ALP), oxidative stress [malondialdehyde (MDA), nitric oxide (NO)], antioxidants [cellular glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), GPx], and TNF-α and IL-1β pro-inflammatory cytokines were analyzed in liver tissue. Additionally, histopathological alterations, including hepatocellular necrosis, inflammatory infiltration, and sinusoidal congestion, were examined to assess tissue-level damage. Results: The findings showed that MTX exposure caused significant liver toxicity, indicated by higher serum ALP, ALT, and AST levels, decreased antioxidant enzyme activity, and increased pro-inflammatory cytokine production. Notably, ARB co-treatment, especially at 50 and 100 mg/kg doses, effectively counteracted these detrimental effects. Histopathological analysis confirmed that ARB mitigated MTX-induced liver damage, including necrosis, inflammation, and sinusoidal congestion. Conclusions: Arbutin demonstrates strong hepatoprotective effects against MTX-related toxicity by reducing inflammation, oxidative stress, and liver injury. The results suggest its potential as an adjunct therapeutic option for MTX treatment.