Agomelatine mitigates methotrexate-induced hepatotoxicity by modulating CD38/GLUT1 and the BAX/BCL2 axis in rats

Background Despite its broad therapeutic use, methotrexate (MTX) frequently causes hepatotoxicity through mechanisms linked to oxidative stress, mitochondrial impairment, and apoptosis. Agomelatine (AGO), a melatonergic agent originally developed as an antidepressant, has attracted interest due to reports of antioxidant and anti-apoptotic actions. To date, however, its potential role in mitigating MTX-induced hepatotoxicity has not been systematically examined. The present study was designed to address this gap. Methods Twenty-four male Wistar rats were divided into four groups: Control, MTX (20 mg/kg, i.p., day 2), AGO (20 mg/kg/day, oral, 7 days), and MTX + AGO. Liver injury was evaluated using histopathological scoring (H&E), immunohistochemical detection of CD38 and GLUT1, serum ALT/AST activities, and RT-qPCR analysis of BAX and BCL2 expression. Results MTX administration induced severe hepatocellular necrosis, sinusoidal congestion, and inflammatory infiltration, accompanied by marked increases in CD38 and GLUT1 expression and a pro-apoptotic shift in the BAX/BCL2 ratio. AGO co-treatment significantly ameliorated histopathological damage, suppressed CD38 and GLUT1 expression (p ≤ 0.05), and restored apoptotic balance by lowering BAX and enhancing BCL2 expression. Serum ALT and AST levels showed mild improvement in the MTX + AGO group compared with MTX. Conclusion This study provides the first experimental evidence that agomelatine (AGO) protects against methotrexate (MTX)-induced hepatotoxicity. We also report for the first time that oxidative and metabolic stress in MTX-induced liver injury is reflected by CD38 and GLUT1 upregulation. AGO co-treatment significantly attenuated these alterations, improving liver architecture, suppressing CD38 and GLUT1 expression, and restoring the BAX/BCL2 balance toward cell survival. Together, these findings highlight AGO as a novel hepatoprotective candidate and establish CD38 and GLUT1 as new immunohistochemical markers of MTX-induced hepatotoxicity.