Trimetazidine mitigates methotrexate‐induced liver damage: Insights From biochemical, histological, and in silico analyses

Abstract This study aimed at generating preliminary evidence for the potential utility of repurposing the clinically approved anti‐ischemic drug trimetazidine (TMZ) against methotrexate (MTX)‐induced hepatotoxicity. In this study, rats received MTX (30 mg/kg) with or without TMZ pretreatment (20 mg/kg). MTX caused a 2.7–3.6‐fold increase in serum transaminases, while TMZ pretreatment caused a 37%–40% reduction. Regarding oxidative markers, MTX significantly suppressed the antioxidant glutathione (GSH) levels by 37% and elevated malondialdehyde (MDA) levels by 29%, while TMZ boosted GSH levels by 40% and reduced MDA levels by 20%. Next, we assessed nuclear factor kappa B (NF‐κB) (p‐65), nuclear factor erythroid 2‐related factor 2 (Nrf2) and hemoxygenase‐1 (HO‐1) to find that MTX significantly elevated the levels of the proinflammatory nuclear factor kappa B (NF‐κB) (p65) by 2.4‐fold, while TMZ pretreatment reduced its levels by 48%. Conversely, MTX decreased the levels of Nrf2, HO‐1, and adenosine triphosphate (ATP) by 55%–71%, while TMZ led to a threefold increase in their levels. Regarding apoptosis, MTX caused a five to sixfold elevation in B‐cell lymphoma 2 associated X (Bax)/B‐cell lymphoma 2 (BCL2) ratio and caspase‐3, while TMZ pretreatment caused a threefold reduction in their levels. An in silico analysis of TMZ protein target‐prediction revealed statistically enriched pathways related to oxidative stress, inflammation, and apoptosis. In conclusion, pretreatment with TMZ successfully ameliorated MTX‐induced alterations in serum aminotransferases, liver histology, oxidative stress, and apoptosis. Pathway enrichment analysis (PEA) showed that TMZ is involved in multiple signaling and immune‐related pathways that might be, at least partly, implicated in its cytoprotective effects.