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

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.