Marigold ( Tagetes erecta L. ) attenuates methotrexate-induced hepatotoxicity in rats: associations with antioxidant, inflammatory, and apoptotic markers

Abstract

Tagetes erecta L. (marigold) possesses antioxidant and anti-inflammatory properties; however, its effects when administered shortly after methotrexate (MTX) exposure remain insufficiently characterized. This study evaluated marigold flower ethanolic extract (MFEE) against MTX-induced hepatotoxicity in rats. Forty male Sprague–Dawley rats were randomly allocated into four groups (n = 10/group): control, MFEE (400 mg/kg/day, orally), MTX (20 mg/kg, single intraperitoneal injection), and MTX + MFEE. In the combined group, MFEE administration commenced 2–4 h after MTX injection and continued daily for seven days. Liver-function indices, oxidative-stress markers, inflammatory mediators, hepatic gene expression, histopathology, and caspase-3 immunoreactivity were evaluated. Compared with MTX alone, MFEE reduced serum alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase activities by 15.1%, 17.7%, and 22.1%, respectively, decreased total and direct bilirubin by 43.5% and 35.9%, and increased albumin by 21.3% (P < 0.05). MFEE decreased hepatic malondialdehyde and tumor necrosis factor-α levels, restored glutathione, superoxide dismutase activity, and interleukin-10 levels, and reduced caspase-3 immunoreactivity (P < 0.05). Furthermore, MFEE partially reversed MTX-induced transcriptional alterations in antioxidant-defense (Nfe2l2, Keap1, Hmox1, and Nqo1), inflammatory (Rela, Tnf, and Il6), and apoptotic (Bax, Bcl2, and Casp3) genes (P < 0.01–0.001), while ameliorating hepatic histopathological lesions. Overall, early post-exposure MFEE attenuated MTX-associated liver injury, accompanied by improved oxidative, inflammatory, apoptotic, and histopathological indices. However, transcriptional changes indicate pathway-associated responses rather than direct evidence of pathway activation or causal mechanisms without protein-level and pathway-specific functional validation.