Bioactivity and Toxicological Studies of Ethanolic Extract of Monodora myristica Seeds in Male Albino Rats

Abstract

Monodora myristica (African nutmeg) is a west African spice with reported ethnomedicinal use yet its cardioprotective and toxicological effects remain underexplored. This study evaluated the phytochemical composition and cardioprotective effects of ethanolic seed extract of M. myristica in indomethacin- and metoprolol-induced toxicity in rats. Thirty male albino rats (n = 6/group) were assigned to control, drug-only, and co-treatment groups. Animals received indomethacin (0.5 mg/mL) or metoprolol (0.5 mg/kg), with or without M. myristica extract (200 mg/kg) for 28 days. Serum and cardiac homogenates were analyzed for antioxidant enzymes, lipid peroxidation, CK, LDH, and lipid profile. Proximate analysis revealed high carbohydrate (29.6%) and crude fat (23.5%), with essential minerals such as magnesium (72.7 mg/100 g). Phytochemical screening confirmed flavonoids, tannins, alkaloids, and saponins. Indomethacin and metoprolol suppressed antioxidant defenses (SOD: 1.08 ± 0.05 to 0.61 ± 0.03 U/mL protein; CAT: 175 ± 4.3 to 102 ± 3.9 µmol/mL) and elevated MDA (1.50 ± 0.07 to 4.01 ± 0.13 mg/dL). Extract co-treatment significantly restored antioxidant enzymes (GPx: 115.3 ± 0.4 vs. 75.0 ± 1.9 U/L protein in indomethacin-only, p < 0.05) and reduced MDA (2.00 ± 0.09 mg/dL). Dyslipidemia induced by metoprolol (cholesterol: 138.2 ± 4.2 mg/dL vs. control 75.1 ± 2.8 mg/dL) was corrected by the extract (98.4 ± 3.5 mg/dL). CK showed only minor, non-significant changes, while LDH elevations were partially normalized. Histology confirmed myocardial protection in extract-treated groups. M. myristica mitigates drug-induced oxidative stress, lipid peroxidation, and dyslipidemia, supporting its ethnomedicinal application and potential as a functional food or nutraceutical for cardiovascular health.