International Journal of Biochemistry Research & Review

Paracetamol overdose is a primary cause of drug-induced hepatotoxicity, mediated through oxidative stress pathways. This study determined the protective efficacy of Allium cepa methanolic extract against paracetamol-induced liver damage. Methanol extract yield of Allium cepa and phytochemical screening was carried out using standard methods. Thirty six (36) adult male albino rats comprising of six (6) normal and thirty(30) hepatotoxic rats were used for this study. Toxicity was induced using  paracetamol (500 mg/kg) orally. Treatment with the extract and observation was done for 21 days. Experimental rats were divided into six groups: normal control, paracetamol control (500 mg/kg), and four treatment groups receiving paracetamol plus Allium cepa extract (50, 100, 150, and 200 ml/kg). Liver functions were determined through liver biomarkers (ALT, AST, ALP, bilirubin, proteins, albumin and globulin), oxidative stress parameters (MDA, GSH, CAT, SOD), and histopathological examination. The percentage yield of the methanol extract of  Allium cepa was found to be 36%w/w. Phytochemicals screening recorded appreciable amount of saponin, alkaloid, flavonoids cardiac glycosides etc. Paracetamol administration caused significant elevation of ALT (53.00 ± 2.45 IU/L) and AST (33.20 ± 2.59 IU/L) compared to normal controls. Co-treatment with Allium cepa extract demonstrated dose-dependent protection, with the 200 ml/kg dose normalizing ALT (26.60 ± 1.52 IU/L) and AST (22.00 ± 2.12 IU/L). The extract significantly reduced oxidative stress by lowering MDA and elevating GSH, CAT, and SOD activities. Histopathological analysis confirmed preserved liver tissue architecture in extract treated groups. The results indicate that A. cepa extract may have provided significant protection against paracetamol-induced hepatotoxicity through antioxidant mechanisms and functional preservation, supporting its potential therapeutic application.