Vol. 9, Issue 7, Part C (2025)

Oxidative stress, characterized by an imbalance between reactive oxygen species (ROS) production and cellular antioxidant defenses, plays a pivotal role in cellular damage and disease. This study investigated the toxicological effects of crude oil-contaminated and uncontaminated Mangifera indica stem bark extracts on oxidative stress markers in female Wistar albino rats. Eighty rats were assigned to five groups, receiving daily oral doses of either 250 or 3500 mg/kg body weight of crude oil-contaminated (extract C) or uncontaminated (extract F) aqueous extracts, or distilled water (control), over 90 days. Liver, kidney, and heart tissues were analyzed for lipid peroxidation (malondialdehyde, MDA), total protein content, and antioxidant enzyme activities (catalase, superoxide dismutase, glutathione peroxidase, and reduced glutathione). Results revealed a significant increase (p<0.05) in MDA levels in all tissues of treated animals compared to controls, with the most significant elevation in animals in group 3 (3500 mg/kg extract C), likely due to hydrocarbon and heavy metal toxicity. Total protein levels significantly increased in liver and kidney but decreased non-significantly in heart tissues of treated animals. Antioxidant enzyme activities significantly decreased (p<0.05) in animals administered with extract C, with animals in group 3 showing the highest reductions, attributed to ROS overload from crude oil metabolites. Animals administered with extract F exhibited dose-dependent effects, with high doses of phytochemicals potentially acting as pro-oxidants. These findings highlight the exacerbated oxidative stress induced by crude oil contaminants and underscore the need for biomarkers and therapeutic strategies to mitigate environmental toxicity.