Vol. 7, Issue 2, Part B (2025)

Oil pollution, a stealthy environmental threat stemming from the extraction, processing, and transport of crude oil, profoundly impacts ecosystems and human well-being, especially in areas like Nigeria’s Niger Delta, where widespread contamination degrades farmlands and medicinal plants. This study investigated the biochemical impacts of aqueous extracts from crude oil-contaminated (C) and uncontaminated (F) Mangifera indica stem barks on Wistar albino rats. Stem bark and soil samples were collected from a crude oil-contaminated farmland in Rivers State, Nigeria, and a control site at the University of Benin. Aqueous extracts from these stem barks were administered orally at 250 or 3500 mg/kg body weight to five groups of female rats (n=16) for 90 days. Liver, kidney, and heart tissues were analyzed for RNA, DNA, and protein concentrations. Gene expression of kidney injury molecule-1 (KIM-1), monocyte chemoattractant protein-1 (MCP-1), phosphofructokinase-1 (PFK-1), O-GlcNAcase (OGA), O-GlcNAc transferase (OGT), and glutathione peroxidase (GPx) were quantified via Image J software, with β-Actin serving as the reference primer. Significant reductions (p<0.05) in RNA, DNA, and protein concentrations were observed in treated groups compared to controls, with the most significant decreases in rats receiving 3500 mg/kg of extract C, likely due to crude oil metabolites and high phytochemical doses inducing oxidative stress and genotoxicity. Upregulation (p<0.05) of KIM-1, MCP-1, PFK-1, OGA, and GPx genes in treated rats indicated renal injury, metabolic stress, and antioxidant responses, particularly in the C-treated group at 3500 mg/kg. OGT expression showed dose-dependent increases, suggesting cellular stress via altered glycosylation. These effects could be attributed to reactive oxygen species from crude oil metabolites and phytochemicals, disrupting biomolecular integrity and cellular function. The findings highlight the toxicological risks of crude oil-contaminated plant extracts, with implications for environmental and public health in contaminated regions.