Vol. 7, Issue 1, Part B (2025)

This study investigated the biochemical effects of aqueous extracts from crude oil-contaminated (C) and uncontaminated (F) Mangifera indica stem bark on female Wistar albino rats. Stem barks were collected from oil-polluted agricultural land in Umuechem, Rivers State (C), and an uncontaminated site at the University of Benin, Edo State (F). Aqueous extracts were prepared by soaking 100 g of powdered bark in 1000 ml distilled water for 72 hours, followed by filtration, concentration via rotary evaporator, and freeze-drying. Eighty rats were divided into five groups: a control group received distilled water, while four treatment groups were administered 250 mg/kg or 3500 mg/kg body weight of C or F extracts orally via gavage for 90 days. Progesterone levels significantly decreased (p<0.05) in animals treated with C and F extracts, with the greatest reduction in animals in group 3 (C, 3500 mg/kg), likely due to crude oil’s endocrine-disrupting properties and phytoestrogens, flavonoids, and terpenes in F extracts. Lipid profiles showed significant increases (p<0.05) in total cholesterol (TC), LDL-C, VLDL-C, and triglycerides in all treated groups compared to the control, with animals in group 3 exhibiting the highest elevation, attributed to liver damage from crude oil metabolism and free radical-induced membrane disruption by F extract phytochemicals, such as saponins, tannins, and quercetin. HDL-C levels significantly decreased (p<0.05) in animals in groups treated with C and F extracts, linked to hepatocyte damage from crude oil metabolites and polyphenol-induced oxidative stress in F extracts. These dose-dependent effects highlighted the toxicological impact of crude oil and phytochemicals on hormonal and lipid metabolism, underscoring environmental and health risks in oil-polluted regions like the Niger Delta, where crude oil spills annually released approximately two million barrels, severely impacting agriculture, marine life, and human health.