Vol. 6, Issue 2, Part A (2024)

In Nigeria today, most of our food crops are produced in rural areas, which unfortunately are also the primary sites of crude oil exploration. Despite the substantial revenue generated from these areas, the government pays little attention to preventing or minimizing the effects of oil spills during exploration. The negative impact of crude oil exploration and exploitation on the health of exposed individuals cannot be overstated, regardless of the economic benefits. Furthermore, the consumption of crude oil-contaminated plant extracts by rural populations in oil-rich regions-who use them as traditional medicine-has raised concerns about safety both locally and internationally. This study aimed to investigate the effects of administering aqueous extracts of both crude oil-contaminated and uncontaminated Mangifera indica stem bark in Wistar albino rats. A total of 80 female Wistar albino rats, with an average weight of 155 g, were used. Crude aqueous extracts of M. indica stem bark contaminated with crude oil were collected from an oil spill site at Ibeno shoreline in Akwa Ibom State, Nigeria, and compared with aqueous extracts of M. indica stem bark from an uncontaminated environment at the University of Benin, Ugbowo, Benin City, Edo State. The rats were divided into five groups: Group I served as the control, while Groups II and III received 250 mg/kg and 3500 mg/kg body weight of aqueous extract of contaminated M. indica, respectively. Groups IV and V received 250 mg/kg and 3500 mg/kg body weight of aqueous extract of uncontaminated M. indica. The experiment lasted 90 days. The results showed significant increases (p<0.05) in monocytes, lymphocytes, granulocytes, platelets (PLT), white blood cell (WBC) counts, and procalcitonin (PCT), along with significant decreases (p<0.05) in hemoglobin (HB) and red blood cell (RBC) counts in rats from Groups II, III, and V compared to the control group. Group III exhibited the highest significant increase. In contrast, rats in Group IV, which received 250 mg/kg of aqueous extract from uncontaminated Mangifera indica, showed non-significant decreases in granulocytes, RBC, PCT, and HB levels. These variations were found to be dose-dependent and influenced by the source of the extracts. Hence, these findings indicate that the administration of aqueous extracts from both crude oil-free and contaminated plants resulted in an increase in immune cell levels, such as white blood cells (WBCs), while simultaneously decreasing red blood cell (RBC) levels. This response suggests a triggered immune reaction due to the toxicity of the extracts in rats, indicating their hematotoxic potential.