Hepatotoxicological evaluation of water-soluble fraction (WSF) of Bonny Light crude oil (BLCO) in Wistar albino rats

Background: It is common practice to pay more attention to the clearing of visible surface petroleum spills in streams and rivers which serve as the main source of drinking water in polluted sites in the Niger Delta area rather than taking cognizance of dissolved aromatic hydrocarbons and metallic ions which are major components of petroleum products. For this reason, the toxicological effect of the water soluble fraction (WSF) of Bonny light crude oil (BLCO) was evaluated.
Methods: The range finding test was determined to be higher than 100% and showed no mortality or physical changes after 7 days. Wistar albino rats were exposed to three different concentrations (25, 50 and 100%) of WSF (BLCO) for a period of 28days.
Results: Data from the study showed a significant (p≤0.05) increase in liver marker enzymes [aspartate amino transferase (AST), alanine amino transferase (ALT), alkaline phosphatase (ALP)] and biochemical parameters (cholesterol, urea, total and direct bilirubin) in rats exposed to WSF (BLCO). Generally, the increase in the level of biochemical parameters was concentration dependent with rats in the group treated with 100% concentration showing the highest activity when compared with control. There was a marginal decrease in the level of packed cell volume (PCV) and haemoglobin (Hb) in rats exposed to WSF (BLCO). White blood cell (WBC) of rats exposed to 25 and 50 % WSF (BLCO) increased marginally whereas a significant (p≤ 0.05) increase was observed in the group exposed to 100% of WSF (BLCO). The histological examination of rats exposed to different concentrations (25, 50 and 100%) of WSF (BLCO) were characterized by fatty change, inflammation of the cell whereas rats in the control group showed normal architecture.
Conclusion: The findings of this study highlights the deleterious and toxicological effects of exposure to water polluted by dissolved aromatic hydrocarbons probably present in WSF (BLCO).