Hepatotoxic Effects of the Dermal Exposure of Albino Rats to Bonny Light Crude Oil

Abstract The effect of consistent exposure of the inhabitants in the Niger Delta region of Nigeria to crude oil may induce undesirable biochemical changes in the biota. Alterations in some hepatic function indices of male and female albino rats exposed to Bonny light crude oil (BLCO) by skin application were investigated. Sub lethal dose (500mg/kg body weight) of the BLCO was applied to shaved portion of the dorsal skin of the exposed rats while controls were similarly exposed to a placebo. After 30 days intervals sets of rats were weighed, sacrificed and their blood collected for serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT) and serum albumin (SA) assay. The rat liver was also carefully excised, weighed and examined for histological changes. Results show that the relative liver weight decreased by 66.97% after 90 days in the males and increased by 9.25% after 90 days in females. SGOT and SGPT levels increased significantly (p< 0.05) in both male and female rats during the study period. Changes in SGPT levels were more pronounced in the females compared to the males. The SA content decreased by 15.4% after 30 days and increased significantly (p< 0.05) by 52.1% after 90 days for the males. In the females, SA content increased by 12.5% after 30 days and decreased by 5.3% after 90 days. Histological examination of the liver cells of rats exposed for 90 days showed vacuolar degeneration, macrovisicular steatosis of hepatocytes and areas of necrosis compared to controls. These effects were more pronounced among the female rats compared to the males. These results suggest that the prolonged dermal exposure of albino rats to BLCO which leads to absorption into the blood stream and subsequent uptake by the liver may exert damaging effect on hepatocytes thereby causing hepatotoxicity.