RELATIVE HEPATOTOXIC INFLUENCE OF BENZENE THROUGH ORAL, INTRANASAL, INTRAPERITONEAL AND INTRAVENOUS EXPOSURE IN WISTAR RATS

Benzene is a common industrial and environmental chemical that is known to have hematotoxic and hepatotoxic effect. This study investigated the relative toxicity of orally, intranasally, intraperitoneally and intravenously administered benzene in liver of Wistar rats using biochemical and oxidative stress biomarkers. Thirty albino male rats were divided into five groups such as control that received distilled water and oral, intranasal, intraperitoneal and intravenous group that received 400 mg/kg of benzene daily for seven days. Findings revealed that all the exposed groups (orally, intravenously, and intraperitoneally) had significant high plasma activities of alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) and however, the oral route has the highest activity across all the liver function enzymes. Furthermore, the level of antioxidant molecule such as reduced glutathione and antioxidant enzymes superoxide dismutase, catalase and glutathione S-transferase were significantly depleted in liver homogenate with concomitant increase in malondialdehyde (MDA) levels in all the treated groups relative to control. More importantly, though the activity of superoxide dismutase was significant reduced in intranasal relative to control and intravenous there is more relative reduction in the activities of catalase and glutathione s-transferase in oral route of exposure compared to other treated groups. Therefore, this study concludes that exposure to benzene through oral gavage may be more potent predisposing factor to liver damage compared to intranasal, intraperitoneal and intravenous exposures. The findings highlight the importance of regulatory policies on exposure routes to risk assessment and to provide mechanistic understanding to predictive toxicology and other occupational health protection.