Histopathological Effects of Oral BTEX Exposure on the Kidneys, Thymus, and Pancreas in Male Wistar Rats

Background: BTEX compounds (benzene, toluene, ethylbenzene, and xylenes) are hazardous volatile organic compounds commonly found in petroleum derivatives, coal tar, industrial solvents, and a wide range of household products. Due to their pervasive environmental presence and potential for bioaccumulation, understanding their toxicological and histopathological effects is essential. Although extensively studied for their systemic toxicity, their specific effects on vital organs following oral exposure remain underexplored. Objective: This research aimed to assess the histopathological consequences of oral exposure to varying doses of BTEX on the kidneys, pancreas, and thymus in male Wistar rats. Methods: A BTEX mixture was formulated based on the reported LD₅₀ values of each constituent. Twenty-four adult Wistar male rats were randomly divided into four groups: a control group and three experimental groups receiving low (200 µL), medium (400 µL), and high (600 µL) doses of BTEX via oral gavage daily for six weeks. After the exposure period, histopathological analysis was conducted on the kidneys, pancreas, and thymus using standard hematoxylin and eosin staining. Histological alterations were assessed and scored based on severity. Results: Kidney tissue from all BTEX-treated groups exhibited significant damage, including congestion, vacuolar degeneration, epithelial necrobiosis, tubular necrosis, inflammatory infiltration, and thickening of the glomerular basement membrane. Pancreatic tissue showed congestion, islet cell vacuolation and necrosis, and acinar epithelial changes, most pronounced at the low dose. In the thymus, only the low-dose group exhibited vascular congestion, while medium- and high-dose groups displayed no pathological changes. Conclusion: Oral exposure to BTEX, even at low doses, resulted in notable histopathological alterations in the kidneys and pancreas, while the thymus remained relatively unaffected. These findings highlight the potential toxicity of BTEX and the need for further research into its long-term health implications.