Histopathological and immunohistochemical evidence of the carcinogenic potential of ethidium bromide in the colon of Wistar albino rats

Ethidium bromide is a dye that is commonly used as a stain in various molecular biology techniques. This study assessed the carcinogenic potential of ethidium bromide (EtBr) on the colon of Wistar rats through histological and histochemical analyses. In this study, forty (40) healthy male Wistar albino rats weighing 100± 20g were employed. They were segregated into eight groups, each consisting of five rats. Group I served as the control, whereas Groups II through VIII received oral doses of 5, 10, 20, 40, 60, 80 and 100mg EtBr per kilogram body weight (kg-1 bd wt) respectively once weekly for a duration of 24 weeks. The light microscopy examination of hematoxylin and eosin stained sections of the colon demonstrated the typical architecture of rat colons in the control group, while groups II through VIII exhibited indications of precancerous and/or cancer-related alterations, including hyperchromatic nuclei and prominent nucleoli. Immunohistochemistry analysis utilizing cytokeratin 20 (CK 20) on colon sections revealed negative results for rats in the control group (Group I) and positive outcomes for rats exposed to ethidium bromide. This research provides conclusive evidence indicating the carcinogenic potential of ethidium bromide in Wistar albino rats.