Investigation of genotoxic changes in mammary epithelial cells and bioactivity of dioxins at reporter gene level in breast milk

Organochlorinated chemicals including dioxins and dioxin-like compounds threat environment and human health. They can easily contaminate living fields and bioaccumulate in adipose tissue in living organisms because of their chemical structures. Because these chemicals have toxic effect on several systems in the organism we considered that bioactivity of these substances should detect at reporter gene level using body fluid. Dioxins and dioxin-like compound can accumalated in breast milk which contain fat. So, human breast milk is one of the critical samples for both mother and baby in order to observe for dioxins. In this study, 50 milk samples were collected from lactating mothers living in İstanbul. Mothers were asked to fill a questionnaire form including personal, medical and nutritional information. Exfoliated epithelial cells were isolated from collected breast milk. Comet assay was used to determine DNA damage in epithelial cells. DR-CALUX assay was used to determine dioxin level in the breast milk. Dioxin level of 27 of samples was above the detection limit. It was observed that DNA damage were high at samples which include high dioxins. These results provide evidence that dioxins can cause genotoxicity in mammary epithelial cells. Furthermore, it was shown that CALUX assay can be used for human biomonitoring and also the human breast milk is very suitable biological sample for this purpose.