DNA damage and oxidative stress induced at low doses by the fungicide hexachlorobenzene in human intestinal Caco-2 cells.

Context: Hexachlorobenzene (HCB), a persistent chlorinated organic chemical, could be detected in human tissues in several countries of the world. Human exposure to Persistent Organic Pollutants (POPs) occurring primarily through diet, HCB and its metabolites are therefore supposed to interact directly with intestinal mucosa.

Objective: The aim of this study was to investigate the possible effects of low doses of HCB on DNA integrity, cellular viability, differentiation and oxidative status in vitro in human colonic carcinoma cell line Caco-2.

Materials And Methods: Cells were exposed to increasing doses of HCB for 14 days to assess the cytotoxic, genotoxic and oxidative properties of this compound. The involvement of oxidative stress in the observed effects was evaluated by co exposure of Caco-2 cells with HCB and α-tocopherol.

Results: Exposure of Caco-2 cells to HCB resulted in a dose-dependent cytotoxicity, DNA damages and alterations of the cell layer integrity and the barrier function. Moreover, exposure of Caco-2 cells to HCB led to an enhancement of H(2)O(2) production and to an increased activity of antioxidant enzymes. In addition, Co exposure of Caco-2 cells to HCB and α-tocopherol reversed the effects observed in cells exposed to HCB alone.

Conclusion: These results suggested that HCB effects on Caco-2 cells could be linked, at least in part, to its pro-oxidative potential.