Cadmium and decabrominated diphenyl ether mixture: In vitro evaluation of cytotoxic, prooxidative and genotoxic effects

• We tested the hypothesis that a mixture of Cd and BDE-209 may produce greater cytotoxicity and DNA damage than the individual chemicals alone.
• We tested if the ROS production is a mechanism involved in combined Cd and BDE-209 toxicity.
• Human colon carcinoma cell line (SW 480) was used as an in vitro test system.
• Mixture toxicity was evidenced by cytotoxicity associated with ROS generation.
• Factorial regression model revealed synergism between chemicals for cytotoxicity and additive interaction for ROS production.

In order to look into the combined effects of Cd and BDE-209 in vitro, this study was aimed at examining cytotoxic and genotoxic effects using the human colon carcinoma cell line (SW 480) as a biological test system as well as to determine if ROS production was one of the possible mechanisms of their mixture action. This cell line was chosen since ingestion of contaminated food/water represents an important route of exposure to both Cd and BDE-209, which is why intestinal cells are a common target for the contaminants present in food and water. Cells were treated with single Cd in concentrations of 2.5, 7.5 or 15 μg Cd/mL (corresponding to 22, 67 or 134 μM), single BDE-209 in concentrations of 2.5, 5 or 10 μg BDE209/mL (corresponding to 2.5, 5 or 10 μM), and their mixtures (design 3 × 3).Mixture of Cd and BDE-209 has shown clear potential to reduce the viability of SW 480 cells, as evidenced by cytotoxicity associated with ROS generation. Factorial regression models used to identify type of interaction revealed synergism related to mixture citotoxicity and additive interaction for the effect on ROS production. The results from this introductory study could contribute to the issue of possible adverse effects associated with co-exposure and body burden with two persistent environmental pollutants, Cd and BDE-209.