Cytotoxic effects of individual and binary combinations of zearalenone and ochratoxin a on liver

Co-contamination with mycotoxin represents a serious concern for human and animal health. In this in vitro study, we investigated the combined effects of ZEA and OTA, mycotoxins which frequently contaminate cereals, in binary mixtures on the viability of human liver cancer cell line (HepG2). Cell viability was assessed after 24 h using a neutral red assay. An antagonistic effect was observed for binary toxins combinations affecting 25% of cell viability (CI=4.18), which turn into a synergistic effect as followed: slight at IL₅₀ (CI=1.51), moderate at IL₇₅ (CI=0.554) and strong at IL₉₀ (CI=0.203). In conclusion, our results show an important additive and even synergistic cytotoxic effect of two commonly occurred mycotoxins: zearalenone and ochratoxin when they are present simultaneously in food or feed. The co-exposure to mycotoxins lead to a higher toxicity than the exposure to single toxin. Our study provides important data for mycotoxins risk assessment. In this context, a re-evaluation of the guidance levels for mycotoxins will be required in the future, in order to reduce the health risk associated with the possible consumption of mycotoxin co-contaminated food or feed.