Individual and Combined Cytotoxic Effects of Co-Occurring Deoxynivalenol Family Mycotoxins on Human Gastric Epithelial Cells

Mycotoxin contamination is a significant health concern for human beings, but health risk assessments are usually based on one single mycotoxin, which might neglect the additive or competitive interactions between co-occurring mycotoxins. In this study, we assessed the individual or combined toxicological effects to multiple deoxynivalenol-family mycotoxins, namely deoxynivalenol (DON), Nivalenol (NIV), and their acetyl derivatives of 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON), deoxynivalenol-3-glucoside (D3G), and Fusarenon-X (FX) based on the human gastric epithelial (GES-1) cells. GES-1 cells were treated at different concentrations over 24 h and cell viability was measured by a cell counting kit (CCK8). The results show that D3G has no toxicity and 3-ADON is less potent in reducing cell viability compared to DON, whereas 15-ADON and FX appear to be slightly less potent than their parent compounds of DON and NIV on GES-1 cells. In general, the toxic ability of individual mycotoxins was shown as 3-ADON << 15-ADON < DON < FX < NIV, in an increasing order. All mixtures caused a dose-dependent decline of cell viability and the interactions analysis of binary combinations were assessed using the combination index (CI)-isobologram method. For the interaction types of mycotoxins mixtures, the synergistic cytotoxicity of DON + 15-ADON, DON + NIV, and DON + FX at low and/or moderate inhibitory concentration levels (IC10–IC70, IC10–IC80, and IC10–IC40, respectively) were observed. FX + NIV resulted in almost completely synergistic cytotoxicity, whereas 15-ADON + NIV and 15-ADON + FX presented almost entirely antagonistic cytotoxicity on the GES-1 cell model. These results suggest that the simultaneous presence of low-dose type B trichothecenes in dietary food may be more or less toxic than the prediction based on individual mycotoxins.