Preliminary results on the interactive effects of deoxynivalenol, zearalenone and fumonisin B on porcine lymphocytes.

Fusarium mycotoxins, such as fumonisin B (FB), deoxynivalenol (DON) and zearalenone (ZEN), frequently co-occur in feed raw materials and their presence is ubiquitous. The aims of this study were to determine the concentration that inhibits cell viability by 50% (IC values) for each mycotoxin (after 24, 48 and 72 h) and to investigate their combined effects in binary (DON + ZEN: DZ, DON + FB: DF, FB + ZEN: FZ) and ternary (DFZ) mixtures using cyto- and genotoxicity on porcine lymphocytes as endpoints. The potency of cytotoxicity of the three toxins in an increasing order was FB < ZEN < DON. The range of IC values depending on the period of exposure was 0.31-0.42 μg/ml and 16.6- 22.9 μg/ml for DON and ZEN, respectively, and 101.15 μg/ml for FB (50% viability was reached only after 72 h). The main interaction observed was antagonism regarding cytotoxicity. Lower and higher sets of concentrations were used for the genotoxicity (comet assay) experiments. When lower concentrations were used, antagonism was again the main interaction observed. However, at higher concentrations an antagonism was confirmed only for DFZ, whereas for DZ and FZ a synergism was observed. Interactions of DF were inconsistent in different exposure periods in both series of experiments. Further studies with additional endpoints should be performed (e.g. DNA fragmentation, protein synthesis) in order to elucidate the mechanisms underlying the interactions observed.