A rapid and sensitive cytotoxicity screening assay for trichothecenes in cereal samples

The application of a bioassay for toxicity screening of cereal samples has been studied. The sensitive Swiss mouse 3T3 fibroblasts (3T3 cells) were used to determine the cytotoxicity of Fusarium trichothecenes T-2 toxin (T-2), HT-2 toxin (HT-2), deoxynivalenol (DON) and nivalenol (NIV) in cereal samples. Clean-up of the sample extracts was performed using the MycoSep™ #225 column and the cytotoxic effects of the samples were determined using the 5-bromo-2′-deoxyuridine (BrdU) bioassay assessing DNA-synthesis. Trichothecene-free samples of wheat, wheat bran and barley had no toxic effect on the 3T3 cells at sample concentrations up to 400 mg/ml cell culture medium while a few oat samples had an inhibiting effect on the DNA-synthesis. IC50 values (50% response compared with untreated cells) of trichothecene-free wheat and oats spiked with T-2, HT-2, DON and NIV were similar to IC50 values of pure toxins. A cytotoxicity screening of 33 different cereal samples showed that all samples contaminated with a trichothecene concentration higher than the IC50 values of T-2, HT-2, DON and NIV had a clear inhibiting effect on DNA-synthesis of the 3T3 cells. The culture of 3T3 cells on microtiter plates in combination with the simple and rapid sample clean-up using the MycoSep™ #225 column provides a sensitive and easy method for the screening of trichothecenes in cereal samples.