The Use of Isolated Human Lymphocytes in Mycotoxin Cytotoxicity Testing

The cytotoxicity of selected mycotoxins against isolated human lymphocytes was investigated, as a means of detecting mycotoxins in extracts derived from cereal samples. The methodology was based on the ability of viable cells to reduce methyl tetrazolium bromide to a purple formazan dye that could be quantitated by spectrophometric means and hence give a measure of the cytotoxicity of added substances. The results showed that there was good correlation with the occurrence of identified mycotoxins with only a minimum of false positives. For example, of the 13 samples of barley or barley derivatives that were positive for the mycotoxins, fumonisin B(1) (FB1) deoxynivalenol (DON) and ochratoxin A (OTA), all gave positive cytotoxicity responses. Two samples negative for mycotoxins gave no cytotoxicity responses. There was little variation between the results for lymphocytes drawn from the same healthy volunteer on three different occasions. Furthermore, for two of the mycotoxins tested (FB1 and DON) it was possible to correlate general levels of mycotoxins present to the cytotoxic response of the lymphocytes but not for OTA, where it was concluded that interfering substances prevented direct correlation. It was concluded that this method was suited for general application as it could handle relatively high number of samples in a short period of time.