A Study of Single and Combined Cytotoxic Effects of Fumonisin B1, Aflatoxin B1 and Ochratoxin a on Human Mononuclear Blood Cells using Different Cytotoxic Methods
Several studies on cereals destined for animal or human consumption in South Africa and Africa have shown co-contaminations of mycotoxins. There is evidence to suggest that the simultaneous action of different mycotoxins at various concentrations might have synergistic, inhibitive or additive effects on human and animal cells. The aims of this study were to identify combined cytotoxic effects of three of the more commonly occurring mycotoxins (aflatoxin B1 (AFB1) fumonisin B1 (FB1) and ochratoxin A (OTA)) found in South African and other feeds using the methyl thiazoltetrazolium (MTT) cytotoxicity assay, the Comet assay and Flow Cytometry to detect apoptotic and necrotic cells after exposure to the three toxins. Human mononuclear blood cells (mononucleocytes) were exposed to the three mycotoxins both singularly and in combinations at two concentrations (5 and 40ng/ml for OTA and AFB1 and 5 and 40µg/ml for FB1) and at different exposure time of 12, 24 and 48Hours. Results obtained showed cell viability variations dependent on mycotoxin concentrations and time of exposure. In addition, synergistic effects were also observed at the higher doses of 40ng for OTA and AFB1) and 40µg/ml for FB1 of the three mycotoxins compared to combinations of lower doses. However, FB1 showed low cytotoxicity effect inducing inhibitive effect when combined with the other two mycotoxins. These results confirms the hypothesis of possibility of the three mycotoxins when combined induced with synergistic effect and imply that exposure to more than one mycotoxin might change the symptomatology and severity of effects observed during single intoxications by mycotoxins.
