Cytotoxicity and genotoxicity induced by aflatoxin B1, ochratoxin A, and their combination in cultured vero cells

Aflatoxin B1 (AFB1) and ochratoxin A (OTA) are important food-borne mycotoxins that have been implicated in human health. In this study, independent and combinative toxicities of AFB1 and OTA were tested in cultured monkey kidney Vero cells. The experiments reported here were conducted to evaluate the effect of these toxins on cell viability followed by the determination of cell death pathways, using the quantification of DNA fragmentation and the expression of p53 and bcl-2 protein levels. Our results showed that AFB1 and OTA caused a marked decrease of cell viability in a dose-dependent manner. Under the same conditions, these mycotoxins increased fragmented DNA levels. In addition, p53 was activated in response to DNA damage and the expression of the antiapoptotic factor bcl-2 decreased significantly. According to these data, AFB1 and OTA seemed to be involved in an apoptotic process. Moreover, combined AFB1 and OTA induced all the toxicities observed with the mycotoxins separately. Therefore, this combination was classified as an additive response of the two mycotoxins.