Genotoxic activity of the Fumonisin B1 mycotoxin in cultures of bovine lymphocytes

The fumonisins, produced by fungi that infest foodstuffs, in particular corn, are responsible for a series of illnesses and toxicosis in various species of animals, including humans. There is still not detailed information about the genotoxic and mutagenic activity of Fumonisin B1 (FB1), but it is clear that it interferes with growth control, differentiation and cellu- lar apoptosis. The purpose of this study was to assess the genotoxic potential of Fumonisin B1 using in vitro cultures of bovine lymphocytes, through the calculation of the ‘mitotic index’ (MI), the frequency of ‘sister chromatid exchange’ (SCE) and the ‘micronucleus test’ (MN). The bovine lymphocytes were exposed to different concentrations of FB1 (25, 50 and 100 µ M) in order to find out which amount is sufficient to cause a reduction in the mitotic potential of the cells, the onset of MN and a higher frequency of SCE. The results obtained show a considerable reduction in the ‘mitotic index’ with a FB1 concentration of 50 µ M, an increase in the frequency of MN with a concentration of 50 µ M and a significant increase in the SCE with a concentration of 100 µ M. In the light of the information we have obtained, compared with that of other Authors, we feel that the genotoxic poten- tial of FB1 has been underestimated until now and should, therefore, be reconsidered.