Subchronic mycotoxicoses in Wistar rats: Assessment of the in vivo and in vitro genotoxicity induced by fumonisins and aflatoxin B1 , and oxidative stress biomarkers status

Abstract Some evidence suggests that fumonisin B1 (FB1 ), a worldwide toxic contaminant of grains produced by Fusarium verticillioides , exhibits an oxidative stress mediated genotoxicity. We studied the DNA damage (by the alkaline comet and the micronucleus tests) and biomarkers of cellular oxidative stress (malondialdehyde, MDA; catalase, CAT; and superoxide dismutase, SOD) in spleen mononuclear cells of male Wistar rats subchronically (90 days) fed on a control experimental diet (CED) or poisoned with experimental diets contaminated with a culture material containing 100 ppm of FB1 (FED), with 40 ppb of aflatoxin B1 (a common toxic co-contaminant in cereals, AFB1 ED), and with a mixture of both toxins (MED). The DNA damage was found in 13.7%, 81.7%, 98.0% and 99.3% (comet assay) and in 2.8%, 7.0%, 10.8% and 8.8% (micronucleus technique) in groups CED, FED, AFB1 ED and MED, respectively. The MDA levels as well as the CAT and SOD activities were increased in all the poisoned animals. A similar behavior was observed in cells exposed in vitro to the toxins. These data support the hypothesis of an oxidative stress mediated genotoxicity induced by FB1 . Furthermore, the extent of DNA damage assessed by the comet assay suggests a possible protective effect of the fumonisins–AFB1 mixtures in vitro against the genotoxicity induced individually by the toxins.