The genotoxic and cytotoxic effects of ribavirin in rat bone marrow

The genotoxicity of the 2-furylethylene derivative 1-(5-bromofur-2-yl)-2-nitroethene (2-betaNF) has been evaluated in cultured human peripheral blood lymphocytes at concentrations ranging from 0.5 to 15microg/ml. The frequencies of micronuclei (MN) and sister-chromatid exchanges (SCEs) were used and scored as indicators of genetic damage. To asses the role of the metabolism mediated by the enzymes present in the S9 mix, over the possible genotoxic potential of the test agent, the cultures for MN and SCE demonstrations were treated for 3h in presence and in absence of rat liver microsomal fraction. The results indicate that, under the experimental conditions used, the test agent does not induce significant increases in the frequency of micronucleated cells, irrespective of the presence/absence of metabolic fraction. Nevertheless, a slight increase in the SCE frequency was observed in those cultures treated without the S9 mix; although this slight increase disappeared in the experiments carried out with the microsomal fraction. In addition, cytotoxic/cytostatic effects of (2-betaNF) were observed mainly in the cultures treated without the S9 fraction.