RESUMO
Flupyradifurone (FPD), a member of the new class of butenolide insecticides, acts on nicotinic acetylcholine receptors. Studies on genotoxic and carcinogenic effects of FPD are very limited. This is the first study to investigate the cytotoxic and genotoxic effects of FPD and its metabolites on human lymphocyte cultures with or without a metabolic activation system (S9 mix) using chromosomal aberration (CA) and micronucleus (MN) tests. The cultures were treated with 85, 170, and 340 µg/ml of FPD in the presence (3 h treatment) and absence (48 h treatment) of S9 mix. Dimethyl sulfoxide (DMSO) was used as a solvent control. Statistically significant decreases were detected at the medium and highest concentrations for 48 h treatments while decreases in mitotic index (MI) in the presence of the S9 mix were found statistically significant at all FPD concentrations tested when compared with the solvent control. FPD also decreased the nuclear division index (NDI) at the highest concentration (340 µg/ml) in the absence of S9 mix. When compared with the solvent control, increases in CA frequencies were significant at the medium and highest concentrations. Significantly increased MN frequency was only found at the highest FPD concentration in cultures without S9 mix compared with the solvent control while increases in the MN frequencies in the presence of S9 mix were statistically significant at all FPD concentrations. The results of the present study indicate that FPD and its metabolites can show cytotoxic and genotoxic effects in human lymphocytes. More genotoxicity studies are necessary to make a possible risk assessment in humans.