Assessment of the genotoxicity of propineb in mice bone marrow cells using micronucleus assay

Determination of micronuclei frequency in Danio rerio for assessing genotoxicity induced by propineb

The aim of this study was to investigate the genotoxic effect of Propineb fungicide at different concentrations (0.167, 0.335 and 0.670 mg L-1) and different treatment times (24, 48, 72 and 96 h) on Danio rerio. At the end of the treatment periods, blood was collected from the fish with a heparin injector; smear preparations were prepared, fixed and stained. In the prepared preparations, the numbers of cells with MN and erythrocyte nucleus abnormalities were examined. It was found that propineb increased micronucleus formation at all treatment times and concentrations and induced the formation of erythrocytes with morphological abnormal nuclei such as segmented, kidney-shaped, notched, vacuolated nuclei and binucleated. The increase in micronucleus formation and the number of erythrocytes with abnormal nuclei were found to be concentration and treatment time-dependent. In conclusion, in this study, Danio rerio erythrocytes were used to evaluate the genotoxic effects of propineb fungicide on aquatic organisms, which have an important place in environmental risk assessment criteria. Since fungicides used in agricultural control such as propineb may have the potential to be genotoxic to aquatic organisms, the results of toxicity tests should be taken into consideration in the selection and use of concentrations of these chemicals.

Occupational Exposure to Pesticides in Tobacco Fields: The Integrated Evaluation of Nutritional Intake and Susceptibility on Genomic and Epigenetic Instability

Pesticides used at tobacco fields are associated with genomic instability, which is proposed to be sensitive to nutritional intake and may also induce epigenetic changes. We evaluated the effect of dietary intake and genetic susceptibility polymorphisms in MTHFR (rs1801133) and TERT (rs2736100) genes on genomic and epigenetic instability in tobacco farmers. Farmers, when compared to a nonexposed group, showed increased levels of different parameters of DNA damage (micronuclei, nucleoplasmic bridges, and nuclear buds), evaluated by cytokinesis-block micronucleus cytome assay. Telomere length (TL) measured by quantitative PCR was shorter in exposed individuals. Global DNA methylation was significantly decreased in tobacco farmers. The exposed group had lower dietary intake of fiber, but an increase in cholesterol; vitamins such as B6, B12, and C; β-carotene; and α-retinol. Several trace and ultratrace elements were found higher in farmers than in nonfarmers. The MTHFR CT/TT genotype influenced nucleoplasmic bridges, nuclear buds, and TL in the exposed group, whereas TERT GT/TT only affected micronucleus frequency. We observed a positive correlation of TL and lipids and an inverse correlation of TL and fibers. The present data suggest an important role of dietary intake and subjects' genetic susceptibility to xenobiotics-induced damages and epigenetic alterations in tobacco farmers occupationally exposed to mixtures of pesticides.

Assessment of genotoxicity of Lannate-90® and its plant and animal metabolites in human lymphocyte cultures

This study evaluated direct and metabolic genotoxic effects caused by Lannate-90®, a methomyl-based formulation (90 % active ingredient), in human lymphocyte cultures using sister chromatid exchange assay (SCE). Two processes were used for the plant promutagens evaluation: in vivo activation, applying the insecticide systemically in plants for 4 h and subsequently adding plant metabolites containing extracts to lymphocyte cultures; and in vitro activation, where the insecticide was incubated with Vicia faba S10 mix plus human lymphocyte culture. Direct treatment with the insecticide significantly increased SCE frequency in human lymphocytes (250-750 mgL-1), with cellular death observed at 1000 mgL-1 concentration. Using the extracts of Vicia faba treated with Lannate-90® to treat human lymphocytes, a dose-response relationship was observed. In lymphocyte cultures treated directly with the insecticide for 2 h, a negative response was obtained. When S10 mix was added, SCE frequency did not change significantly. Meanwhile, a mixture of S9 mammalian metabolic mix and Lannate-90® increased the SCE frequency, with an observed concentration-dependent response. Although Lannate-90® induced cellular death at the highest concentrations, it did not cause a delay in cell proliferation in any of the treatments, confirming its genotoxic action. This study is one of the first to evaluate and compare the direct effect of Lannate-90® in two bioassays, animal and vegetal, and the effect of plant and animal metabolism on its genotoxic potential.