engleski

Effect of organochlorine, pyrethroid and neonicotinoid insecticides on fragmentation and deletion rate of TP53 gene and primary DNA damage

Previous reports indicated adverse effect of herbicides on TP53 as a gene which damage promotes carcinogenesis. We evaluated three insecticides, with an emphasis on green agriculture, on their TP53 gene fragmentation and primary DNA damaging potential. Chlorpyrifos, α-cypermethrin as widely used representative of pyrethroids, and imidacloprid as a neonicotinoid, were tested in low concentrations equivalent of acceptable daily intake, residential exposure level, occupational exposure limit for each of insecticides. Common concentration of 3 µg/ml also was tested. Human peripheral blood lymphocytes were treated in extended cultures for 14 days. Comet assay endpoints, rates of TP53 gene fragmentation and deletion were assessed by comet-FISH technique. No increase in tail length or tail intensity compared to control (13.8±1.19 µm and 0.09±0.20% of DNA, respectively) was observed ; only for 3 µg/ml of imidacloprid tail length significantly increased (14.5±1.06 µm). Concerning TP53 structural integrity, no significant increase in rate of gene fragmentation or deletion was detected compared to control (6.7% and 3.3%, respectively). Statistically insignificant increase in TP53 migration in the comet tail was spotted at 3 µg/ml of α-cypermethrin (16.7%) and imidiacloprid (13.3%). Insignificant increase in TP53 deletion rate was observed for α-cypermethrin at 3 µg/ml (10.0%) compared to control (3.3%). Obsereved effects on level of primary DNA damage and TP53 structural integrity and copy number could not be considered biologically significant. At the low concentrations in extended term exposure applied in the study all three insecticides may be considered safe. This work was supported by Croatian Science Foundation under the project 8366.

chlorpyrifos; α-cypermethrin; imidacloprid; gen fragmentation; comet assay; FISH

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