Genotoxic and aneugenic properties of an imidazole derivative

Assessment of Potential Clastogenic Effect of the Insecticide Mospilan® 20SP in Human Peripheral Blood Lymphocytes After in Vitro Exposure

Acetamiprid, that is known as the commercial formulation Mospilan® 20SP is the part of the neonicotinoid insecticide group and is widely used against various pests. In our study we assessed the potential clastogenic effects of Mospilan® in human peripheral blood lymphocytes in vitro using a chromosome aberration test. The lymphocytes were treated with acetamiprid in the concentration range of 5, 10, 25 and 50 µg.ml−1 for 24 and 48 h. After 24 h exposure, the insecticide induced statistically significant higher levels of chromosome aberrations from the concentration of 10 µg.ml−1 (P < 0.05 and P < 0.001) and a significant decrease in mitotic index (MI) at the concentrations of 25 and 50 µg.ml−1 (P < 0.05 and P < 0.01), respectively. After a 48 h exposure, we found a dose dependent increase in the percentage of chromosome aberrations at all concentrations (P < 0.05; P < 0.01 and P < 0.001) and a decrease in MI at concentrations of 25 and 50 µg.ml−1 (P < 0.05 and P < 0.01). Our results indicated that neonicotinoid insecticide formulations containing acetamiprid may have potential cytotoxic and genotoxic effects.

Assessment of cytogenetic damage in bovine peripheral lymphocytes exposed to in vitro tebuconazole-based fungicide

The tebuconazole-based fungicide was tested in vitro for its potential genotoxic and cytotoxic effects on cultured bovine peripheral lymphocytes. Following 24h and 48 h of incubation, several cytogenetic endpoints were investigated such as: Chromosome Aberrations (CAs); Sister Chromatid Exchanges (SCEs); Micronuclei (MN); Mitotic Index (MI); Proliferation Index (PI); and Cytokinesis Block Proliferation Index (CBPI). The cultured lymphocytes were exposed to the fungicide formulation at concentrations of 3, 6, 15, 30 and 60 μg mL(-1). Statistical significant increases were seen in the CA assays at concentrations ranging from 6 to 30 μg mL(-1) for 24h. The higher doses caused a decrease or total inhibition of chromosome damages in comparison to the last active dose, or the control values. The Fluorescence in situ Hybridisation (FISH) technique was also used for the study of stable/unstable structural chromosomal aberrations and numerical aberrations of aneuploidy/polyploidy at the concentrations of 6 and 15 μg mL(-1). Under conditions of our study, no reciprocal translocations were detected. The more frequent types of aberrations were trisomies and monosomies; both have been identified in association with either bovine chromosome 5 or 7. No statistical significant value was seen in the induced MN; but, the clear, evident reduction of the CBPI was observed. Significant elevations of SCE were observed after the applications of the fungicide formulation at doses from 15 to 60 μg mL(-1) in each donor for 24h. The highest concentrations also caused a statistical significant decrease in the PI. The treatment for 48 h failed to exhibit any genotoxic activity of the fungicide.

In vitro aneugenic effects of the fungicide thiabendazole evaluated in human lymphocytes by the micronucleus assay

Thiabendazole is a benzimidazole-derived compound widely employed in agriculture as anthelmintic and fungicide. It is also used as a post-harvest fungicide for imported citrus fruits during transport and storage, and thus, it was found at high concentration in fruits and vegetables. Several studies have analyzed the potential genotoxic effect of thiabendazole on different prokaryotic and eukaryotic systems, but in many cases, results were contradictory. In the present study, the genotoxic potential of thiabendazole have been evaluated, by micronucleus assay in freshly isolated human peripheral lymphocytes. The cells were incubated with 0.5, 5 and 50 μg/ml concentrations of the tested substance for 48 h at 37°C. Mitomycin C at final concentration of 0.01 μg/ml culture was used as a positive control. The results indicated that the thiabendazole significantly (P < 0.05) increased the micronucleus frequency compared with the negative control in all treatment concentrations, indicating a potential aneugenic hazard of thiabendazole in cultured human peripheral lymphocytes. The cytokinesis-block proliferation index value, however, was not decreased significantly compared with the negative control. Significant (P < 0.05) differences in the micronuclei frequency were also found between the lower dose (0.5 μg/ml) and the other two analyzed doses of thiabendazole. In contrast, no differences were found between 5 and 50 μg/ml of thiabendazole and between DMSO and negative control. Finally, control cultures treated with the known mutagen MMC showed a very consistent increase in MN with respect to the negative controls.