Micronucleus frequency in sheep lymphocytes after in vitro exposure to fungicide tolylfluanid

Abstract

The fungicide tolylfluanid (N - dichlorofluoromethylthio-N′, N - dimethyl - N - p - tolylsulfamide), was investigated by cytokinesis-block micronucleus assay. Tolylfluanid at the lowest concentration (1 × 10^{− 6}mol L^{− 1})did not influence significantly the frequency of micronuclei in sheep lymphocyte cultures in comparison with control (32.33 ± 3.51/1000 binucleated cells versus 30.33 ± 2.82/1000 binucleated cells in dimethylsulfoxide (DMSO) control, P = 0.44). Higher tolylfluanid concentrations (1 × 10^{− 4} and, 1 × 10^{− 5} mol L^{− 1}) resulted in a significant dose-dependent increase in the number of micronuclei in comparison with control (74.00 ± 13.00/1000 binucleated cells and 52.67 ± 10.12/1000 binucleated cells versus 30.33 ± 2. 82/1000 binucleated cells in DMSO control, P = 0.005 and 0.02, respectively, ANOVA followed by Tukey test P < 0.05). Many of the treated cells also possessed multiple micronuclei. Tolylfluanid did not affect the nuclear division index at all treatment concentrations. Our in vitro results thus demonstrate that tolylfluanid had a significant genotoxic effect at only the highest concentration tested.

Keywords:

• Tolylfluanid
• micronucleus assay
• sheep lymphocytes
• genotoxicity
• cytotoxicity

Acknowledgments

This study was supported by Vedecká grantová agentúra Ministerstva školstva SR a slovenskej akadémie vied Scientific Grant Agency of the Ministry of Education of Slovak Republic and the Slovak Academy of Sciences VEGA Grant No. 1/0545/08 and the National Reference Laboratory for Pesticides, University of Veterinary Medicine and Pharmacy in Košice, Slovakia. Authors declare that there are no known conflicts of interest concerning this paper with other authors.

Notes

***Significantly different from the control P = < 0.001 (ANOVA).

**Significantly different from the control P = 0.005 (ANOVA).

*Significantly different from the control P = 0.020 (ANOVA).

† Significantly different from the control P < 0.05 (Tukey test, all pairwise multiple comparison procedures); ns–statistically non -significant difference;