In-vivo genotoxicity of the synthetic pyrethroid pesticide "cypermethrin" in rat liver cells by comet assay

ABSTRACT

The comet assay [single-cell gel electrophoresis, "SCGE"] is a simple method for measuring deoxyribonucleic acid [DNA] strand breaks in eukaryotic cells. The assay has applications in testing different chemical and physical agents for genotoxicity and monitoring environmental contamination with genotoxins. The objective of the present study was to evaluate the genotoxic effects of the synthetic pyrethroid pesticide "cypermethrin ", which is widely used in Egypt in pest- control programs in agriculture and in public health as well. Male rats were sacrificed 1, 7 or 14 clays after administration of single oral dose 1/30, 1/10 or 1/5 LD50 of commercial formulation of cypermethrin. Single liver cell suspensions were prepared and Comet assay was performed. With the SCGE assay, a clear induction of DNA damage was observed. It is generally noticed that all pesticide treatments yielded statistically significant [p<0.0001] DNA damage. In conclusion, cypermethrin induced a clear significant positive dose-dependent increase in DNA damage in the rat liver cells exposed to cypermethrin as compared with controls. But the effects in the SCGE were generally decreased with time after treatments. The results of the present work suggested that comet assay might be a suitable and sensitive endpoint in genotoxicity evaluation of pesticides, but we confirm that various tests should be used for detecting the mutagenic activity of pesticides