DNA single strand breaks of perchloroethylene and its bio-degradation products by single cell gel electrophoresis assay in mammalian cell system

Abstract

Perchloroethylene (tetrachloroethylene, PCE), a dry cleaning and degreasing solvent, can enter groundwater through accidental leak or spills. PCE can be degraded to trichloroethylene (TCE), 1,1-dichloroethylene (DCE) and vinyl chloride (VC) as potential bio-product. These compounds have been reported that they can cause clinical diseases and cytotoxicity. However, only a little genotoxic information of these compounds has been known. In this study, we investigated DNA single strand breaks of PCE, TCE, DCE and VC by single cell gel electrophoresis assay, (comet assay) which is a sensitive, reliable and rapid method for DNA single strand breaks with mouse lymphoma L5178Y cells. From these results, 37.5 mu g/ml of PCE, 189 mu g/ml of TCE and 56.4 mu g/ml of DCE were revealed significant DNA damages in the absence of S-9 metabolic activation system meaning direct-acting mutagen. And in the presence of S-9 metabolic activation system, 41.5 mu g/ml of PCE, 328.7 mu g/ml of TCE and 949 mu g/ml of DCE were induced significant DNA damage. In the case of VC, it was revealed a significant DNA damage in the presence of S-9 metabolic activation system. Therefore, we suggest that chloroethylene compounds (PCE, TCE, DCE and VC) may be induced the DNA damage in a mammalian cell.