디젤분진이 체세포에서의 DNA 손상에 미치는 영향

초록

Diesel exhaust particle (⁄2.5 μm, DEP2.5) is known to be probarbly carcinogenic (IARC group 2A). DEP2.5 contains organic compounds such as polycyclicaromatic hydrocarbon (PAH), heterocyclic compounds, phenols, and nitroarenes. Reactive oxygen species (ROS) are generated by DEP2.5 without any biological activation system. Therefore, an alternative mechanism by which DEP2.5 could be carcinogenic is known by the generation of oxidative DNA damage. The aim of this study was to investigate genotoxic effects of DEP2.5 using single cell gel electrophoresis. In order to evaluate the mechanisms of DEP2.5 genotoxicity, the rat microsome mediated and DNA repair enzyme treated comet assays together with routine comet assay were performed. DEP2.5 was collected from diesel engine bus and dichloromethane extract was obtained. The organic extract of DEP2.5 revealed DNA damage itself in NIH/3T3 cells. And it showed both oxidative and microsome mediated DNA damages. Vitamin C as an model antioxidant reduced DNA damage in endonuclase III treated comet assay. One of flavonoid, galangin as a CYP1A1 inhibitor reduced DNA damage in the presence of S-9 mixture. Our results show that DEP2.5 are genotoxic and a great source of oxidative stress, but antioxidants can significantly reduce oxidative DNA damages. And DEP2.5 may contain indirect mutagens which can be inhibited by CYP inhibitors.

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