Comparetive Studying The Cyto-genotoxicity Induced By Cigarette Smoke Condensates (CSCs) With And Without S9 In Vitro

Objective To study comparatively the cyto-genotoxic effects induced by CSCs with and without S9 on human peripheral lymphocytes in vitro,and to observe whether S9 can enhance the cyto-genotoxic effects induced by CSCs.Methods The cyto-genot-oxic effcts induced by CSCs with and without S9 were detected using comet assay,micronucleus assay(CBMN),neutral red uptake(NRU) assay,CCK-8 assay,cell apoptosis assay and TCR gene mutation test in vitro.In six assays,human peripheral lympho-cytes served as the target cells and were exposed to CSCs with and without S9 at the doses of 25,50,75,100,125 ug/ml for 3 hours(in comet assay,NRU assay and TCR gene mutation test) or 4 hours(in CBMN assay,CCK-8 assay and cell apoptosis assay).Results The results of six assays show that the cyto-genotoxic effects induced by both CSC+S9 or CSC-S9 increased with the exposure doses,i.e.the viability of human lymphocytes decreased with CSCs doses,DNA damage of human lymphocytes, the frequencies of micronuclei and the TCR gene mutation rates increased with CSCs doses,and the dose-effect relationship appeared.The cyto-genetoxic effects induce by CSCs+S9 were lower,as compared with the cyto-genetoxic effects induce by CSCs- S9.There were significant differences of cyto-genotoxicity between CSCs+S9 and CSCs-S9 at some exposure doses in five assays except for CBMN assay.Conclusion Both CSCs+S9 and CSCs-S9 could induce the cyto-genotoxic effects on human lymphocytes in vitro,but +S9 could not enhance the cyto-genotoxic effects induced by CSCs on human lymphocytes in vitro.