ABSTRACT
<p><b>OBJECTIVE</b>To investigate the cyto-genotoxicity of cigarette smoke condensates (CSCs) in human peripheral blood lymphocytes with different assays in vitro.</p><p><b>METHODS</b>Human lymphocytes were exposed to particle matter of cigarette smoke combined with or without S9 mixtures at doses of 25, 50, 75, 100 and 125 microg/ml for 3 h. The cytotoxicity induced by CSCs was detected by CCK-8 assay. The DNA damage, DNA repair (repair time: 30, 60, 90, 120 and 240 min, respectively) and the somatic cell mutations induced by 75 microg/ml CSCs were measured by comet assay, hprt gene and TCR gene mutation tests, respectively.</p><p><b>RESULTS</b>CCK-8 assay indicated that the cell viability decreased with CSCs doses. At the doses of 100, 125 microg/ml, the cell viability of CSCs +S9 group was significantly higher than that of CSCs -S9 group (P < 0.05, P < 0.01). In comet assay, DNA damage significantly increased in a dose-dependent manner, as compared with controls (P < 0.01). Moreover, there was significant difference between -S9 group and +S9 group (P < 0.05, P < 0.01). The Mf-TCR at each dose group was significantly higher than that of controls (P < 0.05, P < 0.01). The Mf-hprt at high-dose groups were significantly higher than that of controls (P < 0.01), and significant difference of Mf-TCR and Mf-hprt at high doses of CSCs between -S9 group and +S9 group (P < 0.05, P < 0.01). The DNA damage induced by CSCs +S9 or CSCs -S9 could be repaired, but DNA repair speed was different between -S9 group and +S9 group (P < 0.05, P < 0.01).</p><p><b>CONCLUSION</b>CSCs may induce cyto-genotoxicity in human peripheral blood lymphocytes in vitro, but S9 mix could reduce the toxicity of CSCs and impact DNA repair speed.</p>