Abstract
The ability of tetracyclines (TCs) to induce chromosome aberrations was examined by using cultured human fibroblasts (HFG/MS cells) derived from gingival tissues. Treatment of HFG/MS cells with tetracycline. EHCl (TC), chlortetracycline. EHCl (CTC), demeclocycline. EHCl (DMC) or minocycline. EHCl (MINO) at 100-1, 000. μM for 48 h reduced colony-forming efficiency (CFE) in a dose-dependent manner. The rank order of the inhibitory effect of TCs on CFE was CTC< MINO<TC<DMC. No significantly different increases in the frequency of chromosome aberrations were observed in HFG/MS cells treated with any compound at 100-1, 000. μM for 24 or 48h. In addition, chromosome aberrations were not observed in HFG/MS cells following treatment with TCs at 10-100. μM for 1h in Ca2+-and Mg2+-free phosphate-buffered saline. No significant increases in the frequency of chromosome aberrations were detected when HFG/MS cells were treated with MINO at 100-1, 000. μM for 2h in the presence of exogenous metabolic activation mediated by rat liver post-mitochondrial supernatant. The results indicate that there is no clastogenic activity of TCs against cultured human fibroblasts from gingival tissues under certain conditions.
