Protective effect of butylated hydroxytoluene (BHT) against the clastogenic activity of cadmium chloride and potassium dichromate in Chinese hamster ovary cells

The effect of butylated hydroxytoluene (BHT), a widely used food additive, on chromosomal alterations induced by cadmium chloride (CC) and potassium d ichromate (PD) in Chinese hamster ovary (CHO) cells was studied both at met aphase and anaphase-telophase. CHO cells were cultured for 15-16 h in the p resence of PD (6.0, 9.0 or 12.0 mu M), BHT (1.0 mu g/ml), or PD plus BHT as well as CC (0.5, 1.0 and 2.0 mu M), BHT or CC plus BHT for the analysis of chromosomal aberrations. To perform the anaphase-telophase test, cells wer e cultured in cover glasses and treated 8 h before fixation with the same c hemicals. An extra dose of CC (4 mu M) was used in this test. Both metal sa lts significantly increased chromosomal aberration frequencies in relation to untreated controls, and to DMSO- and BHT-treated cells. Post-treatment w ith BHT decreased the yield of chromosomal damage in relation to treatments performed with CC and PD. However, chromosomal aberration frequencies were significantly higher than those of the controls. In the anaphase-telophase test, CC significantly increased the yield of lagging chromosomes with the four doses employed and the frequency of lagging fragments with the highes t dose. In combined treatments of CC and BHT, frequencies of the two types of alterations decreased significantly in relation to the cells treated wit h CC alone. No significant variation was found in the frequencies of chroma tin bridges. Significant increases of numbers of chromatin bridges, lagging chromosomes and lagging fragments were found in cells treated with PD. The protective effect of BHT in combined treatments was evidenced by the signi ficant decrease of chromatid bridges and lagging chromosomes in relation to PD-treated cells. Whereas BHT is able to induce chromosomal damage, it can also protect against oxidative damage induced by other genotoxicants.