The protection of Vitamin E and selenium against carbon tetrachloride-induced genotoxicity in ovine peripheral blood lymphocytes.

The protective effect of Vitamin E and selenium was studied for the possibility of decreasing the chromosome aberrations (CA), micronuclei (MN) and sister chromatid exchanges (SCE) induced by carbon tetrachloride (CCl(4)) in ovine peripheral lymphocytes cultured in vitro. The cultures of lymphocytes from two healthy lambs were treated with carbon tetrachloride at concentrations of 2, 4, 8, and 16 microg/ml for the last 48 h of cultivation and subsequently with the same doses of CCl(4) and Vitamin E and selenium. A possible metabolic modification in carbon tetrachloride genotoxicity was detected with the application of S9 fraction for 2h. No positive clastogenic effect of CCl(4), and subsequently no protective effect of either antioxidant was obtained in the CA assay. In the MN assay for 48 h, an increase and, respectively, a decrease in the frequency of MN was found in cultures treated with CCl(4) alone and in cultures treated concurrently with CCl(4), Vitamin E and selenium at concentrations of 8 and 16 microg/ml (P<0.001 and P<0.01). High statistical significance was achieved in SCE assay after the treatment of ovine peripheral lymphocytes with CCl(4) at all concentrations tested (P<0.001), except the lowest dose. A significant decrease in SCEs was obtained in cultures treated simultaneously with CCl(4), Vitamin E and selenium (P<0.001). The highest dose (16 microg/ml) was also shown to improve the cell-cycle kinetics in comparison with corresponding unprotected dose (P<0.01). Insufficient confirmation of the genotoxicity of CCl(4) and the protective effect of the antioxidants, respectively were seen in cultures with metabolic activation.