The Protective Role of Thiola against the Genotoxic Effect of Potassium Dichromate in Mice in vivo.

Abstract

The genotoxic effect of hexavalent potassium dichromate (K2Cr2O7) was investigated in mice in vivo using sister chromatid exchange (SCE) and chromosomal aberration analysis. K2Cr2O7 induced a significant increase in the frequency of SCE's after intraperitoneal (i.p.) treatment with the doses 6, 12, 24 mg kg-1b.wt. which correspond to 1/8, 1/4 and 1/2 of the experimental LD50. The lowest tested dose 3 mg kg-1b.wt. had no effect with respect to SCE's and its effect reached 6.57 ± 0.36/cell compared with 5.80± 0.55/cell for the control. The frequency of SCE's reached 9.03 ±0.20 after treatment with the highest tested dose of K2Cr2O7, a value which is less than that induced by mitomycin C (13.10 ± 0.40) as the positive control. Thiola at the concentrations of 20 and 50 mg kg-1b.wt. had moderate but non-significant effect for minimizing the frequency of SCE's induced by different doses of K2Cr2O7.With respect to chromosomal aberrations, all the tested concentrations of K2Cr2O7 (3, 6, 12, 24 mg kg-1b.wt.) induced a significant increase in the percentage of chromosomal aberrations in mouse bone marrow as well as in mouse spermatocytes 24 h after single i.p. treatment. The incidence of chromosomal damage increased significantly with increasing the dose. However mitomycin C induced higher effect. The results also show that the pretreatment with thiola at the dose of 50 mg kg-1b.wt. significantly reduced the percentage of chromosomal aberrations induced by K2Cr2O7 in all the treatment groups and the results confirm the protective role of thiola which has been proved previously against the genotoxicity of some mutagens.