Inhibition of mitomycin C-induced sister chromatid exchanges by vitamin C in vivo.

The aim of this experiment was to test the modulation of genotoxicity produced by vitamin C (V-C) challenged against mitomycin C (MMC) in vivo, by analyzing the sister chromatid exchanges (SCE) and cell proliferation kinetics. We used the mouse bone marrow cytogenetic method, and tested three dosages of V-C (3, 5, and 7 g/kg of body weight), along with the appropriate positive (2 mg MMC/kg body weight) and negative V-C controls. The results showed that V-C caused a strong inhibition of SCEs induced by MMC in the three dosages administered. The highest dose (7 g/kg) caused an SCE inhibition of 70.02%, while the lower ones caused an inhibition of 54.61% and 52.30%, respectively. It was also clear that V-C per se does not increase the level of SCEs in mouse bone marrow cells. On the other hand, V-C induced a slight decrease in cell proliferation that was stronger when combined with MMC. Our data suggest that V-C effectively inhibit the SCE damage in vivo, but caution must be taken because of the observed cytotoxicity.