Potentiation of sodium chromate(VI)-induced chromosomal aberrations and mutation by vitamin B2 in Chinese hamster V79 cells.

The effect of vitamin B2, which is capable of reducing chromium(VI) to chromium(V), on chromosomal aberrations and mutation caused by Na2CrO4 was investigated in Chinese hamster V79 cells. Pretreatment with 200 microM vitamin B2 (riboflavin) for 24 h prior to exposure to Na2CrO4 (2.5-5 microM) resulted in an increase of metal-induced chromosomal aberrations and mutation at the HGPRT locus. These and other previous studies suggest that vitamin B2 enhances the clastogenic and mutagenic action of chromate compounds, through its ability to directly reduce chromium(VI) in cells.