Hexavalent chromium and ascorbic acid interaction on proliferation of the human cell line NHIK3025

When cells from the human cell line NHIK3025 were cultured for 4 days, with hexavalent chromium (K2Cr2O7) at a concentration of 8 . 10(-7)M, the relative cell number was reduced to 38%. This effect of hexavalent chromium was abolished if ascorbic acid and chromate were added simultaneously to the incubation medium, but not if ascorbic acid was added 24 h prior to chromate addition. Dehydroascorbic acid was not able to reduce the effect of K2Cr2O7 either when added simultaneously or when added 24 h prior to chromate exposure. Therefore, the cells could only be protected against the toxic effect of hexavalent chromium when ascorbic acid was added at the same time as K2Cr2O7.