Effects of sodium nitrite and potassium sorbate on in vitro cultured mammalian cells.

The food additives sodium nitrite and potassium sorbate had cytostatic and cytotoxic effects on in vitro cultured V79 hamster cells and EUE human fibroblasts if administered in an acid environment (pH 4.95). The strong cytotoxic effect of sodium nitrite and that of the combined action of sodium nitrite and potassium sorbate was observed along the inhibition of macromolecular synthesis. In this respect, potassium sorbate was less effective. The decreased plating efficiency of the cells and the inhibition of de novo DNA synthesis induced by these substances aroused the question whether they also have genotoxic effects on V79 cells. Statistical analyses showed that sodium nitrite induced more 6-TG-resistant (6-TGr) mutants as compared to the untreated control. However, this elevation did not correspond to the level of inhibition of DNA synthesis determined during the followed period of time after the removal of the substance. Potassium sorbate and a combination thereof with sodium nitrite, in our experiments, had no mutagenic effects.