Inhibition of Polycyclic Aromatic Hydrocarbon-induced Neoplasia by Sodium Cyanate¹

The effects of sodium cyanate on the occurrence of 7,12-dimethylbenz(a)anthracene- and benzo(a)pyrene-induced neoplasia have been studied in rodents. Sodium cyanate added to the diet for 8 days prior to challenge with 7,12-dimethylbenz(a)anthracene inhibits 7,12-dimethylbenz(a)anthracene-induced mammary neoplasia in female Sprague-Dawley rats. Likewise, sodium cyanate in the diet inhibits the occurrence of benzo(a)pyrene-induced neoplasia of the forestomach and lung of ICR/Ha mice. Inhibition of benzo(a)pyrene-induced pulmonary neoplasia in A/J mice also is brought about by this compound. The identification of sodium cyanate as an inhibitor of chemical carcinogenesis adds a new chemical structure to those found previously to have inhibitory properties.