The role of chromium(V) in the mechanism of chromate-induced oxidative DNA damage and cancer

The role that high valent chromium intermediates play in the oxidative DNA damage produced by the human carcinogen chromate Cr(VI) is of increasing interest for establishing a mechanism of genotoxicity and mutagenicity for this metal. In this review, the authors summarize experimental evidence for the formation of high valent chromium complexes (primarily the +5 oxidation state) and radical species from the reductive metabolism of Cr(VI). A case is made for a direct- or metal-mediated pathway by high valent chromium to initiate oxidative DNA damage, although the role of radical species in this oxidative process cannot be ruled out.