On the mechanism of the antitumor activity of ferrocenium derivatives

Contradictory results exist in the literature about the antineoplastic activity of ferrocenes and their ferrocenium salts; additionally, little is known about the mechanism by which such drugs become active towards cancer cells. In the present paper we show that only ferrocenium species are able to inhibit the growth of Ehrlich ascites tumor cells in vivo and we propose that the cytotoxic activity of ferrocenium salts is not based on their direct linking to DNA, but on their ability to generate oxygen active species which induce oxidative DNA damage.