Although knowledge of cancer management is extensive, mortality is not currently declining in this area. It is therefore important to implement a long-term strategy that would aim to prevent these serious diseases. Ferrocene-related organometallic compounds are promising candidates for design of new drugs since they can exhibit much greater biological activity than their phenyl analogs. In our work, we focused on investigating the cytotoxic and antiproliferative effects of five ferrocenyl derivatives toward selected tumor cell lines. We found that some of these substances significantly reduced Jurkat cell survival and, to a lesser extent, that of the HeLa, MCF7, A549, and MDA cells. Long-term treatment of HeLa cell cultures with these agents resulted in a significant blockade of formation of tumor cell colonies. We found that one of the mechanisms of action of the compounds is likely to display an effect on the redox state of the mitochondria at a final concentration of 10(-4) and 10(-5) mol l(-1). Of the compounds tested, the indanonyl ferrocene derivative (C) was the most effective, especially via glutathione depletion. Based on the obtained results, it can be concluded that synthetic substances containing iron have potential antitumor activity.
