Nitrosonium Cation as a Cytotoxic Component of Dinitrosyl Iron Complexes with Thiol-containing Ligands (based on the Experimental Work on MCF7 Human Breast Cancer Cell Culture).

Here we demonstrate that binuclear dinitrosyl iron complexes with thiol-containing ligands (glutathione and mercaptosuccinate, B-DNIC-GSH and B-DNIC-MS, respectively) exert cytotoxic effects on MCF7 human breast cancer cells. We showed that they are mediated by nitrosonium cations released from these complexes (NO). This finding is supported by the cytotoxic effect of both B-DNICs on MCF7 cells evidenced to retain or was even promoted in the presence of N-Methyl-D-glucamine dithiocarbamate (MGD). MGD recruits an iron nitrosyl group [Fe(NO)] from the iron-dinitrosyl fragment [Fe(NO)] of B-DNIC-MS forming stable mononitrosyl complexes of iron with MGD and releasing NO cations from a [Fe(NO)] fragment.