Nitrosonium Cation as an Antitumor Component of Dinitrosyl Iron Complexes with Thiol-Containing Ligands

The combination of two compounds such as the binuclear form of dinitrosyl iron complexes with glutathione (B-DNIC-G, 100 µM/kg, s/c) and sodium diethyldithiocarbamate (DETK, 500 µM/kg, i/p), administered eight times, causes two week-lasting complete inhibition of solid tumor development in mice after tumor transplantation (Lewis lung carcinoma). However, when the antitumor effect was evaluated on the 20th day after the end of drug administration, the maximum activityinhibition of tumor growth by 60% − was observed when drugs were administered in the order DETK, and then after an hour B-DNIC-G, while when drugs were used in reverse order, tumor growth inhibition was not greater than 30%. Based on the analysis of EPR measurements of tumor tissues (day 15 of tumor development), it was concluded that the inhibition of tumor growth was caused by nitrosonium cations released from B-DNIC-G during the breakdown of these complexes under the action of DETC. .