RESUMO
The antioxidant and anticancer properties of dirhenium dicarboxylates of cis- and transconfiguration with different organic ligands in a model of tumor growth (Guerin carcinoma) were studied. It was shown that compounds of different configuration had similar antitumor effect, and dirhenium (III) cis-dicarboxylates were characterized by higher antioxidant activity and degree of activation of erythrocyte superoxide dismutase (SOD) in comparison with trans-isomers. The dependence between the structure of dirhenium (III) dicarboxylates and their ability to activate erythrocyte SOD in the model of tumor growth was shown for the first time. The in vitro studies have shown that rhenium compounds of cis- and transconfiguration interacted similarly with erythrocyte SOD, changing the protein secondary structure. In contrast to trans-dicarboxylate, for cis-dicarboxylate the SOD-like activity was demonstrated to be on the first minutes of the xantine-oxidase reaction. The studied features of the interaction between rhenium compounds and SOD in vitro explain only partly the activation of SOD in experiments in vivo. The attempt is made to explain the differences in the mechanisms of antioxidant activity of dirhenium cis- and trans-dicarboxylates.