Antioxidant activity of melatonin and glutathione interacting with hydroxyl and superoxide anion radicals

Abstract

Based on the analysis of the results obtained by quantum chemical modeling of interaction between reduced glutathione (GSH) and melatonin (MLT) molecules with oxygen radicals (•OH and • OOˉ) it was found that this interaction occured following the acid-base mechanism, where MLT and GSH acted as a base in respect of •OH, and as acid in respect of •OOˉ. We have carried out the correlation of the results of quantum chemical calculations (density redistribution, energetic characteristics) under the interaction of MLT and GSH molecules with •OH and •OOˉ in changing macroscopic properties of the process of electroreduction of free oxygen radicals in the presence of antioxidants (potential and maximal current wave reduction waves). This was a direct experimental macroscale evidence of the results of theoretical modeling at the nanoscale level that pointed to a marked antioxidant activity of glutathione compared with melatonin.