Interaction between Vitamins C and E When Scavenging the Superoxide Radical Shown by Hydrodynamic Voltammetry and DFT

In this study, we examine the cooperative effect between vitamins C and E that mitigates oxidative stress by using experimental and computational methods. We performed superoxide scavenging experiments on each vitamin individually and their combination using rotating ring-disk electrode voltammetry. The results indicate that vitamins E and C together produce more effective scavenging of superoxide as evaluated by a steeper slope in the efficiency graph, -7.2 x 104, compared to that of vitamin E alone, -1.8 x 103, or vitamin C alone, -1.3 x 104. Density Functional Theory calculations agree with our experimental results, and we describe a mechanism for the antioxidant action of individual vitamins E and C, plus the synergistic action when both vitamins interact. This process involves the restoration of vitamin E by vitamin C and includes pi-pi interactions between superoxide and scavengers. The overall result produces an increase in scavenging superoxide radicals when both vitamins act together.