The Controversial Role of Glucose-6-Phosphate Dehydrogenase Deficiency on Cardiovascular Disease: A Narrative Review

Figure 2

Indirect production of prooxidant and antioxidant molecules by the pathway catalyzed by G6PD. The NADPH produced in the reaction catalyzed by G6PD contributes to the formation of both free radicals and antioxidant molecules; hence, the net effect on the cellular redox balance depends on its concentration in vivo. Under normal conditions, and in the presence of oxygen, NADPH generates the anion radical superoxide, which in turn reacts with hydrogen peroxide to form the hydroxyl radical. At the same time, NADPH feeds the NOS reaction to form NO which at low concentrations has an antioxidant action and contributes to the scavenging of the superoxide radical. It can be hypothesized that in the case of G6PD deficiency, the superoxide scavenging by NO is significantly abated which results in increased oxidative stress and damage to a variety of macromolecules.