Figure 7.

(a) The polyol pathway becomes a major pathway for NADH production under diabetic conditions. NADH is produced in the second reaction catalyzed by sorbitol dehydrogenase. (b) Proposed approach that may alleviate complex I NADH pressure and minimize superoxide production. This could be achieved by a molecule (a protein or a chemical) that can transport electrons from NADH directly to CoQ by bypassing complex I. As this bypass electron transport occurs without proton pumping, no superoxide should be produced, thereby facilitating NADH oxidation and minimizing superoxide production.