Figure 2.

Schematic presentation of stages of polyol pathway: (I) glucose reduction to sorbitol by AR (using NADPH as a cofactor) followed by (II) sorbitol oxidation to fructose by SDH (using NAD⁺ as a cofactor).

Notes: Adapted from Safi SZ, Qvist R, Kumar S, Batumalaie K, Ismail IS. Molecular mecha nisms of diabetic retinopathy, general preventive strategies, and novel therapeutic targets. Biomed Res Int. 2014;2014:801269. Copyright © 2014 Sher Zaman Safi et al.31

Abbreviations: AR, aldose reductase; NAD⁺, nicotinamide adenine dinucleotide – oxidized; NADH, nicotinamide adenine dinucleotide – reduced; NADP⁺, nicotinamide adenine dinucleotide phosphate – oxidized; NADPH, nicotinamide adenine dinucleotide phosphate – reduced; SDH, sorbitol dehydrogenase.