The Beneficial Effects of Saffron Extract on Potential Oxidative Stress in Cardiovascular Diseases

Figure 3

Reactive oxygen species (ROS) generation in cardiovascular diseases. NAD(P)H: nicotinamide adenine dinucleotide (phosphate); eNOS: endothelial nitric oxide synthase; NO^●: nitric oxide; O₂^●−: superoxide; HOCl: hypochlorite; SOD: superoxide dismutase activity; H₂O₂: hydrogen peroxide; ONOO⁻: peroxynitrite; OH^●: hydroxyl radicals; GSH: glutathione; GSSG: oxidized glutathione; GPx: glutathione peroxidase; Trx: thioredoxin. O₂^●− can be generated in extracellular myocardium by NAD(P)H, uncoupled eNOS, xanthine oxidase, and mitochondrial respiration chains. H₂O₂ can be spontaneously converted to OH^●− by Fe²⁺/Fe³⁺ reaction and SOD. H₂O₂ can detoxify H₂O and O₂ by GSH peroxidase, Trx peroxidase, and catalase. Additionally, the uncoupling of eNOS decreases NO^● production in endothelial cells, which is further aggravated by the reduced expression and activity of eNOS. Myeloperoxidase uses hydrogen peroxide to oxidize chloride to form a strong oxidant (HOCl).