[Retracted] Natural Antioxidants Improve the Vulnerability of Cardiomyocytes and Vascular Endothelial Cells under Stress Conditions: A Focus on Mitochondrial Quality Control

Figure 1

Mechanism of oxidative stress-mediated by different stress conditions. Under stress conditions (small red rectangle), cells release free radicals (H₂O₂, NO, OH, and ONOO⁻), leading to the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS). Excessive ROS and RNS production reduce the activity of antioxidant enzymes in the mitochondrial antioxidant system, causing ROS-mediated stress damage and the subsequent appearance of oxidative stress markers (red circles). H/R: hypoxia/reoxygenation; I/R: ischaemia/reperfusion; SOD: superoxide dismutase; GSH-Px: glutathione peroxidase; PRX: peroxiredoxin; CAT: catalase; MDA: malondialdehyde; 8-OHG: 8-hydroxyguanosine; 8-OHdG: 8-2-hydroxydeoxyguanosine.