Bioactive Flavonoids in Protecting Against Endothelial Dysfunction and Atherosclerosis

Atherosclerosis is a common cardiovascular disease closely associated with factors such as hyperlipidaemia and chronic inflammation. Among them, endothelial dysfunction serves as a major predisposing factor. Vascular endothelial dysfunction is manifested by impaired endothelium-dependent vasodilation, enhanced oxidative stress, chronic inflammation, leukocyte adhesion and hyperpermeability, endothelial senescence, and endothelial-mesenchymal transition (EndoMT). Flavonoids are known for their antioxidant activity, eliminating oxidative stress induced by reactive oxygen species (ROS), thereby preventing the oxidation of low-density lipoprotein (LDL) cholesterol, reducing platelet aggregation, alleviating ischemic damage, and improving vascular function. Flavonoids have also been shown to possess anti-inflammatory activity and to protect the cardiovascular system. This review focuses on the protective effects of these naturally-occuring bioactive flavonoids against the initiation and progression of atherosclerosis through their effects on endothelial cells including, but not limited to, their antioxidant, anti-inflammatory, anti-thrombotic, and lipid-lowering properties. However, more clinical evidences are still needed to determine the exact role and optimal dosage of these compounds in the treatment of atherosclerosis.