|
The flavonoids are one of the most numberous and widespread groups of natural constituents. The low molecular weight of benzo-γ-pyrone derivatives are ubiquitous in plants and are vegetables, nuts, seeds, leaves, flowers, and bark. The flavonoids constitute of a large class of compounds, ubiquitous in plants, containing a number of phenolic hydroxyl groups attached to ring structures, conferring the antioxidant activity. Epidemiologic studies suggest that the dietary intake of antioxidants constitutes a risk factor for vascular disease, indicating that oxidation may be important in the pathogenesis of human atherosclerosis. Elevated plasma low density lipoprotein (LDL) cholesterol concentration are associated with accelerated atherosclerosis, LDL is oxidized by smooth muscle cells, resulting in several chemicals and physical changes of LDL. Oxidized LDL is responsible for cholesterol loading of macrophages, foam cells formation and atherogenesis. There have been insulficient tests of the protective effects of flavonoids against LDL oxidation to make definitive statements about their structure activity relationships. However, hydroxylation of the flavone nucleas can appears to be advantageous because polyhydroxylated aglycone flavonoids are potent inhibitor of LDL modification. This identification may lead to new and more effective antioxidant strategies for abrogating the atherosclerotic process, the leading cause of death and disability in industrialized societies.
|