A SENSITIVE METHOD FOR THE ANALYSIS OF LDL OXIDATION TO DETECT THE ANTIOXIDANT POWER OF NUTRITIONAL COMPOUNDS

摘要

Several nutritional compounds may exert antioxidant activity that can be used for therapeutic applications against oxidative damage. For example their antioxidant capability may reduce or prevent the oxidative modification of low-density lipoproteins (oxLDLs) that are involved in the pathogenesis of the main cardiovascular diseases. To assess the modulation of LDL oxidation, here we propose a method based on the analysis of conjugated dienes, that have shown high sensitivity and reproducibility compared to other tests currently in use. Our recent study based on this method demonstrated that among flavonoids isolated from Psoralea plicata, plicatin B acts like the stronger antioxidant compound when compared with erybraedin, bitucarpin A, and the methoxylated pterocarpan. In comparison to the control they prolonged the lag time 2.5-fold, 1.9-fold, 1.1-fold respectively. In addition plicatin B acts also by copper chelating when compared the Cu2+-mediated LDL oxidation with other compounds generating free radicals like azo coumpond that is used as peroxyl radicals generator. This method also showed the strong antioxidant capability of the powder of Triticum sativum grains Lisosan G. Comparing to vitamin C 0.2 mu g/ml, Lisosan Gat the concentration of 40, 60, 80 mu g/ml resulted more effective to inhibit Cu2+-induced lipid peroxidation (respectively p<0.01, p<0.001 and p<0.001). This method suggests its usefulness in the analysis of new compounds that could be introduced alongside traditional drug therapies in subjects with cardiovascular risks.