The radical scavenging activities of radix puerariae isoflavonoids: A chemiluminescence study

The purpose of this paper was to determine the radical scavenging activities of radix puerariae isoflavonoids (RPI) toward different reactive oxygen species (ROS), including superoxide anion(O2−), hydroxyl radical (OH), lipid-derived radicals (R) and singlet oxygen (1O2), using a chemiluminescence technique. RPI used here contained puerarin (PU), daidzin, daidzein and others as tested by HPLC. O2−, OH, R, and 1O2 were generated from a pyrogallol autoxidation system, Fenton reaction system, H2O2-induced oxidation of unsaturated fatty acid system and NaClO–H2O2 system, respectively. RPI could effectively scavenge O2−, OH, R, and 1O2 at EC50 of 0.08, 0.005, 0.03, and 0.004 mg/ml, respectively. In addition, the radical scavenging activities of RPI were much higher than that of its main component PU, and similar to that of tea polyphenols, indicating that RPI, not PU, was a powerful antioxidant.