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(O.(-)(2)), hydroxyl radical, (OH.), lipid-derived radicals (R.) and singlet oxygen (O-1(2)), using a chemiluminescence technique. RPI used here contained puerarin (PU), daidzin, daidzein and others as tested by HPLC. O.(-)(2), OH., R., and O-1(2) 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 O.(-)(2), OH2.,R., and O-1(2) 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. (C) 2003 Elsevier Ltd. All rights reserved.