Free radical scavenginga activity and flavonoids contents of Polygonum orientale leaf, stem and seed extracts

Abstract

The present study was designed to explore the total flavonoid and taxifolin contents and the radical scavenging activity of 50% ethanol extracts of Polygonum orientale leaf, stem and seed by 2,2- diphenyl-1-picrylhydrazyl (DPPH) assay. The extract with higher total flavonoid content has higher radical scavenging activity. Taxifolin (IC50 = 2.83 μmol/L) has stronger antioxidant activity than that of rutin (IC50 = 3.08 μmol/L). The free radical scavenging potential of the chloroform, ethyl acetate, water, ethanol and methanol extracts of P. orientale seed were also investigated. The free radical scavenging abilities of various extracts were determined as: methanol > ethanol > water > ethyl acetate > chloroform