Polysaccharides from Panax japonicus C.A. Meyer and their antioxidant activities

Polysaccharides named as PP1, PP2, PP3, PP4 and PP5 were extracted and isolated from the rhizomes of Panax japonicus C.A. Meyer, a well-known Chinese traditional medicine, by controlling the final concentration of solution to precipitate the polysaccharides. The molecular weight of polysaccharides was determined by HGPLC chromatography system. The monosaccharide composition was analyzed by Gas chromatography on an Agilent 6890A instrument using a DB-35MS column and flame-ionization detector. All of the polysaccharides were heteropolysaccharides and consisted of arabinose, glucose and galactose. The content of arabinose increased with the increasing of ethanol concentration and PP5 had the most arabinose content in these samples. IR spectra indicated obvious characteristic peaks of polysaccharide, the presence of uronic acids. Their antioxidant activities were evaluated by various established in vitro systems, including scavenging activity of superoxide anion, hydroxyl radical, ABTS and DPPH radicals. Both samples showed inhibitory effects on superoxide, hydroxyl, ABTS and DPPH radical. And PP5 shows more clearly and relatively stronger capacity than other polysaccharides on the protective effect of DNA damage.