Antioxidant and Anticoagulant Activities of Polysaccharides Extracted from Different Parts of Arctium lappa L.

The polysaccharides which extracted from the root,stem and leaf of Arctium lappa L. were studied in this work. The monosaccharide compositions and total sugar contents were determined by PMP pre-column derivatization and phenol-sulfuric acid method. The antioxidant and anticoagulant activities of the polysaccharides were further compared. The polysaccharides of Arctium lappa L. root,stem and leaf all contain different contents of mannose(Man),glucose ammonia(GlcN),rhamnose(Rha),glucuronic acid(GlcA),glucose(Glc),galactose(Gal)and arabinose(Ara). Among them,Arctium lappa L. root had the highest Glc content,followed by GlcA and Gal;Arctium lappa L. stem mainly consisted of Gal,Glc and Ara;and Arctium lappa L. leaf was also dominated by Glc,followed by Gal and Ara. In the antioxidant activity experiments,in the concentration range of 0~1.0 mg/mL,with ascorbic acid as the standard,the scavenging ability to superoxide anion free radicals(O₂^-)was the strongest in Arctium lappa L. stem polysaccharide,followed by Arctium lappa L. leaf polysaccharide,Arctium lappa L. root polysaccharide,and the strongest in hydroxyl radical(OH)scavenging ability was Arctium lappa L. stem polysaccharide and Arctium lappa L. leaf polysaccharide was weaker,Arctium lappa L. root polysaccharide was the weakest. DPPH free radical scavenging capacity and reducing capacity of Arctium lappa L. leaf polysaccharide was the strongest,Arctium lappa L. stem polysaccharide was the second,Arctium lappa L. root polysaccharide was the weakest. In the anticoagulant activity test,in the concentration range of 0~0.3 mg/mL,the activated partial coagulation time and thrombin time were the longest in Arctium lappa L. leaf polysaccharide,the second in Arctium lappa L. root polysaccharide and the shortest in Arctium lappa L. stem polysaccharide. Arctium lappa L. root polysaccharide had the effect of prolonging prothrombin time,while Arctium lappa L. leaf and stem had no effect of prolonging prothrombin time,through comparison,it was found that the anticoagulant activities of the three groups were almost the same,and did not show good anticoagulant activity.