Study on antioxidant activity of polysaccharides from alfalfa,astragalus and extracellular polysaccharide from Bacillus licheniformis TS-01 in vitro

Free radical-scavenging activities of three polysaccharides extracted from alfalfa,astragalus and Bacillus licheniformis TS-01 were analyzed using free radical production in vitro systems(1,1-dipheyl-2-pic-rylhydrazyl radical and hydroxyl radical).The results showed that the three polysaccharides could scavenge free radical.The scavenging capacities of the polysaccharides against 1,1-dipheyl-2-pic-rylhydrazyl and hydroxyl radical increased with the increasing of their concentrations.The concentrations of three polysaccharides which were necessary to decrease the initial concentration(IC50)of DPPH· by 50% were 0.251,0.851,0.412mg/mL,respectively.The order of scavenging rate of three polysaccharides was alfalfa polysaccharideextracellular polysaccharideastragalus polysaccharide.The IC50 of three polysaccharides for hydroxyl radical were 0.573,0.907 and 0.734mg/mL.The order of scavenging rate was same with DPPH·.