Abstract: The aim of this study was to investigate the effects of different extraction methods on antioxidant activities of polysaccharides in Platycodon grandiflorum. Polysaccharides were extracted using hot water extraction,microwave extraction,ultrasonic extraction and complex enzyme extraction,respectively.The antioxidant activities of the extracted polysaccharides were then compared among them based on the total reduction,the antilipid peroxidation on spontaneous hepatic tissue,and the clearance of superoxide anion,hydroxyl radical and DPPH·.The results showed that the antioxidant activity of polysaccharides extracted by microwave extraction was the best,and was significantly higher than those from the other extraction methods (P<0.01). Meanwhile,it showed a strong competence on the clearance of OH and DPPH·,as well as on the anti-lipid peroxidation,the maximum inhibition and the clearance rate could be nearly or over 50%,but it was weak on the clearance of superoxide anion,the maximum clearance rate was 25% only.

Key words: platycodonis, polysaccharides, antioxidant