泡桐花多糖的体内外抗氧化活性

以泡桐花为原料水提醇沉法制备多糖，测定泡桐花多糖的体外、体内抗氧化活性。体外抗氧化测定结果显示，泡桐花多糖对超氧阴离子、羟基自由基清除以及抑制H₂O₂溶血有较好的效果，呈剂量依赖性；质量浓度0.5 mg/mL时，对超氧阴离子和羟基自由基清除率分别达到54.36%，74.62%，超过半数效应50%；质量浓度2 mg/mL时，抗H₂O₂氧化溶血率超过阳性对照组Vc（1 mg/mL）。体内抗氧化测定结果显示，泡桐花多糖低、中、高（日剂量5、10、20 mg/mL，0.2 mL）小鼠灌胃28 d对体质量无影响；血清和心脏、肝脏、肾脏、回肠脏器超氧化物歧化酶（superoxide dismutase，SOD）、还原型谷胱甘肽（glutathione，GSH）、丙二醛（malondialdehyde，MDA）含量和总抗氧化能力（total antioxidant capacity, T-AOC）检测表明，与空白组相比，不同剂量的泡桐花多糖能够增加或显著增加SOD、GSH含量和T-AOC水平（P<0.05），同时降低MDA含量，并存在一定的量效关系。研究表明泡桐花多糖具有良好的抗氧化活性，可作为天然抗氧化剂应用于食药工业。

Antioxidant Activity in Vitro and Vivo of Polysaccharide from Paulownia fortunei Flower

This study aimed at evaluating the antioxidant activity in vitro and vivo of polysaccharide prepared from Paulownia fortunei flower by water extract-alcohol precipitation.In vitro,results showed that Paulownia fortunei flower polysaccharide had a dose-dependent and good effect on scavenging superoxide anion,hydroxyl radical and inhibiting H2O2 hemolysis.When the concentration of polysaccharide controlled at 0.5 mg/mL,the scavenging rates of superoxide anion and hydroxyl radical were 54.36%and 74.62%respectively,with more than half effect of 50%.When at 2 mg/mL,the anti-H2O2 oxidation hemolysis rate was higher than that of the positive control Vc group(1 mg/mL).In vivo,after the experimental mice were administered to oral gavage with Paulownia flower polysaccharide at low,medium and high dosages(5,10 and 20 mg/mL,0.2 mL)for 28 consecutive days.The result showed that Paulownia fortunei flower polysaccharide had no effect on weight of mice;different doses of polysaccharide could enhance or siginificantly enhance the content of superoxide dismutase(SOD),glutathione(GSH),total antioxidant capacity(T-AOC)remarkably in serum,heart,liver,kidney,ileum(P<0.05)when compared with that of the blank group,and reduce the malondialdehyde(MDA)content dramatically with a certain concentration-response relationship.The results indicate that Paulownia fortunei flower polysaccharide had perfect antioxidant activity and could be used as a natural antioxidant in food and medicine industry.