采用水提法和乙醇沉淀法制备得桑葚多糖T2，利用质量分数为4%的ZnSO4盐析法去除桑葚多糖T2中的蛋白质，从而得到桑葚多糖T3，蛋白去除率高达88.52%。然后采用DEAE-52纤维素离子交换层析法对桑葚多糖T3进行分离纯化，共收集到4个组分T3-1、T3-2、T3-3及T3-4，其中T3-1和T3-3为桑葚多糖T3的主要组分。进而，从对细胞氧化损伤保护作用的角度对桑葚多糖T3的4个组分的抗氧化性进行了检测。选用700 μmol/L的H2O2诱导PC-12细胞损伤8 h为细胞氧化损伤模型，考察T3各组分对正常PC-12细胞增殖的影响，发现T3-3可使细胞存活率增大至41.81%。最后以T3-3为研究对象考察其对H2O2诱导的PC-12细胞氧化损伤的保护作用。结果显示，600 μg/mL的T3-3对PC-12细胞氧化损伤具有最强保护作用，表明高浓度的T3-3具有非常强的细胞抗氧化作用。

Mulberry polysaccharide T2 was obtained by water extraction and ethanol precipitation. Proteins were removed by salting out with 4% (mass fraction) ZnSO4 at a rate of 88.52%, to yield mulberry polysaccharide T3, which was isolated and purified by DEAE-52 cellulose ion exchange chromatography. Thus, four fractions: T3-1, T3-2, T3-3, and T3-4 were collected. T3-1 and T3-4 were the main components of mulberry polysaccharide T3. Subsequently, the antioxidant activity of the four components was measured in terms of protective effect on cellular oxidative damage. The cellular oxidative damage model was established after damage of PC-12 cells was induced by treatment with 700 μmol/L H2O2 for eight hours. Effects of all T3 fractions on normal PC-12 cellular proliferation were investigated and the results showed that T3-3 improved cell survival rate to 41.81%. Finally, the protective effect of T3-3 on H2O2-induced oxidative damage in PC-12 cells was investigated. The results showed that 600 μg/mL T3-3 exhibited the strongest protective effect, indicating that T3-3 exerts very strong cellular antioxidant activity at high concentrations.

广东高校国际科技合作创新平台项目（2013gjhz0003）