该研究为比较铁棍山药粗多糖和佛手山药粗多糖的抗糖尿病作用效果，测定两种山药粗多糖对DPPH、PTIO自由基的清除作用，对α-葡萄糖苷酶的抑制作用和降血糖降血脂作用。建立2型糖尿病模型大鼠，选用二甲双胍作为阳性对照药物。两种山药粗多糖对DPPH自由基清除作用的EC50(µg/mL)各为35.38、16.19（p<0.01），对PTIO自由基清除作用的EC50(µg/mL)各为7869.17、8335.78（p<0.01），对α-葡萄糖苷酶的抑制作用（18.85%、15.73%）无显著差异（p>0.05）。与模型组相比，铁棍山药粗多糖组的FBG、TC与LDL-C水平各降低24.38%、28.44%、44.68%（p<0.05，p<0.01），肝糖原含量升高21.83%（p<0.05），CAT与GSH-Px水平各升高363.36%、43.67%（p<0.01）；佛手山药粗多糖组的FBG、TG、TC与LDL-C水平各下降25.62%、28.52%、22.79%、44.73%（p<0.05，p<0.01），SOD与CAT水平各提升7.22%和69.76%（p<0.05）。结果表明，两种粗多糖的抗糖尿病作用机制不同。铁棍山药粗多糖在清除PTIO自由基、减少肝糖原分解、增强CAT和GSH-Px活性方面更具优势，而佛手山药粗多糖则在清除DPPH自由基、降低TG的含量、增强SOD与CAT活性方面作用更佳。

In order to compare the antidiabetic effects of the crude polysaccharides of iron stick yam and bergamot yam, the scavenging effects of the two kinds of crude polysaccharides on DPPH and PTIO free radicals, the inhibitory effects on α-glucosidase, and the hypoglycemic and hypolipidemic effects were determined. Type 2 diabetes model rats were established, and metformin was used as the positive control drug. The EC50 values (µg/mL) of the two kinds of crude polysaccharides were 35.38 and 16.19 for DPPH radical scavenging (p<0.01), and 7869.17 and 8335.78 for PTIO radical scavenging (p<0.01), respectively, with the inhibition of α-glucosidase (18.85% and 15.73%, respectively) being insignificantly different (p>0.05). Compared with the model group, the iron stick yam group had decreased FBG, TC and LDL-C levels (by 24.38%, 28.44% and 44.68%, respectively; p<0.05, p<0.01), increased liver glycogen content (by 21.83%; p<0.05), and increased CAT and GSH-Px levels (by 363.36% and 43.67%, respectively; p<0.01). The bergamot yam group had decreased FBG, TG, TC and LDL-C levels (by 25.62%, 28.52%, 22.79% and 44.73%, respectively; p<0.05, p<0.01), and increased SOD and CAT levels (by 7.22% and 69.76%, respectively; p<0.05). The results indicated that the two crude polysaccharides had different antidiabetic mechanisms. The crude polysaccharide from iron stick yam exhibited more advantages in scavenging PTIO radicals, reducing hepatic glycogenolysis, and enhancing CAT and GSH-Px activities, whilst the crude polysaccharide from bergamot yam was more effective in scavenging DPPH radicals, reducing TG content, and enhancing SOD and CAT activities.

湖北省教育厅科学研究计划项目（B2020094）