Abstract The aim of the present study to isolate the water-soluble polysaccharide from Astragalus membranaceus roots (AMP) and investigate the structural effects on RAW 264.7 murine macrophage and natural killer (NK) cells. AMP mainly consists of carbohydrates (66.2%), proteins (11.8%), and sulfates (18.0%) with minor level of uronic acid (2.0%). The structural modification was carried out by removal of protein and sulfate from AMP through deproteination and desulfation. After deproteination (DP), the protein content was decreased from 11.8% to 5.4%. Similarly, the sulfate content was decreased from 18.0% to 8.1% in desulfated AMP (DS). AMP and DP could stimulate RAW264.7 cells to produce nitric oxide (NO) and up-regulate mRNA expression through NF-κB and MAPKs pathways. However, DS showed a considerably lower level of NO production than AMP and DP, suggesting that DS could not stimulate RAW264.7 cells. AMP and its derivatives significantly increased the natural killer cells (NK cell) proliferation (113.1% to 128.7%) and cytotoxicity against HeLa cells (37.4% to 55.5%). However, DS exhibited the lowest level of NK cells activation through the expression of IFN-γ, TNF-α, Granzyme-B, and NKp44. These results suggest that sulfate groups of AMP might play a crucial role in the RAW264.7 cells and NK cells activation.

中文翻译：

---

黄芪根部提取的硫酸化多糖对RAW264.7和NK细胞的结构特性与活化的关系

摘要 本研究的目的是从黄芪根 (AMP) 中分离水溶性多糖，并研究对 RAW 264.7 鼠巨噬细胞和自然杀伤 (NK) 细胞的结构影响。AMP 主要由碳水化合物 (66.2%)、蛋白质 (11.8%) 和硫酸盐 (18.0%) 和少量糖醛酸 (2.0%) 组成。通过脱蛋白和脱硫从AMP中去除蛋白质和硫酸盐来进行结构修饰。脱蛋白 (DP) 后，蛋白质含量从 11.8% 降至 5.4%。同样，脱硫 AMP (DS) 中的硫酸盐含量从 18.0% 降至 8.1%。AMP 和 DP 可以刺激 RAW264.7 细胞产生一氧化氮 (NO) 并通过 NF-κB 和 MAPKs 途径上调 mRNA 表达。然而，DS 显示出比 AMP 和 DP 低得多的 NO 产生水平，表明 DS 不能刺激 RAW264.7 细胞。AMP 及其衍生物显着增加了自然杀伤细胞（NK 细胞）的增殖（113.1% 至 128.7%）和对 HeLa 细胞的细胞毒性（37.4% 至 55.5%）。然而，DS 通过表达 IFN-γ、TNF-α、颗粒酶-B 和 NKp44 表现出最低水平的 NK 细胞活化。这些结果表明 AMP 的硫酸盐基团可能在 RAW264.7 细胞和 NK 细胞活化中起关键作用。DS 通过表达 IFN-γ、TNF-α、颗粒酶-B 和 NKp44 表现出最低水平的 NK 细胞活化。这些结果表明 AMP 的硫酸盐基团可能在 RAW264.7 细胞和 NK 细胞活化中起关键作用。DS 通过表达 IFN-γ、TNF-α、颗粒酶-B 和 NKp44 表现出最低水平的 NK 细胞活化。这些结果表明 AMP 的硫酸盐基团可能在 RAW264.7 细胞和 NK 细胞活化中起关键作用。