从鼠耳仙人掌（Epiphyllum oxypetalum（DC.）Haw.）中分离和鉴定出一种多糖（EOP），并在体内外评估了其免疫调节活性。通过使用多光谱分析，确定EOP由鼠李糖、阿拉伯糖、半乳糖和半乳甘醛酸以摩尔比为26.65:11.48:53.79:6.04组成，其分子量为5.77×106 Da。此外，确定EOP的骨架结构由（1→4）-连接的β-Galp、（1→2）-连接的β-Rhap、（1→3,4）-连接的β-Galp、（1→2,4）-连接的β-Rhap和（1→4）-连接的α-GalpA组成，以t-β-Arap和t-β-Galp结尾。体外作用于RAW 264.7细胞的免疫调节活性实验显示，EOP可增加巨噬细胞的增殖，增强其吞噬能力，并促进一氧化氮（NO）、肿瘤坏死因子-α（TNF-α）和白细胞介素-6（IL-6）等细胞因子的产生。此外，对斑马鱼进行的体内评估表明，EOP可以减少斑马鱼中荧光微粒的残留含量，表明EOP具有增强巨噬细胞吞噬作用的能力。所有结果表明，EOP具有复杂的结构，并在体内外展示了显著的免疫调节活性，具有在食品和药品行业中有价值的潜力。版权所有 © 2023. Elsevier B.V. 发布。

A polysaccharide (EOP) from Epiphyllum oxypetalum (DC.) Haw. was isolated and identified, and its immunomodulatory activity was evaluated both in vitro and in vivo. By using multispectral analysis, EOP was determined to be composed of rhamnose, arabinose, galactose, and galacturonic acid at a molar ratio of 26.65:11.48:53.79:6.04, and its molecular weight was 5.77 × 106 Da. In addition, backbone structure of EOP was determined to consist of (1 → 4)-linked β-Galp, (1 → 2)-linked β-Rhap, (1 → 3,4)-linked β-Galp, (1 → 2,4)-linked β-Rhap and (1 → 4) -linked α-GalpA, terminating with t-β-Arap and t-β-Galp. The in vitro immunomodulatory activity assay on RAW 264.7 cell showed that EOP increased the proliferation of macrophages, enhanced its phagocytic capability, and promoted the production of cytokines including nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). Furthermore, the in vivo evaluation on zebrafish showed that EOP could reduce the residual content of fluorescent microspheres in zebrafish, which indicated that EOP had the capability to enhance the macrophage phagocytosis. All results suggested that EOP showed a complex structure and exhibited significant immunomodulatory activity both in vitro and in vivo that had the potential to be utilized valuably in food and medicine industries.Copyright © 2023. Published by Elsevier B.V.