山东农业大学食品科学与工程学院郑振佳副教授等|牛蒡中性多糖结构分析与抗炎活性评价

对水提醇沉法获得的牛蒡粗多糖进行分离纯化并对中性多糖组分进行结构表征和抗炎活性评价。通过DEAE-52纤维素柱制备牛蒡中性多糖，通过单糖组成、分子量、紫外、红外、XRD、粒径和核磁等方法对其进行结构表征，利用硫酸铜诱导的斑马鱼急性炎症模型，评价不同剂量牛蒡粗多糖和牛蒡中性多糖对斑马鱼巨噬细胞移动的影响。通过实时荧光定量PCR分析测定核转录因子激活蛋白-1（AP-1）、环氧化酶-2（COX-2）、IKBα、白细胞介素-1β（IL-1β）、白细胞介素-12（IL-12）和髓样分化因子（MyD88）等不同炎性因子mRNA的表达量。结果表明，牛蒡中性多糖重均分子量为2682 Da，数均分子量为2079 Da，主要由果糖和葡萄糖组成，摩尔比为11.32:1，粒径主要分布在80~110 nm。牛蒡中性多糖主要由β构型的呋喃糖组成，有明显的尖而窄的晶体衍射峰，结晶度较高，核磁结果显示其结构为α-D-吡喃葡萄糖基-（1→2）-[β-D-呋喃果糖基-（1→2）]10-β-D-呋喃果糖基。牛蒡中性多糖可以显著（P<0.05）减少斑马鱼巨噬细胞的迁移数目，且当浓度为100 µg/mL时，巨噬细胞数量较模型组下降了41.11%，抗炎效果最佳；牛蒡中性多糖可能通过沉默炎性细胞因子信号传导，抑制TLR4/MyD88/NF-κB信号通路的过度激活，从而抑制炎症反应。本研究可为牛蒡中性多糖的抗炎活性和开发功能性食品提供理论依据。

A neutral polysaccharide was purified by DEAE-52 cellulose column chromatography from the crude polysaccharide of Arctium lappa L. obtained by hot water extraction and ethanol precipitation, and the structure and anti-inflammatory activity of the neutral polysaccharide were characterized. The structure of Arctium lappa L. neutral polysaccharide were investigated through monosaccharide composition, molecular weight, ultraviolet spectra, infrared spectroscopy analysis, X-ray diffraction spectroscopy, particle size analysis and NMR analysis. The effect of different doses of crude polysaccharide and neutral polysaccharide from Arctium lappa L. on macrophage movement was evaluated in zebrafish acute inflammation model induced by copper sulfate. The mRNA expressions of different inflammatory factors such as nuclear transcription factor activator protein-1 (AP-1), cycloxygenase-2 (COX-2), IKBα, interleukin-1β (IL-1β), interleukin-12 (IL-12) and myeloid differentiation factor (MyD88) were determined by real-time PCR analysis. Results showed that the weight-average molecular weight and number-average molecular weight of Arctium lappa L. neutral polysaccharide were 2682 and 2079 Da, which were mainly composed of fructose and glucose with a molar ratio of 11.32:1. The particle size mainly ranged from 80 nm to 110 nm. The neutral polysaccharide of Arctium lappa L. was mainly composed of furanose with β configuration, with obvious sharp and narrow crystal diffraction peaks and high crystallinity. The NMR analysis showed that its structure was α-D-glucopyranosyl-(1→2)-[β-D-fructofuranosyl-(1→2)]10-β-D-fructofuranosyl. Arctium lappa L. neutral polysaccharide could significantly (P<0.05) reduce the migration number of zebrafish macrophages, and the anti-inflammatory effect was the best at the concentration of 100 µg/mL, as well as the number of macrophages decreased by 41.11% compared with the model group. The Arctium lappa L. neutral polysaccharide may be inhibited the overactivation of TLR4/MyD88/NF-κB signaling pathway by silting the signal transduction of inflammatory cytokines. This study could provide a theoretical basis for the anti-inflammatory activity of neutral polysaccharide from Arctium lappa L. and the development of functional foods.