College of Life Sciences, Anhui Agricultural University, Hefei 230036, China.
College of Tea and Food Science and Technology, Anhui Agricultural University, Hefei 230036, China.
Int Immunopharmacol. 2017 Nov;52:119-126. doi: 10.1016/j.intimp.2017.08.030. Epub 2017 Oct 12.
Lilium lancifolium Thunb. is a Chinese traditional plant with various health benefits. In this study, we purified and characterized the water-soluble polysaccharide fraction (LLP-1A) of L. lancifolium. We also investigated the in vitro immune-enhancing activity of LLP-1A in macrophages and the underlying molecular mechanism. Results showed that LLP-1A was mainly composed of mannose and glucose at a molar ratio of 1.77:1, and its molecular weight was approximately 78.61kDa. The Fourier transform-infrared spectra of LLP-1A also revealed typical polysaccharide characteristics: the presence of uronic acid, pyranose rings and β-glycosidic bonds. With regard to its effects on macrophages, LLP-1A enhanced phagocytic activity and induced the NO production in a dose-dependent manner. Further, it induced expression of the cytokines interleukin-6, monocyte chemotactic protein 1, tumor necrosis factor-α and interleukin-1β. With regard to the molecular mechanism, LLP-1A increased protein expression of Toll-like receptor 4 and phosphorylation of the inhibitor of nuclear factor kappa-B kinase, inhibitor of NF-κB, and nuclear factor-kappa B in RAW 264.7 cells. Therefore, the data suggest that LLP-1A significantly upregulated the expression of immune reactive cytokines in RAW 264.7 macrophages through the TLR4-mediated NF-κB signal pathway. Thus, LLP-1A may have immunomodulatory functions that may prove beneficial for the treatment of immune-related diseases.
百合是一种具有多种健康益处的中国传统植物。在本研究中，我们从百合中分离纯化并鉴定了一种水溶性多糖（LLP-1A），研究了 LLP-1A 在巨噬细胞中的体外免疫增强活性及其潜在的分子机制。结果表明，LLP-1A 主要由甘露糖和葡萄糖组成，摩尔比为 1.77:1，分子量约为 78.61kDa。傅里叶变换红外光谱也显示 LLP-1A 具有典型的多糖特征：存在糖醛酸、吡喃环和β糖苷键。LLP-1A 能增强巨噬细胞的吞噬活性，诱导一氧化氮（NO）的产生，并呈剂量依赖性。此外，它还能诱导白细胞介素 6（IL-6）、单核细胞趋化蛋白 1（MCP-1）、肿瘤坏死因子-α（TNF-α）和白细胞介素 1β（IL-1β）等细胞因子的表达。在分子机制方面，LLP-1A 能增加 RAW 264.7 细胞中 Toll 样受体 4（TLR4）和核因子κB 激酶抑制剂（IKK）、核因子-κB（NF-κB）抑制蛋白的磷酸化。因此，数据表明 LLP-1A 通过 TLR4 介导的 NF-κB 信号通路显著上调 RAW 264.7 巨噬细胞中免疫反应性细胞因子的表达。因此，LLP-1A 可能具有免疫调节功能，有助于治疗与免疫相关的疾病。
