title: Purification, characterization and immunoregulatory activity of a polysaccharide isolated from Hibiscus sabdariffa L.
abstract: BACKGROUND
  Hibiscus sabdariffa L. is not only used traditionally as a component of herbal drinks, beverages and flavoring agents but also as a herbal medicine in the drug industry. Bioactive polysaccharides are important constituents of H. sabdariffa that may contribute to the plant's beneficial effects. This study was designed to investigate the structural characteristics of a water-soluble polysaccharide from H. sabdariffa, HSP41, and its immunoregulatory activity on RAW264.7 cells.
  
  
  RESULTS
  HSP41 was mainly composed of arabinose, xylose and mannose at a molar ratio of 1:1.34:15.6, with an average molecular weight of 3.3 × 105Da. Fourier transform infrared (FTIR) spectra exhibited absorption peaks characteristic of HSP41. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed the amorphous form and aggregation conformation of HSP41 respectively. HSP41 significantly induced interleukin 1β (IL-1β) and inducible nitric oxide synthase (iNOS) expression in RAW264.7 cells in vitro, promoting an increase in nuclear factor kB p65 (NF-kB p65) levels in the nucleus.
  
  
  CONCLUSIONS
  The results indicated that HSP41 up-regulated the immune response by stimulating RAW264.7 cell activity. HSP41, a promising immunoregulator, possibly contributes to the health benefits of H. sabdariffa and might have potential applications in health food or medicine. © 2016 Society of Chemical Industry.
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013, Jiangsu, China.|School of Life Science, Shaoxing University, Chengnan Road 900, Shaoxing, 312000, Zhejiang, China.
authors.forename: Daheng
authors.initials: D
authors.lastname: Zheng
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013, Jiangsu, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Zou
authors.affiliation: School of Environment and Safety, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013, Jiangsu, China.
authors.forename: Samuel Jerry
authors.initials: SJ
authors.lastname: Cobbina
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013, Jiangsu, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013, Jiangsu, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
authors.affiliation: School of Environment and Safety, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013, Jiangsu, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Chen
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013, Jiangsu, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Feng
authors.affiliation: School of Pharmacy, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013, Jiangsu, China.
authors.forename: Yanmin
authors.initials: Y
authors.lastname: Zou
authors.affiliation: School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013, Jiangsu, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Zhao
authors.affiliation: School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013, Jiangsu, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013, Jiangsu, China.
authors.forename: Liuqing
authors.initials: L
authors.lastname: Yang
authors.affiliation: School of Environment and Safety, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013, Jiangsu, China.
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Wu
mesh_terms: D000818:Animals; D031584:Hibiscus / Q000737:chemistry*; D053583:Interleukin-1beta / Q000187:drug effects*; D051379:Mice; D016328:NF-kappa B / Q000187:drug effects*; D052247:Nitric Oxide Synthase Type II / Q000187:drug effects*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology*; D000067996:RAW 264.7 Cells
chemical_list: D053583:Interleukin-1beta; D016328:NF-kappa B; D010936:Plant Extracts; D011134:Polysaccharides; D052247:Nitric Oxide Synthase Type II
keywords: Hibiscus sabdariffa L; health food; immunoregulatory activity; polysaccharide; structural characterization