title: Extraction, Characterization and Immunological Activity of Polysaccharides from Rhizoma gastrodiae.
abstract: A response surface and Box-Behnken design approach was applied to augment polysaccharide extraction from the residue of Rhizoma gastrodiae. Statistical analysis revealed that the linear and quadratic terms for three variables during extraction exhibited obvious effects on extraction yield. The optimum conditions were determined to be a liquid-to-solid ratio of 54 mL/g, an extraction temperature of 74 °C, an extraction time of 66 min, and three extractions. These conditions resulted in a maximum Rhizoma gastrodiae polysaccharide (RGP) extraction yield of 6.11% ± 0.13%. Two homogeneous polysaccharides (RGP-1a and RGP-1b) were obtained using DEAE cellulose-52 and Sephadex G-100 columns. The preliminary characterization of RGP-1a and RGP-1b was performed using HPLC-RID, HPGPC, and FTIR. Tests of the immunological activity in vitro showed that the two polysaccharides could significantly stimulate macrophages to release NO and enhance phagocytosis in a dose-dependent manner. In particular, RGP-1b (200 μg/mL) and LPS (2 μg/mL) had almost the same influence on the NO production and phagocytic activity of RAW 264.7 macrophages (p > 0.05). All the data obtained indicate that RGP-1a and RGP-1b have the potential to be developed as a health food.
authors.affiliation: Shaanxi Key Laboratory of Natural Products &amp; Chemical Biology, College of Sciences, Northwest A &amp; F University, Yangling 712100, Shaanxi, China. cjc2009@nwsuaf.edu.cn.
authors.forename: Juncheng
authors.initials: J
authors.lastname: Chen
authors.affiliation: Shaanxi Key Laboratory of Natural Products &amp; Chemical Biology, College of Sciences, Northwest A &amp; F University, Yangling 712100, Shaanxi, China. stian@nwsuaf.edu.cn.
authors.forename: Shan
authors.initials: S
authors.lastname: Tian
authors.affiliation: Shaanxi Key Laboratory of Natural Products &amp; Chemical Biology, College of Sciences, Northwest A &amp; F University, Yangling 712100, Shaanxi, China. shuxiaoying1@163.com.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Shu
authors.affiliation: Shaanxi Key Laboratory of Natural Products &amp; Chemical Biology, College of Sciences, Northwest A &amp; F University, Yangling 712100, Shaanxi, China. duht@nwsuaf.edu.cn.|College of Plant Protection, Northwest A &amp; F University, Yangling 712100, Shaanxi, China. duht@nwsuaf.edu.cn.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Du
authors.affiliation: Shaanxi Key Laboratory of Natural Products &amp; Chemical Biology, College of Sciences, Northwest A &amp; F University, Yangling 712100, Shaanxi, China. lnuk@nwsuaf.edu.cn.
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.affiliation: Shaanxi Key Laboratory of Natural Products &amp; Chemical Biology, College of Sciences, Northwest A &amp; F University, Yangling 712100, Shaanxi, China. wangjunru@nwsuaf.edu.cn.
authors.forename: Junru
authors.initials: J
authors.lastname: Wang
mesh_terms: D000818:Animals; D002460:Cell Line; D007155:Immunologic Factors / Q000737:chemistry* / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism; D029595:Orchidaceae / Q000737:chemistry*; D010587:Phagocytosis; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology; D011134:Polysaccharides / Q000737:chemistry* / Q000494:pharmacology; D027343:Rhizome / Q000737:chemistry
chemical_list: D007155:Immunologic Factors; D010936:Plant Extracts; D011134:Polysaccharides; D009569:Nitric Oxide
keywords: Rhizoma gastrodiae; characterization; immunological activity; optimized extraction; polysaccharides