title: Structural characterization and immunomodulatory effect of a polysaccharide HCP-2 from Houttuynia cordata.
abstract: Immunomodulation of natural polysaccharides has been the hot topic of research in recent years. In order to explore the immunomodulatory effect of Houttuynia cordata Thunb., the water extract was studied and a polysaccharide HCP-2 with molecular weight of 60,000 Da was isolated by chromatography using DEAE Sepharose CL-6B and Sephacryl S-500 [corrected] HR columns. The structure characterization of HCP-2 was performed by Fourier transform infrared spectroscopy (FTIR), acidic hydrolysis, PMP derivation, HPLC analysis and nuclear magnetic resonance spectra (NMR). HCP-2 was elucidated as a pectic polysaccharide with a linear chain of 1,4-linked α-D-galacturonic acid residues in which part of the 6-carboxyl groups were methyl esterified and part of 2-hydroxyl groups were acetylated. The bioactivity assays showed that HCP-2 could increase the secretions of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), macrophage inhibitory protein-1α (MIP-1α), macrophage inhibitory protein-1β (MIP-1β), and RANTES (regulated on activation, normal T cell expressed and secreted) in human peripheral blood mononuclear cells (PBMCs), which play critical roles in the innate immune system and shape the adaptive immunity. Our results implied that HCP-2 could be an immune enhancer.
authors: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region.
authors: Bao-Hui
authors: BH
authors: Cheng
authors: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region.
authors: Judy Yuet-Wa
authors: JY
authors: Chan
authors: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region.
authors: Ben Chung-Lap
authors: BC
authors: Chan
authors: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region.
authors: Huang-Quan
authors: HQ
authors: Lin
authors: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region.
authors: Xiao-Qiang
authors: XQ
authors: Han
authors: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region.
authors: Xuelin
authors: X
authors: Zhou
authors: School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region.
authors: David Chi-Cheong
authors: DC
authors: Wan
authors: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China.
authors: Yi-Fen
authors: YF
authors: Wang
authors: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region.
authors: Ping-Chung
authors: PC
authors: Leung
authors: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region; School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region.
authors: Kwok-Pui
authors: KP
authors: Fung
authors: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region. Electronic address: claralau@cuhk.edu.hk.
authors: Clara Bik-San
authors: CB
authors: Lau
mesh_terms: D002236:Carbohydrate Conformation; D016207:Cytokines / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D052859:Houttuynia / Q000737:chemistry*; D006801:Humans; D056747:Immunomodulation; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008970:Molecular Weight; D011134:Polysaccharides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D016207:Cytokines; D004365:Drugs, Chinese Herbal; C442781:Houttuynia cordata extract; D011134:Polysaccharides
keywords: HCP-2; Houttuynia cordata; Immunomodulation; Pectic polysaccharide; Structural characterization