title: Isolation and characterization of immunostimulatory polysaccharide from an herb tea, Gynostemma pentaphyllum Makino.
abstract: Water-soluble polysaccharide from Gynostemma pentaphyllum herb tea (PSGP) was isolated by hot-water extraction and ethanol precipitation. The chemical components and preliminary immunomodulating activity of PSGP were investigated both in vitro and in vivo. Capillary zone electrophoresis analysis showed that PSGP was a typical nonstarch heteropolysaccharide, with glucose being the main component monosaccharide (23.2%), followed by galactose (18.9%), arabinose (10.5%), rhamnose (7.7%), galacturonic acid (4.7%), xylose (3.9%), mannose (3.1%), and glucuronic acid (1.2%). PSGP could significantly stimulate peritoneal macrophages to release nitric oxide, reactive oxygen species, and tumor necrosis factor-alpha in a dose-dependent manner. This immunostimulating activity of PSGP was further demonstrated by its inhibition on the proliferation of human colon carcinoma HT-29 and SW-116 cells incubated with the supernatant of PSGP-stimulated macrophage culture. It is evident that PSGP is a very important ingredient responsible for at least in part the immunomodulating activity of G. pentaphyllum herb tea.
authors.affiliation: Key Laboratory of Ministry of Education for Medicinal Plant Resource and Natural Pharmaceutical Chemistry, College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China. xbyang@snnu.edu.cn
authors.forename: Xingbin
authors.initials: X
authors.lastname: Yang
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Ying
authors.initials: Y
authors.lastname: Yang
authors.forename: Yun
authors.initials: Y
authors.lastname: Ruan
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D001628:Beverages / Q000032:analysis; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003110:Colonic Neoplasms; D019075:Electrophoresis, Capillary; D029774:Gynostemma / Q000737:chemistry*; D019073:HT29 Cells; D006801:Humans; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D009569:Nitric Oxide / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000276:Adjuvants, Immunologic; D011134:Polysaccharides; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide