title: Preventive effects of Cladosiphon fucoidan against Helicobacter pylori infection in Mongolian gerbils.
abstract: BACKGROUND
  Recently, the acquisition by Helicobacter pylori of resistance to antibiotics has become a serious problem. Therefore, nonantibiotic substances are required to diminish H. pylori-induced gastric lesions. In the present study, the effects of Cladosiphon fucoidan were examined in terms of H. pylori attachment to porcine gastric mucin in vitro and Helicobacter pylori-induced gastritis in vivo.
  
  
  METHODS
  The inhibitory effect of Cladosiphon fucoidan and other polysaccharides on H. pylori attachment to porcine gastric mucin was assayed in vitro with mucin-coated microtiter plates. The effect of Cladosiphon fucoidan on H. pylori-induced gastritis was examined in vivo using Mongolian gerbils. H. pylori-inoculated gerbils were given fucoidan in drinking water. Six weeks after H. pylori-inoculation, gerbils were sacrificed for macroscopic and microscopic examination of gastric lesions and counting of viable H. pylori in the gastric mucosa.
  
  
  RESULTS
  Cladosiphon fucoidan inhibited the H. pylori attachment to porcine gastric mucin at pH 2.0 and 4.0. Two other sulfated polysaccharides, Fucus fucoidan and dextran sulfate sodium, also inhibited the attachment but only at pH 2.0. Inhibitory effects of these three sulfated polysaccharides were not observed at pH 7.2 and nonsulfated polysaccharides, such as mannan and dextran, exerted no influence at any pH. In the in vivo experiment, the H. pylori-induced gastritis and the prevalence of H. pylori infected animals were markedly reduced by fucoidan in a dose-dependent manner, at doses of 0.05 and 0.5% in the drinking water.
  
  
  CONCLUSIONS
  Cladosiphon fucoidan may deserve particular attention as a safe agent that can prevent H. pylori infection and reduce the risk of associated gastric cancer.
authors.affiliation: Cancer Prevention Division, National Cancer Center Research Institute, 5-1-1, Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Shibata
authors.forename: Masaki
authors.initials: M
authors.lastname: Iimuro
authors.forename: Naoaki
authors.initials: N
authors.lastname: Uchiya
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Kawamori
authors.forename: Masato
authors.initials: M
authors.lastname: Nagaoka
authors.forename: Sadao
authors.initials: S
authors.lastname: Ueyama
authors.forename: Shusuke
authors.initials: S
authors.lastname: Hashimoto
authors.forename: Teruo
authors.initials: T
authors.lastname: Yokokura
authors.forename: Takashi
authors.initials: T
authors.lastname: Sugimura
authors.forename: Keiji
authors.initials: K
authors.lastname: Wakabayashi
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology; D001422:Bacterial Adhesion / Q000187:drug effects; D005753:Gastric Mucosa / Q000187:drug effects / Q000382:microbiology / Q000473:pathology; D005756:Gastritis / Q000382:microbiology / Q000473:pathology / Q000517:prevention & control*; D005849:Gerbillinae; D016481:Helicobacter Infections / Q000382:microbiology / Q000473:pathology / Q000517:prevention & control*; D016480:Helicobacter pylori; D009077:Mucins / Q000378:metabolism; D011134:Polysaccharides / Q000302:isolation & purification / Q000494:pharmacology*; D012624:Seaweed / Q000737:chemistry; D013552:Swine
chemical_list: D000900:Anti-Bacterial Agents; D009077:Mucins; D011134:Polysaccharides; C007789:fucoidan