Preventive effects of Cladosiphon fucoidan against Helicobacter pylori infection in Mongolian gerbils.
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.
Shibata
Hideyuki
H
Cancer Prevention Division, National Cancer Center Research Institute, 5-1-1, Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
Iimuro
Masaki
M
Uchiya
Naoaki
N
Kawamori
Toshihiko
T
Nagaoka
Masato
M
Ueyama
Sadao
S
Hashimoto
Shusuke
S
Yokokura
Teruo
T
Sugimura
Takashi
T
Wakabayashi
Keiji
K
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
D000900:Anti-Bacterial Agents; D009077:Mucins; D011134:Polysaccharides; C007789:fucoidan