title: Anti-bacterial effects of enzymatically-isolated sialic acid from glycomacropeptide in aHelicobacter pylori-infected murine model.
abstract: OBJECTIVE
  Helicobacter pylori(H. pylori) colonization of the stomach mucosa and duodenum is the major cause of acute and chronic gastroduodenal pathology in humans. Efforts to find effective anti-bacterial strategies againstH. pylorifor the non-antibiotic control ofH. pyloriinfection are urgently required. In this study, we used whey to prepare glycomacropeptide (GMP), from which sialic acid (G-SA) was enzymatically isolated. We investigated the anti-bacterial effects of G-SA againstH. pylori in vitroand in anH. pylori-infected murine model.
  
  
  METHODS
  The anti-bacterial activity of G-SA was measuredin vitrousing the macrodilution method, and interleukin-8 (IL-8) production was measured inH. pyloriand AGS cell co-cultures by ELISA. Forin vivostudy, G-SA 5 g/kg body weight (bw)/day andH. pyloriwere administered to mice three times over one week. After one week, G-SA 5 g/kg bw/day alone was administered every day for one week. Tumor necrosis factor-α (TNF-α), IL-1β, IL-6, and IL-10 levels were measured by ELISA to determine the anti-inflammatory effects of G-SA. In addition, real-time PCR was performed to measure the genetic expression of cytotoxin-associated gene A (cagA).
  
  
  RESULTS
  G-SA inhibited the growth ofH. pyloriand suppressed IL-8 production inH. pyloriand in AGS cell co-culturesin vitro. In thein vivoassay, administration of G-SA reduced levels of IL-1β and IL-6 pro-inflammatory cytokines whereas IL-10 level increased. Also, G-SA suppressed the expression ofcagAin the stomach ofH. pylori-infected mice.
  
  
  CONCLUSIONS
  G-SA possesses anti-H. pyloriactivity as well as an anti-H. pylori-induced gastric inflammatory effect in an experimentalH. pylori-infected murine model. G-SA has potential as an alternative to antibiotics for the prevention ofH. pyloriinfection andH. pylori-induced gastric disease prevention.
authors.affiliation: Department of Medical Nutrition, Kyung Hee University, 1732, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi 17104, Korea.
authors.forename: Hye-Ji
authors.initials: HJ
authors.lastname: Noh
authors.affiliation: College of Veterinary Medicine, Chonnam National University, Gwangju 61186, Korea.
authors.forename: Hong Bum
authors.initials: HB
authors.lastname: Koh
authors.affiliation: Medinutrol Co. Ltd., Jeonnam 57024, Korea.
authors.forename: Hee-Kyoung
authors.initials: HK
authors.lastname: Kim
authors.affiliation: Medinutrol Co. Ltd., Jeonnam 57024, Korea.
authors.forename: Hyang Hyun
authors.initials: HH
authors.lastname: Cho
authors.affiliation: Department of Medical Nutrition, Kyung Hee University, 1732, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi 17104, Korea.
authors.forename: Jeongmin
authors.initials: J
authors.lastname: Lee
keywords: Helicobacter pylori; Sialic acid; cytotoxin-associated gene A