title: Anti-Helicobacter pylori activity of crude N-acetylneuraminic acid isolated from glycomacropeptide of whey.
abstract: Helicobacter pylori colonizes the gastric mucosa of about half of the world's population, causing chronic gastritis and gastric cancer. An increasing emergence of antibiotic-resistant H. pylori arouses demand on alternative non-antibiotic-based therapies. In this study, we freshly prepared crude N-acetylneuraminic acid obtained from glycomacropeptide (G-NANA) of whey through a neuraminidase-mediated reaction and evaluated its antibacterial ability against H. pylori and H. felis. Overnight cultures of the H. pylori were diluted with fresh media and different concentrations (1-150 mg/mL) of crude G-NANA were added directly to the culture tube. Bacterial growth was evaluated by measuring the optical density of the culture medium and the number of viable bacteria was determined by a direct count of the colony forming units (CFU) on agar plates. For the in vivo study, mice were orally infected with 100 µL (5×10(8) cfu/mL) of H. felis four times at a day's interval, accompanied by a daily administration of crude G-NANA or vehicle. A day after the last infection, the mice were daily administered the crude G-NANA (0, 75, and 300 mg/mL) for 10 days and euthanized. Their stomachs were collected and bacterial colonization was determined by quantitative real-time PCR. Crude G-NANA inhibited H. pylori's growth and reduced the number of viable bacteria in a dose-dependent manner. Furthermore, crude G-NANA inhibited bacterial colonization in the mice. These results showed that crude G-NANA has antibacterial activity against Helicobacter and demonstrated its therapeutic potential for the prevention of chronic gastritis and gastric carcinogenesis induced by Helicobacter infection in humans.
authors.affiliation: Laboratory Animal Resource Center, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu, Korea.
authors.forename: Dong-Jae
authors.initials: DJ
authors.lastname: Kim
authors.affiliation: Laboratory Animal Medicine and Brain Korea 21 PLUS Project, College of Veterinary Medicine, Chonnam National University, Gwangju, Korea.
authors.forename: Min-Jung
authors.initials: MJ
authors.lastname: Kang
authors.affiliation: Department of Biochemistry, College of Medicine, Konyang University, Daejeon, Korea.
authors.forename: Jin-A
authors.initials: JA
authors.lastname: Choi
authors.affiliation: Lifetree Biotechnology Institute, Lifetree Bitotech Co. Ltd., Gyeonggi, Korea.
authors.forename: Dae-Seung
authors.initials: DS
authors.lastname: Na
authors.affiliation: Lifetree Biotechnology Institute, Lifetree Bitotech Co. Ltd., Gyeonggi, Korea.
authors.forename: Jin-Beom
authors.initials: JB
authors.lastname: Kim
authors.affiliation: Lifetree Biotechnology Institute, Lifetree Bitotech Co. Ltd., Gyeonggi, Korea.
authors.forename: Chun-Soo
authors.initials: CS
authors.lastname: Na
authors.affiliation: Laboratory Animal Medicine and Brain Korea 21 PLUS Project, College of Veterinary Medicine, Chonnam National University, Gwangju, Korea.
authors.forename: Jong-Hwan
authors.initials: JH
authors.lastname: Park
keywords: Helicobacter; N-neuraminic acid; antibacterial activity; glycomacropeptide