title: Effect of plaunotol in combination with clarithromycin against clarithromycin-resistant Helicobacter pylori in vitro and in vivo.
abstract: OBJECTIVE
  Recently, there has been a decrease in the eradication rate of Helicobacter pylori due to the increase in antibiotic resistance of this bacterium. Plaunotol, a cytoprotective anti-ulcer agent, exhibits antibacterial activity against H. pylori. The purpose of the present study was to investigate the effect of plaunotol in combination with clarithromycin against clarithromycin-resistant H. pylori clinical isolates.
  
  
  RESULTS
  In the chequerboard titration method, the combination of plaunotol and clarithromycin showed a synergistic effect against 67% (10/15) clarithromycin-resistant strains and an additive effect against the other strains. No indifferent and antagonistic effects were observed against any of the strains tested. In a gastritis model of Mongolian gerbils infected with clarithromycin-resistant H. pylori, the plaunotol (40 mg/kg) and clarithromycin (66.6 mg/kg) combination exhibited synergistic effects; however, neither plaunotol nor clarithromycin alone showed bactericidal effects.
  
  
  CONCLUSIONS
  These results suggest that plaunotol may play a useful role in combination with anti-H. pylori drugs in the treatment of diseases associated with clarithromycin-resistant H. pylori.
authors.affiliation: Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho, Nagoya 467-8601, Japan. msasaki@med.nagoya-cu.ac.jp
authors.forename: Makoto
authors.initials: M
authors.lastname: Sasaki
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Mizoshita
authors.forename: Takashi
authors.initials: T
authors.lastname: Mizushima
authors.forename: Harumi
authors.initials: H
authors.lastname: Inoue
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kamiya
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kataoka
authors.forename: Naotaka
authors.initials: N
authors.lastname: Ogaswara
authors.forename: Tsuneya
authors.initials: T
authors.lastname: Wada
authors.forename: Eiji
authors.initials: E
authors.lastname: Kubota
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Mori
authors.forename: Takaya
authors.initials: T
authors.lastname: Shimura
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Hirata
authors.forename: Kenji
authors.initials: K
authors.lastname: Ando
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Okamoto
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Ohara
authors.forename: Haruhisa
authors.initials: H
authors.lastname: Nakao
authors.forename: Takashi
authors.initials: T
authors.lastname: Joh
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use; D017291:Clarithromycin / Q000008:administration & dosage* / Q000627:therapeutic use*; D004224:Diterpenes; D024881:Drug Resistance, Bacterial; D004359:Drug Therapy, Combination; D005233:Fatty Alcohols / Q000008:administration & dosage* / Q000627:therapeutic use*; D014644:Genetic Variation; D005849:Gerbillinae; D016481:Helicobacter Infections / Q000188:drug therapy*; D016480:Helicobacter pylori / Q000187:drug effects* / Q000235:genetics; D008297:Male; D008826:Microbial Sensitivity Tests; D013047:Specific Pathogen-Free Organisms