title: In vitro inhibition of Helicobacter pylori urease with non and semi fermented Camellia sinensis.
abstract: OBJECTIVE
  Helicobacter pylori is the etiological agent in duodenal and peptic ulcers. The growing problem of antibiotic resistance by the organism demands the search for novel compounds, especially from natural sources. This study was conducted to evaluate the effect of Camellia sinensis extracts on the urease enzyme that is a major colonization factor for H. pylori.
  
  
  METHODS
  Minimum inhibitory concentrations of nonfermented and semifermented C. sinensis methanol: water extracts were assessed by broth dilution method. Examination of the urease function was performed by Mc Laren method, and urease production was detected on 12% SDS polyacrylamide gel electrophoresis from whole cell and membrane bound proteins.
  
  
  RESULTS
  Both extracts had inhibitory effects against H. pylori and urease production. At a concentration of 2.5 mg/ml of nonfermented extract and 3.5 mg/ml of semifermented extract the production of Ure A and Ure B subunits of the urease enzyme were inhibited completely. A concentration of 4 mg/ml of nonfermented and 5.5 mg/ml of semifermented extract were bactericidal for H. pylori.
  
  
  CONCLUSIONS
  C. sinensis extracts, especially the nonfermented, could reduce H. pylori population and inhibit urease production at lower concentrations. The superior effect of nonfermented extract is due to its rich polyphenolic compounds and catechin contents.
authors.affiliation: Microbiology Department, Science and Research Branch of IAU, Tehran, Iran.
authors.forename: A R Shoae
authors.initials: AR
authors.lastname: Hassani
authors.forename: N
authors.initials: N
authors.lastname: Ordouzadeh
authors.forename: A
authors.initials: A
authors.lastname: Ghaemi
authors.forename: N
authors.initials: N
authors.lastname: Amirmozafari
authors.forename: K
authors.initials: K
authors.lastname: Hamdi
authors.forename: R
authors.initials: R
authors.lastname: Nazari
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D028241:Camellia sinensis / Q000737:chemistry*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D016480:Helicobacter pylori / Q000187:drug effects* / Q000201:enzymology* / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability; D010936:Plant Extracts / Q000494:pharmacology*; D014510:Urease / Q000037:antagonists & inhibitors* / Q000096:biosynthesis
chemical_list: D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D010936:Plant Extracts; D014510:Urease