title: Trans-cinnamaldehyde decreases attachment and invasion of uropathogenic Escherichia coli in urinary tract epithelial cells by modulating virulence gene expression.
abstract: OBJECTIVE
  Uropathogenic Escherichia coli is the primary bacterium causing urinary tract infection in humans. Attachment and invasion of urinary tract epithelial cells by UPEC is the first critical step in establishing a successful urinary tract infection. We investigated the efficacy of subinhibitory concentrations of trans-cinnamaldehyde to inhibit uropathogenic E. coli attachment and invasion of human uroepithelial cells. We also determined the trans-cinnamaldehyde effect on uropathogenic E. coli genes encoding virulence factors critical for uroepithelial cell bacterial attachment and invasion.
  
  
  METHODS
  Polystyrene 24-well plates seeded with uroepithelial cells were inoculated with uropathogenic E. coli (about 6.0 log cfu) and subinhibitory concentrations of trans-cinnamaldehyde (0, 325, 560 and 750 μM), and incubated for 60 minutes at 37C. Uroepithelial cells were washed and lysed to enumerate adhered uropathogenic E. coli populations. For the invasion assay uroepithelial cells were treated with gentamicin after incubation and lysed to enumerate invaded uropathogenic E. coli. Also, the trans-cinnamaldehyde effect on uropathogenic E. coli genes encoding attachment and invasion associated virulence factors was determined by real-time quantitative polymerase chain reaction.
  
  
  RESULTS
  Trans-cinnamaldehyde significantly decreased uroepithelial cell attachment and invasion by uropathogenic E. coli (p <0.05). Real-time quantitative polymerase chain reaction revealed that trans-cinnamaldehyde significantly decreased the expression of major genes involved in uropathogenic E. coli attachment and invasion of host tissue (p <0.05). The down-regulating effect of trans-cinnamaldehyde on these genes potentially translated into decreased ability of uropathogenic E. coli to attach and invade bladder cells.
  
  
  CONCLUSIONS
  Trans-cinnamaldehyde may potentially be used as a safe, effective antimicrobial to control uropathogenic E. coli infection. Followup studies in animal models are warranted.
authors.affiliation: Department of Animal Science, University of Connecticut, Storrs, Connecticut 06269, USA.
authors.forename: Mary Anne Roshni
authors.initials: MA
authors.lastname: Amalaradjou
authors.forename: Amoolya
authors.initials: A
authors.lastname: Narayanan
authors.forename: Kumar
authors.initials: K
authors.lastname: Venkitanarayanan
mesh_terms: D000171:Acrolein / Q000031:analogs & derivatives* / Q000494:pharmacology; D001422:Bacterial Adhesion / Q000187:drug effects*; D004847:Epithelial Cells / Q000382:microbiology*; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics* / Q000472:pathogenicity*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D006801:Humans; D014552:Urinary Tract Infections / Q000382:microbiology; D019459:Urothelium / Q000166:cytology*
chemical_list: D000171:Acrolein; C012843:cinnamaldehyde