title: Quorum sensing inhibition activity of garlic extract and p-coumaric acid.
abstract: OBJECTIVE
  The goal of this work was to investigate the influence of DMSO, garlic extract and p-coumaric acid on bacterial quorum sensing (QS).
  
  
  RESULTS
  The decreases in the QS responses of QS reporter strains Escherichia coli pSB401 and pSB536, Agrobacterium tumefaciens NTL4, Chromobacterium violaceum 5999 and wt 494, Pseudomonas putida IsoF/gfp and environmental Pseudomonas chlororaphis were quantified in relation to growth inhibitory effects. DMSO showed no significant QS-specific effects on the strains tested even at close-to-lethal concentrations. Garlic extracts antagonized the activity of QS receptors LuxR, AhyR and TraR, but were toxic at higher concentrations. P-coumaric acid fully inhibited QS responses of 5999, NTL4 and P. chlororaphis, with no influence on cell viability.
  
  
  CONCLUSIONS
  The quorum sensing inhibition activity of garlic was extended to novel receptors, and p-coumaric acid was found to possess previously undescribed QS antagonist properties.
  
  
  CONCLUSIONS
  The results suggest that p-coumaric acid might act as QS inhibitor. Further studies are required to understand its role in the regulation of QS and investigate structurally related compounds.
authors.affiliation: Department of Environmental Biotechnologies, ISRIM Scarl, Strada di Pentima, 05100 Terni, Italy. sofobi@hotmail.com
authors.forename: S F
authors.initials: SF
authors.lastname: Bodini
authors.forename: S
authors.initials: S
authors.lastname: Manfredini
authors.forename: M
authors.initials: M
authors.lastname: Epp
authors.forename: S
authors.initials: S
authors.lastname: Valentini
authors.forename: F
authors.initials: F
authors.lastname: Santori
mesh_terms: D001419:Bacteria / Q000187:drug effects*; D018407:Bacterial Physiological Phenomena / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003373:Coumaric Acids / Q000494:pharmacology*; D015536:Down-Regulation; D005737:Garlic / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D011422:Propionates; D053038:Quorum Sensing / Q000187:drug effects*
chemical_list: D003373:Coumaric Acids; D010936:Plant Extracts; D011422:Propionates; C495469:p-coumaric acid