title: Phytochemicals as Effective Quorum Quenchers Against Bacterial Communication.
abstract: BACKGROUND
  Quorum sensing or the bacterial information flow in an orchestrated manner is an essential feature of many pathogenic bacteria. Quorum quenching molecules (QQ) can inhibit the growth of such bacteria.
  
  
  OBJECTIVE
  The purpose of this study is to evaluate the potential of plant extracts as quorum quenchers and monitor the recent patents.
  
  
  METHODS
  Many available reports and patents are on synthetic ligand molecules or even compounds isolated from cyanobacteria (Honaucin A) and other microorganisms inhibiting quorum sensing molecules. Molecules with Quorum quenching (QQ) ability isolated from plants could inhibit violacein and pyocyanin production in Chromobacterium violaceum and Pseudomonas aeruginosa respectively.
  
  
  RESULTS
  Studies leading to patents are initiated in this comparatively new topic. Hydrolysable tannins such as vescalagin and castalagin isolated from Conocarpus erectus are reported to have anti- quorum sensing activity. The gene product of agr D in gram positive bacteria is modified by endopeptidase to thiolactone peptide which is equivalent to acyl homoserine lactone of gram negative bacteria. General pathways suggested for the quorum sensing inhibition by plant extracts focuses on such autoinducers.
  
  
  CONCLUSIONS
  Medicinal plants and plant extracts are the leading sources of quorum sensing inhibitors. Patents related to quorum sensing inhibitors are taking new leaps in medicine, especially applications relating to the addition of quorum sensing inhibitors on to the surface of implantable or indwelling devices that are helpful in eradicating the trouble of infection in health care industry.
authors.affiliation: Post Graduate Department of Botany and Research Centre, University College, Trivandrum-695 034, Kerala, India. subr44@gmail.com.
authors.forename: Sivaramakrishnan
authors.initials: S
authors.lastname: Subramaniyan
authors.forename: Sasikumar
authors.initials: S
authors.lastname: Divyasree
authors.forename: Girija Sadasivan
authors.initials: GS
authors.lastname: Sandhia
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D002861:Chromobacterium / Q000187:drug effects / Q000378:metabolism; D007211:Indoles / Q000737:chemistry / Q000494:pharmacology; D010330:Patents as Topic; D064209:Phytochemicals / Q000737:chemistry* / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000378:metabolism; D011710:Pyocyanine / Q000737:chemistry / Q000494:pharmacology; D053038:Quorum Sensing / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D007211:Indoles; D064209:Phytochemicals; D010936:Plant Extracts; C088386:homoserine lactone; D011710:Pyocyanine; D015107:4-Butyrolactone; C063155:violacein