title: Curcumin reduces Streptococcus mutans biofilm formation by inhibiting sortase A activity.
abstract: BACKGROUND
  Sortase A is an enzyme responsible for the covalent attachment of Pac proteins to the cell wall in Streptococcus mutans. It has been shown to play a role in modulating the surface properties and the biofilm formation and influence the cariogenicity of S. mutans. Curcumin, an active ingredient of turmeric, was reported to be an inhibitor for Staphylococcus aureus sortase A. The aim of this study was to investigate the inhibitory ability of curcumin against S. mutans sortase A and the effect of curcumin for biofilm formation.
  
  
  METHODS
  The antimicrobial activity of the curcumin to the S. mutans and inhibitory ability of the curcumin against the purified sortase A in vitro were detected. Western-blot and real-time PCR were used to analysis the sortase A mediated Pac protein changes when the S. mutans was cultured with curcumin. The curcumin on the S. mutans biofilm formation was determined by biofilm formation analysis.
  
  
  RESULTS
  Curcumin can inhibit purified S. mutans sortase A with a half-maximal inhibitory concentration (IC50) of (10.2±0.7)μmol/l, which is lower than minimum inhibitory concentration (MIC) of 175μmol/l. Curcumin (15μmol/l) was found to release the Pac protein to the supernatant and reduce S. mutans biofilm formation.
  
  
  CONCLUSIONS
  These results indicated that curcumin is an S. mutans sortase A inhibitor and has promising anti-caries characteristics through an anti-adhesion-mediated mechanism.
authors.affiliation: Center of Stomatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China. dentistpinghu@gmail.com
authors.forename: Ping
authors.initials: P
authors.lastname: Hu
authors.forename: Ping
authors.initials: P
authors.lastname: Huang
authors.forename: Min Wei
authors.initials: MW
authors.lastname: Chen
mesh_terms: D019881:Aminoacyltransferases / Q000378:metabolism*; D001422:Bacterial Adhesion / Q000187:drug effects; D001426:Bacterial Proteins / Q000378:metabolism*; D018441:Biofilms / Q000187:drug effects*; D015153:Blotting, Western; D003474:Curcumin / Q000494:pharmacology*; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D013295:Streptococcus mutans / Q000187:drug effects* / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D019881:Aminoacyltransferases; C120542:sortase A; D003546:Cysteine Endopeptidases; D003474:Curcumin
keywords: Curcumin; Inhibition; S. mutans; Sortase A