title: Effects of mushroom and chicory extracts on the shape, physiology and proteome of the cariogenic bacterium Streptococcus mutans.
abstract: BACKGROUND
  Dental caries is an infectious disease which results from the acidic demineralisation of the tooth enamel and dentine as a consequence of the dental plaque (a microbial biofilm) accumulation. Research showed that several foods contain some components with antibacterial and antiplaque activity. Previous studies indicated antimicrobial and antiplaque activities in a low-molecular-mass (LMM) fraction of extracts from either an edible mushroom (Lentinus edodes) or from Italian red chicory (Cichorium intybus).
  
  
  METHODS
  We have evaluated the antimicrobial mode of action of these fractions on Streptococcus mutans, the etiological agent of human dental caries. The effects on shape, macromolecular syntheses and cell proteome were analysed.
  
  
  RESULTS
  The best antimicrobial activity has been displayed by the LMM mushroom extract with a bacteriostatic effect. At the MIC of both extracts DNA synthesis was the main macromolecular synthesis inhibited, RNA synthesis was less inhibited than that of DNA and protein synthesis was inhibited only by roughly 50%. The partial inhibition of protein synthesis is compatible with the observed significant increase in cell mass. The increase in these parameters is linked to the morphological alteration with transition from cocci of the untreated control to elongated cells. Interestingly, these modifications were also observed at sub-MIC concentrations. Finally, membrane and cytosol proteome analysis was conducted under LMM mushroom extract treatment in comparison with untreated S. mutans cells. Significant changes were observed for 31 membrane proteins and 20 of the cytosol fractions. The possible role of the changed proteins is discussed.
  
  
  CONCLUSIONS
  This report has shown an antibiotic-like mode of action of mushroom and chicory extracts as demonstrated by induced morphogenetic effects and inhibition of specific macromolecular synthesis. This feature as well as the safe use of this extract as result of its natural origin render the LMM both mushroom and chicory extracts suitable for the formulation into products for daily oral hygiene such as mouthwashes or toothpastes.
authors.affiliation: Dipartimento di Patologia e Diagnostica, Sezione di Microbiologia, Università di Verona, Verona, Italy. caterina.signoretto@univr.it
authors.forename: Caterina
authors.initials: C
authors.lastname: Signoretto
authors.forename: Anna
authors.initials: A
authors.lastname: Marchi
authors.forename: Anna
authors.initials: A
authors.lastname: Bertoncelli
authors.forename: Gloria
authors.initials: G
authors.lastname: Burlacchini
authors.forename: Alberto
authors.initials: A
authors.lastname: Milli
authors.forename: Francesco
authors.initials: F
authors.lastname: Tessarolo
authors.forename: Iole
authors.initials: I
authors.lastname: Caola
authors.forename: Adele
authors.initials: A
authors.lastname: Papetti
authors.forename: Carla
authors.initials: C
authors.lastname: Pruzzo
authors.forename: Egija
authors.initials: E
authors.lastname: Zaura
authors.forename: Peter
authors.initials: P
authors.lastname: Lingström
authors.forename: Itzhak
authors.initials: I
authors.lastname: Ofek
authors.forename: David A
authors.initials: DA
authors.lastname: Spratt
authors.forename: Jonathan
authors.initials: J
authors.lastname: Pratten
authors.forename: Michael
authors.initials: M
authors.lastname: Wilson
authors.forename: Pietro
authors.initials: P
authors.lastname: Canepari
mesh_terms: D001422:Bacterial Adhesion / Q000187:drug effects; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D018651:Cichorium intybus / Q000737:chemistry*; D003731:Dental Caries / Q000382:microbiology*; D006801:Humans; D050296:Microbial Viability / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D020543:Proteome / Q000235:genetics / Q000378:metabolism; D020942:Shiitake Mushrooms / Q000737:chemistry*; D013295:Streptococcus mutans / Q000166:cytology* / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D014675:Vegetables / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D010936:Plant Extracts; D020543:Proteome