title: Inhibitory effects of 7-epiclusianone on glucan synthesis, acidogenicity and biofilm formation by Streptococcus mutans.
abstract: The aim of this study was to examine the effects of 7-epiclusianone, a new prenylated benzophenone isolated from the plant Rheedia gardneriana, on some of the virulence properties of Streptococcus mutans associated with biofilm development and acidogenicity. The synthesis of glucans by glucosyltransferases B (GTF B) and C (GTF C) was markedly reduced by 7-epiclusianone showing more than 80% inhibition of enzymatic activity at a concentration of 100 microg mL(-1). Double-reciprocal analysis (Lineweaver-Burk plots) revealed that the inhibition of GTF B activity was noncompetitive (mixed) while GTF C was inhibited uncompetitively. The glycolytic pH drop by S. mutans cells was also disrupted by 7-epiclusianone without affecting the bacterial viability, an effect that can be attributed, in part, to inhibition of F-ATPase activity (61.1+/-3.0% inhibition at 100 microg mL(-1)). Furthermore, topical applications (1-min exposure, twice daily) of 7-epiclusianone (at 250 microg mL(-1)) disrupted biofilm formation and physiology. The biomass (dry-weight), extracellular insoluble polysaccharide concentration and acidogenicity of the biofilms were significantly reduced by the test agent (P<0.05). The data show that 7-epiclusianone disrupts the extracellular and intracellular sugar metabolism of S. mutans, and holds promise as a novel, naturally occurring compound to prevent biofilm-related oral diseases.
authors: Department of Physiological Sciences, State University of Campinas, SP, Brazil.
authors: Ramiro Mendonca
authors: RM
authors: Murata
authors: Luciana Salles
authors: LS
authors: Branco de Almeida
authors: Regiane
authors: R
authors: Yatsuda
authors: Marcelo Henrique
authors: MH
authors: Dos Santos
authors: Tanus Jorge
authors: TJ
authors: Nagem
authors: Pedro Luiz
authors: PL
authors: Rosalen
authors: Hyun
authors: H
authors: Koo
mesh_terms: D001577:Benzophenones / Q000494:pharmacology*; D016227:Benzoquinones / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D005936:Glucans / Q000096:biosynthesis* / Q000378:metabolism; D005964:Glucosyltransferases / Q000037:antagonists & inhibitors*; D013295:Streptococcus mutans / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism
chemical_list: C118110:7-epiclusianone; D001577:Benzophenones; D016227:Benzoquinones; D005936:Glucans; D005964:Glucosyltransferases