title: Effect of a novel type of propolis and its chemical fractions on glucosyltransferases and on growth and adherence of mutans streptococci.
abstract: Flavonoids have been considered the main biologically active components in propolis. However, a new variety of flavonoid-free propolis was recently found and chemically classified as type 6. Because it showed activity against oral microorganisms, this study evaluated the effects of the crude ethanolic extract of this propolis and its chemical fractions on the activity of purified glucosyltransferases (GTFs) and on the growth and adherence of mutans streptococci. The inhibitory effect of propolis extracts on GTF activities was determined either in solution or adsorbed onto saliva-coated hydroxyapatite. Streptococcus mutans Ingbritt 1600, Streptococcus sobrinus 6715, and two clinical isolates of each species were used for antibacterial assays. Susceptibilities to the test extracts were analyzed using the agar diffusion method and by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC); the effect on bacterial adherence to a glass surface was also assessed. The activity of GTFs in solution was effectively inhibited by the ethanolic extract of propolis type 6 (EEP) (>80% inhibition at 0.5 mg/ml), hexane, and chloroform fractions (60-90% inhibition at 100 microg/ml); their inhibitory effects on surface enzymes were less pronounced. The EEP, hexane, and chloroform fractions also showed significant antibacterial activity. The data showed that propolis type 6 remarkably reduced GTF activity and inhibited mutans streptococci growth and adherence; these biological activities are associated with its nonpolar components.
authors.affiliation: Department of Physiological Sciences, Dentistry School of Piracicaba, State University of Campinas Brazil, Sao Paulo.
authors.forename: Simone
authors.initials: S
authors.lastname: Duarte
authors.forename: Hyun
authors.initials: H
authors.lastname: Koo
authors.forename: William Henry
authors.initials: WH
authors.lastname: Bowen
authors.forename: Mitsue Fujimaki
authors.initials: MF
authors.lastname: Hayacibara
authors.forename: Jaime Aparecido
authors.initials: JA
authors.lastname: Cury
authors.forename: Masaharu
authors.initials: M
authors.lastname: Ikegaki
authors.forename: Pedro Luiz
authors.initials: PL
authors.lastname: Rosalen
mesh_terms: D001422:Bacterial Adhesion / Q000187:drug effects* / Q000502:physiology; D004791:Enzyme Inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D005964:Glucosyltransferases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000706:statistics & numerical data; D011429:Propolis / Q000302:isolation & purification / Q000494:pharmacology*; D013295:Streptococcus mutans / Q000187:drug effects* / Q000254:growth & development* / Q000502:physiology
chemical_list: D004791:Enzyme Inhibitors; D011429:Propolis; D005964:Glucosyltransferases