title: [The effects of tea polyphenols on the adherence of cariogenic bacterium to the collagen in vitro].
abstract: OBJECTIVE
  In the first phase of our study, it has been proved that tea polyphenols (TP) can inhibit the preliminary adherence of oral cariogenic bacterium to salivary acquired pellicle. This study is carried on to investigate the effects of tea polyphenols on the preliminary adherence of main cariogenic bacterium to collagen I and reveal the anticarious mechanisms of tea polyphenols further.
  
  
  METHODS
  Tea polyphenols solution was prepared firstly, the concentrations of which were 0.5, 1.0, 2.0 and 4.0 mg/ml. An in-vitro model of experimental pellicle(C-HA) was formed by immerging the hydroxyapatites in 250 micrograms/ml collagen I solution for 1 h. Streptococcus mutans 3a3, Actinomyces viscosus ATCC 19246 and Lactobacillus ATCC 4546 were chosen as the main cariogenic bacterium and radiolabelled by growing them in TPY culture medium supplemented with 3H-thymidine. Two parts of inhibited adherence tests were done with TP-treated C-HA or TP-treated bacterium respectively. In the first one, C-HA was immerged into the TP solution of different concentrations for 1 h before the attachment of bacterium. In the other, the bacterium were mixed with the TP solution for 1 h and then centrifuged and washed before bound to C-HA. KCl buffer solution provided a steady condition to the whole process. Finally, the number of 3H-thymidine-labelled bacterium which attached to C-HA were determined by scintillation counting.
  
  
  RESULTS
  In both the two parts of this study, tea polyphenols solution, the concentrations of which were changed from 1.0 to 4.0 mg/ml could inhibit the attachments of S. mutans 3a3, A. viscosus ATCC 19246 and Lactobacillus ATCC 4546 to C-HA effectively, and the inhibition rates rose with the increase of the concentrations of TP solution. But the inhibitory effects of 0.5 mg/ml TP solution were inconsistent in different tests. The inhibitory functions of tea polyphenols were so prominent that in some experiments, while the concentrations of TP solution were higher than 2.0 mg/ml, the number of 3H-thymidine-labelled bacterium which attached to C-HA was even less than that of the same bacterium which attached to naked HA. These results showed that TP had the remarkable inhibitory efficiency on the attachments of S. mutans, A. viscosus and Lactobacillus to C-HA.
  
  
  CONCLUSIONS
  Tea polyphenols can inhibit the preliminary adherence of Streptococcus mutans, Actinomyces viscosus and Lactobacillus to C-HA effectively. TP may prevent dentine from caries by decreasing the adherence of main cariogenic bacterium to collagen.
authors.affiliation: College of Stomatology, West China University of Medical Sciences.
authors.forename: Y
authors.initials: Y
authors.lastname: Xiao
authors.forename: T
authors.initials: T
authors.lastname: Liu
authors.forename: L
authors.initials: L
authors.lastname: Zhan
authors.forename: X
authors.initials: X
authors.lastname: Zhou
mesh_terms: D016924:Actinomyces viscosus / Q000187:drug effects*; D001422:Bacterial Adhesion / Q000187:drug effects*; D003094:Collagen; D003731:Dental Caries / Q000382:microbiology*; D044622:Dental Pellicle; D004305:Dose-Response Relationship, Drug; D006882:Hydroxyapatites; D066298:In Vitro Techniques; D010636:Phenols / Q000494:pharmacology*; D013295:Streptococcus mutans / Q000187:drug effects*; D013662:Tea / Q000737:chemistry*
chemical_list: D006882:Hydroxyapatites; D010636:Phenols; D013662:Tea; D003094:Collagen