Inhibition of Streptococcus mutans biofilm formation using extracts from Assam tea compared to green tea.
OBJECTIVE
Streptococcus mutans, a gram-positive oral bacterium, has been identified as one of the principal etiological agents of human dental caries. To clarify the nature of the difference anti-biofilm effect against S. mutans between Assam tea from Camellia sinensis var. assamica, partially fermented, and green tea from Camellia sinensis, non-fermented, active agents from the teas were purified.


METHODS
Effects of Assam tea and green tea samples on biofilm were assessed by using the conventional titer plate method and the human saliva-coated hydroxyapatite discs. The purification and identification of inhibitors were performed by using ultrafiltration with centrifugal filter devices and high performance liquid chromatography.


RESULTS
Assam tea has stronger biofilm inhibition activity against S. mutans than green tea. A substance of <10kDa in mass in Assam tea had a high concentration of galloylated catechins and a stronger biofilm inhibiting activity than green tea. In contrast, substances >10kDa in mass from green tea included higher concentrations of polysaccharides composed of galacturonic acid, such as pectin, that enhance biofilm formation.


CONCLUSIONS
The higher concentrations of galloylated catechins in Assam tea may assist in prevention of dental caries, whereas in green tea, this mode of inhibition was likely offset by the presence of pectin. Purification of catechins in partially fermented Assam tea with lower-molecular-weight polysaccharide than pectin may be useful for developing oral care products such as toothpaste and oral care gel pastes.
Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan; Department of Microbiology, School of Life Dentistry at Tokyo, The Nippon Dental University, Tokyo, Japan.
Taketo
T
Kawarai
Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan; Department of Food Science and Technology, College of Bioresource Sciences, Nihon University, Kanagawa, Japan.
Naoki
N
Narisawa
Department of Bacteriology, Ohu University, Fukushima, Japan.
Saori
S
Yoneda
MARUEI Incorporation, Mie, Japan.
Yoshiaki
Y
Tsutsumi
Department of Bioactive Molecules, National Institute of Infectious Diseases, Tokyo, Japan.
Jun
J
Ishikawa
Department of Bioactive Molecules, National Institute of Infectious Diseases, Tokyo, Japan.
Yasutaka
Y
Hoshino
Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan. Electronic address: hsenpuku@nih.go.jp.
Hidenobu
H
Senpuku
D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000494:pharmacology; D003731:Dental Caries / Q000382:microbiology / Q000517:prevention & control; D017886:Durapatite; D006603:Hexuronic Acids / Q000494:pharmacology; D006801:Humans; D010368:Pectins / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*; D012463:Saliva / Q000382:microbiology; D013295:Streptococcus mutans / Q000187:drug effects* / Q000502:physiology*; D013662:Tea / Q000737:chemistry*; D014100:Toothpastes / Q000737:chemistry
D006603:Hexuronic Acids; D010936:Plant Extracts; D013662:Tea; D014100:Toothpastes; C007819:galacturonic acid; D010368:Pectins; D002392:Catechin; D017886:Durapatite
Assam tea; Biofilm; Galloylated catechins; Pectin; Streptococcus mutans