The Tea Catechin Epigallocatechin Gallate Suppresses Cariogenic Virulence Factors of Streptococcus mutans

Abstract

Streptococcus mutans, the primary etiologic agent of dental caries, possesses a series of virulence factors associated with its cariogenicity. Alternatives to traditional antimicrobial treatment, agents selectively inhibiting the virulence factors without necessarily suppressing the resident oral species, are promising. The anticariogenic properties of tea have been suggested in experimental animals and humans. Tea polyphenols, especially epigallocatechin gallate (EGCg), have been shown to inhibit the growth and glucosyltransferases activity of S. mutans. However, their effects on biofilm and cariogenic virulence factors of oral streptococci other than glucosyltransferases have not been well documented. In this study, we investigated the biological effect of EGCg on the virulence factors of S. mutans associated with its acidogenicity and acidurity. The antimicrobial effects of EGCg on S. mutans biofilm grown in chemically defined medium were also examined. EGCg inhibited growth of S. mutans planktonic cells at an MIC of 31.25 g/ml and a minimal bactericidal concentration (MBC) of 62.5 g/ml. EGCg also inhibited S. mutans biofilm formation at 15.6 g/ml (minimum concentration that showed at least 90% inhibition of biofilm formation) and reduced viability of the preformed biofilm at 625 g/ml (sessile MIC 80 ). EGCg at sub-MIC levels inhibited acidogenicity and acidurity of S. mutans cells. Analysis of the data obtained from real-time PCR showed that EGCg significantly suppressed the ldh, eno, atpD, and aguD genes of S. mutans UA159. Inhibition of the enzymatic activity of F 1 F o -ATPase and lactate dehydrogenase was also noted (50% inhibitory concentration between 15.6 and 31.25 g/ml). These findings suggest that EGCg is a natural anticariogenic agent in that it exhibits antimicrobial activity against S. mutans and suppresses the specific virulence factors associated with its cariogenicity.

Polyphenolic Extract from Maple Syrup Potentiates Antibiotic Susceptibility and Reduces Biofilm Formation of Pathogenic Bacteria

“…These phenolic compounds are believed to be promising candidates as complementary therapeutics (6), since they can modify bacterial behavior by affecting bacterial motility (7,8,58), surface adhesion (9), biofilm formation (7,10), quorum sensing (11), and production of virulence determinants (12,13). Traditional medicinal approaches owe their significance to the bioactive components that have their origin in plant sources, and many are associated with routine dietary habits.…”

Antimicrobial peptide GH12 suppresses cariogenic virulence factors of Streptococcus mutans

“…The crude LDH was extracted according to Xu et al [28]. The crude LDH was then treated with GH12 at sub-MIC levels for 30 min.…”

“…The control group was not treated with GH12. The RNA isolation and purification were conducted as described before [28]. First-strand cDNAs were synthesized using PrimeScript™ RT reagent Kit with gDNA Eraser (RR047A; Takara Bio, Shiga, Japan), according to the manufacturer.…”

Adverse Influences of Antimicrobial Strategy against Mature Oral Biofilm

“…In the field of dentistry, it has also been reported that sub-MICs of antimicrobial agents or compounds can inhibit bacterial attachment [54,56,57], biofilm formation [54,55,57,58], and downregulate virulence genes [54,56,59,60]. Moon et al reported N-acetyl cysteine (NAC) that is an antioxidant possessing anti-inflammatory activities, showed a significant decrease of Prevotella intermedia biofilm formation in the presence of sub-MIC [55].…”