Effect of a Berry Polyphenolic Fraction on Biofilm Formation, Adherence Properties and Gene Expression of Streptococcus mutans and Its Biocompatibility with Oral Epithelial Cells

The ability of Streptococcus mutans to adhere to oral surfaces and form biofilm is a key step in the tooth decay process. The aim of this study was to investigate a berry (wild blueberry, cranberry, and strawberry) polyphenolic fraction, commercialized as Orophenol(®), for its antibacterial, anti-biofilm, and anti-adhesion properties on S. mutans. Moreover, the biocompatibility of the fraction with human oral epithelial cells was assessed. Phenolic acids, flavonoids (flavonols, anthocyanins, flavan-3-ols), and procyanidins made up 10.71%, 19.76%, and 5.29% of the berry polyphenolic fraction, respectively, as determined by chromatography and mass spectrometry. The berry polyphenolic preparation dose-dependently inhibited S. mutans biofilm formation while not reducing bacterial growth. At concentrations ranging from 250 to 1000 µg/mL, the fraction inhibited the adhesion of S. mutans to both saliva-coated hydroxyapatite and saliva-coated nickel–chrome alloy. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis showed that incubating S. mutans with the berry polyphenolic fraction was associated with a reduced expression of luxS gene, which regulates quorum sensing in S. mutans. The berry fraction did not show any significant cytotoxicity in an oral epithelial cell model. In conclusion, Orophenol(®), which is a mixture of polyphenols from wild blueberry, cranberry and strawberry, possesses interesting anti-caries properties while being compatible with oral epithelial cells.