Influence of Cranberry Proanthocyanidins on Formation of Biofilms by <i>Streptococcus mutans</i> on Saliva-Coated Apatitic Surface and on Dental Caries Development in vivo

Abstract

Cranberry crude extracts, in various vehicles, have shown inhibitory effects on the formation of oral biofilms in vitro. The presence of proanthocyanidins (PAC) in cranberry extracts has been linked to biological activities against specific virulence attributes of Streptococcus mutans, e.g. the inhibition of glucosyltransferase (Gtf) activity. The aim of the present study was to determine the influence of a highly purified and chemically defined cranberry PAC fraction on S. mutans biofilm formation on saliva-coated hydroxyapatite surface, and on dental caries development in Sprague-Dawley rats. In addition, we examined the ability of specific PAC (ranging from low-molecular-weight monomers and dimers to high-molecular-weight oligomers/polymers) to inhibit GtfB activity and glycolytic pH drop by S. mutans cells, in an attempt to identify specific bioactive compounds. Topical applications (60-second exposure, twice daily) with PAC (1.5 mg/ml) during biofilm formation resulted in less biomass and fewer insoluble polysaccharides than the biofilms treated with vehicle control had (10% ethanol, v/v; p < 0.05). The incidence of smooth-surface caries in rats was significantly reduced by PAC treatment (twice daily), and resulted in less severe carious lesions compared to the vehicle control group (p < 0.05); the animals treated with PAC also showed significantly less caries severity on sulcal surfaces (p < 0.05). Furthermore, specific A-type PAC oligomers (dimers to dodecamers; 0.1 mg/ml) effectively diminished the synthesis of insoluble glucans by GtfB adsorbed on a saliva-coated hydroxyapatite surface, and also affected bacterial glycolysis. Our data show that cranberry PAC reduced the formation of biofilms by S. mutans in vitro and dental caries development in vivo, which may be attributed to the presence of specific bioactive A-type dimers and oligomers.

Inhibition of Streptococcus mutans biofilm formation, extracellular polysaccharide production, and virulence by an oxazole derivative

“…The supernatant was discarded carefully and the pellet resuspended and washed three times with sterile PBS to ensure all the water-soluble extracellular polysaccharide was removed. Alkali-soluble polysaccharides were extracted using 1.0 M NaOH under agitation for 2 h at 37°C according to the procedure of Koo et al (2010). The amount of water-insoluble extracellular polysaccharides was measured using the anthrone method.…”

Purified cranberry proanthocyanidines (PAC-1A) cause pro-apoptotic signaling, ROS generation, cyclophosphamide retention and cytotoxicity in high-risk neuroblastoma cells

“…These fractions were further purified using MCI gel (CHP 20P, 37-75 µ) high porous polymer column [10-50% methanol in water (v/v)] to selectively separate the oligomeric PACs from DP-2 to DP-11 (PACs-1A) from impurities. The PAC-1A composition was characterized using high-performance liquid chromatography (HPLC)-photodiode/ electrochemical detection and matrix-assisted laser desorption/ ionization (MALDI) time-of-flight (TOF) mass spectrometry (16) and further confirmed using LC-MS-MS in product ion scan mode followed by a multiple reaction monitoring (MRM) scan. The identification of high-molecular oligomeric PAC-1A were performed on an API-3000 tandem mass spectrometer (Applied Biosystems, CA, uSA) using an electrospray ionization source in negative-ion mode and the following conditions: curtain gas (10 psi), nebulizer gas (9 psi), collisionally activated dissociation gas (6 psi), TurboIonSpray (ion spray) voltage (-4,200 V), entrance potential (-10 V), collision cell exit potential (-8 V), source temperature (400˚C), declustering potential (-60 V).…”

Molecule Targeting Glucosyltransferase Inhibits Streptococcus mutans Biofilm Formation and Virulence

“…Apart from the extensive use of fluoride, a number of new anticariogenic methods have started to draw attention. Derivatives of natural products, such as cranberry constituents (9), fractions of barley coffee (10), and tea catechins (11,12), have been shown to have inhibitory effects against S. mutans biofilm formation. In addition, numerous small molecules, including tt-farnesol (12), chitosan, 7-epiclusianone (13), and apigenin (14), have been characterized and have been shown to have antibiofilm activity.…”