The preventive effect of grape seed extract on artificial enamel caries progression in a microbial biofilm-induced caries model

Abstract

Objectives: The aim of this study was to evaluate the effect of grape seed extract (GSE) on enamel caries lesion formation in an in vitro Streptococcus mutans biofilm model.

Methods: Enamel fragments were prepared from bovine incisors and divided into six treatment groups (n=12): inoculated Brain Heart Infusion with 1% sucrose (BHIS), 1mg/mL GSE, 2mg/mL GSE, 3mg/mL GSE, 10ppm fluoride as NaF, and uninoculated BHIS. For biofilm formation, tooth fragments were incubated anaerobically in polystyrene 6-well tissue culture plates containing BHIS, the respective agents, and S. mutans (1×10(5)CFU/mL) for 24h at 37°C. Culture medium was replaced with fresh BHIS and respective agents daily over a 7-day period. Following caries lesion formation, lesion depth (LD) and relative optical density (ROD) were determined by polarized light microscopy (PLM) and confocal laser scanning microscopy (CLSM), respectively, to evaluate lesion progression.

Results: LDs of the 2mg/mL GSE group (122.86±13.41μm) and the 3mg/mL GSE group (111.92±11.39μm) were significantly smaller than those of the 1mg/mL GSE (198.33±17.70μm) and control groups (210.86±15.50μm) (p<0.05). Compared with the 2mg/mL and 3mg/mL groups, the control and 1mg/mL GSE groups showed significantly lower ROD values when depth was less than 200μm, indicating greater mineral loss.

Conclusions: Dose-dependent GSE inhibits in vitro enamel caries formation due to its ability to suppress growth of S. mutans and the formation of biofilm. CLINICAL SIGNIfiCANCE: Grape seed extract may be a novel virulence-targeted natural antimicrobial agent for caries prevention.

Keywords: Caries prevention; Enamel caries lesion; Grape seed extract; Microbial biofilm-induced caries model; Streptococcus mutans biofilm.