Inhibitory effect of grape seed extract (GSE) on cariogenic bacteria

Aims: Streptococcus mutans plays an important role in the development of dental caries. Although fluoride and other preventive efforts have led to a dramatic decline in dental caries, the ability to control the actual infection has been limited. The aim of this work was to investigate the effect of a Grape Seed Extract (GSE) on the growth and adherence of S. mutans. Methods: Cytotoxicity assay of GSE was used to determine the non-toxic concentrations to the Hep-2 cell line. The free radical scavenging activity of GSE was measured by using the DPPH assay. Antimicrobial activity of GSE was examined on Streptococcus mutans to determine the MIC (microtiter plate method). The potentiality of GSE on the adherence (biofilm) was tested on growing bacterial cells on the bottom of cell culture plate. In order to check the effect of the treatment on DNA fragmentation, S. mutans was allowed to infect the Hep2cell line in the presence and absence of treatment. Results: The non-toxic dose of GSE and its major constituents (gallic acid, catechin and epicatechin) was 15%, 7%, 5% and 15% respectively. All treatments have the ability to inhibit the growth and formation of S. mutans biofilm with priority to epicatechin (80.98% & 66.25% respectively). The epicatechin could completely inhibit the DNA fragmentation induced by S. mutans. Conclusion: GSE, especially epicatechin showed an interesting action on Streptococcus mutans and could be used for the lowering of this potentially cariogenic species in oral cavity.