Glycyrrhiza glabra extract attenuates polymicrobial interactions and disrupts biofilm formation by cariogenic microbes – an in-vitro study

Objectives: Polymicrobial interactions among oral microflora accelerate biofilm mediated oro-dental infections. Phytocomponents are gaining pre eminence in dental therapeutics owing to their multi factorial activity. Glycyrrhiza glabra (GG) due to abundant phytochemicals shows excellent bioactivity. Current study aims to evaluate the anticariogenic activity of ethanolic extract of Glycyrrhiza glabra and to elucidate possible mechanisms of action.
Materials and methods: Glycrrhiza glabra was subjected to cold extraction and phytochemical analysis was performed. Extract was screened for its antimicrobial activity by well diffusion method and MIC by twofold serial dilution method. Extract was checked for its anti-adhesion, anti-biofilm activity by anti-adherence assay and crystal violet staining method respectively. Inhibitory effects of Glycyrrhiza glabra against extra cellular polysaccharide (EPS) formation and amylase enzyme activity were determined spectrophotometricaly. Polymicrobial interaction studies among the selected cariogens (Streptococcus mutans, Lactobacillus acidophilus, Enterococcus faecalis and Candida albicans) were assessed individually and in combination by co-culture methods. All experiments were performed in triplicates and expressed as mean +/- standard deviation.
Results: Glycyrrhiza glabra extract showed potent antimicrobial activity and effectively reduced adhesion of S. mutans. Extract exhibited increased biofilm depletion and inhibited biofilm formation. Antibiofilm response was mediated directly by extra cellular polysaccharide inhibition and indirectly by inhibiting alpha-amylase activity. Glycyrrhiza glabra also reduced polymicrobial interactions among coaggregating microbes in the biofilms and was more effective than the conventional irrigant.
Conclusions: Glycyrhiza glabra can be ideal as therapeutic agent in biofilm mediated oro-dental infections due to its multiple modes of actions against cariogens.