Anti-adherent activity of Althaea officinalis L. extracts on in-vitro biofilm formation of Streptococcus mutans and Candida albicans

Background and Aim : Denture stomatitis is an inflammatory condition that affects the mucosa underlying complete dentures with a prevalence of about ۳۰% among the Iranian population. In the current study, we evaluate the in-vitro anti-adherent property of alcoholic and aqueous extracts from Althaea officinalis L. (Marshmallow) on biofilms formed by Streptococcus mutans (S. mutans) and Candida albicans (C. albicans) strains which isolated from denture-related stomatitis.Methods : The effect of the extract of Althaea officinalis L. at concentrations of ۰.۵,۱, ۲ and ۴ mg/mL on S. mutans and C. albicans adherence were survived using broth microdilution method (CLSI and M۲۷-S۴). After formation of biofilms in microplates, the extracts were added. Subsequently, the minimum inhibitory concentration (MIC) was determined to evaluate the anti-adherent potential of Althaea officinalis L. extracts.Results : After ۲۴h, MIC of adhesion was observed. The inhibitory effect of the alcoholic extract on C. albicans with a concentration of ۱mg/mL was similar to that of MIC of nystatin. Moreover, the aqueous extract caused significant inhibition of adhesion at ۲mg/mL. Finally, the best effect of both extracts was observed at ۰.۵ mg/mL on S. mutans.Conclusion : The extracts of Althaea officinalis L. showed better anti-adherent activity against S. mutans rather than C. albicans by decreasing MIC. The interaction of S. mutans with other microorganisms like C. albicans on the denture biofilms may contribute to the increased resistance of these strains to antibiotic agents. More studies should consider the action of the herbal on biofilm of clinical strains in the oral cavity.

Keywords:

Streptococcus mutans , Candida albicans , Biofilm , Denture , Stomatitis , Herbal extracts , Adherence