A Potential Green Medicine from Sri Lanka against the Major Cariogenic Bacterium, Streptococcus mutan

Dental caries is the most common infectious disease of mankind. S. mutans is the leading cariogenic bacterium involved in the pathogenesis of dental caries. In Sri Lankan folklore, a traditional betel quid (TBQ) which consists of Piper betle (leaves), Syzygium aromaticum (flower buds), Myristica fragrans (seed and mace), Elettaria cardamomum (fruits), Areca catechu (seeds), Kaempferia galanga (rhizomes) and Coriandrum sativum (seeds) is claimed to protect oral health. Recently, we have scientifically proven its antiperiodontopathic and antigenotoxic effects. In this study, we show the anticariogenic effect of this TBQ through its inhibitory effect on S. mutans. In agar well diffusion assay, hexane, ethyl acetate, methanol and water extracts of this TBQ at a concentration of 100 mg/ml exhibited zones of inhibition with a diameter of 14.5±2.1, 15.5±3.5, 15.5±2.1, 13.8±1.8 mm respectively. Moreover, its ethyl acetate extract showed dose dependant S. mutans inhibitory effects and a MBC of 250 μg/ml. These findings indicate the potential of this TBQ to be developed into a green medicine against S. mutans and prevent dental caries.