In vitro evaluation of the inhibition potential of medicinal plants against dental cariogenic microorganisms

Abstract

Dental caries is one of the most prevalent oral infections affecting individuals in all age groups worldwide. A variety of microorganisms such as Streptococcus mutans, Lactobacillus sp., Vellionella sp. etc. are known to be involved in progression of this infection. Many medicinal plants have been used in various systems of traditional medicine for countering dental caries and other oral infections, and currently these are again in demand for the development of novel therapeutic drugs with minimum side-effects for effective prevention and management of not only oral infections, but also other bacterial infections. This study aimed to determine the antimicrobial, antibiofilm and antiacidogenic potential of selected medicinal plants against dental cariogenic bacteria, namely, Streptococcus mutans, Streptococcus oralis, Lactobacillus rhamnosus. Thirteen methanolic extracts were prepared using various parts of the selected medicinal plants. These extracts were then used to check for the antimicrobial, antibiofilm and antiacidogenic activities against the selected cariogenic bacteria. Although, all thirteen plant extracts that were tested, did show inhibition of cariogenic bacteria at higher concentrations, three extracts, were found to be best in terms of antimicrobial, antibiofilm and antiacidogenic activities. Methanolic extracts of P. betle leaves, V. negundo seeds, S. aromaticum buds showed the best results in all the three parameters. These extracts not only inhibited the growth of cariogenic pathogens even at very low concentrations, depicted by their lowest minimum inhibitory concentrations, but also inhibited biofilm formation as well as acid production by the cariogenic bacteria, two other virulence traits responsible for the establishment of dental caries.