Antibacterial Effects of Natural Herbal Extracts on Streptococcus mutans: Can They Be Potential Additives in Dentifrices?

Background Many plants or herbs exhibit potent antimicrobial activity against various microorganisms. They have no side effects and presumably act against and modulate the factors that are crucial for microbial survival or their activity. Streptococcus mutans is a pioneer bacteria implicated in dental caries. This study aims to evaluate the antimicrobial activity of garlic bulbs, pudina leaves, and mango and eucalyptus twig extracts on Streptococcus mutans by evaluating their zone of inhibition and determining their minimum inhibitory concentration (MIC). Methods Microbiological assay (well diffusion method) to determine zone of inhibition against pure forms of Streptococcus mutans was performed. The antibacterial effects of methanolic extracts of mango twigs, eucalyptus twigs, pudina leaves, and garlic bulbs were studied. Test compounds were further evaluated for their MIC. Results Extracts derived from mango and eucalyptus twigs showed significant antibacterial effects at test concentrations. Pudina and garlic extracts did not show any significant antibacterial effects at similar concentrations. Upon further evaluation of the 2 positive compounds for their MIC, mango twigs demonstrated more antimicrobial potential than eucalyptus twigs at a lower concentration. Conclusion Our observations indicated that the mango twig extracts possess higher antibacterial effects against Streptococcus mutans than other compounds at specific test concentration.