Assessment of Synergistic Antimicrobial Effectiveness of Glycyrrhiza glabra and Syzygium aromaticum Extracts against oral bacteria (Streptococcus mutans)

Dental caries continues to be a major global health issue affecting both adults and children. is driven by dysbiosis of the dental biofilm adherent to the enamel surface. One of the microorganisms frequently associated with dental caries is S. mutans. Given that natural compounds might have fewer adverse effects than synthetic antimicrobials. Objectives: The aim of study was to improve the antimicrobial activity of natural extracts against oral bacteria (S. mutans) by synergistic combination with a mouthwash (chlorhexidine). Methodology: A total of 100 specimens were obtained from patients clinically diagnosed by with dental caries. Methanolic extracts of these plants were prepared. Antimicrobial activity was assessed using two methods: determining the minimum inhibitory concentration (MIC), sub-minimum inhibitory concentration (sub-MIC), and minimum bacterial concentration (MBC) using the broth dilution method and determining the zone of inhibition using the well diffusion method on S. mutans sanguis agar bacitracin. Results: Results show that the 400 mg/ml concentration inhibited the microbial growth of S. mutans with an inhibition zone of 19.23 mm. MBC values ranged from 6.25 to 200 μg/ml, whereas the MIC and sub-MIC concentrations for all investigated extracts and chlorhexidine were 3.125–100μg/ml and 1.5625–50μg/ml, respectively. Clove and licorice are thought to possess antibacterial efficacy owing to their secondary metabolites. Conclusion: Natural antibacterial agents were provided in this study, which can aid in the management of dental caries. If incorporated into mouthwashes and toothpaste, these extracts may have a positive effect on lowering plaque and dental cavities.