Antibacterial Activity of Rhizophora mucronata Leaves Extract and Its Application in Chewing Gum against Streptococcus mutans and Streptococcus viridans

Rhizophora mucronata mangrove has antibacterial activity against pathogenic bacterial mostly dental caries-causing bacteria. This research aimed to determine the antibacterial activity of R. mucronata leaves extract and its application in chewing gum against dental caries-causing bacteria, which are Streptococcus mutans and Streptococcus viridans. The method used included inhibitory assay using different concentrations of R. mucronata leaves extract (5.0, 10.0, 15.0, 20.0, 25.0 mg/mL), followed by application of the extract in chewing gum formulation (2, 3, 4, 5 MIC/Minimum Inhibitory Concentration) to inhibit S. mutans and S. viridans. Results showed that R. mucronata leaves extract had strong antibacterial activity at a concentration of 25.0 mg/mL against S. mutans and S. viridans with inhibition zone diameters of 11.35 mm and 23.74 mm, respectively, and MIC of 0.78 and 0.65 mg/mL, respectively. Higher concentrations of R. mucronata extract resulted in higher inhibition, but lower acceptance in chewing gum, because of the astringent taste and dark green colour formed. The most preferred chewing gum was the one formulated with 2 MIC R. mucronata leaves extract with an acceptance level of 3.6 (slightly like) and inhibition zone diameter of 7.02 mm and 8.60 mm against S. mutans and S. viridans, respectively. Thus, chewing gum prepared with R. mucronata extract has the potential to prevent dental caries.