ANTIBACTERIAL INTERACTION OF COMBINATION OF ETHANOLIC EXTRACT OF ZINGIBER OFFICINALE VAR RUBRUM RHIZOME, BOESENBERGIA PANDURATA RHIZOME, AND STEVIA REBAUDIANA LEAVES WITH CERTAIN ANTIBIOTICS AGAINST INFECTIOUS MOUTH MICROBIAL

Abstract

Objectives: The present study was performed to show the in vitro activities of ethanolic extract of Zingiber officinale var rubrum rhizome, Boesenbergiapandurata rhizome, and Stevia rebaudiana leaves in combination with amoxicillin, vancomycin, or ketoconazole against infectious mouth microbial.Methods: The antibacterial activities were calculated based on minimum inhibitory concentration (MIC) using microdilution method and minimumbactericidal concentration, and the antifungal activity were calculated using minimum fungicidal concentration using agar diffusion method. Theextract-antibiotic interaction was performed using checkerboard method.Results: Among the three extracts studied, B. pandurata rhizome extract had the best antimicrobial activity against S. aureus and S. mutans withMIC value at 128 µg/mL and 64 µg/mL, respectively while Z. officinale rhizome extracts had the best antifungal activity against C. albicans with MICvalue at 2048 µg/mL. The antimicrobial interaction between vancomycin with S. rebaudiana against S. aureus and S. mutans showed a synergisticeffect. Synergism also observed in the combination of amoxicillin with B. pandurata or S. rebaudiana against S. aureus and S. mutans, respectively.The combination of ketoconazole with each of all plant extracts studied against C. albicans showed the synergistic effect. The additive interactionwas observed between amoxicillin with B. pandurata or S. rebaudiana against S. aureus and S. mutans, respectively. There was no antagonism beingobserved in this study.Conclusion: There is a synergistic interaction between plant extract and the antibiotic against S. aureus, S. mutans, and C. albicans, therefore, thecombinations may be useful for infectious mouth microbial treatment.Keywords: Antimicrobial, Interaction, Zingiber officinale var rubrum, Stevia rebaudiana, Boesenbergia pandurata, Ketoconazole, Amoxicllin,Vancomycin, Minimum inhibition concentration, Microdilution, Synergistic, Additive