Synergistic Effect of Honey and Azarian Propolis on Oral Microorganisms: An In Vitro Study

Abstract

Aims and Objectives: Use of herbal and natural extract as mouthwashes has several advantages and prevents emergence of drug resistance. Propolis and honey are two natural materials with biological and antimicrobial properties. Their effect depends on the location and time of harvest. In this study, we aimed to investigate the synergistic effect of Azarian honey and propolis on several oral pathogens to enhance antiseptic properties. Material and Methods: Growth of standard suspensions from six oral bacterial pathogens was investigated using dilutions of 25-0.0121 mg/mL of propolis and 50-1.56% of honey in a medium of trypticase Soy Broth to determine the minimum inhibitory concentration (MIC). One-way ANOVA was used for statistical analysis. Results: Staphylococcus aureus showed the lowest amount of honey MIC. MIC of honey for the Escherichia coli was significantly higher than that of all other bacteria (P < 0.05). Average MIC for Staphylococcus epidermidis was also significantly higher than that of S. aureus (P < 0.05). Minimum bactericidal concentrations for Streptococcus mutans, methicillin-resistant S. aureus, S. aureus, S. epidermidis, and Enterococcus faecalis were 0, 1.56, 0.78, 1.56, and 1.56, respectively. The combination of propolis and honey reduced MIC for all the bacteria. Conclusion: The MICs of the materials in the combined condition were less than the MIC independently, although this difference was not significant in the case of S. aureus for propolis. By mixing these two compounds in medicinal products, a more effective formulation and lower dilution of solvent (alcohol) can be achieved due a synergistic effect. In addition, the weak effect of propolis on Gram-negative bacteria can also be improved.