Leinenbach, M. (2018). Evaluation of essential oils as an alternative to conventional antibiotic. The Young Researcher, 2 (1), 112-122.
The purpose of this study was to determine if synergistic interactions between essential oils can increase their antibacterial efficacy by testing essential oils. The following combinations were assessed for effective inhibition of E.coli and S. aureus growth: tea tree oil as the control solution, tea tree/oregano solution, tea tree/thyme solution, and tea tree/wintergreen solution. A Kirby-Bauer disc diffusion was employed to assess antibiotic efficacy. When comparing the different combinations to the control solution, the results of this study signify the presence of synergistic interactions between select essential oils; the combinations that were proven to increase antibacterial efficacy when compared to the control were the tea tree/oregano and tea/tree thyme solution. The combination with the greatest antibacterial efficacy for inhibiting E. coli and S. aureus growth was tea tree and oregano oil, which had an average inhibition percentage of 59.53% (E. coli) and 55.91% (S. aureus). This result was found to be statistically significant (p < 0.05) using an ANOVA single factor test.
Keywords: essential oils, natural medicine, bacterial growth, synergism