The overuse of antibiotics is of global concern as strains of bacteria learn to outsmart the drugs. Essential oils have shown to fightback with antibacterial potential, based on their complex and varied chemical make up, but more studies are necessary for this to be an accepted solution. In addition, some studies have shown a beneficial synergism of using an antibiotic in combination with an essential oil, and can lead to the reduction in the dose needed of the antibiotic (Sfeir, Lefrancois, Baudoux, Derbre, and Licznar, 2012). Again, further studies are necessary.
In one particular study: In Vitro Antibacterial Activity of Essential Oils Against Streptococcus pyogenes (Sfeir, Lefrancois, Baudoux, Derbre, and Licznar, 2012), the bacteria causing tonsillitis was measured against multiple essential oils chosen for specific chemical composition:
Among eighteen essential oils initially tested using a standardized disk assay method, five were selected based on their highest inhibitory activity agains S. pyogenes. The results showed essential oils with high aldehydes or phenols were the most effective and Cinnamon verum (containing cinnamaldehyde) was the highest. Cymbopogon citratus, Thymus vulgaris, Origanum compactum, and Satureja montana where also in the final group tested (Sfeir, Lefrancois, Baudoux, Derbre, and Licznar, 2012).
Another study, Antibacterial activity of Thymus maroccanus and Thymus broussonetii essential oils against nosocomial infection bacteria and their synergistic potential with antibiotics (Chevalier, Fadli, Hassani, Mezrioui, Pages, and Saad, 2012), evaluated two varieties of thyme essential oil on antibiotic resistant bacteria and their synergistic interactions with antibiotics like ciprofloxacin, gentamicin, pristinamycin, and cefixime. The results showed a high inhibitory reaction of the oils and a 71% synergism rate in use with the antibiotics, and the possibility of needing less antibiotics. This would reduce the toxic side effects and treatment costs, but more research is necessary on this topic (Chevalier, Fadli, Hassani, Mezrioui, Pages, and Saad, 2012).
A final study to mention: Biological and Pharmacological Activities of Carvacrol and Carvacrol Bearing Essential Oils (Baser, 2008), discusses many examples of the antimicrobial benefits of oregano. It mentions carvacrol as the active ingredient and cites many studies on oregano and its antimicrobial, antitumor, analgesic, anti-inflammatory, angiogenic, antiparasitic, antiplatelet, insecticidal, antispasmodic, antimutagenic, and antigentoxic properties!
Can Baser, K. H. (2008). Biological and pharmacological activities of carvacrol and carvacrol bearing essential oils. Current pharmaceutical design, 14(29), 3106-3119.
Saad, A., Fadli, M., Bouaziz, M., Benharref, A., Mezrioui, N. E., & Hassani, L. (2010). Anticandidal activity of the essential oils of Thymus maroccanus and Thymus broussonetii and their synergism with amphotericin B and fluconazol. Phytomedicine, 17(13), 1057-1060.
Sfeir, J., Lefrançois, C., Baudoux, D., Derbré, S., & Licznar, P. (2013). In vitro antibacterial activity of essential oils against Streptococcus pyogenes. Evidence-Based Complementary and Alternative Medicine, 2013.