Essential Oils: Partnering with Antibiotics

Abstract

Essential oils (EO) are volatile, non-lipid-based oils produced as a plant defense mechanism. Studies from our group have validated the potential usefulness of EOs to synergistically and additively work with antibiotics. In this book chapter, we aim to outline some background on the EOs and their uses and applications, to discuss the different mechanisms of action in partnering with antibiotics, and, finally, to explore their potential use against multidrug-resistant bacteria. Applications of EO in therapy will enable the revival of previously sidelined antibiotics and enhance the development of new drug regimens to better mitigate what may be the biggest health challenge by year 2050.

Anti-Biofilm Inhibitory Synergistic Effects of Combinations of Essential Oils and Antibiotics

“…Recently, the idea that essential oils (EOs) can help to limit antibiotic resistance has been accepted by the scientific community [ 3 , 6 , 7 ]. EOs are extracted from various plants through various techniques including fermentation, enfleurage, extraction, and steam distillation [ 7 , 8 ], the latter being the reported technique of choice in the Pharmacopoeia [ 9 ]. EOs show antibiotic, antifungal, insecticidal, and antiviral activities.…”

“…In the literature, there are several data about the EOs activity as antibiotics, and their chemical composition seems to play a pivotal role in their application as antibacterial agents [ 3 , 7 , 9 ].…”

“…The EOs mechanism of action has been extensively reported in the literature and concerns the breakdown of bacterial cell wall, although the effect on the destruction of enzymes or membrane proteins or the spillage of cellular content after cytoplasmic membrane breakage are also possible [ 3 , 10 , 11 ]. According to these data, synergistic effects between antibiotics and EOs against bacteria can occur [ 7 ]. This aspect is important because it will help to reduce the use and the dosage of antibiotics in therapies, decreasing both, the antibiotic resistance and side effects [ 3 , 7 , 9 ].…”

“…According to these data, synergistic effects between antibiotics and EOs against bacteria can occur [ 7 ]. This aspect is important because it will help to reduce the use and the dosage of antibiotics in therapies, decreasing both, the antibiotic resistance and side effects [ 3 , 7 , 9 ].…”

“…Several studies report that whole EOs have an antimicrobial activity stronger than their major components individually tested [ 3 ]. These evidences show that also the minor components present in EOs can play an important role in the antimicrobial activity and the synergistic effect [ 3 , 7 , 9 ]. On the basis of this efforts, we planned to evaluate the synergistic effect of the whole Mentha piperita , Cinnamomun zeylanicum , Origanum vulgare , and Thymus vulgaris EOs with norfloxacin, oxacillin and gentamicin against four bacterial strains that form biofilm.…”