Essential Oils and Their Components as Modulators of Antibiotic Activity against Gram-Negative Bacteria.

Petruta Aelenei,Anca Miron,Adriana Trifan,Alexandra Bujor,Elvira Gille,Ana Aprotosoaie

doi:10.3390/medicines3030019

Abstract

Gram-negative bacteria cause infections that are difficult to treat due to the emergence of multidrug resistance. This review summarizes the current status of the studies investigating the capacity of essential oils and their components to modulate antibiotic activity against Gram-negative bacteria. Synergistic interactions are particularly discussed with reference to possible mechanisms by which essential oil constituents interact with antibiotics. Special emphasis is given to essential oils and volatile compounds that inhibit efflux pumps, thus reversing drug resistance in Gram-negative bacteria. In addition, indifference and antagonism between essential oils/volatile compounds and conventional antibiotics have also been reported. Overall, this literature review reveals that essential oils and their purified components enhance the efficacy of antibiotics against Gram-negative bacteria, being promising candidates for the development of new effective formulations against Gram-negative bacteria.

Highlights

Infectious diseases are the second leading cause of death worldwide, being responsible for approximately 15 million deaths each year [1]
This review summarizes data on essential oils (EOs) and pure volatile compounds that modulate antibiotic activity against Gram-negative bacteria (Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterobacter spp., Proteus vulgaris, Salmonella spp.) with special emphasis on synergistic interactions
EOs and their components can enhance the antibiotic activity against Gram-negative bacteria

Summary

Introduction

Infectious diseases are the second leading cause of death worldwide, being responsible for approximately 15 million deaths each year [1]. Combination therapy, combining conventional antibiotics and natural products, represents a promising strategy in overcoming antibiotic resistance [4,5,6] Such antimicrobial combinations may exhibit synergistic, additive, indifferent or antagonistic effects. Synergy has potential therapeutic applications, as synergistic combinations have higher efficacy and lower toxicity than their components; due to a multitarget activity, such combinations may prevent the emergence of antibiotic resistance and may be effective against multidrug-resistant microbial strains [7]. This review summarizes data on essential oils (EOs) and pure volatile compounds that modulate antibiotic activity against Gram-negative bacteria (Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterobacter spp., Proteus vulgaris, Salmonella spp.) with special emphasis on synergistic interactions

Essential Oils and Volatile Compounds Modulating Antibiotic Activity against

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