The Missing Piece: Recent Approaches Investigating the Antimicrobial Mode of Action of Essential Oils

Abstract

Antibiotic resistance is a major global health issue that has seen alarming rates of increase in all parts of the world over the past two decades. The surge in antibiotic resistance has resulted in longer hospital stays, higher medical costs, and elevated mortality rates. Constant attempts have been made to discover newer and more effective antimicrobials to reduce the severity of antibiotic resistance. Plant secondary metabolites, such as essential oils, have been the major focus due to their complexity and bioactive nature. However, the underlying mechanism of their antimicrobial effect remains largely unknown. Understanding the antimicrobial mode of action of essential oils is crucial in developing potential strategies for the use of essential oils in a clinical setting. Recent advances in genomics and proteomics have enhanced our understanding of the antimicrobial mode of action of essential oils. We might well be at the dawn of completing a mystery on how essential oils carry out their antimicrobial activities. Therefore, an overview of essential oils with regard to their antimicrobial activities and mode of action is discussed in this review. Recent approaches used in identifying the antimicrobial mode of action of essential oils, specifically from the perspective of genomics and proteomics, are also synthesized. Based on the information gathered from this review, we offer recommendations for future strategies and prospects for the study of essential oils and their function as antimicrobials.

Topical Nano Clove/Thyme Gel against Genetically Identified Clinical Skin Isolates: In Vivo Targeting Behavioral Alteration and IGF-1/pFOXO-1/PPAR γ Cues

“…Our results are in accordance with previous studies that ascribed the use of EOs as a promising antimicrobial agent against drug resistant pathogens [63]. Pectis substriata EO exerted a potential activity against resistant staphylococcus strains [64]. The antibiotic-like action of EOs is attributed to the biofilm inhibition [65], membrane disruption and efflux suppression action mechanism [66].…”

Progress in Alternative Strategies to Combat Antimicrobial Resistance: Focus on Antibiotics

“…‘’Essential oils” (EOs) are mixtures of volatile chemical compounds synthesized from different plant parts during secondary metabolism [ 99 , 100 , 101 ]. The term ‘essential oil’ was first used by Paracelsus von Hohenheim, a medieval Swiss physician [ 102 ].…”

“…The term ‘essential oil’ was first used by Paracelsus von Hohenheim, a medieval Swiss physician [ 102 ]. EOs include terpenes, aldehydes, phenolic, terpenoids, and other aromatic constituents that have demonstrated antimicrobial activities [ 99 , 100 , 101 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 ]. EOs mainly contribute to the disruption of the bacterial cell membrane and inhibition of the efflux pump responsible for certain AMR in Gram-negative bacteria [ 100 , 105 , 114 , 115 , 116 , 117 ].…”

“…EOs include terpenes, aldehydes, phenolic, terpenoids, and other aromatic constituents that have demonstrated antimicrobial activities [ 99 , 100 , 101 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 ]. EOs mainly contribute to the disruption of the bacterial cell membrane and inhibition of the efflux pump responsible for certain AMR in Gram-negative bacteria [ 100 , 105 , 114 , 115 , 116 , 117 ]. Other documented modes of action include inhibition of the peptidoglycan layer synthesis of bacterial cell walls by binding to PBPs for Gram-positive bacteria [ 105 , 114 , 115 , 116 , 117 ].…”

“…Other documented modes of action include inhibition of the peptidoglycan layer synthesis of bacterial cell walls by binding to PBPs for Gram-positive bacteria [ 105 , 114 , 115 , 116 , 117 ]. Recent advances in genomics and proteomics demonstrated the ability of EOs to inhibit biofilm formation and quorum sensing (QS) production and increase the expression of oxidative stress proteins [ 100 , 105 ]. Eos, either alone, in combination, or associated with other antibiotics, demonstrated effective antibacterial activity against different pathogens, including MDR bacteria [ 100 , 105 , 118 ].…”