Essential Oils with Microbicidal and Antibiofilm Activity

Abstract

Plants are rich in a wide variety of secondary metabolites with antimicrobial properties. Phytochemistry studies on the plants extracts in general, and on essential oils (EOs) in particular are focused on the isolation and identification of the components of complex mixtures, in order to determine structure - activity correlations (i.e., physiological and/ or ecological roles, bases for the pharmacognosy studies). Problems as microbial resistance to existing antibiotics and the decline in the formulation of new antibiotics generated an increased interest in anti-infective herbal medicines. Some plants are known to be EOs producing, especialy superior plants, angiosperms and gymnosperms, belonging to approximately 50 families, most frequently Apiaceae, Lamiaceae, Myrtaceae, Pinaceae, Zingiberaceae, etc. The antimicrobial activity of EOs and of their components has been demonstrated on a variety of microorganisms. Our aim was to review relevant literature for identifying current research directions regarding EOs, in terms of antimicrobial effects, analysismethods and mechanisms of action. A plethora of methods have been used to test EOs antimicrobial properties concerning the microbial growth inhibition and/ or their anti-pathogenic effect. The reported methods contributed also to the elucidation of their mechanisms of action. Future research is needed for developing EOs related strategies in overlapping the multi-drug resistance and for reducing the required concentrations to achieve a particular antimicrobial and/ or antibiofilm effect to the human health benefit and/or for food safety purposes.

Anti-Haemophilus Activity of Selected Essential Oils Detected by TLC-Direct Bioautography and Biofilm Inhibition

“…Plants produced a wide variety of secondary metabolites that exhibited antimicrobial activity against a variety of pathogens (bacteria, fungi, and viruses) [27,28,29]. Several suggestions, (or hypothesis) can be found in the literature about their antifungal, and antibacterial mode of action, but some of them need clarification.…”

Antivirulence properties and related mechanisms of spice essential oils: A comprehensive review

“…Besides, the general hydrophobicity feature of essential oil compounds promotes their specific interaction with the lipid bilayers of cell cytoplasmic membranes. With the accumulation of compounds, the membranes disintegrate and increase their permeability, causing the leakage of intracellular components and ultimately leading to homeostatic imbalance and cell death (Saviuc et al., 2015). The extent of membrane damage is linked to intrinsic hydrophobicity of individual compounds in essential oils, which can be reflected by the log p ‐value.…”

Oxidative stress and apoptosis induction in human thyroid carcinoma cells exposed to the essential oil from Pistacia lentiscus aerial parts

“…Essential oils (EOs) are natural, volatile, and odorous molecules synthesized by the secretory cells of aromatic plants, located in leaves, flowers, fruits, seeds, barks, and roots [ 1 ]. Mainly composed of terpenes and terpenoids [ 2 ], EOs are currently receiving therapeutic interest fully renewed not only for their well-documented antimicrobial [ 3 , 4 ], antioxidant [ 5 ] and anti-inflammatory [ 6 ] activities, but also for their anticancer properties [ 7 , 8 ] and synergist effect with conventional therapies [ 9 , 10 ].…”