Properties and limits of some essential oils: chemical characterisation, antimicrobial activity, interaction with antibiotics and cytotoxicity

Abstract

Because of the emergence of multi-drug resistance bacteria and fungi, alternatives to conventional antimicrobial therapy are needed. This study aims to evaluate in vitro the antimicrobial activity of: Mirtus communis, Coriandrum sativum, Pelargonium capitatum, Cuminum cyminum, Ocimum basilicum, Citrus aurantium amara, Cymbopogon. winterianus, Cymbopogon martini, Salvia sclarea, Melaleuca alternifolia and Mentha suaveolens essential oils on bacteria and fungi, in relation to their chemical composition. The potential interaction of M. alternifolia (TTO), C. sativum (CDO) and M. suaveolens (EOMS) essential oils when used in combination with gentamicin and fluconazole has been evaluated. The results obtained showed a synergic effect on some bacteria and fungi, with FICI values ≤5. The cytotoxicity of TTO, CDO and EOMS was investigated towards HeLa cells. Only EOMS did not result cytotoxic at the active concentrations on micro-organisms. Further studies are necessary to obtain optimal ratios and dosing regimens for higher therapeutic efficacy and to decrease toxicological profiles.

Use of Pinus sylvestris L. (Pinaceae), Origanum vulgare L. (Lamiaceae), and Thymus vulgaris L. (Lamiaceae) essential oils and their main components to enhance itraconazole activity against azole susceptible/not-susceptible Cryptococcus neoformans strains

“…Currently, EOs are considered as a potential rich source of bioactive antimicrobial compounds to improve antifungal treatment. Moreover, synergy research is actively studying efficacy of EOs and their main components in combination with already existing drugs, so that drug dosages and treatment-related adverse side effects can be significantly reduced, preventing or delaying the development of drug resistant strains [ 6 – 10 , 18 ]. To date, few studies have evaluated the combinatorial effects of EOs with azoles against C. neoformans using in vitro synergy [ 18 ].…”

“…To date, there are few other molecules with any activity towards C.neoformans , leading to heightened interest in finding new alternatives to conventional drugs for the treatment of mycosis caused by this yeast [ 1 ]. Particularly, essential oils (EOs) have emerged in recent years as potential natural and economic alternatives or as adjuvants in combination with conventional antifungal agents and continue to be of great interest [ 5 – 10 ]. A large number of EOs and their major components have shown to exhibit a wide range of biological properties (antibacterial, antifungal, antiviral, anti-inflammatory, anticancer) [ 11 – 16 ].…”

Antioxidant, Antifungal, Antibiofilm, and Cytotoxic Activities of Mentha spp. Essential Oils

“…In addition, Spagnoletti et al [46] reported the antifungal activity of M. suaveolens EO against Candida spp., with MIC values ranging from 760 μg/mL to1560 μg/mL. Scazzocchio et al [70] confirmed the antifungal activity against different strains of CA that was sensitive or resistant to fluconazole. This activity has been evaluated by both DDA and MIC.…”

Coriander (Coriandrum sativum) Essential Oil: Effect on Multidrug Resistant Uropathogenic Escherichia coli

“…Different factors can influence both the qualitative composition and individual components of essential oils. The partial agreement between GC-MS data from different batches of the same CDO brand [10] emphasizes the variability of the chemical composition influenced by features such as genetic, seasonal, geographic, extraction methods and storage conditions [9,[11][12][13][14].…”

“…Coriander (Coriandrum sativum L., Apiaceae), an annual herb native to the Mediterranean region and spread worldwide, is used as a spice and medicinal plant because of many biological effects [6][7][8]. Antimicrobial activity of coriander against both Gram-positive and -negative bacteria, as well as Candida strains, has been investigated [9,10]. The aim of this study was to examine the activity of a commercial essential oil from seeds of C. sativum (CDO) towards UPEC properties: antibacterial response, biofilm formation and cell adhesion capability.…”