Chemical composition, cytotoxicity, antimicrobial and antifungal activity of several essential oils

Abstract

Essential oils (EOs) are known and used for their biological, antibacterial, antifungal and antioxidant properties. Numerous studies have shown that EOs exhibit a large spectrum of biological activities in vitro. The incidence of drug-resistant pathogens and the toxicity of antibiotics have drawn attention to the antimicrobial activity of natural products, encouraging the development of alternative treatments. The aim of this study was to analyse the phytochemical and the cytotoxic characteristic of 36 EOs; we then evaluated the antimicrobial activity of the less-toxic EOs on Gram-positive, Gram-negative and fungi strains. The results showed low cytotoxicity in seven EOs and good activity against Gram-negative and Candida spp. strains. Based on our results, EOs could be proposed as a novel group of therapeutic agents. Further experiments are necessary to confirm their pharmacological effectiveness, and to determine potential toxic effects and the mechanism of their activity in in vivo models.

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

“…MS detection was performed with electron ionization (EI) at 70 eV, operating in the full-scan acquisition mode in the m/z range 40–400. EOs were diluted 1:20 ( v /v) with n -hexane before GC-MS analysis [ 5 ].…”

“…The injector and detector temperatures were set at 250 °C and 300 °C, respectively. EOs and reference standards were diluted 1:20 ( v /v) with n -hexane before GC-FID analysis [ 5 ].…”

“…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 ].…”

Biological Activities of Essential Oils from Leaves of Paramignya trimera (Oliv.) Guillaum and Limnocitrus littoralis (Miq.) Swingle

“…C. tropicalis and C. parapsilosis were more sensitive to the L. littoralis oil compared to the other Candida species tested, and C. parapsilosis was more sensitive to the P. trimera oil compared to the other Candida species in the present study. Given the experimental data obtained in this case and our previous works [30,31], the resistance may vary depending on the species of Candida and the essential oils. The current work indicated that L. littoralis oil was effective against C. tropicalis and C. parapsilosis with MIC and MLC of 2% (v/v), while exerting no cytotoxicity at the same concentration.…”

In vitro activity of hybrid lavender essential oils against multidrug resistant strains of Pseudomonas aeruginosa

“…Two mechanisms of cytotoxic activity have been hypothesized: 1) lipophilic hydrocarbons contained in EOs may accumulate in the lipid layer and distort the lipid-protein interaction; 2) other types of interactions excluding lipid component may occur in the proximity of protein hydrophobic portions, resulting in their destabilization [15]. Among non-phenolic EOs compounds, alkyl substituents (alkenyl groups rather than alkyls) have been reported to influence cytotoxic activity [16]. The present study is in agreement with the above mentioned considerations regarding the activity and efficacy of cytotoxic mechanisms through which EOs act on human cells.…”