Essential oils of Moldavian Thymus species: Chemical composition, antioxidant, anti‐Aspergillus and antigenotoxic activities

Abstract

Thymus species are important aromatic, medicinal and culinary plants with a significant economic value. This study evaluated for the first time the chemical composition and in vitro bioactivities of the essential oils (EOs) from five Moldavian Thymus species (T. vulgaris, T. × citriodorus, T. calcareus) and cultivars (T. vulgaris ‘Faustini’, T. citriodorus ‘Aureus’). The main compounds in Thymus EOs were: thymol in T. vulgaris and T. calcareus EOs (55.44% and 55.45%, respectively), lavandulol in T. × citriodorus EO (54.27%), and geraniol in T. citriodorus ‘Aureus’ and T. vulgaris ‘Faustini’ EOs (60.31% and 31.45%, respectively). T. vulgaris and T. calcareus EOs showed the most potent antioxidant activities (EC50=0.003 mg/mL in ABTS radical cation scavenging assay) and exhibited significant inhibitory effects against aflatoxin‐producing Aspergillus flavus fungus (MIC=0.25 μL/mL). At doses that provided micromolar concentrations of thymol, T. vulgaris and T. calcareus EOs acted genoprotective at preventive and interventional levels against H2O2‐induced genomic damage in V79 cells, the former being more active (6.21% and 5.52% vs. 25.13% and 7.26% tail DNA in pre‐ and post‐treatment protocols, respectively). The genoprotective effects may be ascribed to antioxidant potential and, possibly, to stimulation of DNA repair processes. The Moldavian Thymus species are valuable resources of bioactive EOs for pharmaceutical and food industries (T. vulgaris, T.calcareus) but also for flavor industry and perfumery (T. × citriodorus, T. citriodorus ‘Aureus’, T. vulgaris ‘Faustini’).

Bioactive Natural Compounds and Antioxidant Activity of Essential Oils from Spice Plants: New Findings and Potential Applications

“…Thyme EOs have been described as antimicrobial [ 197 , 198 , 199 ] and antioxidant [ 200 , 201 ]. Due to its antimicrobial and antioxidant properties, the thyme EO is an appropriate food additive and a flavor enhancer for foods and beverages, and is used for pharmaceutical, perfumery, and cosmetic purposes [ 194 , 195 , 196 , 199 , 202 , 203 , 204 ]. Thyme is a strong component in culinary and food processing due to its odor, taste, and antimicrobial activities.…”

“…Chemical composition: The chemical composition of Thymus EO depends on the organ origin, environmental conditions, extraction methods, and other variables, but in general it has been described as containing, as its major compounds, monoterpenes, such as m - and p -cymene, and monoterpenoids, such as thymol and carvacrol [ 204 , 205 ]. Table 7 shows the majority of natural compounds, methodologies for determining the antioxidant activity, and some investigated applications of T. vulgaris EO.…”

“…The best activities were observed for the samples with the highest levels of thymol and carvacrol. Concerning the antimicrobial activity of thymol, it has been widely described in the literature [ 202 , 204 ], and it has been conjectured that its mechanism of action is involved with the perturbation of the lipid fraction of the plasma membrane, resulting in alterations of its permeability [ 107 ].…”

“…They attribute the antioxidant activities to the presence of thymol and carvacrol due to their ability to reduce the free radicals in the three methods investigated. Aprotosoaie et al [ 204 ] also used DPPH, ABTS, and FRAP assays to evaluate thyme EO and reported that the method influenced significantly the antioxidant activity results. The authors also identified that thymol (55.44%), the major constituent in the EO, was responsible for its high antioxidant potential.…”

Chemical Composition and Antimicrobial Activity of the Essential Oil From Euphorbia helioscopia L.

“…21 trans-Dihydrocarvone is a common compound in the essential oils from some plants of the family Lamiaceae, including Mentha dumetorum, Mentha longifolia, Salvia officinalis, Origanum vulgare, and Thymus citriodorus, and some in the family Apiaceae, including Cuminum cyminum and Anethum graveolens. [22][23][24][25][26][27][28] The content of transdihydrocarvone in these 2 families is 0.03%-12.78% and 3.20%-31.11%. In addition, transdihydrocarvone (15.3%-51.2%) is the main compound in all developmental stages of Poiretia latifolia of the family Fabaceae from South America.…”