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It should be remembered that bacteria continue to spread and develop new types of resistance, so further actions are needed to deal with antibiotic resistance. As a result, antibacterial drugs have become less effective, resulting in the accelerated discovery of available alternative treatments, including essential oils. The aim of this work was to intensify and promote the action of two antibiotics, kanamycin, and colistin, to fight antibiotic resistance thanks to the action of essential oil obtained from the flowers of Coridothymus capitatus grown on the Iblei mountains. To this end, a comparison of biological and chemical assays was carried out. The results showed a broad antimicrobial power of the essential oil itself and a great synergistic activity in combination with Kanamycin and Colistin against multidrug-resistant bacteria. These combinations increased the range of antibiotics, leading us to speculate that it could be incorporated into new pharmaceutical formulations for therapies of infections caused by increasingly dangerous bacteria. Antibiotic resistance represents an ever-greater danger to human health. This work re-evaluates the use of colistin and kanamycin thanks to the synergistic action found with the addition of a natural substance to pave the way for new therapeutic strategies.

The purpose of this study was to comparatively reveal for the first time the antioxidant, anti-inflammatory effects of Phlomis pungens and Coridothymus capitatus methanol extracts obtained by using maceration extraction method. According to the results of anti-inflammatory activity, P. pungens methanolic extract demonstrated a more prominent and intensive antiinflammatory effect with 24.7% of inhibitive capacity in the altered edema size after the first hour of carrageenan injection compared to C. capitatus methanolic extract. P. pungens methanolic extract inhibitory effect increased during three hours and reached maximum by 41.9%. According to the results obtained from antioxidant activity experiments, methanol extract of C. capitatus exhibited stronger free radical scavenging (DPPH), cupric reducing (CUPRAC), ferric reducing/antioxidant power (FRAP) and ABTS radical cation scavenging activity than P. pungens extract. In additon, C. capitatus extract had higher ABTS radical cation scavenging and ferric reducing/antioxidant power activity than ascorbic acid, BHT and BHA, respectively. Therefore, this extract can be used in both medicine and food industry as a natural antioxidant source.

In this research, the extracts obtained from various natural products (hazelnut shells, thyme, olive shoots, and walnut leaves), which are indicated to have antioxidative characteristics, which are used during the retanning stage of leather manufacturing and their effects on chromium(VI) formation in leather was examined. Finished leathers were exposed to ageing conditions for 24h at 80oC and for 24h and 72h at 80oC under UV in order to enable chromium(VI) formation in the leathers. Chromium (VI) amounts in each leather sample were measured with a Shimadzu UV-1601 PC UV-Visible spectrophotometer at 540 nm according to the ISO/FDIS 17075 standard method, and how each extract affected chromium (VI) formation in leather was examined. According to the findings of the research; Coridothymus capitatus, Olea europaea, Corylus avellana, and Juglans regia extracts, which were used during the retanning stage of leather manufacturing, significantly reduced chromium(VI) formation in the leather under all three ageing conditions. The best reduction was obtained with Coridothymus capitatus extract in the ratio of 89.24% under the ageing condition of 24h/80oC. It is recommended that different extraction methods, different natural extracts, and different ageing conditions be carried out in the future are to optimize the results of the current study.

Four essential oil samples of Tunisian Thyme (Coridothymus capitatus (L.) Rchb. f.) were collected from two geographycally different areas, either in vegetative state or flowering, and then analyzed by GC and GC-MS. Antibacterial and antifungal in vitro tests done against pathogenic and saprophytic strains of human and animal skin microflora indicate that samples collected in full flowering period were the most efficient. These strong activities may be linked to high levels of carvacrol.

An oil produced from Coridothymus capitatus (L.) Rchb. grown in island of Kos (Greece) has been analyzed by GC/MS and by chiral GC. The principal component of this oil was carvacrol (66.7%). The enantiomeric distribution of α-pinene, camphene, β-pinene, limonene, 1-octen-3-ol, linalool, terpinen-4-ol and α-terpineol in C. capitatus oil is presented for the first time.

The chemical composition, antifungal, antioxidant and cytotoxic activities of the essential oils (EOs) of mint (Mentha suaveolens), thyme (Coridothymus capitatus), oregano (Origanum hirtum) and rosemary (Rosmarinus officinalis) were investigated. The antifungal properties of the EOs were investigated against four species of Candida by a microdilution method. Cytotoxicity was tested on human keratinocyte (HaCaT) and lung cancer (A549) cell lines using the MTT test. DPPH• and ABTS•+ spectrophotometric assays and DPPH•- ABTS•+(HP)TLC-bioautographic assays were used to evaluate the antioxidant activity. The main compounds of thyme and oregano EOs were carvacrol and thymol, respectively; piperitenone oxide and γ-terpinene were the most abundant compounds of mint and rosemary EOs, respectively. All EOs showed activity against all Candida species in a range between 760 ± 290 to 3120 ± 0.0 μg/mL. Among the EOs, that of M. suaveolens showed a stronger cytotoxic activity on HaCaT cells. Thyme, oregano and rosemary EOs exhibited important antioxidant activities by ABTS•+ assay compared with trolox.

Thymus migricus Klokov & Des.-Shost., and T. fedtschenkoi Ronniger var. handelii (Ronniger) Jalas are growing in Eastern Anatolia. Thymus fedtschenkoi var. handehi is an endemic species as the other is Iran-Turan element. Both the species have similar morphological, anatomical and palynological features. However, some differences have been determined in between species. T migricus is similar to T. fedtschenkoi var. handelii but bigger in all its parts. Their leaves dimensions, lateral veins, hairs of outer calyx surface and nutlets shape are morphological different. Exine sculpturing is microreticulate in T. migricus while it is suprareticulate in T. fedtschenkoi.var.handelii in pollen morphology.

Water-soluble extracts from black thyme (Thymbra spicata L.), savory (Satureja cuneifolia Ten.), Spanish oregano (Coridothymus capitatus (L.) Reichb. f.), sweet marjoram (Majorana hortensis Moench), Syrian oregano (Origanum syriacum L.), Toka oregano (Origanum minutiflorum O. Schwarz et P. H. Davis), and Turkish oregano (Origanum onites L.) were screened for antioxidant properties in a battery of six in vitro assays. Total phenol content and qualitative-quantitative compositional analyses were also carried out. The extracts demonstrated varying degrees of efficacy in each screen. The savory extract was the most effective at reducing iron(III), scavenging 1,1-diphenyl-2-picrylhydrazyl radicals, inhibiting ascorbate- iron (III)-catalyzed hydroxyl radical-mediated brain phospholipid peroxidation, and site-specific hydroxyl radical-mediated 2-deoxy-D-ribose degradation. The Syrian oregano extract was the most effective chelator of iron(II), while Spanish and Turkish oregano extracts were the most effective inhibitors of nonsite-specific hydroxyl radical-mediated 2-deoxy-D-ribose degradation. All the extracts contained Folin-Ciocalteu reagent-reactive substances, which was confirmed by the presence of polar phenolic analytes (i.e., hydroxybenzoates, hydroxycinnamates, and flavonoids).

The water-distilled essential oil the leaves of Coridothymus capitatus were analyzed by GC/MS and also analyzed by direct thermal desorption GC/MS. Comparison was made between two analyses techniques. The essential oil consisted mainly of monoterpenes 98.9%, while oxygenated hydrocarbons were identified as 55.6% and non-oxygenated hydrocarbons as 43.6%. As major components were found carvacrol (35.6%), p-cymene (21.0%), thymol (18.6%), γ-terpinene (12.3%), α-terpinene (3.2%), β-myrcene (3.0%) and α-thujene (1.3%) by hydrodistillation and by the GC/MS method. The direct thermal desorption GC/MS analysis also showed the same major components, namely carvacrol (51.6%), thymol (21.7%), pcymene (9.7%) γ-terpinene (8.2%), α-terpinene (1.64%). The essential oil of C. capitatus showed strong activity against S. aureus, P. vulgaris, P. aeruginosa, E. coli, K. pneumonia, B. subtilis, E. faecalis, S. epidermidis and C. albicans.

Water distilled essential oils of Coridothymus capitatus collected from three different locations in Turkey were subjected to GC and GC/MS analysis. Forty compounds were identified in the oils with carvacrol (68.72–77.93%) being the major component.

The existence of three chemotypes of Coridothymus capitatus in Israel—a thymol-type, a carvacrol-type and a mixed-chemotype which contained thymol and carvacrol in the ratio about 1:2—was confirmed. A detailed composition of the volatiles of C. capitatus was studied by GC/MS and, excluding thymol/carvacrol ratio, the components of the oils were found to be nearly identical. With the exception of biosynthetically interrelated γ-terpinene, p-cymene, thymol and carvacrol, the major volatile constituents of C. capitatus were found to be β-caryophyllene, caryophyllene oxide, thymohydroquinone and thymoquinone.

Analysis of the neutral fraction of Coridothymus capitatus essential oil (Spanish origanum oil) revealed 61 components. Of the new components reported there were 25 monoterpenes, 9 sesquiterpenes, 5 aliphatic, 1 phenol and 1 phenyl ether.

Analysis of the phenolic fraction of Coridothymus capitatus essential oil (Spanish origanum oil) indicated 7 major components. One of them is the well known carvacrol and among the others there are one diisopropylphenol and 5 methyldiisopropylphenols, which are found for the first time from a natural source.

Suppression of annuals at various intensities was observed around some shrubs ofCoridothymus capitatus growing on kurkar formation in the coastal hills of Israel. The phenomenon was clearly observed as annuals-free belts of 15–20 cm around ‘aggressive’ shrubs. Quantitatively, density of annuals decreased by 16 fold in the annual-free belts as compared to a distance of 60–80 cm from the canopies of the shrubs. Their dry matter was decreased by 5.4 fold around the shrubs. Suppression rate of emergence of planted seeds of annuals (Plantago psyllium andErucaria hispanica) early in the season was 45% higher around ‘aggressive’C. capitatus than that around ‘non-aggressive’ ones.

Wild populations of Coridothymus capitatus growing in Israel and West Bank of Jordan river were found to consist of at least three chemically distinct varieties, differing in the composition of the phenol fraction of the essential oil. These are thymol-containing, carvacrol-containing or contain thymol and carvacrol in the ratio of approximately 1:2. The thymol-containing variety is abundant, while the carvacrol-containing variety is very rare. The C. capitatus chemovarieties probably only exist in the area studied, because this plant has been extensively studied and is known to contain carvacrol as a main component of its essential oil and is considered to be the most chemically stable species of the genus Thymus. The results of this study led to the conclusion that Origanum oil produced in mandated Palestine during the 1930s and 1940s was distilled not from Coridothymus capitatus, but from Majorana syriaca. The former producer has confirmed this opinion.

The essential oils of MAJORANA SYRIACA, CORIDOTHYMUS CAPITATUS and SATUREJA THYMBRA plants growing wild in Israel were investigated by means of GLC and GLC-MS. 18 components were identified, the main ones being thymol, carvacrol, gamma-terpinene and p-cymene.