Satureja Thymbra Research Articles

The Relationship Between Total Phenol, Total Flavonoid, and IC50 Contents of Different Parts of Satureja thymbra and Nutrient Elements

The goal of this study is to investigate the variations in certain quality parameters, including total antioxidant activity, total phenol and total flavonoid contents, of various organs, including inflorescences, leaves and stems, of the Satureja thymbra plant, which grows naturally in the Kaş district of Antalya. Also, the relationship between these quality parameters and the nutrient content of the plant was revealed. The free radical (DPPH) was used to determine the antiradical scavenging activities of extracts prepared from various parts of the plant. The concentration of the antioxidant compound that can cause a 50 % loss in DPPH free radical activity is expressed by the IC50 value. S. thymbra leaf extracts have higher antiradical scavenging activity (IC50 = 0.11 mg dw/mg-DPPH), total phenol (38.79 mg GAE/g), and total flavonoid (29.0 mg/g) content than extracts of other plant components.

Identification of Potential Inhibitors for Severe Acute Respiratory Syndrome-related Coronavirus 2 (SARS-CoV-2) Angiotensin-converting Enzyme 2 and the Main Protease from Anatolian Traditional Plants

Background: The 2019 novel coronavirus disease (COVID-19) has caused a global health catastrophe by affecting the human population around the globe. Unfortunately, there is no specific medication or treatment currently available for COVID-19. Objective: It is extremely important to find effective drug treatment in order to put an end to this pandemic period and return to normal daily life. In this context and considering the urgency, rather than focusing on the discovery of novel compounds, it is critical to explore the effects of existing herbal agents with proven antiviral properties on the virus. Method: Molecular docking studies were carried out employing three different methods, Glide extra precision (XP) docking, induced fit docking (IFD), and molecular mechanics/generalized born surface area (MM/GBSA), to determine the potential antiviral and antibacterial effects of 58 phytochemicals present in Rosmarinus officinalis, Thymbra spicata, Satureja thymbra, and Stachys lavandulifolia plants against the main protease (Mpro) and angiotensin-converting enzyme 2 (ACE2) enzymes. Results: 7 compounds stood out among all the molecules, showing very high binding affinities. According to our findings, the substances chlorogenic acid, rosmarinic acid, and rosmanol exhibited extremely significant binding affinities for both Mpro and ACE2 enzymes. Furthermore, carnosic acid and alphacadinol showed potent anti-Mpro activity, whereas caffeic acid and carvacrol exhibited promising anti- ACE2 activity. Conclusion: Chlorogenic acid, rosmarinic acid, rosmanol, carnosic acid, alpha-cadinol, caffeic acid, and carvacrol compounds have been shown to be powerful anti-SARS-CoV-2 agents in docking simulations against Mpro and ACE2 enzymes, as well as ADME investigations.

Role of antioxidant activity of essential oils in their acaricidal activities against Rhipicephalus annulatus.

Essential oils of Origanum majorana and Satureja thymbra as well as carvacrol are natural products that are known to have potent antioxidant activities. The current study was designed to investigate the role of the antioxidant properties of these natural products in their acaricidal activities against Rhipicephalus annulatus larvae. The synergistic and/or antagonistic effects of the addition of vitamins E and C and hydrogen peroxide (H2O2) to these natural products were also evaluated. Larval packet tests were used to evaluate the acaricidal activities against the larvae of R. annulatus. The antioxidant effectiveness of these products was determined by a DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging assay. The addition of vitamin E at 100mg/mL to O. majorana and S. thymbra decreased the concentrations required to achieve the death of half of the larvae (LC50) to 0.44 and 0.47%, respectively. The combination of O. majorana and S. thymbra attained the LC50 at 1.54% which was decreased to 0.69% after addition of vitamin E. Also, the addition of vitamin E to carvacrol reduced the LC50 to 0.27%. The total antioxidant activity of these natural products increased significantly in presence of vitamin E. The addition of H2O2 inhibited the acaricidal activity of all tested materials, especially at low concentrations. All treatments induced an increase in lipid peroxidation, whereas carvacrol-treated larvae revealed the lowest values for the superoxide dismutase. Glutathione peroxidase and catalase activity decreased in larvae treated with S. thymbra combined with vitamin E. In conclusion, the addition of vitamins E and C increased the acaricidal activities of the tested compounds, whereas the addition of H2O2 decreased these activities. The antioxidant activities of essential oils and their active components may play an important role in mediating their acaricidal activities.

Allelopathic Effects of Aqueous Extract from Satureja thymbra L. on Seed Germination and Seedling Growth of Pinus halepensis Mill. and Ceratonia siliqua L

The objective of this study was to determine the impact of allelopathic potentials of aqueous extract of Satureja thymbra L. aerial parts on seed germination of Ceratonia siliqua L. and early growth seedling of Pinus halepensis Mill. and Ceratonia siliqua L. Satureja thymbra L. aerial parts were collected from Al-Jabal Al-Akhdar, Libya and collected aerial parts were dried and powdered. The treatments included 100%, 50% and 25% aqueous extracts along with water as a control. One-way analysis of variance (ANOVA) was performed and Regression analysis between treatments vs. root length, shoot length, and number of leaves among Pinus halepensis Mill and Ceratonia siliqua L. were done. The results showed seed germination of Ceratonia siliqua decreased by increasing extract concentration. The highest and lowest seed germination was belonged to control and 100 % extract respectively. In addition, the result showed a significant difference between treatments in root length and the number of leaves of both species. The LSD test showed that root length and number of leaves of Pinus halepensis Mill. and Ceratonia siliqua L. at treatments of 25%, 50% and 100% was significantly different from control. The regression analysis between root length, and number of leaves in Pinus halepensis Mill. and Ceratonia siliqua L. were significantly reduced with the increase in the extract concentration. The results demonstrate that previously mentioned extracts have inhibitory effects on the growth of roots and shoots of Pinus halepensis Mill. and Ceratonia silique L. Thus, it is recommended to use from residual of medicinal plant or select them in crop rotation systems to weed by allelochemicals compounds.

The effect of salinity stress on germination parameters in Satureja thymbra L. (Lamiaceae)

Salinity is an important problem all over the world. The destructive effect of salinity is observed from the seed germination stage. In this study, it was aimed to determine the effect of salinity on seed germination of the medically important Satureja thymbra L., whether pre-treatments are a factor in breaking the salinity stress, and to determine the level of salinity tolerance of this species. In the research, firstly, the seeds were exposed to two pre-treatments (80°C (5 minutes) + 10 ppm GA3 (24 hours), 80°C (5 minutes) + 100 ppm GA3 (24 hours)) and then 8 different NaCl concentrations (0.1 g/l, 1 g/l, 2.5 g/l, 5 g/l, 7.5 g/l,10 g/l, 15 g/l and 30 g/l) were tried. Germination seeds were counted every day and the effects of salinity on germination characteristics were investigated. The highest germination percentage (90%) was obtained at 0.1 g/l NaCl after 80°C (5 min.) + 100 ppm GA3 (24 h.) pre-treatment. The results showed that the effect of salinity was significant on germination parameters in p < 0.05. Obtained results showed that the highest NaCl concentration at which Satureja thymbra seed could germinate was 10 g/l.

Antibacterial activity of plant essential oils obtained from Satureja species against Xanthomonas phaseoli pv. phaseoli and Xanthomonas citri subsp. fuscans

In this study, the antibacterial effects of essential oils obtained from different Satureja species (Satureja cuneifolia Ten., Satureja spicigera (C. Koch) Boiss., Satureja thymbra L., Satureja hortensis L. and Satureja cilicica P.H. Davis) against Xanthomonas phaseoli pv. phaseoli (Smith) Vauterin and Xanthomonas citri subsp. fuscans (Burkholder) Starr & Burkholder, which cause common leaf blight in bean plant, were tested. Essential oils were found to significantly inhibit the growth of bacterial strains of both disease agents in vitro, and the lowest concentrations that prevent bacterial growth were determined for both pathogens. The effects of essential oil applications on seed germination, number of infected cotyledons and disease severity were also evaluated. It was determined that essential oils of S. cuneifolia and S. spicigera has no negative effects on seed germination while essential oils of S. hortensis, S. thymbra and S. cilicica caused a little decrease in seed germination compared to the control. As a result of S. cuneifolia + pathogen and S. spicigera + pathogen applications, no infected cotyledons were detected, and it was determined that the disease development caused by two pathogens was prevented by 100%.

Extraction and identification of the components of Thymbra spicata L. and Satureja khuzestanica Jamzad Oils native to Ilam province by headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS)

Satureja khuzistanica Jamzad (Lamiaceae) and Thymbra spicata L. (Lamiaceae) are medicinal plants belonging to the genera of Satureja and Thymbra, having many uses in traditional Iranian medicine. S. khuzistanica is used to treat different diseases such as cramps, nausea, and infectious diseases. Medicinal plants, extracts and essential oils are of special importance for pharmacy, health and food industries. S. khuzistanica and T. spicata plants were collected from Dehloran located in south of Ilam province in western Iran. Then, they were dried and powdered. Headspace-solid phase microextraction (HS-SPME) and Gas Chromatography-mass Spectrometry (GC-MS) techniques were used to obtain extracts of mentioned plants and identify their active compounds. Essential oil from T. spicata contained 45 chemical compounds, whose main ones were isothymol (36.24%), gamma-terpinene (17.94%), O-cymene (10.92%), trans-caryophyllene (7.81%), alpha-pinene (7.24%), and camphene (3.61%). Also, essential oil from S. khuzestanica contained 43 chemical compounds which main ones were carvacrol (71.99%), camphene (2.84%), alpha-pinene (1.63%), 1,8-Cineole (1.51%). carvone (1.44%) and beta-pinene (1.42). Results from present study indicated that antioxidative and antimicrobial compounds such as carvacrol were found in both plants (S. khuzestanica and T. spicata) from the Laminaceae family. Therefore, essential oils of these plants can find applications as antioxidant, antimicrobial and antiseptic compounds for medicinal and health purposes.

Phytochemical analysis and potential natural compounds against SARS-CoV-2/COVID-19 in essential oils derived from medicinal plants originating from Lebanon. An information note

The aim of the study is to identify potential natural compounds against SARS-CoV-2 occurring in essential oils (EOs) following literature data attesting their anti-viral activity. The epidemic virus that started in December 2019 in Wuhan, China, has spread worldwide as a global pandemic. The interest in the development of drugs from natural products has increased greatly in recent decades. (EOs) have been studied over the centuries and are known to possess various pharmaceutical properties. Recent antiviral and silico methods are used to discover phyto-compounds, suitable for coronavirus treatment. To obtain this result we employed gas chromatography for the analysis of essential oils from Laurus nobilis, Pinus pinea, Pistacia palaestina, Juniperus oxycedrus, Juniperus excelsa, Pinus brutia, Cupressus sempervirens, Lavandula stoechas, Origanum syriacum, O. ehrenbergi, Salvia tribola, Satureja thymbra, Calamintha origanifolia, Foeniculum vulgare, Mentha longifolia, Cuminum cyminum and Pimpinella anisum.

Recruitment pattern in an isolated small population of the Mediterranean dwarf shrub Satureja thymbra L. and implication for conservation

The recruitment pattern of Satureja thymbra (Lamiaceae), in a single and isolated population in Sardinia, was experimentally investigated by human-mediated sowing in the field: 12 plants in two habitats (inside and outside of “phrygana” habitat) were randomly selected as the source of seeds and a total of 2160 seeds were buried in two microhabitats, under the canopy and in open areas (3 replicas × 30 seeds × 12 plants × 2 microhabitats). The experiment was monthly monitored over a 2-year period. Germination and recruitment of S. thymbra were extremely low. Significant differences in the interaction among habitat and cohorts in seedling emergence were found. Differences between cohorts are due to the early emergence, which protected seedlings from seasonal drought. Seedling emergence in both microhabitats was recorded, although no significant differences were found. Additionally, significant differences in survived seedlings for habitat and cohort and for the interaction among them were found. The phrygana habitat showed a positive effect on the persistence of S. thymbra, by protecting plants from human disturbance, hence its conservation is essential to increase the population size of S. thymbra. Our findings, increasing the knowledge of the recruitment pattern of S. thymbra, provide also useful information for its conservation.

The effect of temperature on the phenolic content and oxidative stability of o/w emulsions enriched with natural extracts from Satureja thymbra

Sunflower oil-in-water emulsions were enriched with two Satureja thymbra extracts - obtained by ethyl acetate (EAcs) or ethanol (Es), rosmarinic acid (RA), or quercetin (Que), and the effect of storage temperature (5–40 °C) on the emulsions’ phenolic content and oxidative stability was studied. HPLC analysis of the extracts indicated RA as the main component. The phenolic content of the emulsions decreased during storage, following first-order kinetics, with a temperature-dependent rate. RA was the main compound that decreased, Que followed a slower decrease and the rest flavonoids remained almost constant. The additives protected the emulsion against oxidation according to the order Es > Que > EAcs > RA. The protection factor ranged from 73 to 81% at 5 °C, but decreased to around 53% for Que and Es, 33% for EAcs, and 22% for RA at 40 °C. Emulsions enriched with extracts from S. thymbra retain their phenolic content and oxidative stability at refrigeration temperatures.

Evaluation of Eight Essential Oils for Postharvest Control of Aspergillus carbonarius in Grapes

A range of fungal species are associated with postharvest spoilage of grapes. However, Aspergillus carbonarius is the primary fungus responsible for the contamination of grapes with ochratoxin A, a mycotoxin causing several confirmed negative health effects in humans and animals. Aiming to find a method, safe for consumers, to prevent postharvest decay and ochratoxin A contamination of grapes, the potential use of essential oils as preservatives was investigated. Essential oils of Origanum dictamnus (dittany), Origanum onites (oregano), Origanum microphyllum (marjoram), Thymbra capitata (thyme), Satureja thymbra (savory), Rosmarinus officinalis (rosemary), Laurus nobilis (laurel), and Salvia officinalis (sage) were tested. The essential oil components were identified by gas chromatography-mass spectrometry analysis. A first evaluation of the effectiveness of essential oils was performed in vitro at a range of concentrations up to 300 μL L-1. Based on the results of the in vitro tests, the four most effective essential oils (O. dictamnus, O. onites, T. capitata, and S. thymbra) were tested on Sultana grapes during postharvest storage. The four essential oils tested, which had carvacrol and/or thymol as a common component, at a high concentration significantly reduced or even inhibited growth of the fungus in all treatments. As revealed from the results, the essential oils of O. dictamnus, O. onites, and S. thymbra were the most effective, causing total inhibition of the growth of the fungus with a minimum concentration of 100 μL L-1, followed by the essential oil of T. capitata, which showed total effectiveness with a minimum concentration of 200 μL L-1. Although essential oils of O. microphyllum, L. nobilis, S. officinalis, and R. officinalis had a significant effect on the growth of A. carbonarius, they failed to inhibit its growth at any of the concentrations tested.

Altitude impact on the chemical profile and biological activities of Satureja thymbra L. essential oil

BackgroundSeveral agricultural or environmental factors affect plants’ chemical and pharmacological properties.MethodsIn this study, the essential oil of Libyan Satureja thymbra was isolated from plants collected during two successive years at two different altitudes; Wasita (WEO) and Safsaf (SEO), 156 and 661 m above sea level, respectively.ResultsGC/MS allowed the identification of 21 and 23 compounds, respectively. Thymol prevailed in WEO (26.69%), while carvacrol prevailed in SEO (14.30%). Antimicrobial activity was tested by agar-well diffusion method, and MIC/MLC values were determined by broth dilution method. Values of MIC/MLC were 0.125/0.25 μg/ml for SEO against S. aureus, P. mirabilis and K. pneumonia and for WEO against B. subtilus. It was observed that plants growing at lower altitude in Wasita locality had better antifungal activity, while those growing at higher altitude at Safsaf locality had better antibacterial activity. Both essential oils had a better anthelmintic activity than the standard piperazine citrate against a tested earthworm. However, SEO oil had a significantly higher anthelmintic activity than WEO. Cytotoxicity of the oils tested using SRB assay on human breast cancer (MCF-7) and colon cancer cell lines (HCT-116) showed better activity for SEO, especially against HCT-116 with IC50 2.45 ± 0.21 μg/ml.ConclusionsThus, altitude is an important factor that should be considered as it affected the yield, composition and biology of the plant extracts.

Effect of active packaging with Satureja thymbra extracts on the oxidative stability of fried potato chips

Abstract Satureja thymbra extracts, rich in phenolic acids and flavonoids, were obtained through successive extractions with ethyl acetate and ethanol, and tested as natural antioxidants to prolong the shelf life of fried potato chips. The extracts were more effective when coated on a laminated film used as active packaging for the chips, compared to spraying them on the surface of the fried product or adding to the frying oil. The increased incorporation of the ethanol extract, as coating, from 100 to 300 mg total phenols (expressed as gallic acid equivalents, GAE)/m2 resulted in increased protection, as evidenced through peroxide values, volatile products, and oxygen consumption inside the packaging that remained stable for 55 days. Ethyl acetate extract was very effective up to a concentration of 200 mg GAE/m2, but demonstrated prooxidant activity at higher concentration. Partial migration of the natural polyphenols to the product was observed.

In vitro propagation of Satureja thymbra L. (Lamiaceae): A valuable aromatic-medicinal native plant of the Mediterranean region

Satureja thymbra L. or savory is a highly threatened aromatic-medicinal endemic Mediterranean plant. Micropropagation can play a role in the protection of the natural eco­system. The disinfection protocol involved the immersion of shoot-tip explants in 70% alcohol (1 min) and 3% NaOCl (15 min) giving 61.18% success. The MS medium supplemented with 30 g/l sucrose and 7 g/l Plant Agar was optimum for the initial establishment stage (10-day culture, 92.31% proliferation) and afterwards supplemented extra with 0.5 mg/l BA for multiple shoot induction (5 weeks) (100% proliferation, 5.5 shoots 14.24 mm long). In rooting stage, 1 mg/l IBA gave the highest rooting (58.62%), 0.5 mg/l NAA the maximum root number (12.13) ​​and 0.1 mg/l IAA the largest root length (34.35 mm) (MS medium + 20 g/l sucrose + 6.5 g/l Plant Agar, 7 weeks) (Experiment No. 1). There was a progressive increase in rooting and shoot proliferation increasing the number of subcultures, being highest (100% rooting, 6 roots 70 mm long, 38.1% shoot multiplication, 2 shoots 30 mm long) in the 4th subculture/ 4.5 weeks each in WPM medium (Experiment No. 2). Therefore, best rooting results (50-100%) were accomplished in 3 different composition media: (1 and 2) WPM medium + 20 g/l sucrose + 6 g/l Plant Agar (1st and 4th subculture) and (3) MS medium + 30 g/l sucrose + 1 mg/l IBA + 7 g/l Plant Agar. The ex vitro survival of rooted microshoots after 4 weeks in the greenhouse mist (1 peat moss: 1 perlite) was 81.82%.

Investigation of the toxicity of ethanol extracts obtained from six different Satureja L. species on Colorado Potato Beetle, Leptinotarsa decemlineata (Say, 1824), (Coleoptera: Chrysomelidae)

In the present study, ethanol extracts obtained from Satureja cilicica P. H. Davis, Satureja cuneifolia Ten, Satureja hortensis L., Satureja spicigera (C. Koch) Boiss., Satureja thymbra L. and Satureja montana L. were tested against on the adults and larvae of Colorado potato beetle (Leptinotarsa decemlineata (Say, 1824)). The experiments were conducted in glass Petri dishes and vacuum desiccators including 15 individual for each period with three replicates under laboratory conditions. 10, 15 and 20 mg/mL doses of ethanol extracts conducted in the Petri dishes and the desiccators showed that depending on concentration increase and duration of exposure time resulted between 2.22-100% toxic effects on the potato beetle larvae and adults. In Petri trials, the highest mortality rate was recorded as 100% for the second larval stage at the 20 mg/mL dose of S. spicigera ethanol extract after 96 hours the treatment. In desiccator experiments, the highest toxicity rate was determined as 100% for first larval stage at the 20 mg/mL dose of S. thymbra ethanol extract after 96 hours of the application. In addition to, when LD values of the ethanol extracts ​​were taken into account the highest toxicity of adult period was determined for S. thymbra extract (LD25:0.000, LD50: 0.010 μL/insect), the lowest toxicity was determined for S. cilicica extract (LD90: 436.020 μL/insect). The results obtained from this study suggested that the ethanol extracts of tested Satureja L. species could be used for L. decemlineata larvae and adults as bio-larvicides and insecticides.

Antibacterial effect of some wild medicinal plants in Palestine against multidrug resistant Escherichia coli clinical isolate

Due to the emergence of antibiotic resistant pathogens, plants are being an excellent alternate to fight the further spread of multidrug resistant microorganisms. In this study, six plant species grown wildly in Palestine were used to determine their efficacy against multidrug resistant clinical isolate of Escherichia coli. The dried areal parts of Calamintha incana, Lupins pilosus, Parietaria judica, Satureja thymbra, Thymbra spicata and Verbascum fruticulosum were extracted with water, ethanol and methanol solvents. All extracts were screened for their antibacterial activity using micro-dilution method. Plant extraction with alcohol solvents provided stronger antibacterial effect compared to the aqueous ones. All alcoholic extracts have an inhibitory effect against E. coli except the ethanol extract of L. pilosus and the methanol extracts of V. fruticulosum and C. incana. Moreover, C. incana aqueous extract was the only aqueous extract with bacteriostatic activity. Among the studied plant species, ethanol extract of T. spicata was the most potent one with MBC value 12.5 mg/mL. However, P. judica ethanol extract which exhibited the best MIC effect (6.25 mg/mL) killed E. coli isolate at a 25 mg/mL. In conclusion, obtained results confirmed the efficacy of using some plant extracts as natural antibacterial alternatives. Therefore, it suggests the possibility of using them as drugs for the treatment of other multidrug resistant bacterial isolates.

The Safety Assessment of Toxic Metals in Commonly Used Pharmaceutical Herbal Products and Traditional Herbs for Infants in Jordanian Market.

The objective of this study was to assess the levels of contamination by toxic metals (Pb, Al, Ni, Cd and As) that may be present in 25 infant pharmaceutical herbal products and 15 traditional herbs in Jordan. Both products and medicinal herbs are currently prescribed by paediatricians. They are available as over-the-counter medicines and are sold the in herbal market, ensuring easy accessibility for parents. Inductively coupled plasma-optical emission spectroscopy (ICP-OES), with limit of detections (LODs) of 0.10, 1.00, 0.20, 0.15 and 2.00mg.kg-1 for Pb, Al, Ni, Cd and As respectively, was employed to measure the levels of toxic metals in the samples. Pb, Al and Ni were detected in 88, 76 and 4% of the analysed samples of pharmaceutical herbal products and in 93, 87 and 13% of the analysed samples of traditional herbs, respectively. Neither Cd or As were detected in all analysed samples. The data obtained were subsequently compared by referral to the acceptable limits of toxic heavy metals according to World Health Organisation (WHO) standards. Largely, the results showed acceptable toxic metal levels in the finished pharmaceutical products and the traditional medicinal herbs for infants. One exception to this was Persian Thyme (Satureja thymbra) with Pb content of 41.18mg.kg-1. Also, the daily intake of detected metals through pharmaceutical herbal products was found to be lower than the daily tolerable intake limit set by the regulatory bodies, except of 8% of products that exceeded the tolerable daily intake of Pb set by US FDA, as compared to traditional medicinal herbs, where the tolerable daily intake for Pb, Al and Ni were exceeded in 40, 60 and 8% of the analysed herbs, respectively. The results obtained revealed that the excessive use of medicinal plants as alternative medicine should be used with caution keeping in mind the safety factor in infants.

Antimicrobial Effect of Plant Oils against Some Bacterias Izolated from Patients Samples

Aim: The aim of present study was to compare the antibacterial potential of Thymus sipyleus boiss. subsp. sipyleus boiss. var. sipyleus L. (Thymol and camphor both tested), Satureja thymbra L. and Origanum onites L. by Kirby Bauer disc diffusion method. Methods: We isolated Enterococcus spp., E. coli, Morgonella morganii, Pseudomonas aeruginosa, MSSA, Klebsiella pneumonia and Proteus mirabilis from different patient samples. The antibacterial activity of each oils was evaluated by the Kirby Bauer disc diffusion method. Results: Proteus mirabilis were the most susceptible bacteria against essential oils, followed by Klebsiella pneumonia and Morganella morganii. Pseudomonas aeruginosa did not show susceptibility to any oil. Conclusion: The essential oils of the T. sipyleus, O. onites and S. thymbra were especially very effective against the resistant strains such as Enterococcus spp. and Klebsiella pneumonia. In this group the maximum antimicrobial activity was observed with the essential oils of Origanum onites and Satureja thymbra. We think that these oils can be proposed in treatment process as an alternative application structures in the future.

Antioxidant recovery from hydrodistillation residues of selected Lamiaceae species by alkaline extraction

Aqueous solution of potassium hydroxide (KOH) was used in order to obtain rich in antioxidant activity extracts from Origanum dictamnus, Origanum hirtum, Origanum onites, Rosmarinus officinalis and Satureja thymbra, after removal of the essential oil via hydrodistillation. The increase of extraction time induced lower values of total phenolic content and DPPH radical scavenging ability of the extracts, while lower alkaline concentrations, i.e. 1% and 3%, proved to be more effective than 5% (v/w) KOH. The antioxidant activity of the extracts in sunflower oil was also measured by the oxidative stability index (OSI) method. OSI values decreased as extraction time increased, while the effect of KOH concentration at short extraction time was not significant. S. thymbra, O. hirtum and R. officinalis extracts showed high total phenolic content and good antiradical and antioxidant activity in just 30 min of extraction with KOH 1% (w/v). LC–MS analysis showed that all extracts were rich in phenolic acids, such as caffeic acid and rosmarinic acid, while R. officinalis was also rich in carnosic acid.

Chemical Composition and Antimicrobial Activity of Satureja, Thymus, and Thymbra Species Grown in Lebanon.

The essential oils were extracted by hydrodistillation from Satureja cuneifolia, Satureja thymbra, Coridothymus capitatus, Thymus syriacus, and Thymbra spicata growing wild in Lebanon. Their phytochemical analysis performed by GC/MS showed that the aforementioned species are characterized either by carvacrol (60.9%) or thymol (54.3%) or by a more or less equal amounts of these two phenols. Assessment of their invitro antimicrobial activity against Candida albicans and six pathogenic bacteria using the broth dilution method revealed that the tested oils have a broad activity spectrum with minimum inhibitory concentration ranging from 0.1 to 0.8mg/ml. Among the tested species, S.thymbra EO showed the highest antimicrobial potential whereas T.syriacus showed the lowest inhibitory activity. These results give scientific evidence for the use of those species in the Lebanese folk medicine and lend support to implement them as natural alternatives for synthetic antimicrobials.