Thymus Capitatus Research Articles

Peroxyl Radical Trapping Antioxidant Activity of Essential Oils and Their Phenolic Components.

Essential oils (EOs) are gaining importance as sustainable food antioxidants, but kinetic data on peroxyl radical trapping are missing. Thirteen EOs from 11 botanical species were studied in the inhibited autoxidation of cumene by oxygen-uptake kinetics. EOs of Juniperus oxycedrus, Syzygium aromaticum, Thymus vulgaris, Thymbra capitata, Betula alba, Pimenta racemosa, and Satureja montana, containing 23-86% phenolic components by gas chromatography/mass spectrometry (GC-MS) analysis, afforded inhibition rate constants kinh in the order of 104 M-1 s-1 at 30 °C similar to reference butylhydroxytoluene (2,6-di-tert-butyl-4-methylphenol) (BHT). They matched or outperformed BHT in the protection of olive oil. The EOs Daucus carota and Cedrus atlantica with <1% phenols and those of Apium graveolens and Tagetes minuta with no phenolics had no chain-breaking activity. Key components carvacrol, thymol, eugenol, dihydroeugenol, umbelliferone, conyferyl alcohol, o-cresol, m-cresol, p-cresol, 4-allylphenol, 2,3-xylenol, 2,4-xylenol, and phenol had kinh in the range of 103-104 M-1 s-1 and, along with EOs containing them, could potentially replace BHT in the protection of food products.

GC-MS, FTIR analysis and effects of thyme (Thymbra capitata L. Cav) and rosemary (Rosmarinus officinalis L.) essential oils on the growth and pathogenicity of Botrytis fabae

ABSTRACT This study examined the efficacy of rosemary (Rosmarinus officinalis L.) and thyme (Thymbra capitata L. Cav) essential oils (EOs) in Botrytis fabae management. The key compounds identified in thyme EO were carvacrol (48.13%), 4-Methoxystyrene (17.32%), and cyclohexene (12.37%), whereas the rosemary EO contained α-pinene (55.08%), camphene (10.52%), and d-limonene (7.86%). In vitro tests showed that thyme EO was more effective than rosemary, achieving total inhibition of B. fabae at a concentration of 50 µL compared to 250 µL for rosemary EO. Molecular docking indicated that the primary compounds in each EO interacted with 14 alpha-sterol demethylase. Greenhouse tests confirmed that both EOs significantly reduced disease severity without phytotoxicity. These findings suggest that thyme and rosemary EOs could be effective in B. fabae management, thereby promoting eco-friendly agriculture.

Repellency, Fumigant Toxicity, Antifeedent and Residual Activities of Coridothymus capitatus and Its Main Component Carvacrol against Red Flour Beetle.

Tribolium castaneum is a challenging pest of stored products, causing significant economic losses. The present study explored the efficacy of Coridothymus capitatus essential oil and its primary constituent, carvacrol, as eco-friendly alternatives for managing this pest. To evaluate their insecticidal potential, repellency, fumigant toxicity, and antifeedant properties, progeny inhibition assays were performed. Carvacrol exhibited superior repellency compared to the essential oil, achieving a 92% repellency rate at 2 mg/cm2. Both compounds demonstrated significant fumigant toxicity against T. castaneum, with LC50 values of 168.47 and 106.5 μL/L for the essential oil and carvacrol, respectively, after 24 h. Carvacrol also outperformed the essential oil in antifeedant activity, inducing an 80.7% feeding deterrence at 1.17 mg/g. Moreover, both treatments effectively suppressed the development of the pest's progeny. These results collectively underscore the potent insecticidal properties of C. capitatus essential oil and carvacrol, particularly carvacrol, as promising candidates for the sustainable management of T. castaneum in stored product protection.

Green Synthesis of Hexagonal-like ZnO Nanoparticles Modified with Phytochemicals of Clove (Syzygium aromaticum) and Thymus capitatus Extracts: Enhanced Antibacterial, Antifungal, and Antioxidant Activities.

The green synthesis of ZnO NPs is becoming increasingly valued for its cost-effectiveness and environmental benefits. This study successfully synthesized hexagonal ZnO NPs using a combination of clove (Syzygium aromaticum) and Thymus capitatus extracts. The use of both extracts significantly improved the antibacterial and antioxidant properties of the ZnO NPs. By optimizing synthesis conditions, including ZnCl2 and extract concentrations, hexagonal wurtzite ZnO NPs were produced at room temperature with only drying at 80 °C without high-temperature annealing. The synthesized ZnO NPs exhibited a hexagonal morphology with an average particle size of 160 nm and a crystallite size of 30 nm. Energy-dispersive X-ray spectroscopy (SEM-EDX) confirmed the elemental composition of the ZnO NPs, showing a high carbon content (63.9 wt.%), reflecting the presence of phytochemicals from the extracts coated the ZnO NPs surface. The UV-Vis spectrum revealed an absorption peak at 370 nm and a bandgap energy of 2.8 eV due to lattice defects caused by organic impurities. The ZnO NPs demonstrated exceptional antioxidant activity, with a DPPH radical scavenging rate of 95.2%. They also exhibited strong antibacterial activity against both Gram-positive and Gram-negative bacteria, with inhibition zones of 25 mm against Bacillus subtilis, 26 mm against Escherichia coli, 24 mm against Salmonella typhimurium, 22 mm against Klebsiella pneumoniae, 21 mm against Staphylococcus aureus, 20 mm against Staphylococcus hominis, and 18 mm against Bacillus subtilis at 200 ppm. Furthermore, significant antifungal activity was observed against Candida albicans, with an inhibition zone of 35 mm at the same concentration. These findings underscore the effectiveness of using combined plant extracts for producing ZnO NPs with controlled morphology and enhanced biological properties, highlighting their potential for various biomedical applications.

Chemical Composition, Antifungal, Antioxidant, and Hemolytic Activities of Moroccan Thymus capitatus Essential Oil.

This study aimed to define the chemical composition of Moroccan Thymus capitatus essential oil, and to investigate its in vitro antioxidant and antifungal activities against human pathogenic fungi. Chemical analysis using GC-FID and GC-MS system revealed 28 constituents, representing 99 % of total compounds. Oxygenated monoterpenes represented the highest proportion (79.79 %), among which carvacrol (75.73 %) was the predominant compound, followed by linalol (2.26 %). Monoterpene hydrocarbons represented the second major fraction (16.29 %): within them, the predominant constituents were γ-terpinene (5,55 %), ρ-cymene (5,50 %), and β-caryophyllene (2.73 %). Antioxidant activity was performed by DPPH scavenging, β-carotene bleaching inhibition, and ferric reducing power. T. capitatus revealed pronounced DPPH radical scavenging activity (IC50=110.53 μg mL-1), strong ferric reducing ability (EC50=644.4 μg mL-1), and a remarkable degree of protection against lipid peroxidation during β-carotene bleaching inhibition (IC50=251.76 μg mL-1). Antifungal activity was carried out against Candida, Aspergillus, and Rhizopus species by microdilution method. T. capitatus exhibited potent anticandidal activity (MIC=125-500 μg mL-1) and strong inhibition against filamentous fungi (MIC=250-500 μg mL-1). Its hemolytic activity against human erythrocytes had a low toxic effect at concentrations lower than 1250 μg mL-1. The useful antioxidant properties and broad antifungal effect of T. capitatus EO confirm its considerable potential for the food industry and for phytopharmaceutical production.

Antiviral Efficacy of Coridothymus capitatus Essential Oil Against HSV-1 and HSV-2.

Coridothymus capitatus is a perennial herb with aromatic leaves and flowers, distinct from Thymus vulgaris in its chemical composition, resulting in a unique Thymus Essential Oil (TEO). A main component of TEO, carvacrol, is known for its antimicrobial and insecticidal activity. Carvacrol has potent antibacterial, antioxidant, anti-inflammatory, and antifungal properties, generating interest in traditional medicine. However, studies on its antiviral activity are limited. Given the rise in viral infections and limitations of synthetic antiviral drugs, natural antiviral agents are promising due to their efficacy, lower resistance development, and reduced side effects. This study assessed the antiviral efficacy of TEO compared to that of pure carvacrol. We tested various viruses, revealing significant inhibitory effects of TEO on the replication of only Simplexvirus humanalpha1 (HSV-1) and Simplexvirus humanalpha2 (HSV-2), with specific interference during the early stages of the viral replication cycle after the adsorption period. TEO exhibited inhibitory effects at doses below the cytotoxic threshold, with IC50 values of 47 μg/mL for HSV-1 and 40 μg/mL for HSV-2. Maximum virus inhibition was achieved when TEO was added within 90 min post-infection, indicating interference with early viral replication steps. These findings highlight the potential of TEO as a natural antiviral agent and suggest further research into its mechanisms and clinical applications.

Green biosynthesis of Ag2O nanoparticles by aqueous leaves extract of Thymus capitatus (Lamiaceae): effect of silver nitrate weight in optical and their biological activity

In this study, green synthesis of silver oxide nanoparticles (Ag2O NPs) was achieved by bio-reduction of AgNO3 using Thymus Capitatus leaves extract. The effect of silver precursor contraction (0.1–1 g, AgNO3) was studied. X-ray diffraction confirmed the crystalline nature of Ag/Ag2O NPs with a crystallite size range from 18 to 24 nm. SEM showed that the green synthesizing silver oxide nanoparticles having in general as cubical shape. The obtained Ag2O NPs exhibit absorption at 273 nm with a direct bandgap ranging from 3.87 to 4.02 eV and an indirect bandgap of 2.99–3.44 eV, according to Uv-visible spectra. FTIR analysis exhibit a two weak peak at 517 and 458 cm−1 attributed to silver oxide-NPs vibration, confirming the nanoparticles formation. Among the examined extracts, Ag2O NPs with 1 g weight of AgNO3 showed the highest antioxidant activity with value of 3.42, 18.98 and 18.97 mg/mL for DPPH, FRAP and TAC tests respectively.

Cytotoxic activity of liposomal Thymus capitatus essential oil on HT-29 human colorectal cancer cell line.

Multidrug resistance, severe side effects, and high cancer treatment costs are still well-known issues and remain an open challenge. These factors reduce the therapy's efficiency and safety, seriously affecting human health. Developing therapeutic approaches based on plant extracts, especially based on essential oils with cytotoxic and antioxidant properties, could be of efficacious strategies. This work incorporated Thymus capitatus essential oil (TEO) in liposomes. Thymus capitatus is a plant native to the northern region of Albania and found specifically in the Mediterranean region. TEO has several biological activities and cytotoxic properties. Due to its volatility, poor solubility, and chemical instability, however, its applicability is restricted. Incorporation into liposomes enables its effective use because the exposure time to the active compounds can be extended, increasing its efficacy against colorectal cancer cell lines, as highlighted in in vitro studies. TEO demonstrated detectable cytotoxic action against HT-29 colorectal cancer cells, and this action could be enhanced by applying various formulations of TEO-loaded liposomes to this cell line. Among the tested nanosystems, TEO-Phospholipon 90H liposomes showed more significant cytotoxic effects than TEO-Lipoid S100 liposomes and TEO-Phospholipon 85G liposomes. TEO-Phospholipon 90 H liposomes also maintained its physicochemical stability for six months at 25 °C. This research suggests that TEO, particularly when encapsulated in TEO-Phospholipon 90 H liposomes, may offer a promising therapeutic approach. However, these findings are based on in vitro studies and further in vivo research is needed to validate the efficacy and safety of this approach in clinical settings.

In vitro and in vivo anthelmintic effect of essential oil obtained from Thymus capitatus flowers against Haemonchus contortus and Heligmosomoides polygyrus

Sheep haemonchosis is a disease that causes serious losses in livestock production, particularly with the increase of cases of anthelmintic resistance around the world. This justifies the urgent need of alternative solutions. The aim of this study was to determine the chemical profile, in vitro, and, in vivo, anthelmintic properties of Thymus capitatus essential oil. To evaluate the, in vitro, anthelmintic activity of the T. capitatus EO on Haemonchus contortus, two tests were used: egg hatch assay (EHA) and adult worm motility (AWM) assay. The nematicidal effect of this oil was evaluated, in vivo, in mice infected artificially with Heligmosomoides polygyrus using faecal egg count reduction (FECR) and total worm count reduction (TWCR). Chromatographic characterization of T.capitatus composition using gas chromatography coupled to mass spectrometry (GC-MS) demonstrated the presence of carvacrol (81.16%), as the major constituents. The IC50 values obtained was 1.9 mg/mL in the EHT. In the AWM assay; T. capitatus essential oil achieved 70.8% inhibition at 1 mg/mL after 8 h incubation. The in vivo, evaluation on H. polygyrus revealed a significant nematicidal effect 7 days post-treatment by inducing 49.5% FECR and 64.5% TWCR, using the highest dose (1600 mg/kg). The results of present study, demonstrate that T.capitatus EO possess a significant anthelmintic properties. Furthermore, it could be an alternative source of anthelmintic agents against gastrointestinal infections caused by H. contortus.

Spray Coating of Wood with Nanoparticles from Lignin and Polylactic Glycolic Acid Loaded with Thyme Essential Oils.

Ensuring the longevity of wooden constructions depends heavily on the preservation process. However, several traditional preservation methods involving fossil-based compounds have become outdated because they pose a significant risk to the environment and to human health. Therefore, the use of bio-based and bioactive solutions, such as essential oils, has emerged as a more sustainable alternative in protecting wood from biotic attacks. The entrapment of essential oils in polymeric carrier matrices provides protection against oxidation and subsequent degradation or rapid evaporation, which implies the loss of their biocidal effect. In this work, lignin as well as PLGA nanoparticles containing the essential oils from two different thyme species (Thymus capitatus and T. vulgaris) were applied on beech wood samples using spray coating. The prepared coatings were investigated using FTIR imaging, SEM, as well as LSM analysis. Release experiments were conducted to investigate the release behavior of the essential oils from their respective lignin and PLGA carrier materials. The study found that lignin nanoparticles were more effective at trapping and retaining essential oils than PLGA nanoparticles, despite having larger average particle diameters and a more uneven particle size distribution. An analysis of the lignin coatings showed that they formed a uniform layer that covered most of the surface pores. PLGA nanoparticles formed a film-like layer on the cell walls, and after leaching, larger areas of native wood were evident on the wood samples treated with PLGA NPs compared to the ones coated with lignin NPs. The loading capacity and efficiency varied with the type of essential oil, while the release behaviors were similar between the two essential oil types applied in this study.

Antilisterial Effectiveness of Origanum vulgare var. hirtum and Coridothymus capitatus Essential Oils and Hydrolates Alone and in Combination.

The antimicrobial activity of Origanum vulgare var. hirtum (O) and Coridothymus capitatus (C) essential oils (EOs) and hydrolates (HYs) of the same botanical species was evaluated on sixteen L. monocytogenes strains from food and clinical origins. The antimicrobial activity was assessed by Minimum Inhibitory Concentration (MIC) determination, viable cell enumeration over time up to 60 min, and evaluation of the cellular damage through Confocal Laser Scanning Microscope (CLSM) analysis. EOs exhibited antimicrobial activity with MIC values ranging from 0.3125 to 10 µL/mL. In contrast, HYs demonstrated antimicrobial effectiveness at higher concentrations (125-500 µL/mL). The effect of HYs was rapid after the contact with the cells, and the cell count reduction over 60 min of HY treatment was about 1.2-1.7 Log CFU/mL. L. monocytogenes cells were stressed by HY treatment, and red cell aggregates were revealed through CLSM observation. Moreover, the combinations of EOs and HYs had an additive antilisterial effect in most cases and allowed the concentration of use to be reduced, while maintaining or improving the antimicrobial effectiveness. The combined use of EOs and HYs can offer novel opportunities for applications, thereby enhancing the antimicrobial effectiveness and diminishing the concentration of use. This provides the added benefit of reducing toxicity and mitigating any undesirable sensory effects.

Antibacterial Effect of Eight Essential Oils against Bacteria Implicated in Bovine Mastitis and Characterization of Primary Action Mode of Thymus capitatus Essential Oil.

During the current investigation, eight essential oils (EOs) were tested for their antimicrobial activity against six species, belonging to the genus of staphylococcus, multi-resistant to antibiotics (S. epidermidis, S. cohni, S. wareneri, S. scuiri, S. chromogenes, S. pasteuri), three methicillin-resistant Staphylococcus aureus strains (MRSA) and two strains of Escherichia coli, producing extended-spectrum β-lactamase (ESBL) responsible for bovine mastitis. Our results indicated that the antimicrobial activities of eight EOs varied significantly among the types of EOs and bacterial species. Thymus capitatus and Trachyspermum ammi EOs display important antibacterial activity against all tested strains, with the inhibition zone diameters situated between 20 and 45 mm, while EOs of Artemisia absinthium, Eucalyptus globulus, Eucalyptus camaldulensis, Myrtus communis and Mentha pulegium exerted an intermediate activity. For Cymbopogon citratus, this effect depends on bacteria species. In fact, an important effect was observed against S. warneri, S. epidermidis, S. cohenii, S. pasteuri and MRSA (EC 39+) strains. In addition, the important lytic effect was observed against MRSA strains, showing that Gram-positive bacteria were more sensitive to T. capitatus EO than Gram-negative ones. Concerning the characterization of the mode action of T. capitatus, experiments of kill-time, bacteriolytic, loss of salt tolerance and loss of cytoplasmic material showed that the used EO was able to destroy cell walls and membranes followed by the loss of vital intracellular materials. In addition, it inhibits the normal synthesis of DNA, causing the bacterial death of E. coli and MRSA strains. This study shows the potential of using of EOs, particularly T. capitaus, to inhibit the growth of Gram-positive and Gram-negative bacteria multi-resistant to antibiotics causing bovine mastitis.

Effects of Climate and Weeds on the Establishment of Thyme-Based Living Mulch Systems in Drylands of Cyprus

Backround: Mulching systems are at the spotlight of sustainable soil management as nature-based solutions for combating desertification.&#x0D; Aims: We tested how living mulch systems based on rainfed Thymbra capitata [(L.) Cav.], can be established under different pressure from drought and weeds in dryland carob plantations.&#x0D; Study design: 10 thyme plots in semi-arid climate (SKR); 11 plots in arid climate (VRY); different weed competition intensity (60 thymes per plot).&#x0D; Place and Duration of the Study: South-eastern Cyprus, between December 2019 and 2022.&#x0D; Methodology: Survival and soil cover for 1260 T. capitata seedlings (3-5 cm tall, 16 seedlings per m2) was assessed at the end of 3 dry seasons (d.s.) together with weed community composition, weed abundance (w.a.) and biomass. Climate data and De Martone’s Aridity Index (DMAI) were used to assess drought severity.&#x0D; Results: Around 80% of the thymes survived at the end of the first d.s, that followed a very rainy year (ca. 600 mm annual precipitation; P; ca. +50% than normal; ca. 19 DMAI). Thyme survival appeared unaffected by w.a. in both sites. After a severe drought that occurred the second year (ca. 300 mm P; ca. -22% than normal; ca. 9.5 DMAI) thyme survival rates dropped at the end of the d.s. to ca. 20% at the site with 3 times higher w.a./ biomass (mostly from Avena sp.). However, they were unaffected under low w.a. creating a 29% soil cover (vs.7% in VRY). These results remained till the end of the third d.s.&#x0D; Conclusions: To combat desertification and drought intensification under climatic change, rainfed T. capitata as living mulch appears unaffected by weeds during wet years, or in very dry years under low w.a. However, under high w.a., a weed management system is required if climate is arid.

Chemical composition and biological properties of Thymus capitatus plants from Algerian high plains: A comparative and analytical study

Abstract The Lamiaceae family contains bioactive medicinal compounds mostly used as ornamental plants and traditional medicine, as well as in the food, cosmetics, and pharmaceutical sectors. Common uses include treating high cholesterol, diabetes, respiratory diseases, heart disease, and food poisoning. These medicinal uses were linked to their components and numerous biological properties, including antimicrobial and antioxidants. The goal of this study was to investigate the phytochemicals and biological activities of the petroleum ether extract of Thymus capitatus plant from two different regions of eastern Algeria (Souk ahras and Guelma), as well as to extract volatile oils using a Clevenger device and then analyze by using GC-MS. The results revealed that the total amount of phenolic compounds was better in the phenolic extract of Souk Ahras (3.41 mg GAE g−1), while the amount of flavonoid compounds was higher in the region of Guelma (26.31 mg QE g−1). Following the quantification of phenolic compounds by HPLC, we observed that the phenolic extracts contained most of the standard compounds in variable proportions. Furthermore, we tested the antioxidant activity of the phenolic compounds electrochemically with the cyclic voltammetry method. We concluded that the highest antioxidant content was recorded in the Guelma region extract (3.17 mg GAE g−1). We have also evaluated the antioxidant activity by a chemical method using 2,2-diphenyl-1-picrylhydrazyl, and the results showed that the Guelma extract exhibited a high effectiveness in terms of IC50% values. When extracting the volatile oils, it was found that the highest yield was in the Guelma region

Phytochemical Profiles and Biological Activities of Plant Extracts from Aromatic Plants Cultivated in Cyprus.

Medicinal and aromatic plants' properties, still an interesting research area, are attributed to the presence of various specialized products that possess important pharmacological activities. In the present study, six medicinal/aromatic plants (Sideritis cypria, Origanum dubium, Melissa officinalis, Mentha piperita, Thymus capitatus, and Salvia fruticosa) were evaluated for their phytochemical and nutritive composition, as well as their biological activities, including antioxidant, antimicrobial, and cytotoxic properties. The results obtained indicate that M. piperita was rich in proteins and minerals such as N and Mg, while S. cypria accumulated more K, Na, P, and Ca. The highest content of phenols and flavonoids was observed in M. piperita, followed by O. dubium and T. capitatus, which eventually influenced their high antioxidant capacity. NMR screening revealed the presence of (i) triterpenoids and hydroxycinnamic acid derivatives in M. officinalis; (ii) terpenoids, flavonoids, and phenolic acid derivatives in S. fruticosa; (iii) flavonoids and phenolic acid derivatives in M. piperita; (iv) phenolic monoterpenes in O. dubium and T. capitatus; and (v) terpenoids, flavones, and phenylethanoid glycosides in S. cypria. The results of the antimicrobial activity showed that the tested samples overall had quite good antimicrobial potential. High antibacterial activity was found in O. dubium and T. capitatus, while O. dubium and S. cypria exhibited great antifungal activities. The studied species also had an important effect on the viability of female-derived and colon cancer cells. In particular, in colon cancer cells, the extracts from T. capitatus, M. officinalis, M. piperita, and S. fruticosa exhibited a stronger effect on cell viability in the more metastatic cell line at significantly lower concentrations, indicating an important therapeutic potential in targeting highly metastatic tumors. This finding is worth further investigation. The present study unveiled interesting phytochemical profiles and biological properties of the six medicinal/aromatic plants, which should be further explored, contributing to green chemistry and the possible creation of natural health products for humans' health/nutrition and additives in cosmetics.

Thymbra capitata L. hydrolate as a washing solution for controlling Listeria monocytogenes and spoilage microorganisms on rocket salad

Ready-to-eat (RTE) vegetables, including fresh-cut ones, are exposed to the risk of the foodborne pathogen Listeria monocytogenes. Nowadays, fresh-cut products are widely consumed because of their convenience. Nevertheless, effective washing treatments are required for their preparation, to maintain freshness and microbiological safety. Currently, natural substances are increasingly demanded as alternatives to traditional synthetic washing agents. Therefore, this study investigates the application of Thymbra capitata hydrolate as washing solution for rocket salad (Eruca sativa) stored at 4 °C for 48 h, to evaluate a potential application both during the production process of fresh-cut vegetables, and also at the domestic level. The hydrolate applied at a concentration of 500 μL/mL for 5 min allowed to reduce L. monocytogenes load of about 1 log CFU/g at each time of analysis, and to determine a significant reduction of microbial groups normally found on rocket salad, particularly total mesophilic and psychrotrophic counts. The treatment showed no negative effects on pH, aw, and colour of the rocket salad. At a sensory level, the differences among control and treated samples were minimally perceived only on the first day of analysis but disappeared over time. Therefore, this alternative washing treatment revealed to counteract L. monocytogenes growth and to help maintaining the quality of rocket salad. Hence, it could be optimized for a concrete application, also considering the enhancement of the antilisterial activity, the sustainability and low cost of the hydrolate, which represents a by-product from the production of essential oils.

Effect of Some Medicinal Plants Aqueous Extracts on Two Species of Two Plant Pathogenic Bacteria Pseudomonas savastanoi and Xanthomonas campestris

Mouhanna, A.M., M.A.R. Drakly, M.A. Abou Hasan and H.N.H. Al-Obaydi. 2024. Effect of Some Medicinal Plants Aqueous Extracts on Two Species of Two Plant Pathogenic Bacteria Pseudomonas savastanoi and Xanthomonas campestris. Arab Journal of Plant Protection, 42(3): 382-386. https://doi.org/10.22268/AJPP-001254 This study aimed to evaluate the effect of aqueous extracts of some medicinal plants naturally present in Jableh region, Lattakia governorate on two plant pathogenic bacteria, Pseudomonas savastanoi and Xanthomonas campestris. The inhibitory effect of the bacteria was measured by the diameter length of the inhibition zone around the disc treated with the extract. The aqueous extracts of Ocimum canum, Salvia sclarea, Origamum tytthanthum and Thymus serpyllum showed a significantly higher inhibitory effect on P. savastanoi compared to their effect on X. campestris. Aqueous extracts of Coridothymus capitatus and Majorana syriaca showed similar inhibition effect on the two studied bacteria species. The highest inhibition rate was 99.975 and 99.997% for Coridothymus capitatus and Majorana syriaca extracts against X. campestris and P. savastanoi, respectively, whereas the lowest inhibition rate was for Thymus serpyllum extracts with 25.0 and 16.7% inhibition rate against P. savastanoi and X. campestris, respectively. Results indicate the importance of using these aqueous extracts in the control of bacterial plant diseases. However, such laboratory tests need to be confirmed by extended field trials. Keywords: Aqueous extracts, plant pathogenic bacteria, Pseudomonas savastanoi, Xanthomonas campestris, inhibitory effect.

Chemical Profile of Essential Oils of Selected Lamiaceae Plants and In Vitro Activity for Varroosis Control in Honeybees (Apis mellifera).

The most significant ectoparasitic mite of honeybees, Varroa destructor, has a detrimental effect on bee health and honey output. The principal strategy used by the control programs is the application of synthetic acaricides. All of this has resulted in drug resistance, which is now a major worry for beekeeping. As a result, research on alternate products and techniques for mite management is now required. The aim of this study was to determine whether essential oils (EOs) extracted from botanical species of Lamiacae, typical of the Calabria region of Southern Italy, could reduce the population of the mite V. destructor. Among the best-known genera of the Lamiaceae family are oregano, rosemary and thyme, whose EOs were employed in this study. By steam distillation, the EOs were extracted from Origanum vulgare subsp. viridulum (Martrin-Donos) Nyman, Thymus capitatus Hoffmanns. and Link, Thymus longicaulis C.Presl and Salvia rosmarinus Schleid. plant species harvested directly on the Calabrian territory in their balsamic time. Each EO went to the test in vitro (contact toxicity) against V. destructor. Fifty adult female mites, five for each EO and the positive and negative control, were used in each experimental replicate. The positive controls comprised five individuals treated to Amitraz dilute in acetone, and the negative controls included five individuals exposed to acetone alone. To create the working solution to be tested (50 μL/tube), the EOs were diluted (0.5 mg/mL, 1 mg/mL, 2 mg/mL and 4 mg/mL) in HPLC-grade acetone. After 1 h of exposure, mite mortality was manually assessed. Origanum vulgare subsp. viridulum, Thymus capitatus and Thymus longicaulis were the EOs with the highest levels of efficiency at 2 mg/mL, neutralizing (dead + inactivated), 94%, 92% and 94% of parasites, respectively. Salvia rosmarinus EO gave a lower efficacy, resulting in a percentage of 38%. Interestingly, no adverse effects were highlighted in toxicity tests on honeybees. These results show that these OEs of the Lamiaceae family have antiparasitic action on V. destructor. Therefore, they could be used, individually or combined, to exploit the synergistic effect for a more sustainable control of this parasite mite in honeybee farms.

Stability of antimicrobial, antioxidant, and functional properties of pectin‐based film incorporated with Thymus capitatus and Cinnamomum verum essential oils

AbstractBiopolymer‐based films present numerous environmental advantages. The current study aims to investigate the impact of storage time on the antimicrobial, antioxidant, and functional properties of pectin‐based films containing Thymus capitatus (TEO) and Cinnamomum verum (CEO) essential oils (EOs). Films were prepared using the solution casting method; their different properties were evaluated over 1 month at room temperature. Both types of films displayed strong antimicrobial activity against Staphylococcus aureus (S. aureus), Listeria monocytogenes (L. monocytogenes), Escherichia coli (E. coli), and Salmonella typhimurium (S. typhimurium). Pectin‐based film incorporated with CEO displayed greater antioxidant activity than film incorporated with TEO. The two EOS increased the films' elongation at break and tensile strength. However, their moisture content and thickness decreased. The antibacterial and antioxidant activities of the CEO‐ and TEO‐based films decreased after 4 weeks of storage, while moisture content increased. However, the films' mechanical parameters remained stable during the entire storage period.

Effect of Different Parameters (Treatment Administration Mode, Concentration and Phenological Weed Stage) on Thymbra capitata L. Essential Oil Herbicidal Activity

The essential oil (EO) of Thymbra capitata has been demonstrated to possess herbicidal activity and could be used as an alternative to synthetic herbicides with reduced persistence in soil and new mode of action. Nevertheless, it is necessary to determine the adequate doses for its use, the proper way for its application and the best phenological stage of weeds and crops in which the EO should be applied to obtain maximum efficacy against weeds without compromising crop production. In this work, T. capitata EO was tested at three different concentrations against weeds grown from a citrus orchard soil seedbank untreated with herbicides and against three important weed species grown in substrate to determine the efficacy of the concentrations on different weed species. All experiments were carried out under greenhouse conditions. To find out the best way for applying the EO, it was applied by irrigation and by spraying on the targeted weeds, and to verify the influence of timing, it was tested on Lolium rigidum at two different phenological stages and on wheat at a later phenological stage than weeds. The highest concentration tested (12 µL·mL−1) showed the best performance to control weeds. The more effective mode of application was by spraying on dicotyledons and by irrigation on monocotyledons at the earliest phenological stage. T. capitata EO was phytotoxic for wheat. More trials in different crops are needed to determine the best conditions for its use.