Thymus vulgaris Essential Oil and Its Biological Activity

Evaluation of Antibacterial Activity in Some Algerian Essential Oils and Selection of Thymus vulgaris as a Potential Biofilm and Quorum Sensing Inhibitor Against Pseudomonas aeruginosa

Biofilm formation and virulence factor production by Pseudomonas aeruginosa are identified as the main mechanisms of its antibiotic resistance and pathogenicity. In this context, the study of the chemical composition of three Algerian essential oils (EOs) and the screening of their antibacterial, antibiofilm, and virulence factor inhibitory activities enabled us to select the thyme EO as the best oil to control the P. aeruginosa strain isolated from hospital environments. This EO, composed essentially of thymol (55.82%) associated with carvacrol, had an anti-adhesive activity of 69.8% at a concentration of 5 µL/mL and a biofilm eradication activity of 74.86% at a concentration of 2.5 µL/mL. In addition, this EO was able to inhibit P. aeruginosa twitching motility by 100% at a concentration of 2.5 µL/mL. Pyocyanin was inhibited by 99.33% at a thyme EO concentration of 1.25 µL/mL. Rhamnolipids were significantly inhibited by 63.33% in the presence of thyme EO at a concentration of 1.25 µL/mL after 24 h of incubation. Molecular docking showed that carvacrol and thymol can bind to the three quorum sensing receptors in P. aeruginosa, RhlR, LasR, and PqsR, with good affinities, which can inhibit or modulate biofilm formation and the production of certain virulence factors.

Phytobiotics in poultry: revolutionizing broiler chicken nutrition with plant-derived gut health enhancers

As the global population continues to expand, the demand for broiler chicken production to supply safe and high-quality meat is increasing. To meet this ever-growing demand, broiler chickens with enhanced growth performance are being developed, but they often face challenges related to oxidative stress, which can adversely affect gut health. Phytobiotics, which are plant-derived feed additives known for their antimicrobial, antioxidant, immune-modulating, and growth-promoting properties, have emerged as promising natural alternatives to synthetic antibiotics. This review consolidates recent advancements in the use of phytobiotics-derived products from leaves, roots, seeds, flowers, and their extracts in broiler diets reared under standard experimental conditions, without the introduction of stressors. The focus is on elucidating the key mechanisms through which phytobiotics improve gut health, including their effects on gut morphology, integrity, microflora composition, antioxidant capacity, and immune function. The review highlights the potential of phytobiotics to revolutionize broiler nutrition by acting as natural enhancers of gut health. Research findings reveal that phytobiotics significantly improve intestinal health, and boost growth performance, offering a sustainable approach to managing to gut dysfunction. These findings indicate a potential shift in how gut-health related challenges in broilers can be addressed, moving towards natural phytobiotic therapy. However, several challenges persist. Optimizing the dosage of phytobiotics, ensuring consistent performance, and overcoming the limitations related to their extraction and application are key areas requiring further investigation. The review emphasizes the importance of continued research to refine phytobiotic formulations, explore synergistic effects, and incorporate advanced technologies such as AI-driven methods and precision nutrition to tailor feeding strategies more effectively. Additionally, the development of innovative delivery systems, such as nanoencapsulation, is suggested as a way to enhance the effectiveness and reliability of phytobiotics. By highlighting the potential of phytobiotics to revolutionize broiler nutrition, this review supports the poultry industry's shift towards antibiotic-free and sustainable dietary solutions, offering new perspectives on the future of broiler chicken production.

Enhancing Antimicrobial Activity of Thyme Essential Oil Through Cellulose Nano Crystals-Stabilized Pickering Emulsions

Essential oils (EOs), such as thyme essential oil (TEO), are widely known for their antimicrobial properties; however, their direct application in food systems is limited due to their poor stability, which affects their efficacy. This study aims to improve the stability and antimicrobial efficacy of TEO by encapsulating it in Pickering emulsions stabilized with cellulose nanocrystals (CNC). Two formulations of Pickering emulsions with 5% and 10% TEO were prepared and compared to traditional surfactant-based emulsions. The stability of the emulsions was assessed over 21 days, and particle size, zeta potential, Raman spectroscopy, and FTIR were used for characterization. The antimicrobial activity was tested against several foodborne pathogens, with minimum inhibitory concentration (MIC) values determined. The 10% TEO Pickering emulsion showed antimicrobial activity, with MIC50 values of 4096 µg/mL against Staphylococcus aureus and Escherichia coli, while the 5% TEO formulation had no effect at MIC50 > 8192 µg/mL. The CNC-stabilized Pickering emulsions exhibited superior stability, showing no phase separation over 21 days. The findings suggest that CNC-stabilized Pickering emulsions are effective at improving the stability and antimicrobial performance of TEO, making them a promising natural preservative for food packaging and safety. Further research is recommended to optimize the formulation and broaden TEO's application in food preservation.

Exploring Medicinal Plants for Antimicrobial Activity and Synergistic Effects With Doxycycline Against Bacterial Species

Medicinal plants are rich sources of bioactive compounds with diverse pharmacological properties, including antimicrobial activities. This study aimed to assess the antibiofilm potential of methanol and ethanol extracts from nine selected medicinal plants, as well as their synergistic effects with doxycycline against Bacillus strains. Standard procedures were employed to determine the phytochemical composition, total phenolic, and flavonoid contents of the extracts. The antibacterial activity was evaluated using the broth microdilution method, while biofilm formation was assessed via the microtiter plate method. Antibiofilm activity was determined using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium-bromide (MTT) assay. Combination studies were conducted using the checkerboard microdilution method. All extracts contained phenols, flavonoids, steroids, triterpenes, and anthraquinones. The methanolic extract of Psidium guajava exhibited the highest total phenolic and flavonoid contents (90.48 ± 0.55 mg GAE/g), while the ethanolic extract of Olax subscorpioidea showed the highest flavonoid content (6.48 ± 0.33 mg QE/g). Ethanol extracts of Eucalyptus globulus and Psidium guajava and methanolic extract of Syzygium jambos demonstrated significant antibacterial activity against Bacillus anthracis 34F2 Sterne strains, with a MIC value of 64 μg/mL. Biofilm formation in Bacillus strains was notably enhanced in the presence of glucose. The methanolic extract of O. subscorpioides exhibited the highest biofilm imbibition (85%), while Picralima nitida methanolic extract showed the most effective biofilm eradication (79%). The combination of Solanum torvum ethanol extract with doxycycline displayed synergistic effects against biofilm formation inhibition and eradication in all tested Bacillus strains. Taken together, Solanum torvum ethanol extract shows promise for developing new combination antibacterial therapies.

A double-sided coating paper antibacterial indicator card based on polyvinyl alcohol/sodium carboxymethyl cellulose-anthocyanins and chitosan-halloysite nanotubes loaded essential oil to monitor fish freshness

This study developed a multifunctional paper-based freshness antibacterial indicator card by dual-sided coating on conventional filter paper. The indicator coating was composed of anthocyanins from purple cabbage, and polyvinyl alcohol and sodium carboxymethyl cellulose as substrates while the antibacterial coating contained halloysite nanotubes for loaded thyme essential oil and chitosan. FT-IR, XRD, and SEM analyses revealed that the components were well-mixed, and the paper was tightly bound to the coatings through hydrogen bonds. Additionally, the coating effectively filled the porous fiber gaps in the paper, significantly enhancing the mechanical properties of the paper. The tensile strength of the coated paper was enhanced from 14.28 MPa to a range of 42.25-47.71 MPa, and the bending resistance was increased from 0.35 N·mm to a range of 1.72-1.99 N·mm compared to the uncoated paper. The addition of anthocyanins provided excellent sensitivity to pH and ammonia for the indicator card. Furthermore, the coating including halloysite nanotubes for loaded thyme essential oil exhibited antimicrobial resistance against Escherichia coli and Staphylococcus aureus. When used on fresh carp, the antibacterial indicator card not only indicated the freshness of the carp but also extended the best before date of the fish meat by 1-2 days. The indicator exhibited the most pronounced color transformation and optimal freshness indication performance when the mass fraction of anthocyanins was 2 %.

Lippia origanoides and Thymus vulgaris Essential Oils Synergize with Ampicillin against Extended-Spectrum Beta-Lactamase-Producing Escherichia coli

(1) Background: Could compounds such as monoterpenes and sesquiterpenes present in essential plant oils inhibit bacterial growth as an alternative to help mitigate bacterial resistance? The purpose of this study is evaluating the in vitro antibacterial effect of Lippia organoides EO (LEO) and Thymus vulgaris EO (TEO), individually and in combination with ampicillin, against extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli strains; (2) Methods: Experimental in vitro design with post-test. The EOs were obtained by hydrodistillation and were analyzed by GC. ESBL-producing E. coli strains used were selected from urine cultures and the blaCTX-M and blaTEM resistance genes were identified by end point PCR. The disk diffusion method was used for the susceptibility tests. The MICs and MBCs were determined by microdilution test. Finally, the interaction effect was observed by checkerboard assay; (3) Results: A 39.9% decrease in the growth of the strain thymol in TEO and 70.4% in carvacrol in LEO was shown, observing inhibition halos of 32 mm for both EOs. MICs of 632 and 892 μg/mL for LEO and 738 and 940 μg/mL for TEO were determined. Finally, it was observed that, at low doses, there is a synergistic effect between TEO + LEO and EOs + ampicillin; (4) Conclusions: The findings demonstrate that TEO and LEO have an inhibitory effect on ESBL-producing E. coli, suggesting that they are candidates for further studies in the formulation of antibiotics to reduce bacterial resistance to traditional antibiotics.

Microencapsulation to Harness the Antimicrobial Potential of Essential Oils and Their Applicability in Dairy Products: A Comprehensive Review of the Literature

This literature review explores cutting-edge microencapsulation techniques designed to enhance the antimicrobial efficacy of essential oils in dairy products. As consumer demand for natural preservatives rises, understanding the latest advancements in microencapsulation becomes crucial for improving the shelf life and safety of these products. The bibliometric analysis utilized in this review highlighted a large number of documents published on this topic in relation to the following keywords: essential oils, AND antimicrobials, AND dairy products, OR microencapsulation. The documents published in the last 11 years, between 2013 and 2023, showed a diversity of authors and countries researching this topic and the keywords commonly used. However, in the literature consulted, no study was identified that was based on bibliometric analysis and that critically evaluated the microencapsulation of essential oils and their antimicrobial potential in dairy products. This review synthesizes findings from diverse studies, shedding light on the various encapsulation methods employed and their impact on preserving the quality of dairy goods. Additionally, it discusses the potential applications and challenges associated with implementation in the dairy industry. This comprehensive analysis aims to provide valuable insights for researchers, food scientists, and industry professionals seeking to optimize the use of essential oils with antimicrobial properties in dairy formulations.

Chemical and Bioactive Evaluation of Essential Oils from Edible and Aromatic Mediterranean Lamiaceae Plants

The Lamiaceae family, which includes several well-known aromatic plants, is scientifically relevant due to its essential oils (EOs). In this work, four EOs from Mediterranean species, namely Origanum vulgare L., Rosmarinus officinalis L., Salvia officinalis L., and Thymus vulgaris L., were evaluated for their volatile profiles and the biological activity in vitro to assess their potential use in the food and cosmetic sector. GC/MS analysis revealed dominant compounds, such as carvacrol, thymol, and eucalyptol. Regarding biological action, the samples exhibited antioxidant, cytotoxic, anti-inflammatory, antimicrobial, and antifungal activities, with O. vulgare and T. officinalis standing out. T. vulgaris showed the lowest EC50 in the reducing power assay, and O. vulgare had the lowest EC50 in the DPPH assay. Most EOs also displayed excellent anti-inflammatory responses and antifungal properties, with O. vulgare and T. vulgaris also demonstrating antibacterial activity. All EOs from Mediterranean species showed cytotoxicity against tumoral cell lines. Overall, the selected EOs stood out for their interesting bioactivities, with the obtained results underscoring their potential as natural preservatives and bioactive agents in various industrial applications, including food, pharmaceuticals, and cosmetics.

Exploring Chemical Variability in the Essential Oils of the Thymus Genus

Thyme remains an indispensable herb today, finding its place in gastronomy, medicine, cosmetics, and gardens worldwide. It is highly valued in herbal remedies and pharmaceutical formulations for its antibacterial, antifungal, and antioxidant properties derived from the richness of its essential oil, which comprises various volatile components. However, climate change poses a significant challenge today, potentially affecting the quality of thyme, particularly the extracted essential oil, along with other factors such as biotic influences and the plant's geographical distribution. Consequently, complex diversity in essential oil composition was observed, also influenced by genetic diversity within the same species, resulting in distinct chemotypes. Other factors contributing to this chemodiversity include the chosen agrotechnology and processing methods of thyme, the extraction of the essential oil, and storage conditions. In this review, we provide the latest findings on the factors contributing to the chemovariability of thyme essential oil.

Effect of Light Conditions, Trichoderma Fungi and Food Polymers on Growth and Profile of Biologically Active Compounds in Thymus vulgaris and Thymus serpyllum

The research investigates the influence of different lighting conditions and soil treatments, in particular the application of food polymers separately and in combination with spores of Trichoderma consortium, on the growth and development of herbs-Thymus vulgaris and Thymus serpyllum. The metabolic analysis focuses on detecting changes in the levels of biologically active compounds such as chlorophyll a and b, anthocyanins, carotenoids, phenolic compounds (including flavonoids), terpenoids, and volatile organic compounds with potential health-promoting properties. By investigating these factors, the study aims to provide insights into how environmental conditions affect the growth and chemical composition of selected plants and to shed light on potential strategies for optimising the cultivation of these herbs for the improved quality and production of bioactive compounds. Under the influence of additional lighting, the growth of T. vulgaris and T. serpyllum seedlings was greatly accelerated, resulting in an increase in shoot biomass and length, and in the case of T. vulgaris, an increase in carotenoid and anthocyanin contents. Regarding secondary metabolites, the most pronounced changes were observed in total antioxidant capacity and flavonoid content, which increased significantly under the influence of additional lighting. The simultaneous or separate application of Trichoderma and food polymers resulted in an increase in flavonoid content in the leaves of both Thymus species. The increase in terpenoid content under supplemental light appears to be related to the presence of Trichoderma spores as well as food polymers added to the soil. However, the nature of these changes depends on the thyme species. Volatile compounds were analysed using an electronic nose (E-nose). Eight volatile compounds (VOCs) were tentatively identified in the vapours of T. vulgaris and T. serpyllum: α-pinene, myrcene, α-terpinene, γ-terpinene; 1,8-cineole (eucalyptol), thymol, carvacrol, and eugenol. Tendencies to increase the percentage of thymol and γ-terpinene under supplemental lighting were observed. The results also demonstrate a positive effect of food polymers and, to a lesser extent, Trichoderma fungi on the synthesis of VOCs with health-promoting properties. The effect of Trichoderma and food polymers on individual VOCs was positive in some cases for thymol and γ-terpinene.

Comparative analysis of chemical profiles, antioxidant, antibacterial, and anticancer effects of essential oils of two Thymus species from Montenegro

The essential oils of Thymus vulgaris (TVEO) and Thymus serpyllum (TSEO) show different biological activities. The aim of the study was to evaluate the biological activities of TVEO and TSEO from Montenegro. The main components of TVEO were p-cymene (29.52%), thymol (22.8%) and linalool (4.73%) while the main components of TSEO were p-cymene (19.04%), geraniol (11,09%), linalool (9.16%), geranyl acetate (6.49%) and borneol (5.24%). Antioxidant activity determined via DPPH for TVEO was 4.49 and FRAP 1130.27, while for TSEO it was estimated that DPPH was 4.88 μL/mL and FRAP was 701.25 μmol FRAP/L. Both essential oils were active against all tested bacteria, with the highest level of sensitivity of E. coli with MIC of 1.5625 μL/mL. Essential oils showed strong cytotoxic effects on human cancer cell lines, with IC50 values ranging from 0.20 to 0.24 μL/mL for TVEO and from 0.32 to 0.49 μL/mL for TSEO. TVEO caused apoptosis in cervical adenocarcinoma HeLa cells through activation of caspase-3 and caspase-8, while TSEO caused apoptosis through caspase-3. EOs decreased levels of oxidative stress in normal MRC-5 cells. HeLa cells treated with TVEO had reduced MMP2 expression levels, while cells treated with TSEO had lowered MMP2 and MMP9 levels. The treatment of HeLa cells with TVEO increased the levels of miR-16 and miR-34a, indicating potential tumor-suppressive properties. Our findings suggest that Thymus essential oils may be considered as good candidates for further investigation as cancer-chemopreventive and cancer-therapeutic agents.

Chromosome-level genome assembly provides insights into the genome evolution and functional importance of the phenylpropanoid-flavonoid pathway in Thymus mongolicus

BACKGROUND

Thymus mongolicus (family Lamiaceae) is a Thyme subshrub with strong aroma and remarkable environmental adaptability. Limited genomic information limits the use of this plant.

RESULTS

Chromosome-level 605.2 Mb genome of T. mongolicus was generated, with 96.28% anchored to 12 pseudochromosomes. The repetitive sequences were dominant, accounting for 70.98%, and 32,593 protein-coding genes were predicted. Synteny analysis revealed that Lamiaceae species generally underwent two rounds of whole genome duplication; moreover, species-specific genome duplication was identified. A recent LTR retrotransposon burst and tandem duplication might play important roles in the formation of the Thymus genome. Using comparative genomic analysis, phylogenetic tree of seven Lamiaceae species was constructed, which revealed that Thyme plants evolved recently in the family. Under the phylogenetic framework, we performed functional enrichment analysis of the genes on nodes that contained the most gene duplication events (> 50% support) and of relevant significant expanded gene families. These genes were highly associated with environmental adaptation and biosynthesis of secondary metabolites. Combined transcriptome and metabolome analyses revealed that Peroxidases, Hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferases, and 4-coumarate-CoA ligases genes were the essential regulators of the phenylpropanoid-flavonoid pathway. Their catalytic products (e.g., apigenin, naringenin chalcone, and several apigenin-related compounds) might be responsible for the environmental tolerance and aromatic properties of T. mongolicus.

CONCLUSION

This study enhanced the understanding of the genomic evolution of T. mongolicus, enabling further exploration of its unique traits and applications, and contributed to the understanding of Lamiaceae genomics and evolutionary biology.

Synthetic polyploidization induces enhanced phytochemical profile and biological activities in Thymus vulgaris L. essential oil

Essential oil from Thymus vulgaris L. has valuable therapeutic potential that is highly desired in pharmaceutical, food, and cosmetic industries. Considering these advantages and the rising market demand, induced polyploids were obtained using oryzalin to enhance essential oil yield. However, their therapeutic values were unexplored. So, this study aims to assess the phytochemical content, and antimicrobial, antioxidant, and anti-inflammatory activities of tetraploid and diploid thyme essential oils. Induced tetraploids had 41.11% higher essential oil yield with enhanced thymol and γ-terpinene content than diploid. Tetraploids exhibited higher antibacterial activity against all tested microorganisms. Similarly, in DPPH radical scavenging assay tetraploid essential oil was more potent with half-maximal inhibitory doses (IC50) of 180.03 µg/mL (40.05 µg TE/mg) than diploid with IC50 > 512 µg/mL (12.68 µg TE/mg). Tetraploids exhibited more effective inhibition of in vitro catalytic activity of pro-inflammatory enzyme cyclooxygenase-2 (COX-2) than diploids at 50 µg/mL concentration. Furthermore, molecular docking revealed higher binding affinity of thymol and γ-terpinene towards tested protein receptors, which explained enhanced bioactivity of tetraploid essential oil. In conclusion, these results suggest that synthetic polyploidization using oryzalin could effectively enhance the quality and quantity of secondary metabolites and can develop more efficient essential oil-based commercial products using this induced genotype.

Management of the Brain: Essential Oils as Promising Neuroinflammation Modulator in Neurodegenerative Diseases

Neuroinflammation, a pivotal factor in the pathogenesis of various brain disorders, including neurodegenerative diseases, has become a focal point for therapeutic exploration. This review highlights neuroinflammatory mechanisms that hallmark neurodegenerative diseases and the potential benefits of essential oils in counteracting neuroinflammation and oxidative stress, thereby offering a novel strategy for managing and mitigating the impact of various brain disorders. Essential oils, derived from aromatic plants, have emerged as versatile compounds with a myriad of health benefits. Essential oils exhibit robust antioxidant activity, serving as scavengers of free radicals and contributing to cellular defense against oxidative stress. Furthermore, essential oils showcase anti-inflammatory properties, modulating immune responses and mitigating inflammatory processes implicated in various chronic diseases. The intricate mechanisms by which essential oils and phytomolecules exert their anti-inflammatory and antioxidant effects were explored, shedding light on their multifaceted properties. Notably, we discussed their ability to modulate diverse pathways crucial in maintaining oxidative homeostasis and suppressing inflammatory responses, and their capacity to rescue cognitive deficits observed in preclinical models of neurotoxicity and neurodegenerative diseases.

The efficient activity of plant essential oils for inhibiting Botrytis cinerea and Penicillium expansum: Mechanistic insights into antifungal activity

Botrytis cinerea and Penicillium expansum produce deterioration in fruit quality, causing losses to the food industry. Thus, plant essential oils (EOs) have been proposed as a sustainable alternative for minimizing the application of synthetic fungicides due to their broad-spectrum antifungal properties. This study investigated the efficacy of five EOs in suppressing the growth of B. cinerea and P. expansum and their potential antifungal mechanisms. EOs of Mentha × piperita L., Origanum vulgare L., Thymus vulgaris L., Eucalyptus globules Labill., and Lavandula angustifolia Mill., were screened for both fungi. The results showed that the EO of T. vulgaris and O. vulgare were the most efficient in inhibiting the growth of B. cinerea and P. expansum. The concentration increase of all EO tested increased fungi growth inhibition. Exposure of fungi to EOs of T. vulgaris and O. vulgare increased the pH and the release of constituents absorbing 260 nm and soluble proteins, reflecting membrane permeability alterations. Fluorescence microscopic examination revealed that tested EOs produce structural alteration in cell wall component deposition, decreasing the hypha width. Moreover, propidium iodide and Calcein-AM stains evidenced the loss of membrane integrity and reduced cell viability of fungi treated with EOs. Fungi treated with EOs decreased the mitochondria activity and the respiratory process. Therefore, these EOs are effective antifungal agents against B. cinerea and P. expansum, which is attributed to changes in the cell wall structure, the breakdown of the cell membrane, and the alteration of the mitochondrial activity.

Combining microfluidics and coaxial 3D-bioprinting for the manufacturing of diabetic wound healing dressings

Diabetic foot ulcers (DFUs) are a crucial complication of diabetes, as in a diabetic wound, each step of the physiological healing process is affected. This entails a more easily infectable wound, and delayed tissue regeneration due to the inflammation that occurs, leading to a drastic decrease in the overall patient's quality of life. As a strategy to manage DFUs, skin alternatives and wound dressings are currently receiving a lot of attention as they keep the wound environment "under control", while providing bioactive compounds that help to manage infection and inflammation and promote tissue repair. This has been made possible thanks to the advent of emerging technologies such as 3D Bioprinting to produce skin resembling constructs or microfluidics (MFs) that allows the manufacture of nanoparticles (NPs) that act as drug carriers, in a prompt and less expensive way. In the present proof-of-concept study, the possibility of combining two novel and appealing techniques in the manufacturing of wound dressings has been demonstrated for first time. The novelty of this work consists in the combination of liposomes (LPs) encapsulating the active pharmaceutical ingredient (API) into a hydrogel that is further printed into a three-dimensional scaffold for wound dressing; to the knowledge of the authors this has never been done before. A grid-shaped scaffold has been produced through the coaxial 3D bioprinting technique which has allowed to combine, in one single filament, two different bioinks. The inner core of the filament is a nanocomposite hydrogel consisting of hydroxyethyl cellulose (HEC) and PEGylated LPs encapsulated with thyme oil (TO) manufactured via MFs for the first time. The outer shell of the filament, instead, is represented by a hybrid hydrogel composed of sodium alginate/cellulose nanocrystals (SA/CNC) and enriched with free TO. This provides a combination of two different release ratios of the API, a bulk release for the first 24 h thanks to the free TO in the shell of the filament and a sustained release for up to 10 days provided from the API inside the LPs. Confocal Microscopy verified the actual presence of the LPs inside the scaffold after printing and evaluation using the zone of inhibition test proved the antibacterial activity of the manufactured scaffolds against both Gram-positive and Gram-negative bacteria.

A review of the bioactive properties of Mongolian plants, with a focus on their potential as natural food preservatives

Consumers have recently preferred food that is easy to make and of excellent quality, as well as food that is safe, natural, and minimally processed, but has a longer shelf life. Food deteriorates over time as a result of microbiological, chemical, or physical changes. Phytochemicals derived from medicinal and food plants have long been recognized for their biological activity to protect plants. These bioactivities are designed to increase the shelf life of food while inhibiting the growth of microorganisms. The use of natural plant food preservatives containing bioactive compounds as health-promoting agents is particularly intriguing. Furthermore, due to their effectiveness against food spoilage and foodborne pathogens, natural plant-origin antimicrobial compounds have been investigated as alternatives to synthetic antimicrobial compounds for preserving food quality. This review focused on the plant composition and properties that can be utilized as a natural food preservative, as well as the possibilities of using Mongolian medicinal plants.

Larvicidal activity in vitro of essential oils against Cochliomyia hominivorax

Cochliomyia hominivorax, from the family Calliphoridae, is responsible for causing most myiases in domesticated animals in Brazil. As alternatives to conventional treatments, essential oils (EOs) could possibly be used as natural control of ectoparasites. The aim of this study was to evaluate the in vitro activity of EOs from Salvia sclarea L., Rosmarinus officinalis L., Lavandula hybrida Reverchon, Citrus bergamia Risso, Citrus paradisi L., Juniperus virginiana L., Copaifera reticulata Ducke, Illicium verum Hook f., Pelargonium roseum, Cymbopogon winterianus Jowitt, Cymbopogon flexuosus Steud, Eugenia caryophyllus Spreng, Cinnamomum cassia Presl, Thymus vulgaris L. and Origanum vulgare L. against third-instar larvae of C. hominivorax. To evaluate the mortality rate, filter paper tests were performed at different concentrations and verified after 24 h and 48 h. Essential oils of T. vulgaris, O. vulgare and I. verum induced 100% mortality in the screening test, and their main active components (thymol, carvacrol and anethol, respectively) were also tested alone. In this new test, lethal concentrations (LC50) after 24 h and 48 h, respectively, were 407.1 and 314.2 µg.cm-² for T. vulgaris, 540.9 and 253.8 µg.cm-² for O. vulgare, 314.2 µg.cm-² (after 48 h) for I. verum, 255.6 and 102.3 µg.cm-² for thymol, 970.5 and 931.1 µg.cm-2 for carvacrol and 559.4 µg.cm-2 (after 48 h) for anethol. These results showed the potential of these EOs and their main components for development of ectoparasiticides for veterinary use, especially T. vulgaris EO and thymol.

The effect of induced polyploidy on phytochemistry, cellular organelles and the expression of genes involved in thymol and carvacrol biosynthetic pathway in thyme (Thymus vulgaris)

Induced polyploidy usually results in larger vegetative and reproductive plant organs. In order to study the effect of chromosome doubling on Thymus vulgaris, three levels of colchicine concentration including 0.1, 0.3 and 0.5% (w/v) were applied for 6, 12 and 24 hours on apical meristem of 2- and 4-leaf seedlings. Ploidy level was evaluated by flow cytometry and microscopic chromosome counting. Chemical composition of essential oils extracted by hydro-distillation was analyzed by gas Chromatography/mass spectrometry (GC/MS) and gas Chromatography (GC). The application of 0.3% colchicine at 4-leaf seedling for 6 hours resulted in the highest survival rate and the highest number of tetraploid plants. Cytogenetic and flow cytometry analyses confirmed the increase of chromosome number from 2n=2x=30 in diploids to 2n=4x=60 in induced tetraploids. Tetraploid plants had larger leaves, taller and thicker stems, dense branching, longer trichome, larger stomata, larger guard cells, and decreased number of stomata. The number of chloroplasts and mitochondria increased significantly in tetraploid plants by 1.66 and 1.63 times, respectively. The expression of CYP71D178, CYP71D180 and CYP71D181 increased in tetraploids by 3.27, 7.39 and 2.15 times, respectively, probably resulting in higher essential oil compounds, as tetraploids outyielded the diploid plants by 64.7% in essential oil, 40.9% in thymol and 18.6% in carvacrol content.

Antimicrobial activity of essential oils against Staphylococcus aureus and Staphylococcus chromogenes isolated from bovine mastitis

Staphylococcus aureus and Staphylococcus chromogenes are pathogens frequently detected in bovine mastitis. Treatment and prevention of this disease have been usually carried on with antimicrobials. However, the emergence of bacterial isolates with antimicrobial resistance has aroused interest in new therapeutic alternatives. Plant essential oils (EOs) have been largely studied as antibacterial treatments. In the present study, EOs from five plants were evaluated for their antibacterial activities against S. aureus and S. chromogenes. Bacterial isolates were obtained in a previous study of clinical cases of bovine mastitis. EOs from lemongrass, eucalyptus, lavender, peppermint, and thyme were obtained by hydrodistillation and their chemical compositions were evaluated by gas chromatography (GC). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated for all EOs. The results demonstrated that citral (40.9%), myrcene (24.7%), and geraniol (1.9%) were detected in lemongrass EO; 1,8-cineole (76.9%), α-pinene (8.2%), and ledene (5.1%) in eucalyptus EO; 1,8-cineole (45.2%), camphor (18.2%), and fenchone (14.6%) in lavender EO; L-menthol (38.5%), menthofuran (16.3%), and citronellal (10.6%) in peppermint EO; and thymol (44.2%), p-cymene (24.6%) and 1,8-cineole (9.9%) in thyme EO. More effective antibacterial activities were observed only with the use of lemongrass (MIC and MBC ranging from 0.39 to 3.12 mg/mL and 0.39 to 6.35 mg/mL, respectively) and thyme (MIC and MBC ranging from 0.39 to 1.56 mg/mL and 0.39 to 3.12 mg/mL, respectively). Peppermint, lavender and eucalyptus EOs did not show bactericidal activities. In conclusion, lemongrass and thyme EOs are promising antibacterial alternatives against Staphylococcus species associated with bovine mastitis.

Antibacterial activity of Thymus vulgaris (thyme) essential oil against strains of Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus saprophyticus isolated from meat product

Meat products represent an important component of the human diet and are a good source of nutrients. Food-borne microorganisms are the main pathogens that cause human diseases as a result of food consumption, especially products of animal origin. The objective of the present research was to verify the antibacterial activity of the essential oil of Thymus vulgaris against strains of Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus saprophyticus isolated from meat products. For this, the analyses of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were performed in microdilution plates. The association of the product with antimicrobials was also studied using disk diffusion. And the anti-adherent activity, which was determined in the presence of sucrose, in glass tubes. Thyme oil showed a strong inhibitory activity against K. pneumoniae, P. aeruginosa and S. saprophyticus, with the MIC values ranging from 64 to 512 μg/mL, and bactericidal effect for most strains, with MBC values ranging from 256 to 1,024 μg/mL. T. vulgaris oil exhibited varied interactions in association with the antimicrobials, with synergistic (41.67%), indifferent (50%) and antagonistic (8.33%) effects. Regarding the anti-adherent activity, the test product was effective in inhibiting the adherence of all bacterial strains under study. Therefore, thyme oil presents itself as an antibacterial and anti-adherent agent against K. pneumoniae, P. aeruginosa and S. saprophyticus, being a natural product that can represent an interesting alternative in the efforts to combat foodborne diseases.

Insights into Antimicrobial and Anti-Inflammatory Applications of Plant Bioactive Compounds

Plants have long been thought to contribute to health promotion due to their fiber and phenolic content, as well as their inherent biological potential. The bioactive derivatives of medicinal plants are a valuable resource in the fight against serious diseases all around the world. The present review focuses on the current state of knowledge on the usage and medicinal applications of plant bioactives. Issues concerning the effect of aromatic plant derivatives on human gut microbiota and their antimicrobial and anti-inflammatory potentials are discussed and worth further exploring.

Natural Products for the Prevention and Treatment of Common Cold and Viral Respiratory Infections

The common cold is generally considered a usually harmless infectious disease of the upper respiratory pathway, with mostly mild symptoms. However, it should not be overlooked, as a severe cold can lead to serious complications, resulting in hospitalization or death in vulnerable patients. The treatment of the common cold remains purely symptomatic. Analgesics as well as oral antihistamines or decongestants may be advised to relieve fever, and local treatments can clear the airways and relieve nasal congestion, rhinorrhea, or sneezing. Certain medicinal plant specialties can be used as therapy or as complementary self-treatment. Recent scientific advances discussed in more detail in this review have demonstrated the plant's efficiency in the treatment of the common cold. This review presents an overview of plants used worldwide in the treatment of cold diseases.

On the Future Perspectives of Some Medicinal Plants within Lamiaceae Botanic Family Regarding Their Comprehensive Properties and Resistance against Biotic and Abiotic Stresses

Lamiaceae is one of the largest botanical families, encompassing over 6000 species that include a variety of aromatic and medicinal spices. The current study is focused on three plants within this botanical family: basil (Ocimum basilicum L.), thyme (Thymus vulgaris L.), and summer savory (Satureja hortensis L.). These three species contain primary and secondary metabolites such as phenolic and flavonoid compounds, fatty acids, antioxidants, and essential oils and have traditionally been used for flavoring, food preservation, and medicinal purposes. The goal of this study is to provide an overview of the nutraceutical, therapeutic, antioxidant, and antibacterial key features of these three aromatics to explore new breeding challenges and opportunities for varietal development. In this context, a literature search has been performed to describe the phytochemical profile of both primary and secondary metabolites and their pharmacological uses, as well as to further explore accession availability in the medicine industry and also to emphasize their bioactive roles in plant ecology and biotic and abiotic stress adaptability. The aim of this review is to explore future perspectives on the development of new, highly valuable basil, summer savory, and thyme cultivars. The findings of the current review emphasize the importance of identifying the key compounds and genes involved in stress resistance that can also provide valuable insights for further improvement of these important medicinal plants.

Biological Activity of Hybrid Molecules Based on Major Constituents of Cinnammomun verum and Thymus vulgaris Essential Oils

Plants have been used by humans since ancient times due their antimicrobial and medicinal properties. Essential oils (EOs) are complex mixtures of secondary plant metabolites, including terpenoids, phenylpropanoids, and other aromatic compounds. Cinnamomun verum and Thyme vulgaris EOs and their organic extracts exert numerous biological activities because of their major compounds, particularly thymol, carvacrol, eugenol, and benzoic and cinnamic acid. The structural motifs presented by these phytochemicals are responsible for their biological activities. Modification or hybridization of these structures could lead to new bio-based compounds with improved efficacy or multiple modes of action. In this work, we aimed to develop reliable methods of obtaining six hybrid molecules from the major constituents of C. verum and T. vulgaris EOs. For the first time, we tested their efficacy in the inhibition of the mycelium growth and spore germination of two of the most important phytopathogenic fungi, Fusarium oxysporum and Colletotrichum gloeosporioides, and one opportunistic human pathogen, Aspergillus niger. The cytotoxic activity of the obtained hybrids was assessed using the brine shrimp lethality assay. In addition, we report for the first time a biocatalytic process for the obtention of these bioactive hybrid molecules. The results of this work enable the possibility of using hybrid molecules based on the major constituents of EOs as active ingredients in strategic industries such as agriculture, aquaculture, and pharmaceuticals.

New Insights into the Research of Bioactive Compounds from Plant Origins with Nutraceutical and Pharmaceutical Potential

Plant bioactive compounds are essential for human health due to their multiple biological effects, such as antioxidant, anticarcinogenic, antiallergenic, anti-inflammatory, antimutagenic, and antimicrobial activities, which can have beneficial effects on various noncommunicable diseases, such as autoimmune, inflammatory, cardiovascular, cancer, metabolic, and neurodegenerative diseases [...].

Essential Oils in the Treatment of Various Types of Acne-A Review

Acne is a chronic, common disease that poses a significant therapeutic, psychological and social problem. The etiopathogenesis of this disease is not fully understood. Drugs used in general and external therapy should have anti-seborrhoeic, anticomadogenic, bactericidal, bacteriostatic, and anti-inflammatory properties. Acne treatment is often associated with the long-term use of antibiotics, contributing to the global antibiotic resistance crisis. In order to solve this problem, attention has been paid to essential oils and their terpene components with potent antimicrobial, anti-inflammatory, and antioxidant properties. Research shows that certain essential oils effectively reduce inflammatory acne lesions through mechanisms related to the sebaceous glands, colonization of Cutibacterium acnes, and reactive oxygen species (ROS). An example is tea tree oil (TTO), a more commonly used topical agent for treating acne. TTO has antimicrobial and anti-inflammatory activity. The paper presents the latest scientific information on the activity and potential use of specific essential oils in treating acne. Evidence of antibacterial, anti-inflammatory, and antioxidant activity of several essential oils and their main components was presented, indicating the possibility of using them in the treatment of acne.

Towards Green Strategies of Food Security: Antibacterial Synergy of Essential Oils from Thymus vulgaris and Syzygium aromaticum to Inhibit Escherichia coli and Staphylococcus aureus Pathogenic Food Isolates

Foodborne diseases continue to represent an important public health issue. The control of food spoilage and pathogenic microorganisms is achieved mainly by synthetic chemicals, unfortunately associated to several undesirable aspects. The growing requirement for new and safe alternative strategies has resulted in the research of agents from natural sources with antimicrobial properties, such as essential oils (EOs). This study's purpose was to define the antibacterial profile of thyme (Thymus vulgaris) and cloves (Syzygium aromaticum) essential oils against both Gram-positive and Gram-negative important foodborne pathogenic bacteria. Gas chromatography mass spectrometry analysis was performed for EOs' chemical composition. Qualitative in vitro antimicrobial assays (i.e., agar well diffusion method and disk-volatilization method) allowed for verification of the efficacy of EOs, used individually and in binary combination and both in liquid and vapor phase, against Staphylococcus aureus and Escherichia coli food isolates. Minimal inhibitory concentrations and minimal bactericidal concentration values have been used to quantitatively measure the antibacterial activity of EOs, while the fractional inhibitory concentration index has been considered as a predictor of in vitro antibacterial synergistic effects. The microbiological tests suggest that thyme and cloves EOs, rich in bioactive compounds, are able to inhibit the growth of tested foodborne bacteria, especially in vapor phase, also with synergistic effects. Results provide evidence to consider the tested essential oils as promising sources for development of new, broad-spectrum, green food preservatives.

Effects of EOs vs. Antibiotics on E. coli Strains Isolated from Drinking Waters of Grazing Animals in the Upper Molise Region, Italy

The health and safety of grazing animals was the subject of microbiological monitoring on natural source of drinking waters in the upper Molise region, Italy. Surface water samples, on spring-summer season, were collected and submitted to analyses using sterile membrane filtration, cultural medium, and incubation. The level of environmental microbial contamination (Total viable microbial count, yeasts and fungi) and faecal presence (Total and faecal coliforms, E. coli, and Salmonellae spp.) were carried out. By the selective microbiological screening, twenty-three E. coli strains from drinking waters were isolated and submitted to further studies to evaluate antibiotic resistance by antibiograms vs. three animal and two diffuse human antibiotics. Furthermore, after a fine chemical characterization by GC and GC-MS, three Essential Oils (EOs) of aromatic plants (Timus vulgaris, Melaleuca alternifolia, Cinnamomun verum) aromatograms were performed and results statistically compared. The effects of EOs vs. antibiotics on E. coli strains isolated from drinking waters showed a total absence of microbial resistance. In our experimental conditions, even if some suggestions will be further adopted for better managements of grazing animals, because the health and safety represent a guarantee for both animals and humans.

GC, GC/MS Analysis, and Biological Effects of Essential Oils from Thymus mastchina and Elettaria cardamomum

Spanish marjoram (Thymus mastichina) and cardamom (Elettaria cardamomum) are traditional aromatic plants with which several pharmacological properties have been associated. In this study, the volatile composition, antioxidative and antimigratory effects on human breast cancer (MDA-MB-468 cell line), antimicrobial activity, and antibiofilm effect were evaluated. Results obtained via treatment of human breast cancer cells generally indicated an inhibitory effect of both essential oils (EOs) on cell viability (after long-term treatment) and antioxidative potential, as well as the reduction of nitric oxide levels. Antimigratory effects were revealed, suggesting that these EOs could possess significant antimetastatic properties and stop tumor progression and growth. The antimicrobial activities of both EOs were determined using the disc diffusion method and minimal inhibition concentration, while antibiofilm activity was evaluated by means of mass spectrometry. The best antimicrobial effects of T. mastichina EO were found against the yeast Candida glabrata and the G⁺ bacterium Listeria monocytogenes using the disc diffusion and minimal inhibitory concentration methods. E. cardamomum EO was found to be most effective against Pseudomas fluorescens biofilm using both methods. Similarly, better effects of this oil were observed on G^- compared to G⁺ bacterial strains. Our study confirms that T. mastichina and E. cardamomum EOs act to change the protein structure of older P. fluorescens biofilms. The results underline the potential use of these EOs in manufactured products, such as foodstuffs, cosmetics, and pharmaceuticals.

Effect of Thymus vulgaris L. essential oil and thymol on the microbiological properties of meat and meat products: A review

Since foodborne diseases are often considered as one of the biggest public health threats worldwide, effective preservation strategies are needed to inhibit the growth of undesirable microorganisms in food commodities. Up to now, several techniques have been adopted for the production of safe and high-quality products. Although the traditional methods can improve the reliability, safety, and shelf-life of food, some of them cannot be applied without rising health concerns. Thereby, the addition of various phytochemicals has gained much attention during the last decades, especially for meat products that may be contaminated with pathogenic and spoilage organisms. Thyme (Thymus vulgaris L.), as an important medicinal and culinary herb, is a promising source of bioactive compounds that have a great impact on the microbiological stability of meat by suppressing the undesirable microflora. However, the use of these antimicrobials is still facing difficulties due to their aromatic properties and variable efficacy against targeted species. In this paper, we provide an overview on the potential effects of thyme essential oil (EO) and thymol as bio-preservative agents in meat products. Furthermore, this paper provides insights into the limitations and current challenges of the addition of EOs and their constituents to meat commodities and suggests viable solutions that can improve the applicability of these phytochemicals.

Antioxidant and Anti-Inflammatory Effects of Thyme (Thymus vulgaris L.) Essential Oils Prepared at Different Plant Phenophases on Pseudomonas aeruginosa LPS-Activated THP-1 Macrophages

Thyme (Thymus vulgaris L.) essential oil (TEO) is widely used as an alternative therapy especially for infections of the upper respiratory tract. TEO possesses antiviral, antibacterial, and antifungal properties. The emerging antibiotic resistance of bacterial strains, including Pseudomonas aeruginosa, has prompted the urge to find alternative treatments. In the present study, we examined the anti-inflammatory and antioxidant effects of thymol, the main compound of TEO, and two TEOs prepared at the beginning and at the end of the flowering period that may make these oils promising candidates as complementary or alternative therapies against P. aeruginosa infections. The activity measurements of the antioxidant enzymes peroxidase (PX), catalase (CAT), and superoxide dismutase (SOD) as well as the determination of total antioxidant capacity of P. aeruginosa-activated THP-1 cells revealed that thymol and both TEOs increased CAT and SOD activity as well as the antioxidant capacity of the THP-1 cells. The measurements of the proinflammatory cytokine mRNA expression and secreted protein level of LPS-activated THP-1 cells showed that from the two TEOs, only TEO prepared at the beginning of the flowering period acted as a potent inhibitor of the synthesis of IL-6, IL-8, IL-β, and TNF-α. Our results suggest that not only thymol, but also the synergism or the antagonistic effects of the additional compounds of the essential oils are responsible for the anti-inflammatory activity of TEOs.

Role of Litsea cubeba Essential Oil in Agricultural Products Safety: Antioxidant and Antimicrobial Applications

The essential oil from Litsea cubeba (LCEO) has good antioxidant, antimicrobial, anti-insect properties, which gives it the potential for use as a natural additive to food resources and food products in order to prevent spoilage and extend shelf life. In this study the biological activity related to food preservation was observed. The main volatile organic compounds were geranial (39.4%), neral (29.5%), and limonene (14.3%). Antioxidant activity was 30.9%, which was equal to 167.94 µg of Trolox per mL of sample. Antimicrobial activity showed the strongest inhibition against Serratia marcescens by disk diffusion method and minimum inhibitory concentrations MIC 50 and MIC 90 were the lowest for Micrococcus luteus with values 1.46 and 3.52 µL/mL, respectively. Antimicrobial activity of the LCEO vapor phase showed strong inhibition of microorganisms on apples, pears, potatoes, and kohlrabies. Over 50% of gram-positive and gram-negative bacteria and yeasts were inhibited by a concentration of 500 µL/mL. The inhibition of microorganisms was concentration dependent. Anti-insect activity was also strong, with 100% lethality of Pyrrhocoris apterus at a concentration of 25%. These results suggest that LCEO could be potentially used as a food preservative.

Effect of Essential Oils Supplemented with Caprylic Acid and Sodium Chloride against Faecal ESBL-Producing Escherichia coli Isolated from Pigs

The purpose of the present investigation was to compare the antibacterial activity of six commercial and lab-scale extracted essential oils (EOs) alone or in combination with caprylic acid (CA) and sodium chloride (NaCl) against faecal Escherichia coli with and without extended-spectrum beta-lactamase (ESBL) encoding genes, and of isolates classified as multidrug-resistant (MDR). Gas chromatography−mass spectrometry (GC−MS) was used for the analysis of chemical composition of EOs, while the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays were carried out to elucidate the antibacterial activity of non-supplemented and supplemented EOs against different resistance levels of E. coli strains. The main compounds in commercial EOs were aromatic monoterpenoids (30−56%) and p-cymene (8−35%), while the main compounds in the lab-scale EOs were aromatic monoterpenoids (12−37%) and γ-terpinene (18−22%). Commercial EOs exhibited superior inhibitory activity of E. coli in comparison to lab-scale produced EOs. Antibacterial activity of EOs was significantly enhanced by enrichment of the EOs with NaCl (p < 0.001) or CA (p = 0.012). Most of the non-supplemented EOs exhibited lower activity against MDR and ESBL producing E. coli. In contrast, EOs supplemented with CA and especially NaCl was equally effective against ESBL and non-ESBL as well as MDR and non-MDR E. coli. It was found that supplementation of EOs with NaCl could enhance the antibacterial activity towards ESBL and MDR E. coli isolates. However, additional studies are needed to clarify the potential risks of developing resistance.

Chemical and Biological Characterization of Melaleuca alternifolia Essential Oil

The essential oil of Melaleuca alternifolia, commonly known as tea tree oil, has many beneficial properties due to its bioactive compounds. The aim of this research was to characterize the tea tree essential oil (TTEO) from Slovakia and its biological properties, which are specific to the chemical composition of essential oil. Gas chromatography/mass spectroscopy revealed that terpinen-4-ol was dominant with a content of 40.3%. γ-Terpinene, 1,8-cineole, and p-cymene were identified in contents of 11.7%, 7.0%, and 6.2%, respectively. Antioxidant activity was determined at 41.6% radical inhibition, which was equivalent to 447 μg Trolox to 1 mL sample. Antimicrobial activity was observed by the disk diffusion method against Gram-positive (G⁺), Gram-negative (G^-) bacteria and against yeasts, where the best antimicrobial activity was against Enterococcus faecalis and Candida albicans with an inhibition zone of 10.67 mm. The minimum inhibitory concentration showed better susceptibility by G⁺ and G^- planktonic cells, while yeast species and biofilm-forming bacteria strains were more resistant. Antibiofilm activity was observed against Pseudomonas fluorescens and Salmonella enterica by MALDI-TOF, where degradation of the protein spectra after the addition of essential oil was obtained. Good biological properties of tea tree essential oil allow its use in the food industry or in medicine as an antioxidant and antimicrobial agent.

Gluten-Free Bread and Bakery Products Technology

Gluten, a protein fraction from wheat, rye, barley, oats, their hybrids and derivatives, is very important in baking technology. The number of people suffering from gluten intolerance is growing worldwide, and at the same time, the need for foods suitable for a gluten-free diet is increasing. Bread and bakery products are an essential part of the daily diet. Therefore, new naturally gluten-free baking ingredients and new methods of processing traditional ingredients are sought. The study discusses the use of additives to replace gluten and ensure the stability and elasticity of the dough, to improve the nutritional quality and sensory properties of gluten-free bread. The current task is to extend the shelf life of gluten-free bread and bakery products and thus extend the possibility of its distribution in a fresh state. This work is also focused on various technological possibilities of gluten-free bread and the preparation of bakery products.