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Staphylococcus aureus and Pseudomonas aeruginosa are the most common bacteria co-isolated from chronic infected wounds. Their interactions remain unclear but this coexistence is beneficial for both bacteria and may lead to resistance to antimicrobial treatments. Besides, developing an in vitro model where this coexistence is recreated remains challenging, making difficult their study. The aim of this work was to develop a reliable polymicrobial in vitro model of both species to further understand their interrelationships and the effects of different antimicrobials in coculture. In this work, bioluminescent and fluorescent bacteria were used to evaluate the activity of two antiseptics (chlorhexidine and thymol) against these bacteria planktonically grown, or when forming single and mixed biofilms. At the doses tested (0.4-1,000 mg/L), thymol showed selective antimicrobial action against S. aureus in planktonic and biofilm states, in contrast with chlorhexidine which exerted antimicrobial effects against both bacteria. Furthermore, the initial conditions for both bacteria in the co-culture determined the antimicrobial outcome, showing that P. aeruginosa impaired the proliferation and metabolism of S. aureus. Moreover, S. aureus showed an increased tolerance against antiseptic treatments when co-cultured, attributed to the formation of a thicker mixed biofilm compared to those obtained when monocultured, and also, by the reduction of S. aureus metabolic activity induced by diffusible molecules produced by P. aeruginosa. This work underlines the relevance of polymicrobial populations and their crosstalk and microenvironment in the search of disruptive and effective treatments for polymicrobial biofilms. [ABSTRACT FROM AUTHOR]

Introduction: Klebsiella poses a significant global threat due to its high antibiotic resistance rate. In recent years, researchers have been seeking alternative antimicrobial agents, leading to the introduction of natural compounds such as monoterpenes, specifically thymol and carvacrol. This review aims to illustrate the potential antimicrobial, anti-biofilm, and synergistic traits of thymol and carvacrol in combat against Klebsiella. Methods: Searching PubMed, Scopus, and Web of Science, we reviewed available evidence on the antibacterial effects of thymol, carvacrol, or combined with other compounds against Klebsiella until May 2024. Reference checking was performed after the inclusion of studies. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), fractional inhibitory concentration (FIC), and anti-biofilm activity were gathered, and the MBC/MIC ratio was calculated to assess the bactericidal efficacy. Results: We retrieved 38 articles out of 2,652 studies screened. The gathered data assessed the anti-microbial activity of thymol, carvacrol, and both compounds in 17, 10, and 11 studies, respectively. The mean (± standard deviation) non-weighted MIC was 475.46 μg/mL (±509.95) out of 60 MIC for thymol and 279.26 μg/mL (±434.38) out of 68 MIC for carvacrol. Thymol and carvacrol showed anti-biofilm activities in the forms of disruption, inhibition, and mass reduction of biofilms. The MBC/MIC ratio was lower than 4 in 45 out of 47 cases, showing high bactericidal efficacy. FIC values were gathered for 68 combinations of thymol and carvacrol with other compounds, and they were mostly synergistic or additive. Conclusion: Thymol and carvacrol alone or in combination with other compounds, specifically known antibiotics, show great antimicrobial activity. [ABSTRACT FROM AUTHOR]

Carum copticum L. is one of the medicinal plants belonging to the Apiaceae family that has significant pharmaceutical properties. This plant was first described by Carl von Linnaeus. Carum copticum possesses antimicrobial, antiseptic, antihypertensive, antihyperlipidemic, carminative, antiviral, anesthetic, antitussive, bronchodilatory, hepatoprotective and antiulcer effects which are practical nowadays. Considering the importance of C. copticum, we studied evaluation of titanium dioxide nanoparticles (TiO2 NPs) and light spectrum such as white, white–blue and blue on improvement of antioxidant properties and essential oils. For this purpose, the seedlings were grown under controlled hydroponic conditions and after 3 weeks treated by spraying of different TiO2 NPs concentrations (0, 100, 200, 300 and 400 ppm) on their leaves and then treated by the light. Afterwards, some of the physiological, phytochemical parameters and essential oils were analyzed. The results showed that 300 ppm TiO2 NPs combined with white–blue light is significantly the most effective treatments for improving the quantity of physiological and phytochemical parameters in C. copticum. Furthermore, TiO2 NPs and light play the role of elicitor that can induce remarkable enhanced changes in the desired parameters. In addition, studing of the essential oil contents of C. copticum using Gas chromatography–mass spectrometry demonstrated that thymol, α-pinene and γ-terpinene are the main essential oil components of this plant and the treated seedlings under 300 ppm TiO2 NPs and white–blue light together showed a significant increase in the contents of thymol and γ-terpinene. Besides, α-pinene enhanced considerably at 400 ppm TiO2 NPs combined with white–blue light spectrum.Key message: Titanium dioxide nanoparticles combined with the light spectrum may be considered as proper elicitors to enhance secondary metabolites and essential oils of C. copticum (L.). [ABSTRACT FROM AUTHOR]

The therapeutic efficacy of various concentrations and combinations of thymol, Artemisia absinthium oil and nanoparticle ozone against Nosemosis caused by Nosema ceranae in honey bees was studied. Two-hundred colonies were examined for N. ceranae positivity and negativity under light microscopy; 119 colonies were positive and 81 colonies were negative for Nosemosis. The study evaluated the therapeutic efficacy of 17 different combinations against N. ceranae. Nine of the 17 combinations were applied by spray to frames and eight were applied orally (combinations added to the sugar syrup reservoir) to the hives. Each of the 17 combinations was prepared in 1,000 ml from (2%, 3% and 5%) of thymol and (2% and 3%) A. absinthium oil, and 1,000, 2,000, 4,000, and 8,000 ppm concentrations of nanoparticle ozone. N. ceranae spore counts before and after the treatment were counted on Neubauer thoma slides by the digestion method, and the efficacy of the combinations was determined by the percent reduction test. In spray form, 200 ml 2,000 ppm nanoparticle ozone + 100 ml 3% thymol + 700 ml sugar syrup (efficacy-89.47%) (Group 5) and in oral form, 250 ml 2% thymol + 200 ml 2% A. absinthium oil + 500 ml sugar syrup (efficacy-85.95%) (Group 16), were found to be more effective. In conclusion, the combination of thymol and nanoparticle ozone in spray form was more effective than other combinations in this study. [ABSTRACT FROM AUTHOR]

The increasing threat of antibiotic resistance has created an urgent need for new antibacterial agents, particularly plant-based natural compounds and their derivatives. Thymol, a natural monoterpenoid phenolic compound derived from Monarda citriodora , is known for its aromatic and therapeutic properties, including antibacterial activity. This study focuses on synthesizing dihydropyrimidinone and dihydropyridine derivatives of thymol and exploring their antibacterial properties. The synthesized compounds were tested for their in vitro antibacterial potential against pathogenic microorganisms, specifically Pseudomonas aeruginosa (Gram-negative) and methicillin-resistant Staphylococcus aureus (MRSA) (Gram-positive). Among the synthesized derivatives, compound 3i (ethyl 4-(4-hydroxy-5-isopropyl-2-methylphenyl)-2-imino-6-methyl-1,2,3,4-tetrahydropyrimidine-5-carboxylate) exhibited the most promising antibacterial activity, with minimum inhibitory concentration (MIC) values of 12.5 µM against P. aeruginosa and 50.0 µM against MRSA. Additionally, compound 3i demonstrated a synergistic effect when combined with vancomycin, enhancing its antibacterial efficacy. The optimum fractional inhibitory concentration index (FICI) observed was 0.10 and 0.5 for MRSA and P. aeruginosa , respectively, in combination with vancomycin. In silico analysis of the physiochemical properties of 3i indicated compliance with all drug-likeness rules. Furthermore, molecular docking studies revealed that compound 3i has a stronger binding affinity to the target protein than thymol, providing valuable insights into its potential mechanism of action. [ABSTRACT FROM AUTHOR]

Background: Light is a critical environmental factor in plants, encompassing two vital aspects: intensity and quality. To assess the influence of different light intensities on Origanum majorana L., pots containing the herb were subjected to four levels of light intensity: 20, 50, 70, and 100% natural light. After a 60-day treatment period, the plants were evaluated for metabolite production, including total sugar content, protein, dry weight, antioxidant indices, expression of monoterpenes biosynthesis genes, and essential oil compounds. The experimental design followed a randomized complete blocks format, and statistical analysis of variance was conducted. Results: The results indicated a correlation between increased light intensity and elevated total sugar and protein content, which contributed to improved plant dry weight. The highest levels of hydrogen peroxide and malondialdehyde (MDA) were observed under 100% light intensity. Catalase and superoxide dismutase enzymes exhibited increased activity, with a 4.23-fold and 2.14-fold increase, respectively, under full light. In contrast, peroxidase and polyphenol oxidase enzyme activities decreased by 3.29-fold and 3.24-fold, respectively. As light intensity increases, the expression level of the 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) gene increases. However, beyond a light intensity of 70%, the DXR gene expression level decreased. Furthermore, the expression levels of the cytochrome P450 genes CYP71D178 and CYP71D179 exhibited an increasing trend in response to elevated light intensity. Essential oil content increased from 0.02 to 0.5% until reaching 70% light intensity. However, with further increases in light intensity, the essential oil content decreased by 54 to 0.23%. Conclusions: These findings emphasize the importance of balancing plant growth promotion and stress management under different light conditions. The research suggests that sweet marjoram plants thrive best in unshaded open spaces, resulting in maximum biomass. However, essential oil production decreases under the same conditions. For farmers in areas with an average light intensity of approximately 1700 µmol m−2s−1, it is recommended to cultivate sweet marjoram in shade-free fields to optimize biomass and essential oil production. Towards the end of the growth cycle, it is advisable to use shades that allow 70% of light to pass through. The specific duration of shade implementation can be further explored in future research. [ABSTRACT FROM AUTHOR]

Simple Summary: Global warming is an important issue in the context of climate change affecting cold-water aquaculture. Heat stress induces oxidative stress in fish, hence the use of a functional diet supplemented with antioxidant additives, such as thymol, can be useful to counteract the impact of global warming on aquaculture. In this study, we used thymol-enriched diets to rear rainbow trout fingerlings over an 8-week period followed by a period of heat stress of 48 h. Although thymol had no significant benefits on the growth and innate immunity of the fish, it improved antioxidant capacity and reduced lipid peroxidation and mortality after heat stress. The appropriate thymol dose for these benefits is 100 mg/kg. Rainbow trout fingerlings were fed, in triplicate, diets supplemented with 0 (CTL), 50 (50 TM), 100 (100 TM), 200 (200 TM), 400 (400 TM) and 800 (800 TM) mg/kg of thymol, followed by 48 h of thermal stress. Growth performance and humoral immunological parameters showed no significant responses to dietary thymol concentrations. Fish fed 50–400 mg/kg thymol diets had significantly higher survival after heat stress. Plasma cortisol, glucose, hepatic glutathione peroxidase, glutathione reductase and erythrocyte catalase significantly increased after thermal stress, whereas total plasma antioxidant capacity, ascorbate, and hepatic/erythrocyte reduced-glutathione significantly decreased. There were significant elevations in plasma ascorbate and hepatic glutathione reductase in the 50 TM, 100 TM and 200 TM groups; plasma total antioxidant capacity in the 100 TM and 200 TM groups; hepatic glutathione peroxidase in the 200 TM group; and hepatic-reduced glutathione in the 100 TM, 200 TM and 400 TM groups, compared to CTL. The highest hepatic superoxide dismutase and lowest hepatic malondialdehyde were observed in the 100 TM group before heat stress. These parameters significantly increased after thermal stress in the treatment groups, except in the 100 TM and 200 TM groups. Hepatic catalase showed no significant difference among the treatment groups before thermal stress. Hepatic catalase significantly increased after heat stress in all treatment groups, except in the 100 TM group. Erythrocyte superoxide dismutase significantly increased in the 100 TM group before heat stress, whereas erythrocyte malondialdehyde significantly decreased in the 100 TM and 200 TM groups after thermal stress. Based on the results, 100 mg/kg of thymol can promote antioxidant power and thermal stress resistance in rainbow trout. [ABSTRACT FROM AUTHOR]

Essential oils extracted from natural plants can serve as safe food additives, compared with conventional chemical or synthetic additives. Essential oils have also been incorporated into food packaging materials to impart their bacteriostatic and antioxidant properties. Among them, thymol (THY), a monoterpene phenolic compound extracted from the thyme plant, has been used as a bacteriostatic agent in active packaging materials with functional properties, due to its significant bacteriostatic properties. However, the activity of highly volatile THY is easily affected by the packaging environment. Therefore, appropriate techniques are needed to incorporate the THY into polymer matrices, in order to improve its stability and utilization for controlled release. This study aims to prepare the potato starch films of active packaging, taking the mesoporous nano-silica (mobil composition of matter No. 41, MCM-41) as the controlled-release carrier of THY (THY-MCM-41), potato starch as the film-forming substrate, glycerol as the plasticizer, and calcium chloride as the cross-linking agent. Single-factor experiments were carried out to determine the suitable additive ranges of potato starch, glycerol, calcium chloride, and THY-MCM-41 mass concentration in the packaging film. The L9 (34) orthogonal test was also implemented to investigate the interactive effects of potato starch, glycerol, calcium chloride, and THY-MCM-41 on the thickness, opacity, moisture absorption (MA), water vapor permeability (WVP), tensile strength (TS), and elongation at break (EB) of the packaging film. The optimal conditions were obtained to prepare the potato starch films of active packaging. A systematic investigation was made to clarify the THY release kinetics in the optimal combination of packaging film at different temperatures and relative humidity (RH) environments. A prediction model of THY release was constructed to optimize the THY. The results showed that the optimal properties of the prepared packaging film A were achieved in the TS, MA, WVP, oxygen permeability (OP) and opacity were 7.16 MPa, 89.23%, 1.42 × 10-10 g/(m·s·Pa), 1.02 × 10-15 cm²/s·Pa, and 1.16 mm-1, respectively, when the mass concentrations of potato starch, glycerol, calcium chloride and THY-MCM-41 were 0.04, 0.015, 0.005, and 0.005 g/mL, respectively. Scanning electron microscope (SEM) and Fourier-transformed infrared (FTIR) spectroscopy confirmed that the denser and more uniform microstructure of packaging film was observed, where THY-MCM-41 was uniformly dispersed in the potato starch film, indicating better compatibility with potato starch. Thermogravimetric (TG) analysis showed that the encapsulation of MCM-41 improved the stability of THY in the potato starch film. In addition, the release kinetics of THY in the potato starch film of active packaging demonstrated that the initial explosive release was shifted to a subsequent sustained release under different temperature-RH environments. The active packaging film was prepared to effectively control the release rate of THY for the effective time of THY up to 10d. The release pattern of THY was in accordance with the First-order release model (R² > 0.980), and the release index “n” was less than 0.5, indicating that the release behavior of THY followed Fickian diffusion law. This finding can also provide the theoretical foundation for the precise release of active substances in the development of active packaging films. [ABSTRACT FROM AUTHOR]

The essential oils were isolated from Thymus serpyllum L. leaves, stem, flowers and whole plant using hydrodistillation technique and % yield was determined. The chemical constituents were studied using Gas Chromatography-Mass Spectrometry and Gas Chromatography-Flame Ionisation Detection. The analysis revealed the presence of 38 compounds in the essential oils obtained from different plant parts. Identification of compounds was achieved by detailed analysis of mass spectrum and retention indices. The major constituents of essential oil from the whole plant were thymol (35.25%), p-cymene (27.57%), thymol acetate (8.03%) and γ-terpinene (6.92%). In leaves they were thymol (45.59%), p-cymene (24.26%), thymol acetate (6.41%), and β-bisabolene (5.91%); whereas in flowers these were thymol (68.74%) and thymol acetate (7.40%) and in the stem, these were thymol (55.15%) and thymol acetate (8.01%). Specifically, it is the first report wherein essential oil constituents of T. serpyllum L. whole plant, leaves, flowers, and stems have been analyzed separately. Further, fundamental analysis of complex mass fragmentation patterns of terpenes and terpenoids using EI-MS has been achieved and the logical reason for the fragmentation pattern has been elaborated. Detailed elaboration of the mass fragmentation pattern may strengthen the EI-MS-based compound identification of terpenes and terpenoids from essential oils. [ABSTRACT FROM AUTHOR]

Thymol and carvacrol belong to the class of terpenoids that usually contribute to the flavor, color, and development of plants, and their complexation with CD has been recently reported. Due to their structural similarities, including such guests in CD poses a challenging task to theoretical methodologies. With the present contribution, we applied the recently developed GFN2-xTB multi-equilibrium approach to study the inclusion of those guests into β-CD. The inclusion of 1-adamantane carboxylic acid in β-CD was also investigated for comparison. The study was conducted with a progressive increase in the number of systems in steps, comprising 792, 1,188, and 1,584 systems. Therefore, for the three guest/host pairs studied, complete optimization in vacuum and water with the ALPB continuum method was applied to 10,692 systems at the GFN2-xTB level of theory. Furthermore, single-point calculations at the B97-3c/def2-TZVPP level of theory were carried out using the SMD solvation model. As a result, beyond determining the experimental trend, we addressed that the additional degree of freedom represented by the gamma Euler parameter decreased the errors related to the estimated adjusted binding constants. On the other hand, the use of the B97-3c/def2-TZVPP in conjunction with the set of systems selected by GFN2-xTB (ALPB) must be further investigated since the experimental trend was obtained only with a basis in the difference in electronic energies. [ABSTRACT FROM AUTHOR]

Thymol-loaded polymeric nanocapsules were developed in this study to control volatilization and drug release for repellent application on Rhipicephalus sanguineus nymphs. Policaprolactone-loaded nanocapsules were prepared and characterized by diameter, PdI, zeta potential, pH, entrapment efficiency, and thymol content. Moreover, drug release, skin permeation profile, and repellent activity were evaluated. Nanocapsules showed a mean diameter of 195.7 ± 0.5 nm, a PdI of 0.20 ± 0.01, a zeta potential of −20.6 ± 0.3 mV, a pH of 4.7 ± 0.1, and an entrapment efficiency and a thymol content of 80.1 ± 0.1% and 97.9 ± 0.2%, respectively. The nanosystem progressively released 68.6 ± 2.3% of the thymol over 24 h, demonstrating that it can control drug release. Thymol-loaded nanocapsules showed less epidermis penetration upon skin application than pure thymol (control). Moreover, nanocapsules showed 60–70% repellency for 2 h against Rhipicephalus sanguineus nymphs. Thus, the nanocapsules proved to be a promising alternative for use as an arthropod repellent. [ABSTRACT FROM AUTHOR]

Ticks pose a significant threat due to their ability to lay thousands of eggs, which can persist in the environment for extended periods. While the impact of various compounds on adult and larval ticks has been studied, research on their efficacy against tick eggs is limited. This study evaluated the ovicidal activity of commercial acaricides, disinfectants, and natural products against Rhipicephalus annulatus eggs using the egg hatch assay (EHA). Deltamethrin and cypermethrin caused a non-significant inhibition of hatching (IH%), even at concentrations higher than the recommended levels. By contrast, the acaricides chlorpyrifos, phoxim, and amitraz significantly inhibited hatching at all tested concentrations. Ivermectin also demonstrated significant IH% at various concentrations but did not fully inhibit the hatching process. Among the disinfectants tested, Virkon-S®, TH4, and Chlorox showed insignificant effects, whereas formalin achieved an IH% of only 34.1% at a high concentration of 200 mg/mL. Natural products, carvacrol and thymol, exhibited significant ovicidal activity, with a significant IH%. In a semi-field application, phoxim (0.5 mg/mL) and deltamethrin (0.05 mg/mL) were sprayed on tick eggs on pasture soil from a farm. The results indicated that phoxim-treated eggs had a 40% IH%, while deltamethrin-treated eggs showed only an 8.79% IH%. In conclusion, the acaricides amitraz, phoxim, and chlorpyrifos, as well as the natural products carvacrol and thymol, caused significant toxicity to R. annulatus eggs. [ABSTRACT FROM AUTHOR]

BACKGROUND: Plant fungal diseases pose a significant threat to crop production. The extensive use of chemical pesticides has led to growing environmental safety risks and pesticide resistance of various plant pathogens. Therefore, it is an urgent task to explore novel eco‐friendly fungicidal agents with high efficacy to combat fungal infection. RESULTS: In this study, we rationally designed a series of novel thymol derivatives by incorporation of the sulfonamide moiety and evaluated their biological activities against plant pathogenic fungi. The bioassay results underscored the remarkable in vitro antifungal activity of compounds 5m and 5t against Phytophthora capsici (P. capsici), with EC50 values of 8.420 and 8.414 μg/mL, respectively. Their efficacies were superior to that of widely used commercial fungicides azoxystrobin (AZO, 20.649 μg/mL) and cabendazim (CAB, 251.625 μg/mL). Furthermore, compound 5v exhibited excellent in vitro antifungal activity against Sclerotinia sclerotiorum (S. sclerotiorum), with an EC50 value of 12.829 μg/mL, significantly outperforming AZO (63.629 μg/mL). In vivo bioassays demonstrated the impactful activity of compound 5v against S. sclerotiorum, achieving over 98% curative and protective efficacies at the concentration of 200 μg/mL. Further mechanistic investigations unveiled that compound 5v induced mycelial shrinkage and collapse in S. sclerotiorum, resulting in organelle damage and the accumulation of antioxidant enzyme activity. CONCLUSION: The significant antifungal efficacy of the prepared thymol derivatives shall encourage further exploration of compound 5v as a promising candidate to develop novel fungicides for crop protection. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

An antioxidant, antibacterial, and biocompatible biomaterial is essential to repair skin wounds effectively. Here, we have employed two natural biopolymers, isabgol (ISAB) and konjac glucomannan (KGM), to prepare microporous scaffolds by freezing and lyophilization. The scaffolds are loaded with thymol (THY) to impart potent antioxidant and antibacterial activities. The physicochemical properties of the ISAB+KGM+THY scaffold, like porosity (41.8±2.4 %), swelling, and biodegradation, were optimal for tissue regeneration application. Compared to the control, ISAB+KGM+THY scaffolds promote attachment, migration, and proliferation of L929 fibroblasts. The antioxidant activity of the ISAB+KGM+THY scaffold was significantly improved after loading THY. This would protect the tissues from oxidative damage. The antibacterial activity of the ISAB+KGM+THY scaffold was significantly higher than that of the control, which would help prevent bacterial infection. The vascularization ability of the ISAB+KGM scaffold was not altered by incorporating THY in the ISAB+KGM scaffold. Therefore, a strong antioxidant, antibacterial, and biocompatible nature of the ISAB+KGM+THY scaffold could be useful for various biomedical applications. [ABSTRACT FROM AUTHOR]

Silica (SiO2) particles are widely used in various industries due to their chemical inertness, thermal stability, and wear resistance. The present study describes the preparation and potential use of porous hydrophobic and hydrophilic SiO2 microcapsules (MCs) of a narrow size distribution. First, various layers of SiO2 micro/nano-particles (M/NPs) were grafted onto monodispersed polystyrene (PS) microspheres of a narrow size distribution. Hydrophobic and hydrophilic sintered SiO2 MCs were then prepared by removing the core PS from the PS/SiO2 core–shell microspheres by burning off under normal atmospheric conditions or organic solvent dissolution, respectively. We examined how the size and quantity of the SiO2 M/NPs influence the MC's properties. Additionally, we utilized two forms of hollow SiO2 MC for different applications; one form was incorporated into polymer films, and the other was free-floating. The hydrophobic microcapsules filled with 6% hydrogen peroxide were effective in killing the tomato brown rugose fruit virus (ToBRFV). The hydrophilic microcapsules filled with thymol and thin coated onto polypropylene films were successfully used to prevent mold formation for hay protection. [ABSTRACT FROM AUTHOR]

Consumer demand for high-quality meat has increased. This study aimed to investigate the potential application of cocrystals of thymol and carvacrol in broilers for high-quality meat production. Eight hundred 1-day-old chicks were assigned to four groups fed diets supplemented with 0, 40, 60, and 80 mg/kg of Crystal EO® (CEO), containing 25% cocrystals of thymol and carvacrol in a 42-d feeding trial. The results showed that dietary CEO supplementation decreased the muscle fiber diameter and increased the muscle fiber density, glycogen content, L*45 min value, and proportion of α-linolenic acid in the breast muscle; dietary 40 and 60 mg/kg of CEO decreased the lactate content, MDA concentration, cooking loss, shear force, and thrombogenicity index and increased the proportion of lauric acid in the breast muscle; dietary 60 and 80 mg/kg of CEO increased the glucose content, total superoxide dismutase, and total antioxidant capacity levels of breast muscle. Citrate synthase activity, free radical scavenging capacity, pH24 h and a*45 min values, and the cystine content in the breast muscle were especially higher in the 60 mg/kg CEO group compared to the control group. Collectively, dietary CEO supplementation improved meat quality and nutritional values and enhanced the antioxidant capacity of broiler meat, with 60 mg/kg of CEO having the greatest effect. [ABSTRACT FROM AUTHOR]

ABSTRACT In this study, novel chlorine‐thymol derivatives (1,3‐bis(4‐chloro‐2‐isopropyl‐5 methylphenoxy)propan‐2‐ol (Thy‐OHI) and 2‐[2‐(4‐chloro‐2‐isopropyl‐5‐methylphenoxy)ethoxy]ethanol (Thy‐OHII)) and axially di‐4‐chloro‐2‐isopropyl‐5‐methylphenoxy (Thy‐SiPc), 1,3‐bis(4‐chloro‐2‐isopropyl‐5‐methylphenoxy)propanoxy (Thy‐OHI‐SiPc), and 2‐[2‐(4‐chloro‐2‐isopropyl‐5‐methylphenoxy)ethoxy]ethanoxy (Thy‐OHII‐SiPc) substituted silicon phthalocyanine compounds were obtained, and their structures were elucidated by the combination of various methods such as NMR, IR, UV–Vis, and MS. The inhibitory effects of these compounds (Thy‐OHI, Thy‐OHII, Thy‐SiPc, Thy‐OHI‐SiPc and Thy‐OHII‐SiPc), synthesized for the first time, on cholinesterase enzymes (AChE and BChE) were investigated in the laboratory environment. In the studies, notably Thy‐OHI‐Si and thymol derivative ligand Thy‐OHII displayed significant inhibition against AChE and BChE. [ABSTRACT FROM AUTHOR]

Trachyspermum ammi is widely used among the people in the Arabian Peninsula to treat general respiratory problems including bronchoconstriction. In this study, the fruit extracts and its fractions and purely isolated components obtained from the T. ammi were investigated for their possible bronchodilator potential in an ex vivo model using guinea pig trachea. It was observed that the ethanol extract (TAT) of the plant and its hexane (TAH) and chloroform (TAC) extract fractions completely inhibited carbachol (CCh, 1 µM)-induced contractions at a concentration of 1 mg/mL. As a result of the biological activity-guided purification studies of the chloroform extract (TAC), in which the highest activity was observed, eight sub-fractions were obtained between A-H. Of these, fractions A, D, G were found to have significant activity for tracheal relaxation with 100%, 55 ± 5% and 31 ± 3%, respectively, while the other five fractions were found not to have any activity. Three monoterpene compounds were isolated from the fractions with high activity and their structures were determined by 1D and 2D NMR and mass spectrometric techniques as well as by simple chemical derivatization. In this study, it was determined that the bronchodilator effect of compound 1 (thymol) was demonstrated by the activation of different subtypes of K+ channels. Reported data herein, demonstrated the scientific justification for the traditional use of T. ammi species against asthma and bronchitis. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the acaricidal efficacy, tolerability of the target species, and residue levels of a thymolcontaining gelatin-based hydrogel developed as a controlled release system for varroosis control. The study was carried out on naturally infested honey bee colonies and results were compared with those of negative and positive control groups. The acaricidal efficacy of the negative control, positive control, and hydrogel treatment was 21.93 ± 2.87%, 81.09 ± 2.30%, and 70.32 ± 2.05%, respectively. For tolerability evaluations, the average number of dead bees per colony was determined to be 60.80 ± 8.01, 297.40 ± 21.4, and 86.80 ± 6.94 for the negative control, positive control, and hydrogel treatment, respectively. The average thymol residues in honey were measured as 0.030 ± 0.022 mg/kg, 5.498 ± 3.346 mg/kg, and 0.168 ± 0.110 mg/kg for the negative control, positive control, and hydrogel treatment, respectively. The average thymol concentrations in beeswax were 0.074 ± 0.047 mg/kg, 1.667 ± 0.855 mg/kg, and 0.476 ± 0.278 mg/kg for the negative control, positive control, and hydrogel treatment, respectively. The controlled release system developed in this study was found to prevent the transport of thymol out of the colony due to its structure, which is well tolerated by bees. Consequently, a single application can achieve longer infestation control. Furthermore, the lack of intervention by bees in the system ensures that bee mortality due to contact toxicity and residue levels in honey and beeswax are low. In addition to these advantages of the system, further development is required to increase the acaricide efficacy in order to make it an ideal alternative to existing varroacidal veterinary medicinal products. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of the monoterpenes thymol and p‐cymene on the liver of rats subjected to prolonged immobilization stress and to discover the possible mechanism behind this effect. For 14 consecutive days, the rats were placed in a restrainer for 2.5 h every day to expose them to stress. During the same period, thymol (10 mg/kg, gavage) and p‐cymene (50 mg/kg, intraperitoneally) were also administered. Thymol and p‐cymene prevented the increase in malondialdehyde levels and the decrease in glutathione content in the liver of rats exposed to chronic immobility. They also increased the activity of the glutathione peroxidase enzyme in the liver of stressed animals, but only thymol could increase the activity of superoxide dismutase. These monoterpenes reduced the expression of pro‐inflammatory cytokines tumor necrosis factor‐alpha (TNF‐α), interleukin (IL)‐1β, and IL‐6 and nuclear factor kappa B (NF‐κB) in the liver of stressed animals. They increased the expression of nuclear factor erythroid 2‐related factor 2 (Nrf2) and heme oxygenase‐1 (HO‐1). Thymol and p‐cymene greatly prevented the infiltration of inflammatory cells in the liver parenchyma of stressed rats. In conclusion, the study found that thymol and p‐cymene have a hepatoprotective effect on immobilized rats, likely exerted by suppressing oxidative stress and inflammation, stimulating Nrf2/HO‐1 signaling, and inhibiting the TNF‐α/NF‐κB pathway. [ABSTRACT FROM AUTHOR]

This study investigated the capability of a co-delivery system of thymol (THY) and sulfoxaflor that can serve to minimize the development of epididymal and testicular injury arise from SFX exposures alone. Forty-eight adult male rats were orally treated by gavage for 28 consecutive days. The rats were divided into six groups comprising control, THY alone (30 mg/kg), low SFX alone (79.4 mg/kg), high SFX alone (205 mg/kg) and co-exposure groups. After euthanasia, the rats epididymal and testicular damage and antioxidant status markers, myeloperoxidase (MPO) activity, levels of nitric oxide, total antioxidant capacity (TAC), total oxidative stress (TOS) and lipid peroxidation (LPO) were analyzed. Levels of tumor necrosis factor alpha (TNF-α), interleukin-1 b (IL-1β) and caspase-3 activity were assessed using ELISA kits. The results revealed that SFX exposure caused a significant (p < 0.05) decrease in the body weight, sperm functional parameters, serum testosterone level with widespread histological abnormalities in a dose-dependent manner. Increased relative organ weights, serum levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH) were observed in low SFX-treated rats. Similarly, the epididymal and testicular myeloperoxidase activity, malondialdehyde (MDA), reactive oxygen species (RONS), tumor necrosis-α, interleukin-1β levels and caspase-3 activity were significant (p < 0.05) increased and a significant (p < 0.05) reduction in antioxidant enzyme activities and reduced glutathione (GSH) were revealed in SFX-treated rats. However, co-treatment of THY with SFX prevented SFX-induced epididymal and testicular toxicities. Thus, thymol protected against potential epididymis and testes alterations elicited by oxido-inflammatory mediators and up regulated antioxidant status. [ABSTRACT FROM AUTHOR]

• nSi-DA6, showed a notable increase in shoot and root dry weight, the number of leaves and the chlorophyll content. • nSi-DA6 and nSi-Atonik increased the phenols and flavonoids content and antioxidant activity in the leaves. • Sodium silicate and nSi-DA6 treatments increased the essential oil content in Z. multiflora. • The highest content of carvacrol and thymol was observed with Atonik and Si nanoparticles. Nanoparticles can drastically improve the growth, yield and quality of medicinal plants. In this study, silicon (Si) nanocomplexes were green synthesized from the growth regulators DA-6 and Atonik, and their effects on the growth, bioactive compounds, essential oil yield and composition in Zataria multiflora medicinal plant were compared with sodium silicate, a regular Si nanoparticle, DA-6 and Atonik. The Si-containing treatments such as sodium silicate and nanoparticles significantly increased shoot and root dry weight and the number of leaves, but not the inflorescence dry weight; however, the growth improvement effects of the Si-nanocomplexes were more evident. The nSi-DA6 and nSi-Atonik treatments did not affect the carotenoids and protein contents but increased the chlorophyll content in the leaves. The Si-nanocomplexes by increasing total phenols and total flavonoids enhanced antioxidant activity in the plant. Accumulation of epicatechin, naringenin and rosmarinic in response to the application of the Si-nanocomplexes promotes cardiovascular health effects and antioxidant activity of the plant. The essential oil (EO) content of the plants (2.75 %) increased to about 3.2 % after the application of Si-nanocomplexes. The main compounds of EO were carvacrol, thymol and linalool. The Si-nanocomplexes increased carvacrol and thymol content in the EO, however, linalool content remained unchanged after the treatments. Therefore, the application of silicon nanocomplexes increased the antioxidant and antimicrobial activity of EO without reducing the important factor in the fragrance of the EO. In conclusion, the application of 6 mM of nSi-DA6 and nSi-atonik nanoparticles was suggested to improve the growth and quality of Z. multiflora. [ABSTRACT FROM AUTHOR]

This study evaluated the capability of a thymol nanoemulsion (nTHY) to reduce cross-contamination with Salmonella Enteritidis in ground chicken meat. First, an nTHY (~ 54 nm) was prepared in a high-shear speed system (rotor–stator) and proved stable, remaining below 100 nm for 30 days in storage at 4 °C. Then, a minimum inhibitory concentration assay was performed by combining S. Enteritidis with viable native bacteria from chicken meat. nTHY presented half the MIC that was observed for its non-nanoemulsified versions for Salmonella Enteritidis (MIC = 0.31 mg/mL) and combined with native chicken bacteria (MIC = 0.625 mg/mL). A chitosan (CH) coating containing nTHY (6 mg/mL), equivalent to 10 × MIC (S. Enteritidis + native chicken bacteria), was prepared for in situ evaluation. Two groups of distinct chicken fillets were prepared for cross-contamination during grinding: chicken fillets experimentally contaminated with S. Enteritidis (~ 6.5 log CFU/g) and chicken fillets without S. Enteritidis but with the applied treatments (control, coated with CH, nTHY, and CH + nTHY). nTHY showed a bacteriostatic effect throughout the 7 days of storage. The CH + nTHY coating was the best treatment applied, reducing cross-contamination by up to 1.91 log CFU/g compared to uncoated samples. Thymol nanoemulsions can be natural alternatives to guarantee the microbiological safety of meat and meat products. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigates how carvacrol and thymol affect the quality of semen from Beni Arouss bucks stored in skim milk at 4 °C. Semen from eight bucks was collected weekly for 11 weeks, pooled, and divided into three groups: one diluted in skim milk, and the others diluted in skim milk supplemented with 200 µM of carvacrol and thymol. Sperm motility, viability, abnormalities, membrane integrity, lipid damage, and bacterial growth were assessed during 48 h of storage at 4 °C. After 48 h, carvacrol improved sperm motility, viability, and reduced bacterial growth and lipid damage. Thymol showed similar benefits but did not enhance progressive motility. These beneficial effects are due to the antimicrobial properties of these two compounds, offering potential benefits for livestock breeding. This study aims to investigate the impact of carvacrol and thymol on the quality of Beni Arouss buck semen stored in skim milk at 4 °C. Ejaculates were collected from eight Beni Arouss bucks weekly for 11 weeks, pooled, and then divided into three equal parts. Samples were diluted to 400 × 106 sperm/mL in skim milk (control) and skim milk supplemented with a single dose of 200 µM carvacrol and thymol each. Evaluations of sperm motility, viability, abnormalities, membrane integrity, lipid peroxidation, and bacterial growth were conducted at 0, 6, 24, and 48 h of liquid storage at 4 °C. After 48 h of storage, the results indicate that the addition of carvacrol positively influences total and progressive motility and viability. However, it also leads to a decrease in lipid peroxidation and bacterial growth compared to the control group (p < 0.05). Thymol showed similar results to carvacrol, except for progressive motility (p > 0.05). Bacterial growth was negatively correlated with total and progressive motility and viability (p < 0.05), while no correlation between lipid peroxidation and these parameters was observed (p > 0.05). In conclusion, the addition of carvacrol and thymol to skim milk extender moderately improves the quality of Beni Arouss buck semen after 48 h storage at 4 °C due to its antimicrobial activity. [ABSTRACT FROM AUTHOR]

A novel, simple, rapid, and non-expensive analytical method based on square wave voltammogram at Pt-microelectrode coupled with partial least square multivariate calibration was used for the simultaneous quantitation of thymol (THY) and carvacrol (CAR) in thyme and oregano essential oils. Results demonstrated that the multivariate calibration method successfully exploited the first-order advantage, rendering highly satisfactory quantitative figures (average recoveries not statistically different than 100%). Moreover, the results agree well with those obtained from the official analytical method. Last, the method's environmental sustainability was asserted using the AGREE metric, highlighting its eco-friendly nature. More importantly, the proposed analytical procedure does not require previous sample preparation or electrode surface modification. The results underscore the suitability of the method for determining THY and CAR in essential oils at low concentrations (LOD ~ 7.6 µM) with REP% below 5.6%, meeting the requirements of the green analytical chemistry. [ABSTRACT FROM AUTHOR]

Bacterial biofilm on implants may cause inflammation, which disturbs the process of the implant's integration with the surrounding tissues. Such problems are becoming critical for patients' health, especially in connection with the presence of antibiotic-resistant bacterial strains. Among the existing alternatives for drug treatments are natural-based substances. This study focused on the examination of silica coatings with curcumin and thymol, which were deposited using the sol-gel method on 3D printouts made of Ti6Al4V ELI. This substrate material is commonly used in medicine. The selective laser melting technique used for the manufacturing of samples was in line with the existing procedures applied for individual orthopedic implants. The examination involved the assessment of the coatings' morphology, chemical composition, and biological effect. The antibacterial properties were tested using a flow cytometer using Escherichia coli, and the cytotoxicity on Saos-2 cells was assessed using the LIVE/DEAD test. The obtained results showed that it is possible to produce silica sol-gel coatings with the addition of specific natural substances in concentrations assuring a bacteriostatic effect. The produced coatings did not show any cytotoxic effect, which confirms the possibility of using both curcumin and thymol as additives to coatings used in medicine, e.g., for orthopedic implants. [ABSTRACT FROM AUTHOR]

This work studied the sustainable approach for the development of bio‐based polybenzoxazine composites derived from sustainable thymol and utilized for diverse applications viz., superhydrophobic, high dielectric, and resistant to bacterial corrosion. The molecular structure of benzoxazines was ascertained from spectral analyses and curing behavior was assessed using differential scanning calorimetry (DSC) analysis. The benzoxazines were polymerized through ring‐opening polymerization to assess their thermal stability using TGA. Among the synthesized polybenzoxazines, the poly(BT‐fa) developed using bis‐thymol (BT) and furfurylamine (fa) which possesses the furfural core contributes to higher thermal stability with the enhanced value of char yield of 43%. Thus, poly(BT‐fa) was chosen for the preparation of composites, and found that 15 wt% chicken feather carbon (CFC) and 15 wt% cashew nutshell cake carbon (CSC) used as reinforcements exhibit significantly enhanced decomposition temperature with char yield of 77% and 69% respectively. Dielectric performance of the composites with high k values of 7.66 and 8.66 was obtained for 15 wt% of the CFC and CSC bio‐carbon reinforcements respectively. These bio‐based benzoxazines also exhibited substantial antibacterial activity, indicating their potential utility toward resistance against microbial colonization. Among polybenzoxazines, poly(BT‐sa) exhibits the highest value of water contact angle (WCA) of 151°. To exploit the superhydrophobic properties of polybenzoxazines, the cotton fabrics were coated with poly(BT‐sa). It was found that poly(BT‐sa) coated cotton fabric possesses an excellent WCA value of 161°, which indicates its suitability for self‐cleaning and water‐repellent applications. Further, poly(BT‐oa) possesses enhanced anti‐corrosion‐resistant behavior than that of other polybenzoxazines and contributes to better protection of mild steel surfaces from corrosion. The values of tensile modulus /flexural modulus and tensile strength and flexural strength obtained for poly(BT‐fa) are 5.1/3.7 GPa and 66 ± 1/103 ± 1 MPa, respectively. Data obtained for bi‐functional bio‐based polybenzoxazine composites from different studies suggest that these materials can be used in antimicrobial, superhydrophobic, and corrosion‐resistant applications. [ABSTRACT FROM AUTHOR]

The emergence of non-albicans Candida as a potential causative agent of candidiasis following Candida albicans is occurring globally. It is known that phenolic cresols, thymol, and carvacrol have anti-Candida characteristics. However, there are few papers that disclose the mechanism of action, which is characterized by a damaged cell wall and ergosterol synthesis, as well as calcium-induced death in C. albicans. This work utilized in-silico docking analysis to examine the molecular targets of thymol and carvacrol in Candida glabrata. The results were then validated in vitro by antifungal susceptibility testing and growth curve analysis. The study incorporated C. glabrata deletion mutants for the target proteins to gain understanding of the function of these proteins in the antifungal effects of the two monoterpenoids. After conducting molecular docking and in silico toxicity evaluations, thymol and carvacrol were chosen for in vitro investigations. Experimental tests conducted in a laboratory setting have shown that both phytocompounds exhibit strong binding affinity towards cell wall synthesis proteins (Kre1p, Kre2p, Ecm33p), calcium channel proteins (Mid1p, Ecm7p), and proteins involved in the ergosterol synthesis pathway (Erg5p). These proteins are likely to be the specific targets for the anti-Candida properties of the two isomeric monoterpenoids in C. glabrata. Minimum inhibitory concentration (MIC50) values for thymol and carvacrol range from 50 µg/ml to 75 µg/ml. The wild-type strains exhibit a minimum fungicidal concentration of 100 µg/ml for thymol and 125 µg/ml for carvacrol. The results underscore the significance of these proteins in the fungal reaction to thymol and carvacrol and also indicate a promising opportunity for the development of novel antifungal treatment methods utilizing these proteins. [ABSTRACT FROM AUTHOR]

The ectoparasitic mite Varroa destructor has become a major worldwide pest of the honey bees (Apis mellifera L). Intensive use of chemical acaricides has led to the development of acaricide resistance in mites, thereby reducing the efficacy of acaricides and causing contamination of hive products. Thus, natural products such as essential oils can become an important alternative to synthetic chemicals in controlling Varroa mites. In this study, essential oil from Thymus schimperi grown in the Ethiopian highland was investigated for its chemical composition and toxicity against Varroa mites through complete exposure tests. Hydrodistillation of T. schimperi leaves yielded a pale yellow essential oil (0.8% v/w) with a strong and pleasant odor. Analyzed by GC-MS, 29 compounds, comprising 96.67% of the oil, were identified. Carvacrol (34.84%), thymol (23.03%), and p-cymene (14.20%) were found to be the main constituents. In the toxicity assay, T. schimperi essential oil showed high acaricidal activity against Varroa mites, with a 4 h-LC50 value of 109.16 µg/ml (5.46 mg oil/l air volume). Among the main constituents, thymol and carvacrol induced high toxicity to Varroa mites, with 4 h-LC50 values of 70.71 µg/ml (3.54 mg thymol/l air volume) and 106.10 µg/ml (5.31 mg carvacrol/l air volume), respectively. However, p-cymene was less effective in toxicity testing (4 h-LC50 > 5000 µg/ml). The results show for the first time that the essential oil of Thymus schimperi and its two main constituents, thymol and carvacrol, are highly acaricidal and can be used to control Varroa mite infestations. [ABSTRACT FROM AUTHOR]

Abstract Staphylococcus aureus and Pseudomonas aeruginosa are the most common bacteria co-isolated from chronic infected wounds. Their interactions remain unclear but this coexistence is beneficial for both bacteria and may lead to resistance to antimicrobial treatments. Besides, developing an in vitro model where this coexistence is recreated remains challenging, making difficult their study. The aim of this work was to develop a reliable polymicrobial in vitro model of both species to further understand their interrelationships and the effects of different antimicrobials in coculture. In this work, bioluminescent and fluorescent bacteria were used to evaluate the activity of two antiseptics (chlorhexidine and thymol) against these bacteria planktonically grown, or when forming single and mixed biofilms. At the doses tested (0.4-1,000 mg/L), thymol showed selective antimicrobial action against S. aureus in planktonic and biofilm states, in contrast with chlorhexidine which exerted antimicrobial effects against both bacteria. Furthermore, the initial conditions for both bacteria in the co-culture determined the antimicrobial outcome, showing that P. aeruginosa impaired the proliferation and metabolism of S. aureus. Moreover, S. aureus showed an increased tolerance against antiseptic treatments when co-cultured, attributed to the formation of a thicker mixed biofilm compared to those obtained when monocultured, and also, by the reduction of S. aureus metabolic activity induced by diffusible molecules produced by P. aeruginosa. This work underlines the relevance of polymicrobial populations and their crosstalk and microenvironment in the search of disruptive and effective treatments for polymicrobial biofilms.

Abstract Background Light is a critical environmental factor in plants, encompassing two vital aspects: intensity and quality. To assess the influence of different light intensities on Origanum majorana L., pots containing the herb were subjected to four levels of light intensity: 20, 50, 70, and 100% natural light. After a 60-day treatment period, the plants were evaluated for metabolite production, including total sugar content, protein, dry weight, antioxidant indices, expression of monoterpenes biosynthesis genes, and essential oil compounds. The experimental design followed a randomized complete blocks format, and statistical analysis of variance was conducted. Results The results indicated a correlation between increased light intensity and elevated total sugar and protein content, which contributed to improved plant dry weight. The highest levels of hydrogen peroxide and malondialdehyde (MDA) were observed under 100% light intensity. Catalase and superoxide dismutase enzymes exhibited increased activity, with a 4.23-fold and 2.14-fold increase, respectively, under full light. In contrast, peroxidase and polyphenol oxidase enzyme activities decreased by 3.29-fold and 3.24-fold, respectively. As light intensity increases, the expression level of the 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) gene increases. However, beyond a light intensity of 70%, the DXR gene expression level decreased. Furthermore, the expression levels of the cytochrome P450 genes CYP71D178 and CYP71D179 exhibited an increasing trend in response to elevated light intensity. Essential oil content increased from 0.02 to 0.5% until reaching 70% light intensity. However, with further increases in light intensity, the essential oil content decreased by 54 to 0.23%. Conclusions These findings emphasize the importance of balancing plant growth promotion and stress management under different light conditions. The research suggests that sweet marjoram plants thrive best in unshaded open spaces, resulting in maximum biomass. However, essential oil production decreases under the same conditions. For farmers in areas with an average light intensity of approximately 1700 µmol m−2s−1, it is recommended to cultivate sweet marjoram in shade-free fields to optimize biomass and essential oil production. Towards the end of the growth cycle, it is advisable to use shades that allow 70% of light to pass through. The specific duration of shade implementation can be further explored in future research.

Common thyme (Thymus vulgaris L., Lamiaceae) is one of the most well-known plants in the world, widely used in medicine, culinary arts, and cosmetics. The aim of this study was to analyse the content and composition of essential oils (EO) obtained from the T. vulgaris commercial samples grown in Estonia and in various European countries. Gas chromatography was used to characterize the quality and diversity of chemotypes of the studied plant raw material of different origins. The samples of the T. vulgaris herb contained 3â28 mL/kg of EO, and in five samples it was below the European Pharmacopoeia (Ph. Eur.) requirement (minimum 12 mL/kg). In total, 44 EO compounds were identified in the essential oils of the studied T. vulgaris samples. Among them, five principal compounds were carvacrol (2.3â87.5%), thymol (0.9â71.2%), p-cymene (0.3â26.0%), γ-terpinene (0.1â16.1%), and (E)-β-caryophyllene (0.6â9.2%). It was concluded that the main compound of T. vulgaris EO (n = 37) was thymol with an average content of 41.1%. Monoterpenoids (90.5%) and sesquiterpenoids (5.7%) were the most dominating groups of terpenoids in the studied EO. Regarding the minimum and maximum content of key compounds in EO, none of the studied samples (n = 22) fully met the requirements of Ph. Eur. 11. The content of the four most important terpenoids (thymol, carvacrol, p-cymene, and γ-terpinene) in the EO of T. vulgaris does not change much from the beginning to the end of the flowering period. Correlations between the content of the most important (>2%) components (n = 14) of the studied EO (n = 37) showed a level >0.9 in several cases. Among seven studied chemotypes of T. vulgaris EO, five contained thymol as one of the main components.

IntroductionGarden thyme (Thymus vulgaris L.), is a small perennial plant native to the Mediterranean region that is now found worldwide. It is commonly used as a culinary herb and for medicinal purposes as well (Silva et al., 2021). Thymol is one of the main and active chemical compounds of thyme. It has been shown to have antibacterial, antifungal and antiviral properties and is often used as a natural preservative in food and cosmetic products (Hammoudi et al., 2022). Golubkina et al. (2020) reported that the use of mycorrhizal fungi as a technology that is compatible with the environment and by increasing plant access to nutrients and increasing resistance to stresses as well as improving water absorption, can lead to improved plant growth. Today, the use of organic compounds such as humic acid can affect many morphological, physiological and biochemical processes of plants and lead to improvement in plant growth (Mousavi et al., 2022).Materials and MethodsIn order to investigate the effects of foliar application of humic acid fertilization and mycorrhizal fungi symbiosis on Thymus vulgaris L., a factorial layout has been applied, based on a randomized complete block design with three replications at the field of the research farm of Islamic Azad University, Takestan Branch during 2020-2021 and 2021-2022 growing seasons. Experimental factors included three species of mycorrhiza fungi (control, Glomus mosseae, G.etunicatum and G.intradices) and humic acid fertilizer levels included (control, 150 and 300 mg.L-1). Important traits such as plant height, herbal fresh weight, essential oil percentage, and yield, flavonoid content, root colonization percentage, thymol and carvacrol percentage were measured and analyzed.Results and DiscussionThe results showed that the effects of the treatments were significant at the 1% level for all investigated traits. For the characteristics of essential oil percentage and essential oil yield, the interaction effect was also significant at 1%, with an observed increase of over 200%. The application of 300 mg/liter humic acid resulted in a 14% increase in root colonization and a 16% increase in flavonoid percentage. Similarly, the application of mycorrhiza increased these traits by 23% and 30%, respectively. Thymol and carvacrol were the most abundant essential oil compounds. It can be concluded that the quality of thyme essential oil improved under the treatments. Among the mycorrhizae used in this research, G. mosseae mycorrhizae were more effective than the other two types. The results suggest that the application of mycorrhiza has a more significant impact on improving the examined traits compared to humic acid.ConclusionBased on the results of this study, application of mycorrhiza due to creating a symbiotic relationship with the roots of the garden thyme plant and humic acid spraying could increase the quantity and quality of the produced product. mycorrhiza was better than the use of humic acid in most treatments.

Abstract Mosquito-borne diseases, such as malaria, dengue, and Zika, pose major public health challenges globally, affecting millions of people. The growing resistance of mosquito populations to synthetic insecticides underscores the critical need for effective and environmentally friendly larvicides. Although chemical pesticides can initially be effective, they often lead to negative environmental consequences and health hazards for non-target species, including humans. This study aimed to evaluate the larvicidal effects of Trachyspermum ammi essential oil and Delphinium speciosum extract on the larvae of three major mosquito species: Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus. Mosquito larvae of Ae. aegypti, An. stephensi, and Cx. quinquefasciatus were reared under controlled laboratory conditions. The larvicidal activity of T. ammi essential oil and D. speciosum extract was evaluated through standard bioassays, using various concentrations of essential oils (10, 20, 40, 80, and 160 ppm) and extracts (160, 320, 640, 1280, and 2560 ppm) to determine the lethal concentration (LC50) values after 24 h of exposure. Fresh plant materials were collected, with the essential oil extracted via hydro-distillation, and the extract prepared using methanol solvent extraction. The chemical composition of T. ammi essential oil was examined using gas chromatography-mass spectrometry (GC-MS). Additionally, the preliminary analysis of the chemical compounds in D. speciosum extract was carried out using thin layer chromatography (TLC) and nuclear magnetic resonance spectroscopy (NMR) techniques. The results indicated that the essential oil of T. ammi exhibited more effective larvicidal activity compared to the D. speciosum extract. Specifically, the essential oil demonstrated LC50 values of 18 ppm for Cx. quinquefasciatus and 19 ppm for Ae. aegypti. In contrast, the D. speciosum extract showed the strongest larvicidal effect against An. stephensi, with an LC50 of 517 ppm. Concentrations of 40 ppm of the essential oil and 1280 ppm of the extract resulted in 100% mortality across all three species. Both the essential oil of T. ammi and the D. speciosum extract exhibited concentration-dependent larvicidal activity, and these results were statistically significant (p

The thymol chemotype of the essential oil of Thymus vulgaris (EOTV-T) and its nanoemulsion (NEOTV-T) were investigated as anesthetics in the management of Colossoma macropomum. The stability of nanoemulsions was analyzed by zeta potential and dynamic light scattering for an interval of 37 days prior to carrying out two anesthesia experiments. The first experiment determined anesthesia induction and recovery intervals for juveniles anesthetized with different concentrations of EOTV-T and NEOTV-T. Based on the obtained induction and recovery curve, the second experiment adopted concentrations of 75 mg/L of EOTV-T and 50 mg/L of NEOTV-T for use during biometric management every 10 days for 60 days of cultivation of juvenile C. macropomum. The results showed that NEOTV-T had an average diameter of less than 100 nm for up to 22 days and was more effective at inducing anesthesia than EOTV-T. The continuous use of anesthetics during biometrics did not affect juvenile performance in terms of growth, feed consumption, and survival. Furthermore, no significant differences were observed in hematological and biochemical parameters between juveniles of the control treatment and those subjected to biometric management using 75 mg/L of EOTV-T and 50 mg/L of NEOTV-T. It can be concluded that the essential oil of T. vulgaris and its nanoemulsion can be used to facilitate the management of juvenile C. macropomum without compromising their performance or well-being. [ABSTRACT FROM AUTHOR]

Nanostructured lipid carrier (NLC) is a second-generation smart delivery system with a solid matrix at room temperature. This carrier system consists of biocompatible surfactants and lipid materials and is accepted by regulatory authorities for use in various delivery systems. This study is a comparative study between the function of thymol-loaded NLC and thymol-nanoemulsion (NE) in Na-alginate coating to extend the shelf life of fresh chicken meat. Results indicated that the droplet size of the NE and NLC was 105.7 and 164.2 nm with encapsulation efficiency of 99% and 96%, respectively. The agar diffusion method results exhibited higher inhibition zones for free thymol and NE than those for NLC against S. aureus and E. coli. Meanwhile, a faster release profile for thymol was observed in NE than in NLC. The lowest peroxide values, TVBN amounts, microbial quality (against total viable counts, Enterobacteriaceae, lactic acid bacteria, and total mold and yeast), and the highest sensory attributes and color parameters were achieved in nanocomposite alginate coatings. Overall, Al-NE, Al-NLC, and Al-NE-NLC can be potent alternatives for improving the shelf life and stability of fresh chicken fillets during cold storage. In this regard, Al-NLC may be a better choice due to its higher sensory scores over time. [ABSTRACT FROM AUTHOR]

Sheath blight of rice is a global disease that significantly reduces rice yield. This study reports the antifungal activity of an active compound of essential oil, thymol, at different concentrations against Rhizoctonia solani (strain RS‐Gvt). In vitro assay results indicated that thymol concentrations (0.5 mg mL−1 and 0.25 mg mL−1) completely inhibited (100%) the mycelial growth of RS‐Gvt (p ≤ 0.01). Microscopic observations of thymol‐treated mycelium of RS‐Gvt at 0.0312 mg mL−1 and above concentrations, revealed a distorted mycelial morphology with deformed hyphae. Hyphae showed a bead‐like appearance, reduction in size, and constriction of the hyphae at uneven points with increased hyphal density often entangling with each other. Further, an on‐field experiment was conducted to study the field bio‐efficacy of thymol for two consecutive Kharif seasons of 2022 and 2023 using a factorial RCBD design. The disease severity was measured as the percent disease index (PDI), and the results of two seasons were pooled. Pathogen (RS‐Gvt) and thymol were inoculated in different combinations/methods as main treatments (M1‐M3), and concentrations of thymol (0.0625–1.0 mg ML−1) as sub‐treatments. The results indicated that all two factors significantly (P = 0.05) influenced the PDI and grain yield. The pooled data of two seasons indicated a significant difference between the main treatments (M1: RS‐Gvt + thymol together; M2: thymol sprayed first followed by RS‐Gvt; M3: RS‐Gvt first followed by thymol spray) on PDI (53.39–59.67) and grain yield (4.16–4.75 t ha−1). M1 exhibited a lower PDI (53.39) and a higher grain yield (4.75 t ha−1) compared to M2 and M3, indicating a protective mode of action of thymol against sheath blight disease of rice. The sub‐treatments have shown significant variation in PDI and grain yield. The PDI and grain yield ranged from 33.70 (at 1 mg mL−1) to 66.21 (at 0.0625 mg mL−1) and 4.18 (at 1 mg mL−1) to 5.26 (at 0.0625 mg mL−1) t ha−1, respectively, among the thymol concentrations. This indicates that increasing concentrations of thymol have negatively influenced the PDI and positively impacted the yield. Therefore, the spray of 1 mg mL−1 of thymol at the potential disease‐infection stage is most effective in controlling the sheath blight disease of rice. This study provides an alternative green bioactive compound for controlling the sheath blight disease, and thymol can be included in developing eco‐friendly integrated disease management practices. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Introduction and objectives: Klebsiella pneumoniae is an opportunistic pathogen that plays a major role in the development of nosocomial infections. One of the most important mechanisms of resistance to beta-lactam antibiotics is the production of beta-lactamase enzymes by this bacterium. The aim of this study was to determine the frequency of AmpC beta-lactamase producing clinical isolates of K. pneumoniae in Guilan and investigating the inhibitory effect thymol on these isolates. Methods: Sixty isolates of K. pneumoniae were isolated and identified from clinical laboratories in Rasht during 2022. The pattern of antibiotic susceptibility in isolates was determined and beta-lactamase production was investigated using combined disk method. The presence of AmpC encoding genes including FOX, CITM and DHAM beta-lactamase genes in isolates was determined by PCR. The growth inhibitory effect of thymol on these isolates was determined using disck diffusion and broth microdilution and the efflux inhibitory effect was determined by Cartwheel methods. Results: Among tested isolates 46 (76.6%) showed multi drug resistant phenotype. Of the 22 phenotypically AmpC-producing isolates, CITM and DHAM genes were detected in 12 (20%) and 7 (11.66%) isolates respectively and 4 isolates had both CITM and DHAM genes at the same time. Thymol, showed growth and efflux inhibitory effects against all tested K. pneumoniae isolates. Conclusion: The results of the present study suggest the necessity of finding a successful treatment option to prevent the spread of infections caused by AmpC producing K. pneumoniae. According to the results, the use of thymol can provide a basis for the development of a new treatment against multi-drug resistant Klebsiella pneumoniae.

Background and Aim: In drug delivery, the formation of cyclodextrin complexes is a widely used strategy to overcome biopharmaceutical challenges associated with various active pharmaceutical ingredients, such as poor water solubility, initial instability, and low bioavailability. Given the anti-cancer properties of thymol, this study aimed to evaluate the effects of thymol-loaded nanoparticles in a beta-cyclodextrin complex and to assess their anti-cancer effects in melanoma skin cancer cells (A2058) by examining the expression of the VEGF and VEGFR genes. Methods: The synthesized nanoparticles were characterized using various methods, including zeta potential analysis, ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). To determine the cytotoxicity of the synthesized nanocomplex, the MTT assay was performed with β-CD-Thymol nanoparticle concentrations ranging from 62.5 to 500 μg/ml. The Chorioallantoic Membrane (CAM) assay was conducted to evaluate the cytotoxicity of the synthesized β-CD-Thymol nanoparticles in the context of angiogenesis. Finally, the expression levels of genes involved in angiogenesis (VEGF and VEGFR) were analyzed using real-time PCR. Results: Dynamic light scattering analysis revealed that the mean size of the nanoparticles was 116.20 nm, with a zeta potential of -21.64 mV. FTIR studies indicated the presence of several biologically active functional groups in the synthesized nanoparticles. Additionally, the anti-cancer effects and inhibitory role of the β-CD-Thymol complex were confirmed by a significant reduction in the expression of angiogenesis-related genes (VEGF and VEGFR) in A2058 cells treated with the β-CD-Thymol nanoparticle complex (P < 0.001). The results from the CAM assay further supported these findings. Conclusion: The findings of this study demonstrated a significant decrease in the expression of genes involved in angiogenesis, specifically VEGF and VEGFR, indicating that the β-CD-Thymol complex effectively inhibits angiogenesis in the A2058 skin cancer cell line. Overall, in addition to inhibiting the formation of new blood vessels, the β-CD-Thymol nanostructure shows promise as an anti-angiogenic agent by modulating the expression of VEGF and VEGFR genes.

[Objective] This study aimed to evaluate the antimicrobial efficacy of essential oil (EO) from diverse chemotypes of Lippia graveolens against oxytetracycline-resistant Aeromonas hydrophila, which primarily affects the tilapia aquaculture (O. niloticus) in Guatemala. [Methodology] L. graveolens were collected in three departments in Guatemala. The EO was obtained by hydrodistillation and characterized using gas chromatography and mass spectrometry (GC/MS). Subsequently, an antimicrobial assay was conducted using disk and dilution susceptibility tests and evaluation of synergistic interactions among the chemotypes. Each test was performed in triplicate. [Results] The analysis revealed the presence of twenty-seven compounds in the EO obtained from the chemotypes, with the main class being monoterpenes. The major constituents identified were cis-Dihydro-β-terpineol (8.84%) in chemotype I, carvacrol (51.82%) in chemotype II, and thymol (79.62%) in chemotype III. All EO chemotypes of L. graveolens demonstrated the ability to inhibit the A. hydrophila growth. Thymol chemotype exhibited the strongest inhibitory effect against bacterial growth, with a minimum inhibitory concentration (MIC) of 92.4 µg/mL and a minimum bactericidal concentration (MBC) of 184.8 µg/mL. Furthermore, the results suggest that there is no synergistic or additive effect when combining different chemotypes of L. graveolens. [Conclusions] This is the first report of L. graveolens chemotypes exhibiting antimicrobial activity against oxytetracycline-resistant A. hydrophila. The findings suggest that the chemotype thymol could be a potential treatment for infections in the tilapia aquaculture in Guatemala.

Developing a spectroscopic approach to assess the medicinal substance thymol was one of the research's objectives. Using an oxidative coupling reaction between thymol solution and N,N-dimethyl-p-phenylenediamine dihydrochloride solution (N,N-DMPPDADH) in alkaline media with potassium periodate as an oxidizing agent, the current technology forms a blue-colored soluble product. The wavelength at which a colored product exhibits maximum absorption is 600 nm. According to Beer's law, the concentration range covered by the approach under review is 1.25–20.00 μg/mL of thymol. The specific molar absorbance value of 10725.71 L/mol cm indicates the method's sensitivity. The Sandell significance value was 0.014 μg/cm2, which represents sensitivity per unit length. The precision of the method is demonstrated to be commendable, and the low relative standard deviation value of 0.16% supports this. This method's accuracy in identifying thymol at such low quantities is demonstrated by its confirmed detection limit of 0.0124 μg/mL. The developed technique has been useful in screening thymol in pharmaceutical products, with mouthwash being the focus of particular attention. Thymol content in real-world samples was accurately determined using the approach, as evidenced by the reported 101.13% recovery rate of thymol in the examined samples.

Objective: Trichomonas vaginalis is a sexually transmitted protozoan parasite that usually causes infections in women. Metronidazole is used as the first choice in the treatment of this parasitic disease, but there is a need for new drugs since 1980’s with increasing numbers of reported resistance. In this study, it was aimed to determine the antitrichomonal activity of the major components of Cinnamomum zeylanicum (cinnamon) and Thymusvulgaris (thyme) essential oils, cinnamaldehyde, carvacrol and thymol against metronidazole resistant and susceptible T. vaginalis strains, and to determine their interaction with metronidazole by checkerboard method. Methods: Cinnamaldehyde, carvacrol, thymol and metronidazole were obtained commercially. Two clinical isolates and one metronidazole resistant T. vaginalis reference strain were used in the study. MIC50 and MLC values of essential oil components and metronidazole were determined by broth microdilution method. The combinations of essential oil components with metronidazole were determined by the checkerboard method. Results: According to in vitro activity tests, cinnamaldehyde was determined to be most effective essential oil component. Clinical isolates were susceptible to metronidazole. In combination study, metronidazole showed synergy with cinnamaldehyde and carvacrol, and partial synergy with thymol. Conclusion: It was determined that cinnamaldehyde, carvacrol and thymol, which are known to have high antimicrobial activity, also have strong activity against T. vaginalis isolates and show a synergistic interaction with metronidazole. The use of metronidazole at lower doses in the synergistic interaction may contribute to the literature in terms of reducing drug side effects, creating a versatile antimicrobial target, and reducing the rate of resistance development.

An ultrasound-assisted dispersive liquid–liquid microextraction by solidifying floating organic droplets, coupled to a form of temperature-programmed gas chromatography flame ionization detection, has been developed for the extraction and determination of thymol and carvacrol. This method utilizes undecanol as the extraction solvent, offering advantages such as facilitating phase transfer through solidification and enhancing solvent-focusing efficiency. The optimal gas chromatography conditions include a sample injection volume of 0.2 µL, a split ratio of 1:10, and a flow rate of 0.7 mL min−1. The extraction conditions entail an extraction solvent volume of 20 µL, a disperser solvent (acetone) volume of 500 µL, pH 7.0, 7.0% NaCl (3.5 M), a sample volume of 5.0 mL, an ultrasound duration of 10 min, and a centrifuge time of 7.5 min (800 rpm). These conditions enable the achievement of a high and reasonable linear range of 3.5 to 70. 0 μg mL−1 for both thymol and carvacrol. The detection limits are found to be 0.95 and 0.89 μg mL−1, respectively, for thymol and carvacrol. The obtained relative standard deviations, 2.7% for thymol and 2.6% for carvacrol, demonstrate acceptable precision for the purpose of quantitative analysis. [ABSTRACT FROM AUTHOR]

[Objective] To study the thymol regulate rice salt tolerance in saline soil. [Method] Selecting rice filed with high salinity (salinity 0. 4‰) in Dongtai City, Jiangsu Province as the research object, self-developed natural bio-stimulator (5% thymol) at flowering period was sprayed, in order to evaluate the effect of thymol on the regulation of rice salt tolerance in filed. [Result] Spraying thymol was able to enhance the physiological status of flag leaves in saline soil, such as the increase in chlorophyll content, proline content and reducing sugar content. Spraying thymol increased the grain plumpness, kernel number per spike and thousand kernel weight in saline soil. Spraying thymol enhanced rice viscosity and prolamin content, and decreased rice amylose content in saline soil. [Conclusion] Spraying thymol effectively stimulated rice tolerance against salinity in field by maintaining productivity and rice quality in saline soil. This may provide scientific basis for the development of novel regulators conferring salt tolerance and its applying technology in field. [ABSTRACT FROM AUTHOR]

Among the most alarming postharvest fungal pathogens affecting the shelf life of citrus fruits are green (Penicillium digitatum) and blue (Penicillium italicum) molds. This in vitro study was aimed to evaluate the essential oils (EOs) of Cymbopogon flexuosus (CF) and Monarda citriodora (MC) and their principal components against these fungal pathogens. The composition of selected EOs was analyzed using Gas Chromatography- Mass Spectrometry (GC-MS) and Gas Chromatography-Flame Ionization Detector (GC-FID). Citral (83.81%) and thymol (62.51%) were identified as major components and were isolated by column chromatography from CF and MC EO respectively followed by characterization using spectral techniques such as Fourier Transform Infrared Spectroscopy (FTIR), Proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR) and Carbon Nuclear Magnetic Resonance Spectroscopy (13C-NMR). Among EOs and their major components, thymol displayed promising potential against both Penicillium species with MIC values of 50 and 80 mg L-1 respectively. Molecular docking studies also confirmed the stable binding interaction of both components, particularly thymol with the active sites of target proteins i.e. 14-α-demethylase and chitin synthase of P. digitatum and P. italicum with the docking scores of -5.07, -5.41 kcal/mol and -5.78, -5.23 kcal/mol respectively. Optical microscopy studies revealed hyphal thinning and fragmentation at frequent sites with contraction of cytoplasmic content indicating incipient plasmolysis. The tested principal components, citral and thymol were predicted to exhibit similar mechanism of action to that of synthetic recommended molecules as revealed by molecular docking. Therefore, these findings provide empirical support to explore thymol as a promising eco-friendly antifungal agent for postharvest application in Kinnow. [ABSTRACT FROM AUTHOR]

Lemon bee balm (Monarda citriodora Cerv. ex-Lag) is a noble industrial medicinal and aromatic plant species, which is used as digestive, antifungal, anti-inflammatory and menstrual irregularity remedies in traditional medicine. It is a common source of thymol and other active constituents with recognized antimicrobial properties. A multilocation field trial was performed to evaluate essential oil (EO) yield stability, secondary metabolites and economic returns in eight diverse geographical environment conditions (GEC) in India. The secondary metabolites viz., essential oil content and oil yield were found to be highest in tropical and sub-tropical regions. The essential oil content was found to be higher in inflorescence part at all the experimental sites and found to be highest (0.85±0.21%) at BR-JALAUN. The highest EO yield (130.25±3.25 kg ha−1), net return (Rs. 1,22,125.00±245.21 ha−1) and benefit cost (B:C) ratio (2.67±0.17) was recorded at FFDC-KANNAUJ. The thymol content percentage was found to be highest on physiological maturity (>95% flowering) [PM] and on 75% flowering [FS-II] and it began to decline on seed formation stage at all the experimental sites. The significantly highest thymol content percentage was found on PM (86.65±3.91%) and on FS-II (84.21±3.78%) at TBR-JHANSI. On the basis of the gas chromatography and mass spectrophotometry analysis, twenty constituents were isolated. The inflorescence EO contains more thymol than the EO from leaves with stem which in turn was characterized by a higher content of p-cymene, γ-terpinene, carvacrol, α-phellandrene, α-pinene, myrcene, α-terpinene, citral and β-caryophyllene. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the antioxidant, anti-inflammatory, and anticancer properties of thymol, carvacrol, and their equimolar mixture. Antioxidant activities were assessed using the DPPH, ABTS, and ORAC methods. The thymol/carvacrol mixture exhibited significant synergism, surpassing the individual compounds and ascorbic acid in DPPH (IC50 = 43.82 ± 2.41 µg/mL) and ABTS (IC50 = 23.29 ± 0.71 µg/mL) assays. Anti-inflammatory activity was evaluated by inhibiting the 5-LOX, COX-1, and COX-2 enzymes. The equimolar mixture showed the strongest inhibition of 5-LOX (IC50 = 8.46 ± 0.92 µg/mL) and substantial inhibition of COX-1 (IC50 = 15.23 ± 2.34 µg/mL) and COX-2 (IC50 = 14.53 ± 2.42 µg/mL), indicating a synergistic effect. Anticancer activity was tested on MCF-7, MDA-MB-231, and MDA-MB-436 breast cancer cell lines using the MTT assay. The thymol/carvacrol mixture demonstrated superior cytotoxicity (IC50 = 0.92–1.70 µg/mL) and increased selectivity compared to cisplatin, with high selectivity indices (144.88–267.71). These results underscore the promising therapeutic potential of the thymol/carvacrol combination, particularly for its synergistic antioxidant, anti-inflammatory, and anticancer properties against breast cancer. This study paves the way for developing natural therapies against breast cancer and other conditions associated with oxidative stress and inflammation, leveraging the synergistic effects of natural compounds like thymol and carvacrol. [ABSTRACT FROM AUTHOR]

Background: 5-fluorouracil (5-FU) is a widely used, highly effective chemotherapeutic agent. However, its therapeutic efficacy is often limited by associated adverse effects, with hepatotoxicity being frequently reported with 5-FU therapy. Thymol is a monoterpene found in thyme (Thymus vulgaris L., Lamiaceae) and is known for its antioxidant, anti-apoptotic, and anticancer activities. This study aimed to explore the hepatoprotective activity of thymol against 5-FU-induced liver injury. Methods: Rats received two intraperitoneal doses of 5-FU (150 mg/kg) either alone or in combination with thymol at doses of 60 mg/kg or 120 mg/kg. Liver enzymes, oxidative stress, and apoptotic markers, in addition to histopathological changes, were assessed. Results: 5-FU induced marked liver injuries as evidenced by elevated liver enzymes and histopathological changes, in addition to abnormalities of oxidative and apoptotic markers. The administration of thymol ameliorated the 5-FU-induced oxidative damage through increasing hepatic antioxidants and lowering lipid peroxidation. Apoptotic response markers such as Bax, Bcl-2, Bax/Bcl-2 ratio, and PARP were also improved. Furthermore, Western blotting analysis showed that thymol modulated the 5-FU-induced changes in the expression of Akt/GSK-3β and p44/42 MAPK (ERK1/2) signaling pathways. Conclusions: Our research is the first to shed light on thymol's potential protective effect against 5-FU- induced hepatotoxicity by inhibiting oxidative and apoptotic pathways and modulating the Akt/ GSK-3β as well as p44/42 MAPK (ERK1/2) signaling pathways. [ABSTRACT FROM AUTHOR]

Carvacrol and thymol are broad-spectrum natural antimicrobial agents. To reduce their volatility and improve their antimicrobial performance, synergistic systems were prepared loading the active molecules in zinc-modified clays. Montmorillonite (MMT) and zeolite (ZEO) were modified with zinc ions (ZnMMT and ZnZEO), with well-known antimicrobial properties, and then with carvacrol or thymol, reaching the 26 ± 3% and 33 ± 2% w/w of loading, respectively. The resulting hybrid materials were characterized by FT-IR, XPS, XRD, TGA, and GC-MS to evaluate carvacrol/thymol release in simulating food matrices. Antimicrobial assays carried out using spoiler and pathogenic bacterial strains showed that the antimicrobial activity of both thymol and carvacrol was largely preserved once they were loaded into Zn-modified clays. However, MMT hybrids showed an antibacterial activity significantly higher than ZEO hybrids at 50 mg/mL of thymol and carvacrol. For this reason, deeper antimicrobial evaluations were carried out only for ZnMMT composites. ZnMMT loaded with thymol or carvacrol produced inhibition zones against most of the target strains, also at 3.12 mg/mL, while the positive controls represented by the single molecule thymol or carvacrol were not active. The hybrid materials can be useful for applications in which the antimicrobial activity of natural molecules need to be displayed over time as requested for the control of microbial pathogens and spoilage bacteria in different applications, such as active packaging, biomaterials, and medical devices. [ABSTRACT FROM AUTHOR]