Concentrations Of Thymol Research Articles

Improved yields and essential oil composition of ajowan (Trachyspermum ammi L.) and soil fertility properties in intercropping systems

ABSTRACT Legume-based intercropping systems have been proposed as sustainable and eco-friendly systems with potential to improve crop production and soil fertility. A field experiment was conducted in two growing seasons (2017 and 2018) to determine optimal intercropping patterns of ajowan (Trachyspermum ammi L.) and fenugreek (Trigonella foenum-graecum L.) to increase yield and quality of the ajowan and to improve soil properties. The treatments evaluated in this study were sole cropping of ajowan (A) and fenugreek (F), replacement intercropping series of A:F (1:1, 4:4, 3:1, and 1:3 ratios) and additive intercropping series of A:F (100:12.5, 100:25, 100:37.5, 100:50, 100:62.5, 100:75, and 100:87.5 ratios). The results showed that the highest biological yield (4172.7 kg ha−1), seed yield (1009.7 kg ha−1), and essential oil yield (42.0 kg ha−1) of ajowan were obtained in the additive pattern A:F 100:25. The highest concentrations of thymol and γ-terpinene, the major chemical components of ajowan essential oil, were recorded for the A:F 100:25 intercropping pattern. Total LER and ATER indices were above one in all of the intercropping patterns. The concentrations of soil total organic carbon (TOC) and nitrogen (TON), available forms of NO3 − and NH4 +, Mg2+, K+, as well as basal respiration (BR) and substrate-induced respiration (SIR) in the A:F 100:25 intercropping pattern were greater than for the fenugreek and ajowan sole crops. Overall, the analysis showed that the A:F 100:25 additive intercropping pattern had positive and strong effects in terms of increased yield and quality of ajowan and improvement of soil fertility.

In vitro and in vivo study of the antiparasitic effect of thymol on poultry drinking water

The current study evaluates the antiparasitic effect of thymol on reducing parasite burden, especially Cryptosporidium load, in poultry drinking water and in improving zootechnical performances of chicks. The first experiment assessed in vitro the anti-cryptosporidium activity of NP (thymol-based product) on drinking water samples using microscopic counting. Samples were treated by increasing concentrations of thymol (1, 2 and 4 g L-1 of NP). In vivo, chicken were randomly assigned to three groups (control and chicks consuming treated water with two concentration of thymol (1 and 2 g L-1 of NP). Water treatment efficiency was evaluated on the intestinal parasitic load and zootechnical performances of animals (Body weight, body weight gain, food intake and the consumption index). In vitro the anti-cryptosporidium effect was dose dependent (p <0.05; p <0.01; p <0.001). The in vivo test showed that the intestinal parasitic load was significantly lower (p <0.05; p <0.01; p <0.001) in the group treated with 2 g L-1 of NP. Additionally, results showed a significant increase (p <0.05; p <0.1; p <0.001) in the body weight and the body weight gain of treated groups during the whole rearing period compared to the control. Furthermore, treated groups represent a lower consumption index compared to the control.

Thymol-enriched extract from Thymus vulgaris L leaves: Green extraction processes and antiaggregant effects on human platelets

This work focuses on the selection and the optimization of an efficient green-extraction method, used to recover a thymol-enriched extract from thyme (Thymus vulgaris L), as well as the evaluation of the inhibitory effect of this latter on the human platelet aggregation. Different innovative extraction techniques, namely bead milling extraction, ultrasound and microwave assisted extraction, were tested for their ability to recover a high added value extract from thyme. Among all tested eco-extraction techniques, microwave extraction (MAE) was the best method in term of its extraction yield (20.84% ± 0.51), thymol concentration (731.71 mg/g) and total phenolic (23.53 ± 1.83 mg (GAE)/g of extract) and flavonoid (6.22 ± 0.35 mg of QE/g of extract) contents. Moreover, thyme extract obtained by microwave assisted extraction (TMAE) showed the most active antioxidant effect comparing to the other tested extracts. Based on these results, TMAE was chosen to be evaluated for its antiplatelet effect. Thereby, arachidonic acid, collagen and ADP were used to induce the platelet aggregation on human platelet rich plasma taken from healthy controls and results revealed that TMAE strongly inhibited the induced platelet aggregation. Indeed, TMAE exhibited potent antiaggregant activity by inhibiting platelet activation, secretion and aggregation. Additionally, cytotoxicity assay on normal HEK-293 cells showed that TMAE has no cytotoxic effect even at high concentration (8 mg/ml) and can further be taken up to various biomedical applications mainly in the prevention of cardiovascular diseases.

A green approach to develop zeolite-thymol antimicrobial composites: analytical characterization and antimicrobial activity evaluation

In this work, the development, analytical characterization and bioactivity of zeolite-thymol composites, obtained using wet, semi-dry and dry processes, were carried out in order to obtain sustainable and powerful antimicrobial additives. FT-IR, XRD, DSC, TGA, SEM and B.E.T. analyses were carried out to gain comprehensive information on the chemical-physical, thermal, and morphological features of the composites. GC-MS analyses allowed quantifying the active molecule loaded in the zeolite, released by the functionalized composites and its stability over time. Among the three procedures, the dry approach allowed to reach the highest thymol loading content and efficiency (49.8 ± 1.6% and 99.6 ± 1.2%, respectively), as well as the highest composite specific surface area value, feature which promises the best interaction between the surface of the composite and the bacterial population. Therefore, the bioactive surface of composites obtained by this solvent-free method was assayed for its antimicrobial activity against four microbial strains belonging to Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans species. The higher antimicrobial activity produced by the solvent-free composite in comparison with that of pure thymol, at the same thymol concentration, was ascribed to the large interfacial contact between the composite and the bacterial target. This feature, together with its enhanced storage stability, suggested that this composite could be employed as effective additives for the development of antimicrobial biointerfaces for food, home and personal care applications.

Chemical comparison of the essential oils of Lippia Origanoides in two agroclimatic zones of the Colombian Caribbean coast

The objective of this research is to compare the chemical profiles of the essential oils of Lippia origanoides leaves collected in Santa Marta and Sincelejo at different hours. The leaves were harvested at 6:00 a.m., 12:00 p.m, and 6:00 p.m, the essential oils were extracted by hydrodistillation assisted by microwave radiation and the chemical profiles were determined by gas chromatography coupled to mass spectrometry. The results showed Thymol as the major metabolite in all samples, however, Sincelejo presented the highest percentages of Thymol with 68.02% at 6:00 a.m., while in Santa Marta at 6:00 p.m was 63.19%. In all cases, the lowest concentrations of Thymol were found at 12:00 md, because high temperatures can volatilize this compound and in the case of Santa Marta, because it is a coastal area and temperature at noon is higher than in Sincelejo. Therefore, concentrations of 33.12% and 59.06% were found respectively. A similar case occurs with Ocimeno and 3-Tujeno, which showed a decrease of concentration in this period.

Thymol Protects against Aspergillus Fumigatus Keratitis by Inhibiting the LOX-1/IL-1β Signaling Pathway.

To explore the anti-inflammatory effects and mechanisms of action of thymol in Aspergillus fumigatus (A. fumigatus) keratitis. The minimum inhibitory concentration of thymol against A. fumigatus was detected. To characterize the anti-inflammatory effects of thymol, mouse corneas and human corneal epithelial cells were pretreated with thymol or dimethyl sulfoxide (DMSO) before infection with A. fumigatus spores. Slit-lamp microscopy, immunohistochemistry, myeloperoxidase detection, quantitative real-time polymerase chain reaction, and Western blotting were used to assess infection. Neutrophil and macrophage recruitment, in addition to the secretion of LOX-1 and IL-1β, were quantified to evaluate the relative contribution of thymol to the inflammatory response. We confirmed that the growth of A. fumigatus was directly inhibited by thymol. In contrast with the DMSO group, there was a lower degree of inflammation in the mouse corneas of the thymol-pretreated group. This was characterized by significantly lower clinical scores, less inflammatory cell infiltration, and lower expression of LOX-1 and IL-1β. Similarly, in vitro experiments indicated that the production of LOX-1 and IL-1β was significantly inhibited after thymol treatment, in contrast with the DMSO-pretreated group. Our findings demonstrate that thymol exerted a direct fungistatic activity on A. fumigatus. Furthermore, thymol played a protective role in fungal keratitis by inhibiting LOX-1/IL-1β signaling pathway and reducing the recruitment of neutrophils and macrophages.

Phenolic compounds from Thymus vulgaris, Artemisia annua extracts and pure Thymol were tested against twenty Pseudomonas spp. strains for antibacterial and anti-biofilm activities

The widespread use of broad-spectrum antibiotics has resulted in antibiotic resistance for many human bacterial infections, making multi-drug resistance a significant challenge in the treatment of infectious diseases. The antibacterial impact of phenolic plant extracts has been studied in new and different ways. The phenolic extract of Thymus vulgaris, Artemisia annua and pure thymol were used to study bacterial biofilm formation. In addition, the experiments were carried out to determine the lowest inhibitory concentrations in order to evaluate the antibacterial impact (MICs) against 20 isolations of Pseudomonas species. In this report, the plant extract was analyzed by HPLC techniques to determine the Thymol value. Although the Thymus vulgaris and Artemisia annua phenolic plant extracts and pure thymol concentrations (50, 25, 12.5, 6.25, 3.125, 1.250 and 0.006 mg/ml) (W/V)) were used through antibiotic and biofilm inhibition assay. The best results of MICs of T. vulgaris, A. annua extract and pure Thymol against bacteria isolates were 5.000 mg/ml, 1.250 mg/ml and 0.006 mg/ml, respectively. Stimulatory, the effect of T. vulgaris, A. annua extract and pure Thymol on biofilm formation were gave 10 mg/ml, 5mg/ml and 0.006 mg/ml respectively.

Antifungal activity of thymol against the main fungi causing pomegranate fruit rot by suppressing the activity of cell wall degrading enzymes

Postharvest rot of pomegranate fruits due to fungal infections causes the loss of a significant amount of fruit. In this study, the antifungal effects of thymol on the growth of Aspergillus niger (A. niger) and Penicillium commune (P. commune) were investigated. Molecular sequence analysis of internal transcribed spacer (ITS) gene was used to identify fungal species. ITS of rDNA amplified by polymerase chain reaction (PCR), sequenced and after basic local alignment search, it was registered in GenBank database. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of thymol for both fungi were 250 and 500 μg mL−1, respectively. Scanning electron microscopy (SEM) in A. niger colony showed cell deformation due to destruction of the cell membrane and loss of cell wall strength at 250 μg mL−1 after 168 h. Evaluation of P. commune cell morphology showed that thymol at 250 μg mL−1 caused superficial wrinkles, bifurcation of hyphal apex and no spore production was observed. Thymol suppressed fungal growth by reducing cellulase and pectinase activity. The smallest cellulase and pectinase halo diameter was found at 125 μg mL−1 of thymol. Thymol at 500 μg mL−1 had a similar fungicidal effect compared with thiabendazole (1500 μg mL−1).

Effects of carvacrol and thymol on the antioxidant and detoxifying enzymes of Rhipicephalus microplus (Acari: Ixodidae)

The present study was conducted to evaluate the effects of carvacrol and thymol on the antioxidant and detoxifying enzymes of larvae from two populations of R. microplus: Jaguar (tick population resistant to six classes of acaricides) and Porto Alegre (susceptible tick population). Carvacrol and thymol were tested at concentrations ranging from 0.14 to 5.0 mg mL−1 in both populations to determine the LC50. In addition, the LC1, LC25, and LC75 were estimated using the LC50 and HillSlope of each compound. Larvae of both populations of R. microplus were then treated with the LC1, LC25, LC50, and LC75 of each monoterpene, and those that survived were processed to evaluate the effects of the compounds on the antioxidant and detoxifying systems of larvae; these effects were assessed by determining the activity of the enzymes, glutathione-S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX). Larvae from the Jaguar population treated with different lethal concentrations of carvacrol and thymol displayed a dose-dependent increase in CAT, GPX, SOD, and GST after treatment with LC25. Further, larvae treated with the LC75 had the highest levels of enzyme activity for carvacrol (1.76 mg mL−1) and thymol (1.32 mg mL−1). CAT, GPX, SOD, and GST activity in Porto Alegre population larvae treated with carvacrol and thymol also increased significantly up to the LC50 of each monoterpene. However, at the LC75 of carvacrol and thymol, a decrease in the activity of all enzymes was observed for this tick population. These findings indicate that carvacrol and thymol induced increased activity of all evaluated enzymes at different lethal concentrations in R. microplus larvae from two populations. Such findings unveil the possible mechanisms of action of these natural acaricides.

Assessment of Sex-Specific Toxicity and Physiological Responses to Thymol in a Common Bean Pest Acanthoscelides obtectus Say.

Acanthoscelides obtectus Say (Coleoptera: Chrysomelidae: Bruchinae), is one of the most important pests of the common bean Phaseolus vulgaris L. Without appropriate management it may cause significant seed loss in storages. In search for means of environmentally safe and effective protection of beans we assessed biological activity of thymol, an oxygenated monoterpene present in essential oils of many aromatic plants. We studied contact toxicity of thymol on bean seeds and its effects on adult longevity and emergence in F1 generation. Furthermore, we determined acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT), mixed-function oxidase (MFO), carboxylesterases (CarE) and glutathione S-transferase (GST) activities in response to 24 h exposure of beetles to sublethal and lethal thymol concentrations. Our results showed that thymol decreased adult survival, longevity and percentage of adult emergence. Higher median lethal concentration (LC50) was recorded in females indicating their higher tolerance comparing to males. Overall, activities of SOD, CAT and CarE increased at sublethal and MFO increased at both sublethal and lethal thymol concentrations. On the other hand, GST and AChE activities decreased along with the increase in thymol concentrations from sublethal (1/5 of LC50, 1/2 of LC50) to lethal (LC50). Enzyme responses to the presence of thymol on bean seed were sex-specific. In the control group females had lower CarE and higher SOD, CAT and GST activity than males. In treatment groups, females had much higher CAT activity and much lower CarE activity than males. Our results contribute to deeper understanding of physiological mechanisms underlying thymol toxicity and tolerance which should be taken into account in future formulation of a thymol-based insecticide.

Transcriptomics Reveals the Effect of Thymol on the Growth and Toxin Production of Fusarium graminearum.

Fusarium graminearum is a harmful pathogen causing head blight in cereals such as wheat and barley, and thymol has been proven to inhibit the growth of many pathogens. This study aims to explore the fungistatic effect of thymol on F. graminearum and its mechanism. Different concentrations of thymol were used to treat F. graminearum. The results showed that the EC50 concentration of thymol against F. graminearum was 40 μg/mL. Compared with the control group, 40 μg/mL of thymol reduced the production of Deoxynivalenol (DON) and 3-Ac-DON by 70.1% and 78.2%, respectively. Our results indicate that thymol can effectively inhibit the growth and toxin production of F. graminearum and cause an extensive transcriptome response. Transcriptome identified 16,727 non-redundant unigenes and 1653 unigenes that COG did not annotate. The correlation coefficients between samples were all >0.941. When FC was 2.0 times, a total of 3230 differential unigenes were identified, of which 1223 were up-regulated, and 2007 were down-regulated. Through the transcriptome, we confirmed that the expression of many genes involved in F. graminearum growth and synthesis of DON and other secondary metabolites were also changed. The gluconeogenesis/glycolysis pathway may be a potential and important way for thymol to affect the growth of F. graminearum hyphae and the production of DON simultaneously.

Thymol improves salinity tolerance of tobacco by increasing the sodium ion efflux and enhancing the content of nitric oxide and glutathione

Background and objectiveSalt stress is one of the most important abiotic stresses affecting the yield and quality of tobacco (Nicotiana tabacum). Thymol (a natural medicine) has been widely used in medical research because of its antibacterial and anti-inflammatory activities. However, the influence of thymol on the root growth of tobacco is not fully elucidated. In this study, the regulatory effects of different concentrations of thymol were investigated.MethodologyHere, histochemical staining and biochemical methods, non-invasive micro-test technology (NMT), and qPCR assay were performed to investigate the effect of thymol and mechanism of it improving salinity tolerance in tobacco seedlings.ResultsIn this study, our results showed that thymol rescued root growth from salt stress by ameliorating ROS accumulation, lipid peroxidation, and cell death. Furthermore, thymol enhanced contents of NO and GSH to repress ROS accumulation, further protecting the stability of the cell membrane. And, thymol improved Na+ efflux and the expression of SOS1, HKT1, and NHX1, thus protecting the stability of Na+ and K+.ConclusionOur study confirmed the protecting effect of thymol in tobacco under salt stress, and we also identified the mechanism of it, involving dynamic regulation of antioxidant system and the maintenance of Na+ homeostasis. It can be a new method to improve salinity tolerance in plants.

Evaluation of the membrane damage mechanism of thymol against Bacillus cereus and its application in the preservation of skim milk

The goal of this study was to elucidate the mechanism by which thymol caused membrane damages in Bacillus cereus cells and the feasibility of its application in the preservation of skim milk. The minimum inhibitory concentration (MIC) of thymol was determined using the broth microdilution method. The membrane potentials, intracellular adenosine triphosphate (ATP) concentrations, and pH gradients across the membrane were characterized using fluorescence spectroscopy. The degree of membrane damage and membrane structural integrity were observed under an electron microscope. The quantity of B. cereus in skim milk at different temperatures and concentrations of thymol was calculated using the plate counting method. As a result, the MIC of thymol against B. cereus BNCC 103930 was 0.625 mg/mL. Thymol significantly induced B. cereus cell dysfunction, membrane potential hyperpolarization, pH gradient dissipation, the blockade of ATP synthesis, and intracellular ATP depletion. Confocal laser scanning microscopy (CLSM) and field emission gun scanning electron microscope (FEGSEM) assays revealed pronounced membrane damages of B. cereus after thymol administration. Of note, low thymol concentrations, together with low-temperature storage, have the potential to control B. cereus in skim milk. These results indicated that thymol could be used as a food additive preventing B. cereus food poisoning. • The antimicrobial mechanism of thymol against Bacillus cereus was described. • Cell dysfunction induced by thymol was characterized using fluorescent probes. • Thymol causes morphological damages in Bacillus cereus. • Thymol controls the growth of Bacillus cereus in skim milk stored at low temperature.

Effect of thymol on physical properties, antimicrobial properties and fresh-keeping application of cherry tomato of starch/PBAT extrusion blowing films

In order to explore the effects of thymol on the antimicrobial activity, structure, physical properties and fresh-keeping application of starch/PBAT composite films, different contents of thymol (0, 1%, 3% and 5%) were used to prepare antimicrobial composite films by extrusion blow molding. The results indicated that tourier transform infrared spectroscopy showed there was intermolecular hydrogen bonding force among starch/PBAT and thymol. The inhibition effect on Botrytis cinerea and the preservation effect of cherry tomato of the composite film were significantly improved, the hardness and nutritional characteristics of cherry tomato were maintained, and the fruit decay rate was reduced. The addition of thymol increased the water vapor permeability of the starch based composite films, but reduced the interaction between the composite film and water. Although thymol reduced the mechanical properties of the composite film, high concentration of thymol further improved the mechanical properties. In conclusion, the high concentration of thymol improved the comprehensive properties of starch composite film, and proved the application prospect of the film as active food packaging material.

Carvacrol and Thymol Combat Desiccation Resistance Mechanisms in Salmonella enterica Serovar Tennessee.

Some Salmonella enterica serovars are frequently associated with disease outbreaks in low-moisture foods (LMF) due to their ability to adapt efficiently to desiccation stress. These serovars are often persistent during food processing. Disruption of these resistance responses was accomplished previously using the membrane-active lipopeptide, paenibacterin. This study was initiated to determine how desiccation resistance mechanisms are overcome when Salmonella Tennessee, a known resistant serovar, is treated with the membrane-active food additives carvacrol and thymol. Knowing that the minimum inhibitory concentrations (MICs) of carvacrol and thymol against Salmonella Tennessee are 200 and 100 µg/mL, the concentrations tested were 100–400 and 50–200 µg/mL, respectively. Results show that desiccation-adapted Salmonella Tennessee, prepared by air drying at 40% relative humidity and 22–25 °C for 24 h, was not inactivated when exposed for 4.0 h to less than 2xMIC of the two additives. Additionally, treatment of desiccation-adapted Salmonella Tennessee for 120 min with carvacrol and thymol at the MIC-level sensitized the cells (1.4–1.5 log CFU/mL reduction) to further desiccation stress. Treating desiccation-adapted Salmonella Tennessee with carvacrol and thymol induced leakage of intracellular potassium ions, reduced the biosynthesis of the osmoprotectant trehalose, reduced respiratory activity, decreased ATP production, and caused leakage of intracellular proteins and nucleic acids. Carvacrol, at 200–400 µg/mL, significantly downregulated the transcription of desiccation-related genes (proV, STM1494, and kdpA) as determined by the reverse-transcription quantitative PCR. The current study revealed some of the mechanisms by which carvacrol and thymol combat desiccation-resistant Salmonella Tennessee, raising the feasibility of using these additives to control desiccation-adapted S. enterica in LMF.

Physical, Mechanical, and Water Vapor Barrier Properties of Starch/Cellulose Nanofiber/Thymol Bionanocomposite Films.

The application of starch films, such as food packaging materials, has been restricted due to poor mechanical and barrier properties. However, the addition of a reinforcing agent, cellulose nanofibers (CNF) and also thymol, into the films, may improve the properties of films. This work investigates the effects of incorporating different concentrations of thymol (3, 5, 7, and 10 wt.%) on physical, mechanical, water vapor barrier, and antibacterial properties of corn starch films, containing 1.5 wt.% CNF produced using the solvent casting method. The addition of thymol does not significantly affect the color and opacity of the films. It is found that the tensile strength and Young’s modulus of the films decreases from 10.6 to 6.3 MPa and from 436.9 to 209.8 MPa, respectively, and the elongation at break increased from 110.6% to 123.5% with the incorporation of 10 wt.% thymol into the films. Furthermore, the addition of thymol at higher concentrations (7 and 10 wt.%) improved the water vapor barrier of the films by approximately 60.0%, from 4.98 × 10—9 to 2.01 × 10—9 g/d.m.Pa. Starch/CNF/thymol bionanocomposite films are also found to exhibit antibacterial activity against Escherichia coli. In conclusion, the produced starch/CNF/thymol bionanocomposite films have the potential to be used as antibacterial food packaging materials.

Combination of cypermethrin and thymol for control of Rhipicephalus microplus: Efficacy evaluation and description of an action mechanism

The cattle tick Rhipicephalus microplus is one of the most important ectoparasites in the tropical and subtropical regions of the world. Synthetic pyrethroids are widely used to control this tick, and the selection of resistant populations is a huge problem worldwide. The activity of thymol, a natural monoterpene, free or in combination with other compounds, has been demonstrated against different species of ticks. However, the mode of action is not fully understood. The present study aimed to evaluate the efficacy and the potential mode of action of the combination of cypermethrin and thymol on ticks from two populations with different levels of susceptibility to cypermethrin (low and high susceptibility). The isolated acaricidal activity of cypermethrin and thymol on larvae was carried out in different concentrations. The combination with different concentrations of cypermethrin and fixed concentrations of thymol (1300µg/mL for the low susceptibility population; 690µg/mL for the high susceptibility population) were performed. Adult engorged females were divided into five experimental groups (n=20): 1) Control group untreated; 2) Control group: 2.0% (v/v) DMSO; 3) Thymol group: 1300µg/mL thymol; 4) Cypermethrin group: 3700µg/mL cypermethrin; 5) Association of cypermethrin (3700µg/mL)+thymol (1300µg/mL). A subgroup was used to study the efficacy of the reproductive parameters and another subgroup, with ten adults from each treatment, was used to quantify thymol and cypermethrin by HPLC chromatographic analysis. All compounds tested were effective on larvae from both populations, and the combination with thymol decreased the LC50 of cypermethrin (232.4 to 52.7µg/mL) on the low-susceptibility population. The combination of thymol and cypermethrin was effective in both populations of R. microplus (reproductive performance of engorged females) when compared to the untreated control group, even with higher percent control values (pop. 1: 93.5±5.6% and pop. 2: 92.7±1.1%) than the group treated only with cypermethrin (pop. 1: 87.3±7.3% and pop. 2: 83.5±1.2%). From the HPLC analyzes, a higher concentration of cypermethrin (pop. 1: 30.3±6.9 and pop. 2: 45.4±17.7ng/mg) was detected in the tissues of engorged females treated with the combination compared to analyte concentrations in groups treated with cypermethrin only (pop. 1: 12.4±4.4 pop. 2: 25.5±9.4ng/mg). This was the first study to investigate the acaricidal efficacy of the combination of thymol+cypermethrin on R. microplus and demonstrate that the presence of thymol increases the concentration of cypermethrin in the internal tissues of engorged females through a possible mechanism for increasing the penetration of cypermethrin at the cuticular level.

DEVELOPMENT AND EVALUATION OF MOUTH DISSOLVING ANTIINFLAMMATORY TABLET CONTAINING FENOPROFEN

Fenoprofen belongs to Biopharmaceutical Classification System (BCS) class II drugs which are poorly soluble in water. The objective of present research work was to prepare fast dissolving tablets of fenoprofen using varying concentrations of three different sublimating agents to improve the dissolution rate. Seven formulations were prepared containing different concentrations of camphor, ammonium bicarbonate and thymol as sublimating agent along with primogel as a superdisintegrant. Tablets were manufactured by direct compression method. The prepared tablets were evaluated for pre-compression and post-compression parameters result, for all formulations result was within official limits. DSC studies revealed that there were no interactions between the drug and the excipients used. From in vitro drug release studies the dissolution studies, cumulative percentage of drug release versus time was evaluated. It also reflects that the formulations F4 and F15 containing 45 mg and 67.5 mg of thymol respectively showed fast drug release of 100.00% and 99.56 % respectively in 30 minutes as compared with formulations containing other sublimating agents. Among all the formulations, F6 and F7 tablets showed complete drug release within 30 minutes and rapid dissolution.

Anesthetic efficacy and hemato-biochemical effects of thymol on juvenile Nile tilapia, Oreochromis niloticus

In this study, two experiments were performed to investigate the anesthetic efficiency, hematological and biochemical effects of thymol on Nile tilapia, Oreochromis niloticus. In the first experiment, in order to estimate thymol anesthetic efficacy, tilapia juveniles were exposed to anesthetic baths at six different concentrations of thymol (10, 20, 40, 60, 80, and 100 mg L−1) and the induction and recovery times were recorded. The second experiment was performed with five treatments: CON (non-anesthetized fish), TH1 (anesthesia with 80 mg L−1 thymol within 1 min), TH5 (anesthesia with 30 mg L−1 thymol within 5 min), EU1 (anesthesia with 80 mg L−1 eugenol within 1 min), and EU5 (anesthesia with 30 mg L−1 eugenol within 5 min). The results showed that thymol at 10 mg L−1 concentration failed to induce anesthesia; however 20–100 mg L−1 concentrations induced anesthesia within 491–56.3 s. A strong negative relationship was detected between thymol concentrations and induction times (R2 = 0.906). Anesthesia had no significant effects on plasma albumin, triglyceride, cholesterol, alanine aminotransferase, and the blood mean corpuscular hemoglobin levels. The anesthetized fish exhibited significant elevations in plasma cortisol, glucose, lactate, and the blood hematocrit and mean corpuscular volume; these parameters exhibited significant elevations in the fish anesthetized by 30 mg L−1 anesthetics, compared to the 80 mg L−1. Plasma globulin, total protein, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, catalase, superoxide dismutase, and the blood hemoglobin and red blood cell significantly increased, as mean corpuscular hemoglobin concentration decreased, in the fish anesthetized by 30 mg L−1 anesthetics, compared to the CON fish. The anesthetized fish showed similar plasma glutathione levels, all significantly lower than the CON fish. The EU5 fish exhibited significant elevation in the plasma malondialdehyde levels, compared to the CON fish. In conclusion, thymol anesthetic efficacy was similar to eugenol in Nile tilapia weighing ~40 g at water temperature of 26 °C. Considering the physiological responses, slight but significant elevations in plasma proteins, lactate, lactate dehydrogenase, and malondialdehyde levels attest that thymol may induce less stress, hypoxia, and oxidative stress in the fish than eugenol, but further studies are needed to provide robust and clinically applicable data to support this hypothesis.

Thymol loaded zein microparticles obtained by spray-drying: Physical-Chemical Characterization

The use of thymol in the food industry may be restricted due to its high instability to temperature, oxygen, light and humidity. This disadvantage may be postponed by microencapsulation . Microparticles were obtained by spray-drying technique at a drying temperature of 130 °C and 0.385 g per 100 g of zein for thymol concentration. In these conditions, 49.5% encapsulation efficiency was achieved and microparticles featured an average size of 14.3 μm measured by laser beam diffraction on a Mastersizer 2000 equipment. Morphologically they revealed a spherical shape with smooth surface and mild roughness. Thermal analysis showed protection to thymol at a temperature above the degradation temperature of the compound (200 °C). Delivery tests presented a release of thymol at 90% on the first day, classified as burst release according to Fick's second law. • The active ingredient thymol was microencapsulated using zein by spray drying. • The physico-chemical characteristics of the microparticles were obtained using different techniques. • The antioxidant activity of thymol was retained after the encapsulation process. • Nitrogen adsorption indicated non-porous solids.