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International Microbiology : the... Aug 2022Biofilm formation associated with quorum sensing (QS) is a community behaviour displayed by many gram-negative pathogenic bacteria that provide survival advantages in...
Biofilm formation associated with quorum sensing (QS) is a community behaviour displayed by many gram-negative pathogenic bacteria that provide survival advantages in hostile conditions. The inhibitors of QS interrupt bacterial communication and coordinated cell signalling for community aggregation in the biofilm. Thymol, a natural monoterpenoid, was tested against QS in Chromobacterium violaceum. As the first step, the interaction of thymol with cviR protein was investigated using in silico approach followed by validation using detailed in vitro experiments. The QS and biofilm studies were performed using the wild type of strain C. violaceum ATCC 12,472 and a mini-Tn5 mutant CV026. The MIC of thymol was established by the broth micro-dilution method, and IC value for violacein inhibition was quantified spectrophotometrically by extracting the violacein from the treated cells. Inhibitory effect of thymol on the biofilm was quantified by the crystal violet staining method, and scanning electron microscopy (SEM) was employed for biofilm visualization. The expression of biofilm associated genes (hmsH, hmsR, pilB, and pilT) was evaluated by qRT-PCR analysis. The in silico molecular interactions of thymol with cviR exhibited a G-score of - 5.847 kcal/mol, binding with TYR-80 and SER-155 by Pi-Pi stacking and H-bond, respectively. The MIC of thymol was 160 µg/mL, and the IC for violacein inhibition was estimated to be 28 µg/mL. The thymol treatment significantly reduced the biofilm viability and biomass by > 80% along with disruption of the well-organized biofilm architecture. QS inhibitory activity of thymol resulted in the reduction of exopolysaccharide production, swarming motility, and downregulation of biofilm-associated hmsH, hmsR, pilB, and pilT genes. This data establishes the QS inhibitory role of thymol in the biofilm formation in C. violaceum.
Topics: Anti-Bacterial Agents; Biofilms; Chromobacterium; Gram-Negative Bacteria; Plant Extracts; Quorum Sensing; Thymol
PubMed: 35554762
DOI: 10.1007/s10123-022-00247-8 -
Chemistry & Biodiversity Mar 2022Thymol is a monoterpene phenolic derivative extracted from the Thymus vulgaris which has antimicrobial effects. In the present study, thymol-loaded chitosan nanogels...
Thymol is a monoterpene phenolic derivative extracted from the Thymus vulgaris which has antimicrobial effects. In the present study, thymol-loaded chitosan nanogels were prepared and their physicochemical properties were characterized. The encapsulation efficiency of thymol into chitosan and its stability were determined. The in vitro antimicrobial and anti-biofilm activities of thymol-loaded chitosan nanogel (Ty-CsNG), free thymol (Ty), and free chitosan nanogel (CsNG) were evaluated against both Gram-negative and Gram-positive multidrug-resistant (MDR) bacteria including Staphylococcus aureus, Acinetobacter baumanii, and Pseudomonas aeruginosa strains using the broth microdilution and crystal violet assay, respectively. After treatment of MDR strains with sub-minimum inhibitory concentration (Sub-MIC) of Ty-CsNG, free Ty and CsNG, biofilm gene expression analysis was studied. Moreover, cytotoxicity of Ty-CsNG, free Ty, and CsNG against HEK-293 normal cell line was determined using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method. The average size of Ty-CsNG was 82.71±9.6 nm, encapsulation efficiency was 76.54±0.62 % with stability up to 60 days at 4 °C. Antibacterial activity test revealed that Ty-CsNG reduced the MIC by 4-6 times in comparison to free thymol. In addition, the expression of biofilm-related genes including ompA, and pgaB were significantly down-regulated after treatment of strains with Ty-CsNG (P<0.05). In addition, free CsNG displayed negligible cytotoxicity against HEK-293 normal cell lines and presented a biocompatible nanoscale delivery system. Based on the results, it can be concluded that Ty-CsNG can be considered a promising candidate for enhancing antimicrobial and anti-biofilm activities.
Topics: Anti-Bacterial Agents; Biofilms; Chitosan; HEK293 Cells; Humans; Microbial Sensitivity Tests; Nanogels; Thymol
PubMed: 34989129
DOI: 10.1002/cbdv.202100426 -
International Journal of Biological... May 2020Essential oils are natural antimicrobils and have been frequently incorporated into edible films aimed at extending shelf-life of food products. In this study, thymol...
Essential oils are natural antimicrobils and have been frequently incorporated into edible films aimed at extending shelf-life of food products. In this study, thymol nanoemulsions co-emulsified by natural emulsifiers (i.e., blend of gelatin and soy lecithin) were prepared and incorporated into gelatin films. The physical and antimicrobial properties of gelatin films were characterized. Thymol nanoemulsions incorporation increased the water vapor permeability and elongation at break of gelatin film, but decreased the moisture content and tensile strength. With nano-scale and uniform particles, the surface of films containing thymol nanoemulsions was smooth and continuous. Due to the hydrophobic property of lecithin and thymol, the water contact angle of gelatin film increased to above 90°. Moreover, sustained release of thymol from gelatin films was also observed, and these films exhibited effective inhibition activities against both Gram-positive and Gram-negative bacteria. Therefore, gelatin films containing thymol nanoemulsions co-emulsified by gelatin and lecithin may have great potentials to be applied as novel and GRAS biodegradable packaging materials to achieve the goal of extending the shelf life of food products.
Topics: Anti-Infective Agents; Bacteria; Chemical Phenomena; Drug Carriers; Emulsions; Gelatin; Microbial Sensitivity Tests; Nanostructures; Particle Size; Permeability; Steam; Tensile Strength; Thymol
PubMed: 32045609
DOI: 10.1016/j.ijbiomac.2020.02.066 -
Animal : An International Journal of... Feb 2019Chronic heat stress (CHS) exposure negatively impairs avian' immunoneuroendocrine interplay. Thymol has shown several bioactive properties including antioxidant,...
Chronic heat stress (CHS) exposure negatively impairs avian' immunoneuroendocrine interplay. Thymol has shown several bioactive properties including antioxidant, bactericidal, antifungal and gamma-aminobutyric acid modulator activities. Indeed, supplementation with thymol has been used with positive effects on poultry production and immune-related variables. This study evaluates whether a thymol dietary supplementation can be used as a new functional feed strategy to mitigate CHS deleterious effects on endocrine, biochemical and immune-related variables. Starting at 100 days of age, 24 fully adult Japanese quail were fed with a diet supplemented with thymol (≈80 mg/quail per day) and other 24 quail remained non-supplemented (control diet). Between 119 and 127 days of age, half of the quail within those groups were submitted to a CHS by increasing environmental temperature from 24°C to 34°C during the light phase and the other half remained at 24°C (non-stressed controls). A period of 3 days after CHS ended (during the recovery period), corticosterone, albumin, total proteins and globulins and glucose concentrations, inflammatory response, antibody production and heterophil to lymphocyte (H/L) ratio were assessed. No differences between groups were found in basal corticosterone concentrations. Total proteins, total globulins and glucose concentrations were found elevated in the previously CHS group compared with their control counterparts. Regardless of the previous CHS exposure, thymol supplementation increased albumin concentrations and inflammatory responses and decreased antibody titers. An interaction between thymol supplementation and prior CHS exposure was found on the H/L ratio. Quail previously exposed to CHS and supplemented with thymol showed similar H/L values than their control non-stressed counterparts, suggesting that thymol has a stress preventive effect on this variable. The present findings together with the already reported thymol bioactive properties, suggest that feed supplementation with this compound could be a useful strategy to help overcoming some of the CHS induced alterations.
Topics: Animal Feed; Animals; Coturnix; Diet; Dietary Supplements; Female; Heat Stress Disorders; Heat-Shock Response; Thymol
PubMed: 29983133
DOI: 10.1017/S175173111800157X -
International Journal of Molecular... May 2024Antimicrobial resistance (AMR) poses an emanating threat to humanity's future. The effectiveness of commonly used antibiotics against microbial infections is declining...
Antimicrobial resistance (AMR) poses an emanating threat to humanity's future. The effectiveness of commonly used antibiotics against microbial infections is declining at an alarming rate. As a result, morbidity and mortality rates are soaring, particularly among immunocompromised populations. Exploring alternative solutions, such as medicinal plants and iodine, shows promise in combating resistant pathogens. Such antimicrobials could effectively inhibit microbial proliferation through synergistic combinations. In our study, we prepared a formulation consisting of Miller (AV), Thymol, iodine (I), and polyvinylpyrrolidone (PVP). Various analytical methods including SEM/EDS, UV-vis, Raman, FTIR, and XRD were carried out to verify the purity, composition, and morphology of AV-PVP-Thymol-I. We evaluated the inhibitory effects of this formulation against 10 selected reference strains using impregnated sterile discs, surgical sutures, gauze bandages, surgical face masks, and KN95 masks. The antimicrobial properties of AV-PVP-Thymol-I were assessed through disc diffusion methods against 10 reference strains in comparison with two common antibiotics. The 25-month-old formulation exhibited slightly lower inhibitory zones, indicating changes in the sustained-iodine-release reservoir. Our findings confirm AV-PVP-Thymol-I as a potent antifungal and antibacterial agent against the reference strains, demonstrating particularly strong inhibitory action on surgical sutures, cotton bandages, and face masks. These results enable the potential use of the formulation AV-PVP-Thymol-I as a promising antimicrobial agent against wound infections and as a spray-on contact-killing agent.
Topics: Thymol; Microbial Sensitivity Tests; Iodine; Anti-Infective Agents; Aloe; Anti-Bacterial Agents; Humans; Drug Compounding
PubMed: 38732168
DOI: 10.3390/ijms25094949 -
Molecules (Basel, Switzerland) Sep 2022Due to the current concerns against opportunistic pathogens and the challenge of antimicrobial resistance worldwide, alternatives to control pathogen growth are...
Due to the current concerns against opportunistic pathogens and the challenge of antimicrobial resistance worldwide, alternatives to control pathogen growth are required. In this sense, this work offers a new nanohybrid composed of zinc-layered hydroxide salt (Simonkolleite) and thymol for preventing bacterial growth. Materials were characterized with XRD diffraction, FTIR and UV-Vis spectra, SEM microscopy, and dynamic light scattering. It was confirmed that the Simonkolleite structure was obtained, and thymol was adsorbed on the hydroxide in a web-like manner, with a concentration of 0.863 mg thymol/mg of ZnLHS. Absorption kinetics was described with non-linear models, and a pseudo-second-order equation was the best fit. The antibacterial test was conducted against O157:H7 and strains, producing inhibition halos of 21 and 24 mm, respectively, with a 10 mg/mL solution of thymol-ZnLHS. Moreover, biofilm formation of inhibition was tested, with over 90% inhibition. Nanohybrids exhibited antioxidant activity with ABTS and DPPH evaluations, confirming the presence of the biomolecule in the inorganic matrix. These results can be used to develop a thymol protection vehicle for applications in food, pharmaceutics, odontology, or biomedical industries.
Topics: Anti-Bacterial Agents; Antioxidants; Biofilms; Free Radicals; Microbial Sensitivity Tests; Thymol; Zinc
PubMed: 36234690
DOI: 10.3390/molecules27196161 -
Pharmacokinetic study of thymol after intravenous injection and high-dose inhalation in mouse model.Pharmacology Research & Perspectives Oct 2019Thymol is generally recognized as a safe substance by the FDA and has been widely used in the pharmaceutical, food, and cosmetic industries. Pharmacokinetic (PK) studies... (Comparative Study)
Comparative Study
Thymol is generally recognized as a safe substance by the FDA and has been widely used in the pharmaceutical, food, and cosmetic industries. Pharmacokinetic (PK) studies of thymol have been previously conducted for oral administration, but there has been no PK study for inhalation administration or intravenous (IV) injection. This study aims at exploring and comparing the inhalation and IV PK profile of thymol in a mouse model. The inhalation PK for mouse model was corrected with fur/skin absorption. Thirty-two male CD-1 mice were randomized into two study arms, Arm-A for intravenous (n = 16) and Arm-B for inhalation (n = 16). The amount of thymol in the mouse serum was measured for Arm-A and for Arm-B at the highest dose. Furthermore, 48 mice were utilized for fur/skin absorption of thymol. In total, 320 mouse serum samples for thymol were analyzed by LC/MS method. After inhalation, the peak concentration of thymol in mouse serum was 42.3 ng/mL ( ) and occurred at 2 minutes ( ). The AUC of the inhaled thymol at 0-60 minutes (AUC) was 464 ng/mL/min. From 10-60 minutes post-dose, the PK inhalation curve appeared to be higher than that for the IV injection. This is likely attributed to the effect of absorption of thymol through the fur/skin of mice. After an adjustment by fur/skin absorption, the PK profile for net inhalation closely matched the two-compartment model. In fact, the bioavailability for the net inhalation of thymol was 74% and 77% relative to that for IV injection per AUC and AUC, respectively.
Topics: Administration, Inhalation; Animals; Biological Availability; Chromatography, Liquid; Injections, Intravenous; Male; Mass Spectrometry; Mice; Models, Animal; Random Allocation; Thymol
PubMed: 31452900
DOI: 10.1002/prp2.515 -
Anti-protozoal activity of Thymol and a Thymol ester against Cryptosporidium parvum in cell culture.International Journal For Parasitology.... Apr 2021Cryptosporidium parvum is a protozoan parasite that infects intestinal epithelial cells causing malabsorption and severe diarrhea. The monoterpene thymol has been...
Cryptosporidium parvum is a protozoan parasite that infects intestinal epithelial cells causing malabsorption and severe diarrhea. The monoterpene thymol has been reported to have antifungal and antibacterial properties but less is known about the antiparasitic effect of this compound. Terpenes are sometimes unsuitable for therapeutic and food applications because of their instability. Esterification of terpenes eliminates this disadvantage. The present study evaluates the effects of thymol (Th) and a thymol ester, thymol octanoate (TO), against C. parvum infectivity in vitro. The cytotoxicity IC value for TO after 24 h of treatment was 309.6 μg/mL, significantly higher than that of Th (122.5 μg/mL) in a human adenocarcinoma cell line (HCT-8). In the same way, following 48 h of treatment, the cytotoxicity IC value for TO was significantly higher (139 μg/mL) than that of Th (75.5 μg/mL). These results indicate that esterification significantly reduces Th cytotoxicity. Dose-dependent effects were observed for TO and Th when both parasite invasion and parasite growth assays were evaluated. When evaluated for their activity against C. parvum growth cultured in vitro in HCT-8 cells, the anti-cryptosporidial IC values were 35.5 and 7.5 μg/mL, for TO and Th, respectively. Together, these findings indicate that esterified thymol has anti-cryptosporidial effect comparable with its parental compound thymol, but with improved safety margins in mammalian cells and better physicochemical properties that could make it more suitable for diverse applications as an antiparasitic agent.
Topics: Animals; Cell Culture Techniques; Cryptosporidiosis; Cryptosporidium; Cryptosporidium parvum; Esters; Humans; Thymol
PubMed: 33647675
DOI: 10.1016/j.ijpddr.2021.02.003 -
Anti-cancer Agents in Medicinal... Feb 2018Colon cancer is one of the most deadly and common carcinomas occurring worldwide and there have been many attempts to treat this cancer. The present work was designed in...
BACKGROUND
Colon cancer is one of the most deadly and common carcinomas occurring worldwide and there have been many attempts to treat this cancer. The present work was designed in order to evaluate thymol as a potent drug against colon cancer.
MATERIALS AND METHODS
Cytotoxicity of thymol at different concentrations was evaluated against a human colon carcinoma cell line (HCT-116 cells). Fluorescent staining was carried out to evaluate the level of ROS as well as mitochondrial and DNA fragmentation and immunoblot analysis were performed to confirm apoptosis and mitoptosis.
RESULTS AND CONCLUSION
Results of the study demonstrated that thymol efficiently created an oxidative stress environment inside HCT-116 cells, a colorectal carcinoma cell line, through induction of ROS production along with intense damage to DNA and mitochondria, as observed through Hoechst and rhodamine 123 staining, respectively. Moreover, expression of PARP-1, p-JNK, cytochrome-C and caspase-3 proteins was up-regulated, suggesting HCT-116 cells underwent mitoptotic cell death. Therefore, thymol could be used as a potent drug against colon cancer due to its lower toxicity and prevalence in natural medicinal plants.
Topics: Antineoplastic Agents; Cell Death; Cell Proliferation; Cell Survival; Colorimetry; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; HCT116 Cells; Humans; Oxidative Stress; Reactive Oxygen Species; Structure-Activity Relationship; Thymol; Tumor Cells, Cultured
PubMed: 28356011
DOI: 10.2174/1871520617666170327121228 -
Journal of Pediatric Urology Oct 2023Uropathogenic Escherichia coli (UPEC) is a common cause of urinary tract infections (UTI) in children and currently is one of the leading medical problems. Due to the...
BACKGROUND
Uropathogenic Escherichia coli (UPEC) is a common cause of urinary tract infections (UTI) in children and currently is one of the leading medical problems. Due to the increase in antibiotic resistance rate, herbal medicines with lower side effects were considered.
OBJECTIVE
This study aimed to identify the afa, fimH, and sfa genes of UPEC bacteria isolated from pediatric UTI to investigate the effect of the thyme on the expression of fimH gene.
STUDY DESIGN
In this cross-sectional study, 160 UPEC were isolated from pediatric UTIs. An antibiotic susceptibility test was performed on six families of antibiotics, including beta-lactams, quinolones, aminoglycosides, carbapenems, sulfonamides, and nitrofurantoin. The micro-broth dilution method was used to determine MIC of thymol. The biofilm production ability of isolated strains was quantified by the microtiter plate method. The PCR technique was used to detectfimH, afa, and sfa adhesion genes, and real-time PCR was used to measure the fimHgene expression.
RESULTS
The results of the antibiogram showed that the lowest and highest resistance related to meropenem and imipenem (zero), and 72.5% for cephalothin. MIC showed 80.7% of the isolates were sensitive to thymol. The biofilm production results showed that 3.12%, 53.75%, and 43.12% of the isolates were strong, weak, and no-biofilm (Zero) producers, respectively. After thymol treatment, 26.25% and 73.75% of isolates were weak and no-producer (Zero) biofilms, respectively and there was a significant correlation (P-value = 0.042) compared to the control group. The frequency of fimH, sfa, and afa genes was 53.1%, 49.4%, and 29.4%, respectively. The expression of fimHgene after 48 h thymol treatment decreased significantly (P-value< 0.05).
CONCLUSION
Due to the significant effects of thymol in preventing the expression of the adhesion gene (fimH) of UPEC bacteria, our study is a proof-of-concept study evaluating bacterial sensitivity to Thymol and its effect on biofilm production in vitro. Given the demonstrated promising results of Thymol's effectiveness and the increase in bacterial antibiotic resistance, further studies should be undertaken to determine the safety and effectiveness of Thymol use in the clinical treatment of urinary tract infection. We believe that Thymol may prove to be an effective adjunct to the treatment of bacterial urinary tract infections.
Topics: Humans; Child; Thymol; Uropathogenic Escherichia coli; Cross-Sectional Studies; Escherichia coli Infections; Urinary Tract Infections; Anti-Bacterial Agents
PubMed: 37481428
DOI: 10.1016/j.jpurol.2023.07.001