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1.
Appl Microbiol Biotechnol ; 104(5): 2163-2178, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31980918

RESUMO

Tea tree oil (TTO) and its two characteristic components (terpinen-4-ol and 1,8-cineole) have been shown to inhibit Botrytis cinerea growth. In this study, we conducted a transcriptome analysis to determine the effects of TTO and its characteristic components, alone and in combination, against B. cinerea. Most differentially expressed genes (DEGs) from B. cinerea cells treated with terpinen-4-ol participated in the biosynthesis of secondary metabolites, and the metabolism of amino acids, carbohydrates, and lipids. All treatments containing terpinen-4-ol potentially induced mitochondrial dysfunction and oxidative stress. These were further confirmed by the decreased activities of several enzymes (e.g., succinate dehydrogenase (SDH), malate dehydrogenase (MDH), α-ketoglutarate dehydrogenase (α-KGDH), isocitrate dehydrogenase (ICDH)), the increased activities of certain enzymes (e.g., catalase (CAT), peroxidase (POD), superoxide dismutase (SOD)), and increased content of hydrogen peroxide (H2O2). 1,8-Cineole mainly affected DEGs involved in genetic information processing, resulting in cell death. This study provides insight into the molecular mechanism of B. cinerea inhibition by TTO, and explains the synergistic effect of terpinen-4-ol and 1,8-cineole on B. cinerea.


Assuntos
Antifúngicos/farmacologia , Botrytis/efeitos dos fármacos , Botrytis/genética , Óleo de Melaleuca/farmacologia , Antifúngicos/química , Botrytis/crescimento & desenvolvimento , Sinergismo Farmacológico , Eucaliptol/farmacologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Perfilação da Expressão Gênica , Peróxido de Hidrogênio/metabolismo , Óleo de Melaleuca/química , Terpenos/farmacologia , Transcriptoma/efeitos dos fármacos
2.
PLoS One ; 14(12): e0227220, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31881054

RESUMO

In this study, essential oils (EO)-incorporated multi-walled carbon nanotubes (MWCNTs) filters were developed for achieving dual functions in effective removing bacteria from aqueous solutions and inactivating bacteria cells captured on the filters. Tea tree essential oil (TTO), lemon essential oil (LEO), and TTO-LEO-mixture were coated on MWCNTs filters with different MWCNTs loadings ranging from 3 mg to 6 mg. MWCNTs filters with 6.0 mg MWCNTs showed complete removal (100%) of E. coli cells from PBS buffer with 6.35 log10 decrease of cell numbers. TTO, LEO, and TTO/LEO Mix (1:1) coatings at the volume of 50 µL on MWCNTs filters achieved bacterial removal rates of >98%, and highly effective inactivation efficiency. TTO coatings had the highest antimicrobial efficacies than LEO and Mix coatings, MWCNTs filters with 50 µL TTO coating showed 100% inhibitory rate of the captured bacteria on the filter surfaces. Those captured but survived cells on filters with less TTO coating (20µL) significantly reduced their salt tolerances to 30 and 40 g/L NaCl in LB agar, and became less salt tolerance with longer incubation time on the filters. The developed TTO-MWCNTs filters had much higher antimicrobial efficacies than the filters with dual functions developed previously.


Assuntos
Antibacterianos/administração & dosagem , Portadores de Fármacos/química , Escherichia coli/efeitos dos fármacos , Nanotubos de Carbono/química , Óleos Vegetais/administração & dosagem , Óleo de Melaleuca/administração & dosagem , Antibacterianos/farmacologia , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/prevenção & controle , Humanos , Óleos Vegetais/farmacologia , Óleo de Melaleuca/farmacologia
3.
Res Vet Sci ; 127: 76-81, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31678456

RESUMO

Antimicrobial resistance is increasing within the porcine industry with consequential high impact on human health, leading to a need for new antimicrobials. Lately, the scientific community has turned its interest towards natural compounds, and different essential oils have been tested on spermatozoa for preliminary assessment of toxicity before considering them as good substitutes for standard antibiotics. The aim of the present work was to investigate the potential antimicrobial effect of Melaleuca alternifolia and Rosmarinus officinalis essential oils, already evaluated for toxicity, on swine artificial insemination doses deprived of spermatozoa and stored at 16 °C for 5 days. This was accomplished by setting up an in vitro model with a standardized quantity of E. coli. Essential oils, previously chemo-characterized by means of gas chromatography, were tested at 0.2 and 0.4 mg/ml. Analyses, performed at 24 and 120 h, included optical density evaluation, bacterial DNA quantification by qPCR, and colony count. The results demonstrate that both Melaleuca alternifolia and Rosmarinus officinalis essential oils, at a concentration of 0.4 mg/ml, are capable of delivering similar effects to ampicillin, used as control, on the experimental samples. At the lower concentration, M. alternifolia essential oil seemed more effective when compared to R. officinalis. Overall, these findings strengthen the hypothesis of the potential use of phyto-complexes as antimicrobial agents for reproductive biotechnologies.


Assuntos
Anti-Infecciosos/farmacologia , Escherichia coli/efeitos dos fármacos , Óleos Voláteis/farmacologia , Sêmen/efeitos dos fármacos , Óleo de Melaleuca/farmacologia , Animais , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Sêmen/microbiologia , Sus scrofa
4.
Artigo em Inglês | MEDLINE | ID: mdl-30910599

RESUMO

Mycotoxins are secondary metabolites produced by varieties of fungi that contaminate food and feed resources and are capable of inducing a wide range of toxicity. This problem is extensively aggravated due to the increasing replacement of fish meal by plant-derived proteins. Among the mycotoxins, aflatoxins have received a great deal of attention owing to their great prevalence in plant feedstuffs and to the detrimental effects on animals. The objective of this study was to evaluate whether dietary supplementation with tea tree (Melaleuca alternifolia) oil (TTO) would avoid or minimize the negative impacts on silver catfish (Rhamdia quelen) fed with aflatoxins-contaminated diets. Four treatments were tested: control (fish fed with a control diet); AFB (fish fed with a mycotoxin-contaminated diet - 1893 µg kg-1 of AFB1 and 52.2 µg kg-1 AFB2); TTO (fish fed with a control diet + 1 mL kg-1 of TTO), and TTO + AFB (fish fed with a mycotoxin contaminated diet - 2324 µg kg-1 of AFB1 and 43.5 µg kg-1 AFB2 + 1 mL kg-1 of TTO). Diets were tested in three replications and analyzed at days 5 and 10 of dietary intake. Significantly reduced antioxidant enzymes (SOD, GPx, and GST) and increased lipid peroxidation (LOOH) and protein carbonyl (PC) content in plasma and liver, with 16.6% mortality occurrence, were observed in the group fed aflatoxin-contaminated diet. Furthermore, aflatoxins also significantly increased plasmatic and hepatic ROS levels and decreased hepatic antioxidant capacity against peroxyl radical (ACAP) levels. Plasma cortisol levels were not altered by aflatoxicosis, but the intoxication induced hepatose. Notwithstanding, addition of TTO to the groups receiving aflatoxins showed a protective effect, avoiding the increase of ROS, LOOH, and PC levels in plasma and liver. Moreover, TTO treatment ameliorated the aflatoxin-associated liver damage. Thus, TTO supplementation at concentration of 1 mL kg-1 in feed may be used in fish to increase antioxidant status and reduce the negative effects caused by aflatoxins toxicity.


Assuntos
Aflatoxinas/toxicidade , Ração Animal/análise , Peixes-Gato , Doença Hepática Induzida por Substâncias e Drogas/veterinária , Doenças dos Peixes/induzido quimicamente , Óleo de Melaleuca/farmacologia , Animais , Anti-Infecciosos Locais/uso terapêutico , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Contaminação de Alimentos , Hidrocortisona , Distribuição Aleatória , Óleo de Melaleuca/administração & dosagem
5.
Molecules ; 24(6)2019 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-30893764

RESUMO

The growing interest towards essential oils stems from their biological capabilities that include antibacterial and antioxidant effects. Such properties may be extremely useful in the reproductive field; nonetheless essential oils show toxic effects that can lead to cell disruption. The present study aimed to evaluate and compare the effects of tea tree oil (TTO) and its principal component terpinen-4-ol (TER) on the morpho-functional parameters of swine spermatozoa. Experimental samples were prepared by suspending 15 × 107 spermatozoa in 5 mL of medium with different concentrations of the above-mentioned compounds: from 0.2 to 2 mg/mL at an interval of 0.2 for TTO, while TER concentrations were adjusted according to its presence in TTO (41.5%). After 3 h incubation at 16 °C, samples were analyzed for pH, viability, acrosome status, and objective motility. The results highlighted a concentration-dependent effect of TTO with total motility as the most sensitive parameter. TER was better tolerated, and the most sensitive parameters were related to membrane integrity, suggesting a different pattern of interaction. The study confirms the importance of evaluating the effects of natural compounds on spermatozoa before exploiting their beneficial effects. Spermatozoa seem to be good candidates for preliminary toxicological screenings in the light of their peculiar properties.


Assuntos
Melaleuca/química , Espermatozoides/efeitos dos fármacos , Óleo de Melaleuca/farmacologia , Terpenos/farmacologia , Animais , Masculino , Suínos , Terpenos/química
6.
J Appl Microbiol ; 126(4): 1161-1174, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30614164

RESUMO

AIMS: As a natural antimicrobial agent, Melaleuca alternifolia oil (MAO) is generally recognized to be safe and effective in the inhibition of phytopathogenic fungi. Due to lack of comprehensive studies on MAO for controlling postharvest Aspergillus, we investigated the preservative mechanism of MAO and its components against Aspergillus ochraceus in postharvest grapes to evaluate their potential effectiveness as fruit preservatives. METHODS AND RESULTS: In our study, the compositions in MAO were analysed by gas chromatography-mass spectrometry. The inhibitory effects of MAO and its main constituents against A. ochraceus were compared by scanning electron microscopy and transmission electron microscopy observation, and metabolic analysis. Two components of MAO, α-terpineol and terpene-4-alcohol, showed higher antifungal effects than MAO, of which α-terpineol caused the worst leakage of cytoplasm and most serious hyphae distortions and spore disruptions. The downregulation of metabolic pathways of A. ochraceus was strongest with α-terpineol. The best inhibitory efficacy against A. ochraceus in grapes also occurred with α-terpineol. 3-Carene showed little inhibitory effect. CONCLUSIONS: These results demonstrate that not all components in MAO possess antimicrobial effects, and α-terpineol is the main contributor of MAO's A. ochraceus inhibition effect. SIGNIFICANCE AND IMPACT OF THE STUDY: α-Terpineol may be used as an alternative natural preservative for the postharvest storage of grapes and other fruits.


Assuntos
Antifúngicos/farmacologia , Aspergillus ochraceus/efeitos dos fármacos , Doenças das Plantas/prevenção & controle , Óleo de Melaleuca/farmacologia , Vitis/microbiologia , Antifúngicos/química , Cicloexenos/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Monoterpenos/farmacologia , Doenças das Plantas/microbiologia , Óleo de Melaleuca/química , Terpenos/farmacologia
7.
Curr Microbiol ; 76(1): 108-116, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30421144

RESUMO

Melaleuca alternifolia tea tree oil (TTO) is largely used in cutaneous infections. Clinical observations reported antibacterial, antifungal, and antiviral activities, whereas in vitro experiments ascribed most of biological properties to terpinen-4-ol. Since different plant chemotypes and storage conditions result in variations of chemical composition of commercially available TTO, in this study we investigated the antimicrobial activity and the chemical profile of ten commercially available TTO products. The antimicrobial activity was assessed against Candida glabrata, Herpes simplex virus type 1 (HSV-1), methicillin-resistant Staphylococcus aureus (MRSA), and Pseudomonas aeruginosa grown in planktonic mode or biofilms. Only five out of ten TTO batches reported significant antimicrobial activity. The identified TTO products reduced bacterial survival in biofilms, generated oxidative damage in C. glabrata, and diminished HSV-1 infectivity. GC-MS analysis revealed that all the analyzed TTO batches fitted into the terpinen-4-ol chemotype even if we reported great variability in composition of nine major ISO-specified TTO components. Overall, we were not able to ascribe the antimicrobial activity to the content in terpinen-4-ol. We therefore conclude that the antimicrobial activity of TTO results from complex interaction among different components.


Assuntos
Anti-Infecciosos/farmacologia , Candida glabrata/crescimento & desenvolvimento , Herpesvirus Humano 1/crescimento & desenvolvimento , Melaleuca/química , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Pseudomonas aeruginosa/crescimento & desenvolvimento , Óleo de Melaleuca/farmacologia , Biofilmes/efeitos dos fármacos , Candida glabrata/efeitos dos fármacos , Herpesvirus Humano 1/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Terpenos/farmacologia
8.
Molecules ; 23(10)2018 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-30304862

RESUMO

PURPOSE: Herein, an extended investigation of Tea tree oil (TTO) against a number of multi-drug resistant (MDR) microorganisms in liquid and vapor phases is reported. METHODS: The activity of TTO was tested against methicillin-sensitive Staphylococcus aureus (MSSA), Escherichia coli, and clinical strains of methicillin-resistant S. aureus (MRSA), extended-spectrum beta lactamases producer carbapenem-sensitive Klebsiella pneumoniae (ESBL-CS-Kp), carbapenem-resistant K. pneumoniae (CR-Kp), Acinetobacter baumannii (CR-Ab), and Pseudomonas aeruginosa (CR-Pa). Minimal inhibitory/bactericidal concentrations (MIC/MBCs) and synergistic activity between TTO and different antimicrobials were determined. In the vapor assay (VP), TTO-impregnated discs were placed on the lid of a petri dish and incubated for 24 h at 37 °C. RESULTS: TTO showed a potent bactericidal activity against all the tested microorganisms. TTO in combination with each reference antimicrobial showed a high level of synergism at sub-inhibitory concentrations, particularly with oxacillin (OXA) against MRSA. The VP assay showed high activity of TTO against CR-Ab. CONCLUSION: Evaluation of in-vitro activity clearly indicated TTO as a potential effective antimicrobial treatment either alone or in association with known drugs against MDR. Therefore, TTO could represent the basis for a possible role in non-conventional regimens against S. aureus and Gram-negative MDR. TTO in VP might represent a promising option for local therapy of pneumonia caused by CR-Ab.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Bactérias Gram-Negativas/efeitos dos fármacos , Melaleuca/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Óleos Voláteis/farmacologia , Óleo de Melaleuca/farmacologia , Antibacterianos/química , Sinergismo Farmacológico , Cromatografia Gasosa-Espectrometria de Massas , Testes de Sensibilidade Microbiana , Óleos Voláteis/química , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Óleo de Melaleuca/química
9.
Molecules ; 23(10)2018 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-30336602

RESUMO

The problem of antibiotic resistance among pathogens encourages searching for novel active molecules. The aim of the research was to assay the anti-quorum sensing (anti-QS) and antibiofilm potential of Melaleuca alternifolia essential oil and its main constituent, terpinen-4-ol, to prevent the infections due to methicillin-resistant Staphylococcus aureus strains as an alternate to antibiotics. The tea tree oil (TTO) was evaluated for its potential in inhibiting QS-dependent phenomena such as violacein production in Chromobacterium violaceum, swarming motility of Pseudomonas aeruginosa PAO1, and biofilm formation in MRSA strains on glass. The results showed that terpinen-4-ol was able to inhibit MRSA strain biofilm formation on the glass strips by 73.70%. TTO inhibited the violacein production at a mean inhibitory concentration (MIC) value of 0.048 mg/mL by 69.3%. At 100 µg/mL TTO and terpinen-4-ol exhibited inhibition in swarming motility of PAO1 by 33.33% and 25%, respectively. TTO revealed anti-QS and anti-biofilm activities at very low concentrations, but it could be further investigated for new molecules useful for the treatment of MRSA infections.


Assuntos
Chromobacterium/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Infecções Estafilocócicas/tratamento farmacológico , Terpenos/farmacologia , Biofilmes/efeitos dos fármacos , Chromobacterium/patogenicidade , Humanos , Melaleuca/química , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/patogenicidade , Percepção de Quorum/efeitos dos fármacos , Infecções Estafilocócicas/microbiologia , Óleo de Melaleuca/farmacologia , Terpenos/química
10.
Microb Pathog ; 123: 304-313, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30041003

RESUMO

Staphylococcus aureus (S. aureus) is a Gram-positive bacterium that causes a wide range of diseases, including food poisoning. Tea tree oil (TTO), an essential oil distilled from Melaleuca alternifolia, is well-known for its antibacterial activities. TTO effectively inhibited all 19 tested strains of S. aureus biofilm and planktonic cells. Phenotype analyses of S. aureus biofilm cells exposed to TTO were performed by biofilm adhesion assays, eDNA detection and PIA release. RNA sequencing (RNA-seq) was used in our study to elucidate the mechanism of TTO as a potential antibacterial agent to evaluate differentially expressed genes (DEGs) and the functional network in S. aureus ATCC 29213 biofilms. TTO significantly changed (greater than a 2- or less than a 2-fold change) the expression of 304 genes in S. aureus contained in biofilms. The levels of genes related to the glycine, serine and threonine metabolism pathway, purine metabolism pathway, pyrimidine metabolism pathway and amino acid biosynthesis pathway were dramatically changed in the biofilm exposed to TTO. Furthermore, the expression changes identified by RNA-seq analysis were verified by real-time RT-PCR. To the best of our knowledge, this research is the first study to report the phenotype and expression profiles of S. aureus in biofilms exposed to TTO.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Perfilação da Expressão Gênica/métodos , RNA Bacteriano/análise , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Óleo de Melaleuca/farmacologia , Aminoácidos/genética , Aminoácidos/metabolismo , Aderência Bacteriana/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Genes Bacterianos/genética , Redes e Vias Metabólicas/efeitos dos fármacos , Redes e Vias Metabólicas/genética , Testes de Sensibilidade Microbiana , Fenótipo , Análise de Sequência de RNA
11.
J Parasitol ; 104(5): 473-478, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30016200

RESUMO

The objective of this study was to examine the efficacy of 7.5% tea tree oil (TTO) eyelash shampoo on the density of Demodex (Acari: Demodicidae) and ocular symptoms in patients with demodectic blepharitis. A total of 135 patients diagnosed with demodectic blepharitis, following clinical inspection and parasitological examinations, were included in the study. Patients were treated with eyelash shampoo, with or without TTO. Full Demodex reduction was attained in 36% of the patients who used eyelash shampoo with TTO, and the average Demodex count was reduced from 6.33/eyelash to zero ( P < 0.001). In contrast, the average Demodex count in patients who did not achieve full reduction (64%) was reduced from 12.46/eyelash to 4.15/eyelash ( P < 0.001). Full reduction was observed in 11.7% of patients who used TTO-free eyelash shampoo, and average Demodex count reduced from 2.00/eyelash to zero ( P = 0.017). The average Demodex count was reduced from 11.98/eyelash to 7.91/eyelash in patients (88.3%) who did not achieve full reduction ( P = 0.024). Additionally, ocular symptom scores (which are generated based on subjective experiences of itching, burning, the feeling of a foreign body in the eye, eye redness, and cylindrical dandruff) were reduced significantly ( P < 0.001) in patients who used the eyelash shampoo with TTO. The symptom scores remained almost the same in patients who used TTO-free eyelash shampoo ( P > 0.05). In conclusion, it was determined that eyelash shampoo with TTO is 3 times more effective at achieving full Demodex reduction, significantly reducing the Demodex count, and relieving ocular symptoms in patients where full reduction cannot be attained, without adverse side effects.


Assuntos
Anti-Infecciosos Locais/uso terapêutico , Blefarite/tratamento farmacológico , Infecções Oculares Parasitárias/tratamento farmacológico , Infestações por Ácaros/tratamento farmacológico , Óleo de Melaleuca/uso terapêutico , Animais , Anti-Infecciosos Locais/farmacologia , Blefarite/parasitologia , Infecções Oculares Parasitárias/parasitologia , Pestanas/parasitologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infestações por Ácaros/parasitologia , Ácaros/efeitos dos fármacos , Ácaros/crescimento & desenvolvimento , Distribuição Aleatória , Estudos Retrospectivos , Óleo de Melaleuca/farmacologia
12.
Biomed Pharmacother ; 103: 1253-1261, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29864906

RESUMO

The purpose of this study was to investigate some possible mechanisms underlying the in vitro antitumor activity of tea tree oil (TTO) on human and mouse breast cancer cells (MCF-7 and 4T1, respectively) and its cytotoxicity on fibroblasts (HFF-1) and on peripheral blood mononuclear cells (PBMCs). TTO High-Resolution Gas Chromatography (HRGC) showed seventeen main constituents, such as Terpinen-4-ol, γ-Terpinene, and α-Terpinene. High TTO concentrations (≥ 600 µg/mL) showed a remarkable antitumor activity, decreasing cell viability and cell proliferation of MCF-7 and 4T1 cells. TTO at 300 µg/mL increased the number of MCF-7 cells in the early stages of apoptosis and increased the BAX/BCL-2 genes ratio. TTO, mainly at 300 µg/mL, decreased cell growth and arrested MCF-7 cells in the S phase of the cell cycle. Lower antitumor concentrations (≤300 µg/mL) evaluated in MCF-7 and 4T1 cells were not cytotoxic to PBMCs and HFF-1. Also, TTO (300 µg/mL) was able to induce cell proliferation in fibroblasts after 72 h, indicating non-cytotoxic effect in these cells. TTO exhibited in vitro antitumor effect on MCF-7 and 4T1 cells by decreasing cell viability and modulating apoptotic pathways and cell cycle arrestment of MCF-7 cells. In this sense, our study provides new perspectives on the potential use of TTO for the development of new alternative therapies to treat topically locally advanced breast cancer (LABC).


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/patologia , Fibroblastos/citologia , Leucócitos Mononucleares/citologia , Óleo de Melaleuca/farmacologia , Adulto , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Fibroblastos/efeitos dos fármacos , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Modelos Biológicos , Adulto Jovem
13.
BMJ Open ; 8(5): e018507, 2018 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-29858405

RESUMO

INTRODUCTION: In remote Aboriginal communities in Australia, scabies affects 7 out of 10 children before their first birthday. This is more than six times the rate seen in the rest of the developed world. Scabies infestation is frequently complicated by bacterial infection, leading to the development of skin sores and other more serious consequences, such as septicaemia and chronic heart and kidney diseases. Tea tree oil (TTO) has been used as an antimicrobial agent for several decades with proven clinical efficacy. Preclinical investigations have demonstrated superior scabicidal properties of TTO compared with widely used scabicidal agents, such as permethrin 5% cream and ivermectin. However, current data are insufficient to warrant a broad recommendation for its use for the management of scabies because previous studies were small or limited to in vitro observations. METHODS AND ANALYSIS: A pragmatic first trial will examine the clinical efficacy of a simple and low-cost TTO treatment against paediatric scabies and the prevention of associated secondary bacterial infections, with 1:1 randomisation of 200 participants (Aboriginal children, aged 5-16 years and living in remote Australia) into active control (permethrin 5% cream) and treatment (5% TTO gel) groups. The primary outcome for the study is clinical cure (complete resolution). Secondary outcome measures will include relief of symptoms, recurrence rate, adverse effects, adherence to treatment regimen and patient acceptability. ETHICS AND DISSEMINATION: The project has received approvals from the University of Canberra Human Research Ethics Committee (HREC 16-133), Wurli-Wurlinjang Health Service Indigenous subcommittee and the Aboriginal Medical Services Alliance Northern Territory reference group. The results of this study will be published in core scientific publications, with extensive knowledge exchange activities with non-academic audiences throughout the duration of the project. TRIAL REGISTRATION: ACTRN12617000902392; Pre-results.


Assuntos
Anti-Infecciosos Locais/farmacologia , Escabiose/tratamento farmacológico , Óleo de Melaleuca/farmacologia , Adolescente , Criança , Pré-Escolar , Feminino , Serviços de Saúde do Indígena/organização & administração , Humanos , Estimativa de Kaplan-Meier , Masculino , Northern Territory , Modelos de Riscos Proporcionais , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
14.
Dent Mater J ; 37(4): 659-666, 2018 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-29731487

RESUMO

We evaluated effectiveness of tea tree oil (TO) and lemongrass oil (LO) for removal of Candida biofilm from denture base resin and their influence on that surface. Biofilm of C. albicans was formed on resins, and immersed in various concentrations of each oil and distilled water (DW). The biofilm removal effect was determined by incubating specimens in RPMI medium containing Alamar blue (AB) and measuring absorbance. Wear test was also conducted, and surface condition of resins was determined using laser scanning microscope and digital microscope. Specimens immersed in the TO and LO solutions tended to have a lower AB value at higher concentrations and longer soaking times. Use of these agents resulted in less surface roughness as compared to DW. Our results suggest that TO and LO were valid to remove biofilm attached to resin with lower levels of abrasion, and these are effective for use in denture cleaner.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Bases de Dentadura , Higienizadores de Dentadura/farmacologia , Óleos Vegetais/farmacologia , Óleo de Melaleuca/farmacologia , Terpenos/farmacologia , Adesão Celular/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Microscopia Confocal , Propriedades de Superfície , Escovação Dentária
15.
Parasitology ; 145(12): 1510-1520, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29667560

RESUMO

Australian tea tree oil (TTO) and its extract terpinen-4-ol (T4O) are found to be effective in moderating demodex-related diseases. Their possible effects are lowering the mite counts, relieving the demodex-related symptoms and modulating the immune system especially the inflammatory response. This review summarizes the topical treatments of TTO and T4O in human demodicosis, their possible mechanism of actions, side-effects and potential resistance in treating this condition. Although current treatments other than TTO and T4O are relatively effective in controlling the demodex mite population and the related symptoms, more research on the efficacy and drug delivery technology is needed in order to assess its potential as an alternative treatment with minimal side-effect profile, low toxicity and low risk of demodex resistance.


Assuntos
Melaleuca/química , Infestações por Ácaros/tratamento farmacológico , Ácaros/fisiologia , Óleo de Melaleuca/farmacologia , Terpenos/farmacologia , Animais , Humanos , Infestações por Ácaros/parasitologia , Pele/parasitologia , Óleo de Melaleuca/química , Óleo de Melaleuca/isolamento & purificação , Terpenos/química , Terpenos/isolamento & purificação
16.
J Fish Dis ; 41(5): 791-796, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29350421

RESUMO

Nanoencapsulated Melaleuca alternifolia essential oil (tea tree oil, TTO) is a natural alternative treatment, with 100% therapeutic efficacy in fish experimentally infected with Pseudomonas aeruginosa, and has also potent protective effects linked with antioxidant properties. However, the pathways responsible for the antioxidant capacity remain unknown. Thus, this study evaluated whether the inhibition of seric xanthine oxidase (XO) activity can be considered a pathway involved in the antioxidant capacity of nanoencapsulated TTO in fish experimentally infected with P. aeruginosa. Seric samples from fish infected with P. aeruginosa showed increased XO activity, as well as increased uric acid and reactive oxygen species (ROS) levels. In contrast, the prophylactic treatment with nanoencapsulated TTO prevented these infection-induced alterations. Based on the evidence obtained, the upregulation of seric XO activity induced pro-oxidative effects in the serum of fish experimentally infected with P. aeruginosa, due to excessive formation of uric acid, which stimulates the release of ROS. This treatment was able to prevent the upregulated seric XO activity and, consequently, the excessive formation of uric acid and ROS. In summary, inhibition of seric XO activity can be considered a pathway involved in the antioxidant capacity of nanoencapsulated TTO in fish experimentally infected with P. aeruginosa.


Assuntos
Antibacterianos/farmacologia , Peixes-Gato , Doenças dos Peixes/tratamento farmacológico , Infecções por Pseudomonas/veterinária , Pseudomonas aeruginosa/efeitos dos fármacos , Óleo de Melaleuca/farmacologia , Animais , Antioxidantes/metabolismo , Doenças dos Peixes/microbiologia , Proteínas de Peixes/antagonistas & inibidores , Proteínas de Peixes/sangue , Nanocápsulas , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Xantina Oxidase/antagonistas & inibidores , Xantina Oxidase/sangue
17.
Braz J Biol ; 78(3): 436-442, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29185608

RESUMO

In this study were evaluated the anaesthesia and analgesic effects of clove Eugenia caryophyllata, tea tree Melaleuca alternifolia and basil Ocimum basilicum essential oils (EO) during handling of yellowtail clownfish Amphiprion clarkii. Juveniles (3.70 ± 0.75 cm and 1.03 ± 0.50 g; mean ± standard deviation) were submitted to concentrations of 40, 50, 60, 70 and 80 µl L-1 of clove, 150, 200, 250, 300 and 350 µl L-1 of basil and 200, 300, 400, 500 and 600 µl L-1 of tea tree oils (n=10/concentration), previously defined in pilot tests. Individually and only once, fish from each treatment were placed in a glass recipient containing 1 L of seawater at a temperature of 25 °C, salinity of 35 g L-1 and the specific concentration of diluted EO (stock solution). Control (only seawater) and blank (seawater and ethanol at the highest concentration used to dilute the oils) treatments were also conducted. After reaching the stage of surgical anaesthesia, fish were submitted to biometry and a sensibility test. After that, they were transferred to clean seawater for anaesthesia recovery. The times of induction needed to reach each anaesthesia stage and anaesthesia recovery were recorded. Animals were observed for 72 hours after the procedures. All the EO provoked anaesthesia and analgesic effects in A. clarkii, but basil oil is not recommended because it caused involuntary muscle contractions and mortality in 100% and 12% of fish, respectively. The lower concentrations that promote suitable induction and recovery times are 50 µl L-1 of clove oil and 500 µl L-1 of tea tree oil. However, due to its complementary high analgesic efficiency, clove oil is recommended as the ideal anaesthetic for A. clarkii.


Assuntos
Analgesia/veterinária , Analgésicos/farmacologia , Anestesia/veterinária , Anestésicos/farmacologia , Óleo de Cravo/farmacologia , Óleos Voláteis/farmacologia , Óleos Vegetais/toxicidade , Óleo de Melaleuca/farmacologia , Analgesia/métodos , Anestesia/métodos , Animais , Relação Dose-Resposta a Droga , Peixes , Contração Muscular/efeitos dos fármacos , Óleos Vegetais/efeitos adversos , Especificidade da Espécie
18.
AAPS PharmSciTech ; 19(3): 1133-1140, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29218583

RESUMO

Highly resistant pathogens may be developed in patients with immune disorders after prolonged exposure to antibiotics, a growing threat worldwide. In order to overcome these problems, this study introduces a new class of engineered nanosystems comprising of tea tree oil nanoemulsion (TTO NE) loaded with Ag nanoparticles (NPs). Silver shows a strong toxicity towards a wide range of microorganisms. Also, TTO NE could be employed as a promising and safe antimicrobial agent for local therapies of bacterial infections. The nanosystem was prepared by low-energy method. Mean droplet size of the NE was found to be 17.7 nm. Results of the antibacterial assays showed promising ability of the designed nanosystem for eradication of Gram-positive and Gram-negative bacteria (95%). Also, it was shown that introducing colloidal Ag NPs to the TTO NE exerted a synergistic effect against Escherichia coli (FIC 0.48) while only an additive effect was observed against Staphylococcus aureus (FIC 0.75). The antibacterial effects of TTO NE+Ag NPs together with their compatibility with human cells can present them as a suitable candidate to fight against the antibacterial resistance threat.


Assuntos
Antibacterianos/administração & dosagem , Nanopartículas Metálicas , Prata/administração & dosagem , Óleo de Melaleuca/administração & dosagem , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Sinergismo Farmacológico , Emulsões , Escherichia coli/efeitos dos fármacos , Humanos , Prata/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Óleo de Melaleuca/farmacologia
19.
Microb Pathog ; 113: 432-437, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29162482

RESUMO

Microbial biofilms represent a challenge in the treatment of infections, due to the low efficacy of the antimicrobials. This study evaluated the antimicrobial effect of nanoparticles of Melaleuca alternifolia (TTO) in dental biofilm. Thirty-eight volunteers used an oral device in situ in situ including four bovine enamel specimens for 07 days. From the fifth day four solutions were applied randomly for each specimen: Physiological Saline Solution (0.85% NaCl) (C+), Chlorhexidine 0.12% (CHX), M. alternifolia oil 0.3% (TTO), and a nanoparticle solution of 0.3% M. alternifolia oil (NPTTO). The nanoparticles of TTO were characterized for pH, IPD, medium size, zeta potential and Transmission Electron Microscopy. Antimicrobial activity was evaluated by viable microorganisms count and the structure of the biofilm by atomic force microscopy. The NPTTO presented pH 6.4, particle diameter of 197.9 ± 1 nm, polydispersion index of 0.242 ± 0.005, zeta potential of -7.12 mV and ±0:27 spherical shape. The C+ resulted in 100% of bacterial vitality, while CHX, TTO and NPTTO showed 34.2%, 51.4% and 25.8%, respectively. The AFM images showed biofilms with an average roughness of 350 nm for C+, 275 nm for CHX, 500 nm for TTO and 100 nm for NPTTO. The NPTTO demonstrated excellent antimicrobial activity in the biofilm formed in situ and will possibly be used in future for the treatment/prevention of oral biofilms.


Assuntos
Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Melaleuca/química , Nanopartículas/química , Exsudatos de Plantas/farmacologia , Adulto , Animais , Bactérias/efeitos dos fármacos , Aderência Bacteriana/efeitos dos fármacos , Brasil , Bovinos , Clorexidina/farmacologia , Contagem de Colônia Microbiana , Esmalte Dentário/microbiologia , Placa Dentária/tratamento farmacológico , Placa Dentária/microbiologia , Placa Dentária/prevenção & controle , Feminino , Humanos , Concentração de Íons de Hidrogênio , Masculino , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Tamanho da Partícula , Projetos Piloto , Cloreto de Sódio/farmacologia , Óleo de Melaleuca/farmacologia , Fatores de Tempo , Adulto Jovem
20.
Am J Chin Med ; 45(8): 1631-1648, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29121804

RESUMO

Melaleuca alternifolia concentrate (MAC) is the refined essential oil of the Australian native plant Melaleuca alternifolia. MAC has been reported to suppress the production of pro-inflammatory cytokines in both murine RAW264.7 macrophages and human monocytes stimulated with lipopolysaccharide (LPS). However, the mechanisms involved in this effect remain unclear. This study aims to delineate the molecular mechanisms that drive the anti-inflammatory activity of MAC and its active component, terpinen-4-ol, in macrophages. The effects of MAC on RAW264.7 cells were studied using western blotting, real-time PCR, an electrophoretic mobility shift assay (EMSA), and NF-[Formula: see text]B luciferase reporter assays. Our results showed that MAC significantly increased both the mRNA and protein levels of heme oxygenase-1 (HO-1) via p38 and JNK MAPK activation. In addition, we showed that MAC significantly increased the activation and nuclear translocation of NF-E2-related factor 2 (Nrf2), a key transcription factor regulating HO-1 induction. MAC was also associated with significant inhibition of iNOS expression, NO production, and NF-[Formula: see text]B activation. HO-1 was required for these anti-inflammatory effects as tin protoporphyrin IX (SnPPIX), an HO-1 inhibitor, abolished the effects of MAC on LPS-induced iNOS, NO, and NF-[Formula: see text]B activation. Our results indicate that MAC induces HO-1 expression in murine macrophages via the p38 MAPK and JNK pathways and that this induction is required for its anti-inflammatory activity.


Assuntos
Anti-Inflamatórios , Expressão Gênica/efeitos dos fármacos , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Mediadores da Inflamação/metabolismo , Melaleuca/química , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Óleo de Melaleuca/farmacologia , Animais , Humanos , Camundongos , Monócitos/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Células RAW 264.7 , RNA Mensageiro/metabolismo , Óleo de Melaleuca/isolamento & purificação , Terpenos/isolamento & purificação , Terpenos/farmacologia
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