Tea tree oil, a vibrant source of neuroprotection via neuroinflammation inhibition: a critical insight into repurposing Melaleuca alternifolia by unfolding its characteristics / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Over the past few decades, complementary and alternative treatments have become increasingly popular worldwide. The purported therapeutic characteristics of natural products have come under increased scrutiny both in vitro and in vivo as part of efforts to legitimize their usage. One such product is tea tree oil (TTO), a volatile essential oil primarily obtained from the native Australian plant, Melaleuca alternifolia, which has diverse traditional and industrial applications such as topical preparations for the treatment of skin infections. Its anti-inflammatory-linked immunomodulatory actions have also been reported. This systematic review focuses on the anti-inflammatory effects of TTO and its main components that have shown strong immunomodulatory potential. An extensive literature search was performed electronically for data curation on worldwide accepted scientific databases, such as Web of Science, Google Scholar, PubMed, ScienceDirect, Scopus, and esteemed publishers such as Elsevier, Springer, Frontiers, and Taylor & Francis. Considering that the majority of pharmacological studies were conducted on crude oils only, the extracted data were critically analyzed to gain further insight into the prospects of TTO being used as a neuroprotective agent by drug formulation or dietary supplement. In addition, the active constituents contributing to the activity of TTO have not been well justified, and the core mechanisms need to be unveiled especially for anti-inflammatory and immunomodulatory effects leading to neuroprotection. Therefore, this review attempts to correlate the anti-inflammatory and immunomodulatory activity of TTO with its neuroprotective mechanisms.

Effect of polycaprolactone nanocapsules loaded with essential oils on biofilm formation by Staphylococcus aureus strains isolated from bovine mastitis cases

Abstract Bovine infectious mastitis is largely resistant to antibacterial treatment, mainly due to mechanisms of bacterial resistance in the biofilms formed by Staphylococcus aureus. Melaleuca (MEO) and citronella essential oils (CEO) are promising agents for reducing or eliminating biofilms. Free melaleuca oil presented a medium Minimum Inhibitory Concentration (MIC) of 0.625% and a Minimum Bactericidal Concentration (MBC) of 1.250%, while free citronella oil showed medium MIC and MBC of 0.313%. Thus, free CEO and MEO demonstrate bacteriostatic and bactericidal potential. We generated polymeric nanocapsules containing MEO or CEO and evaluated their efficacy at reducing biofilms formed by S. aureus. Glass and polypropylene spheres were used as test surfaces. To compare the responses of free and encapsulated oils, strains were submitted to 10 different procedures, using free and nanoencapsulated essential oils (EOs) in vitro. We observed no biofilm reduction by MEO, free or nanoencapsulated. However, CEO nanocapsules reduced biofilm formation on glass (p=0.03) and showed a tendency to diminish biofilms on polypropylene (p=0.051). Despite nanoencapsulated CEO reducing biofilms in vitro, the formulation could be improved to modify the CEO component polarity and, including MEO, to obtain more interactions with surfaces and the biofilm matrix

Melaleuca armillaris essential oil as an odor reducer in intestinal ostomy bags: a semi-experimental study / Aceite esencial de Melaleuca armillaris reductor de olores en bolsas de ostomía intestinal: estudio cuasi-experimental / Óleo essencial de Melaleuca armillaris redutor de odor em bolsas de estomia intestinal: estudo quase experimental

ABSTRACT Objective: Evaluate the effect of essential oil in odor reduction for intestinal ostomy bags. Method: Primary study, semi-experimental, prospective clinical trial with quantitative approach. A product prepared with Melaleuca armillaris leaves was tested in ostomy pouches, with and without effluents, for adhesion and odor control. Instrument: Labeled Magnitude Scale. Results: Colostomized participants, with a mean age of 73 ± 14.94, predominantly males; and informal caregivers, with a mean age of 44 ± 8.98, predominantly females. In the visual evaluation of the oil, 100% of the participants perceived its adherence. Regarding the evaluation of effluent odor by the colostomized, five reported "strong odor" before oil use and, six reported "weak" odor after use (p = 0.005). Five informal caregivers reported "very strong" effluent odor before oil use; and one reported "weak" and nine reported "moderate" after use (p = 0.0025). Conclusion: There was a reduction in the odor of effluents in the ostomy pouches with the essential oil of Melaleuca armillaris at 10%. Application for patent registration in the Brazilian National Institute of Industrial Property (INPI) under no. BR 10 2020 026987 9.

RESUMEN Objetivo: Evaluar el efecto del aceite esencial en la reducción del olor en bolsas de ostomía intestinal. Método: Estudio primario, ensayo clínico cuasi-experimental, prospectivo de tipo cuantitativo. Se evaluó un preparado con hojas de Melaleuca armillaris, probado en bolsas de recogida con y sin efluentes, en cuanto a adherencia y olor. Se aplicó como instrumento la Escala de Magnitud Etiquetada. Resultados: Los participantes colostomizados tenían edad media de 73 años ± 14,94, con predominio del sexo masculino, y los cuidadores informales, edad media de 44 años ± 8,98 y prevalencia mayor para el sexo femenino. En la evaluación visual del aceite, el 100% de los participantes notaron la adherencia. Respecto a la evaluación del olor del efluente por los pacientes colostomizados, cinco reportaron sentir un "olor fuerte" antes de usar el aceite y, después del uso, seis reportaron sentir un olor "débil" (p = 0,005). Cinco cuidadores informales detectaron un olor "muy fuerte" de los efluentes antes de usar el aceite y, después de usarlo, uno sintió un olor "débil" y nueve "moderado" (p = 0,0025). Conclusión: El olor de los efluentes en las bolsas de recolección con el aceite esencial de Melaleuca armillaris se redujo en un 10%. Solicitud de registro de patente ante el INPI bajo el n. BR 10 2020 026987 9.

RESUMO Objetivo: Avaliar o efeito do óleo essencial na redução de odor em bolsas de estomia intestinal. Método: Estudo primário, ensaio clínico quase experimental, prospectivo, com abordagem quantitativa. Preparado com folhas de Melaleuca armillaris, foi testado em bolsas coletoras, sem e com efluentes, quanto à aderência e odor. Instrumento: escala de magnitude rotulada. Resultados: Participantes colostomizados, com média de 73 anos ± 14,94, predomínio do sexo masculino; e cuidadores informais, com média de 44 anos ± 8,98, predomínio do sexo feminino. Na avaliação visual do óleo, 100% dos participantes perceberam a aderência. Em relação à avaliação do odor dos efluentes pelos colostomizados, cinco relataram "odor forte" antes do uso do óleo e, após o uso, seis relataram odor "fraco" (p = 0,005). Cinco cuidadores informais detectaram odor "muito forte" dos efluentes antes do uso do óleo e, após o uso, um "fraco" e nove "moderado" (p = 0,0025). Conclusão: Houve redução do odor dos efluentes nas bolsas coletoras com o óleo essencial de Melaleuca armillaris a 10%. Pedido registro de patente no INPI sob nº. BR 10 2020 026987 9.

Performance, meat quality, and lipidemia of meat-type quails fed with diets containing essential oils / Desempenho, qualidade da carne e lipidemia de codornas de corte alimentadas com rações contendo óleos essenciais

This study evaluated the effect of essential oil (ESOL) of Mentha piperita and Melaleuca alternifolia on meat-type quails. To examine performance, a completely randomized design was used, with four treatments and eight repetitions each, using seven birds per repetition. To assess lipidemia, a completely randomized design in a 4 × 2 factorial scheme was used, with four treatments and two collection conditions using eight repetitions and one bird per repetition. Weight gain, feed intake, feed conversion, carcass yield, cholesterol, high-density lipoporteins, triglycerides, pH, and brightness of quail breast meat were assessed. The data were analyzed for homoscedasticity and normality, and the means were subjected to analysis of variance. Adding M. piperita and M. alternifolia ESOL to the diets of meat-type quails can improve performance, carcass yield, and meat quality characteristics, comparable to the use of performance-enhancing antibiotics. The use of zinc bacitracin, M. piperita, and M. alternifolia under different collection conditions did not increase the serum levels of low-density and very low-density lipoproteins. The variation coefficients measured after 12 hours of fasting were 86% lower than without fasting.

Objetivou-se com este estudo avaliar o efeito do uso dos óleos essenciais (OLES) de Mentha piperita e Melaleuca alternifolia em codornas de corte. Para o estudo do desempenho foi utilizado o delineamento inteiramente ao acaso, com quatrotratamentos e oito repetições, sendo sete aves por repetição. Para o estudo da lipidemia utilizou-se o delineamento inteiramente casualizado em esquema fatorial: 4x2, consistindo em quatro tratamentos e duas condições de coleta, com oito repetições, sendo uma ave por repetição. As variáveis analisadas foram: ganho de peso, consumo ração, conversão alimentar, rendimento de carcaça, colesterol, HDL, triglicerídeos, pH, capacidade de retenção de água, perda de peso por cozimento, luminosidade na carne do peito de codornas. Os dados obtidos foram analisados quanto à homocedasticidade e normalidade, as médias foram submetidas à análise de variância. O uso de OLES de M. piperita e M. alternifolia na dieta de codornas de corte pode proporcionar desempenhos zootécnicos, rendimentos de carcaça e características de qualidade da carne comparáveis ao uso de antibióticos melhoradores de desempenho. A redução no nível de colesterol HDL foi notada nas aves tratadas com Bacitracina de zinco e com os OLES de M. piperita e M. alternifolia, em 8,12; 16,52 e 3,36% respectivamente. O uso da Bacitracina de zinco, da M. piperita e da M. alternifolia associado às diferentes condições de coleta não aumentaram os valores séricos de LDL, VLDL. Os coeficientes de variação aferidos na condição "após 12 horas de jejum" apresentaram-se 86% inferiores à condição "sem jejum".

In vitro and in vivo efficacy of tea tree essential oil for bacterial and yeast ear infections in dogs / Uso in vitro e in vivo do óleo essencial de Melaleuca (Melaleuca alternifolia) em otites bacterianas e por leveduras

Otitis externa is a common complaint in dogs. Bacteria and yeasts are commonly involved and may perpetuate inflammatory reactions inside the ear canal. Otoscopy, cytological examination of secretion and microbiological culture embody forms of diagnosis. Cytology also has great use in accessing treatment evolution. Therapy usually consists of cleaning ear canals and subsequent use of antibiotics or antifungal products. As some of them may cause hypersensitivity and even ototoxicity, searching for new pharmacological bases is currently necessary and justifies this study, which aimed to evaluate in vitro and in vivo efficacy of tea tree essential oil for bacterial and yeast ear infections in dogs. Twenty-eight dogs from a particular shelter in Cuiabá (Mato Grosso, Brazil), presenting clinical signs of otitis externa, were enrolled in this clinical trial. In all of them, clinical and cytological evaluations, as well as culture and susceptibility testing of the affected ears were carried out. From each dog, one ear was treated with 5% tea tree essential oil lotion and the other with standard otic formulation, according to the type of infection (bacterial, yeast or both). In vitro susceptibility testings of all ear cultures, to the same drugs used in treatment, were also carried out. Culture results showed 62.5% bacterial and fungal infection, 33.9% bacterial infection and 3.6% fungal infection, from the 56 ear samples collected. The most common microorganisms isolated were Staphylococcus intermedius, Staphylococcus aureus, Proteus mirabilis and Malassezia pachydermatis. Gram-positive bacteria were susceptible to gentamycin in 60.5% and resistant in 16.3% of the samples. Five percent tea tree essential oil formulation produced a 5mm clear zone of inhibition around the disks in one of the 63 samples evaluated. Pure (100%) tea tree essential oil formulation produced a 10mm clear zone of inhibition around the disks in four of the 63 samples evaluated, a 9mm zone in three samples, an 8mm zone in 16 samples, a 7mm zone in seven samples, a 6mm zone in two samples and there was no clear zone in 31 samples. Inhibition zones were produced by strains of Staphylococcus intermedius, Staphylococcus hyicus, Corynebacterium sp., Proteus mirabilis and Enterobacter sp. tea tree essential oil ear solution significantly induced remission of clinical signs both in bacterial and yeast ear infections. It also reduced as much Malassezia pachydermatis ear infection as the nystatin solution used in this study, while gentamycin solution showed better antibacterial effect. More studies should be conducted to evaluate in vitro diffusion properties of tea tree essential oil. Good antimicrobial spectrum and the absence of adverse reactions confirm the importance of developing a tea tree formulation as an alternative therapy for ear infections in dogs.(AU)

Otite externa é queixa frequente em cães. Bactérias e leveduras estão comumente envolvidas e podem perpetuar as reações inflamatórias dentro do canal auditivo. Dentre as formas de diagnóstico, encontram-se a otoscopia, o exame citológico da secreção e a cultura microbiológica. Citologia também tem grande utilidade no acesso à evolução do tratamento. A terapia consiste de limpeza dos canais auditivos e posterior utilização de antibióticos ou produtos antifúngicos. Como alguns antimicrobianos utilizados no tratamento podem causar hipersensibilidade e até mesmo ototoxicidade, a busca por novas bases farmacológicas justifica a existência deste estudo, que teve como objetivo avaliar in vitro e in vivo a eficiência do óleo de Melaleuca alternifolia em otites bacterianas e fúngicas de cães. Vinte e oito cães, de um abrigo particular, apresentando sinais clínicos de otite externa, foram incluídos neste estudo clínico. Todos passaram por avaliação clínica, citologia e cultura de material das orelhas afetadas. De cada animal, uma orelha foi tratada com óleo de Melaleuca 5% e a outra com formulação ótica padrão, de acordo com a afecção (bacteriana, fúngica ou mista). As culturas também foram submetidas a testes de susceptibilidade in vitro aos mesmos agentes utilizados no tratamento in vivo. Os resultados da cultura mostraram 62,5% de infecção mista (bacteriana e fúngica), 33,9% de infecção bacteriana e 3,6%, de infecção fúngica a partir das 56 orelhas. Os micro-organismos mais isolados foram Staphylococcus intermedius, Staphylococcus aureus, Proteus mirabilis e Malassezia pachydermatis. As bactérias GRAM-positivas foram sensíveis à gentamicina em 60,5% e resistentes em 16,3% das amostras. A formulação com 5% de óleo essencial de Melaleuca produziu uma zona de inibição de 5mm em torno dos discos em uma das 63 amostras avaliadas. A formulação pura (100%) do mesmo produto produziu uma zona de 10mm de inibição em quatro das 63 amostras analisadas, uma zona de 9 mm em três amostras, uma zona de 8mm em 16 amostras, uma zona de 7mm em sete amostras, uma zona de 6mm em duas amostras e não havia nenhuma zona clara em 31 amostras. Zonas de inibição foram produzidas por estirpes de Staphylococcus intermedius, Staphylococcus hyicus, Corynebacterium sp., Proteus mirabilis e Enterobacter sp. Clinicamente, a formulação com o óleo essencial de melaleuca induziu significativamente uma melhora nas manifestações, tanto nas otites bacterianas quanto nas causadas por leveduras, sendo estatisticamente semelhante ao tratamento com nistatina (nas otites por levedura), mas menos eficaz que a solução de gentamicina nas otites bacterianas. Mais estudos devem ser realizados para avaliar as propriedades de difusão in vitro do óleo essencial de melaleuca. O bom espectro antimicrobiano, a boa resposta clínica e a ausência de reações adversas confirmam a possibilidade de desenvolvimento de formulação ótica com o óleo essencial de melaleuca, como uma alternativa para a terapia de infecções do ouvido em cães.(AU)

Lactoferrin, chitosan and Melaleuca alternifolia-natural products that show promise in candidiasis treatment

Abstract The evolution of microorganisms resistant to many medicines has become a major challenge for the scientific community around the world. Motivated by the gravity of such a situation, the World Health Organization released a report in 2014 with the aim of providing updated information on this critical scenario. Among the most worrying microorganisms, species from the genus Candida have exhibited a high rate of resistance to antifungal drugs. Therefore, the objective of this review is to show that the use of natural products (extracts or isolated biomolecules), along with conventional antifungal therapy, can be a very promising strategy to overcome microbial multiresistance. Some promising alternatives are essential oils of Melaleuca alternifolia (mainly composed of terpinen-4-ol, a type of monoterpene), lactoferrin (a peptide isolated from milk) and chitosan (a copolymer from chitin). Such products have great potential to increase antifungal therapy efficacy, mitigate side effects and provide a wide range of action in antifungal therapy.

In vitro effects of Melaleuca alternifolia essential oil on growth and production of volatile sulphur compounds by oral bacteria

ABSTRACT Objective Halitosis can be caused by microorganisms that produce volatile sulphur compounds (VSCs), which colonize the surface of the tongue and subgingival sites. Studies have reported that the use of natural products can reduce the bacterial load and, consequently, the development of halitosis. The aim of this study was to evaluate the antimicrobial activity of the essential oil of Melaleuca alternifolia on the growth and volatile sulphur compound (VSC) production of oral bacteria compared with chlorhexidine. Material and Methods The effects of these substances were evaluated by the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) in planktonic cultures of Porphyromonas gingivalis and Porphyromonas endodontalis. In addition, gas chromatography analyses were performed to measure the concentration of VSCs from bacterial cultures and to characterize M. alternifolia oil components. Results The MIC and MBC values were as follows: M. alternifolia - P. gingivalis (MIC and MBC=0.007%), P. endodontalis (MIC and MBC=0.007%=0.5%); chlorhexidine - P. gingivalis and P. endodontalis (MIC and MBC=1.5 mg/mL). M. alternifolia significantly reduced the growth and production of hydrogen sulfide (H2S) by P. gingivalis (p<0.05, ANOVA-Dunnet) and the H2S and methyl mercaptan (CH3SH) levels of P. endodontalis (p<0.05, ANOVA-Dunnet). Chlorhexidine reduced the growth of both microorganisms without altering the production of VSC in P. endodontalis. For P. gingivalis, the production of H2S and CH3SH decreased (p<0.05, ANOVA-Dunnet). Conclusion M. alternifolia can reduce bacterial growth and VSCs production and could be used as an alternative to chlorhexidine.

Antifilarial and Antibiotic Activities of Methanolic Extracts of Melaleuca cajuputi Flowers

We evaluated the activity of methanolic extracts of Melaleuca cajuputi flowers against the filarial worm Brugia pahangi and its bacterial endosymbiont Wolbachia. Anti-Wolbachia activity was measured in worms and in Aedes albopictus Aa23 cells by PCR, electron microscopy, and other biological assays. In particular, microfilarial release, worm motility, and viability were determined. M. cajuputi flower extracts were found to significantly reduce Wolbachia endosymbionts in Aa23 cells, Wolbachia surface protein, and microfilarial release, as well as the viability and motility of adult worms. Anti-Wolbachia activity was further confirmed by observation of degraded and phagocytized Wolbachia in worms treated with the flower extracts. The data provided in vitro and in vivo evidence that M. cajuputi flower extracts inhibit Wolbachia, an activity that may be exploited as an alternative strategy to treat human lymphatic filariasis.

Análisis multivariable de la composición química de aceite esencial dehojas de Melaleuca quinquenervia que crece en Cuba / Multivariate analysis of the chemical composition of the essential oil from leaves of Melaleuca quinquenervia growing in Cuba

El aceite esencial de Melaleuca quinquenervia de la Ciénaga de Zapata, Cuba, obtenido a escala piloto con un rendimiento promedio de 0,8%, presentó una densidad relativa y un índice de refracción promedios de 0,9253g/mL y 1,4827 respectivamente. La determinación de su composición química por cromatografía de gases acoplada a espectrometría de masas permitió identificar 42 compuestos, de los cuales 26 se sometieron al Análisis por Componentes Principales y al Análisis por Conglomerados. Dichos análisis permitieron la separación de las muestras en dos grupos con diferencias significativas (p<0,05) entre los contenidos promedios de sus principales constituyentes. A partir de dichos análisis se estableció la presencia de dos quimiotipos diferentes: uno con elevados contenidos de viridiflorol (33,8 por ciento), seguido por el 1,8-cineol (21,8 por ciento), y otro quimiotipo del tipo 1,8-cineol (30,0 por ciento) con un contenido relativamente elevado de viridiflorol (24,6 por ciento). Ambos quimiotipos presentaron concentraciones similares de los monoterpenos limoneno y αlfa-pineno.

The essential oil of Melaleuca quinquenervia from Ciénaga de Zapata, Cuba, obtained at pilot scale with average yield of 0.8%, showed average relative density and refraction index of 0.9253g/mL and 1.4827 respectively. It ́s chemical composition determination by gas chromatography coupled to Mass Spectrometry allow identifying 42 compounds, 26 of which were submitted to Principal Components Analysis and to Conglomerates Analysis. Such analyses allowed the separation of the samples into two groups with significant differences (p<0.05) between the average contents of its main components. From such analyses, it was established the presence of two different chemotypes: one with high contents of viridiflorol (33.8 percent), followed by 1,8-cineol (21.8 percent), and another chemotype rich in 1,8-cineol (30,0 percent) with a relatively high content in viridiflorol (24.6 percent). Both chemotypes showed similar concentrations of limonene and αlfa-pinene monoterpenes.

Antimicrobial activity of Melaleuca sp. oil against clinical isolates of antibiotics resistant Staphylococcus aureus

PURPOSE: To extract the Melaleuca sp. oil and to assess its in vitro inhibitory effect against Staphylococcus aureus isolates obtained from lower limb wounds and resistant to several antibiotics. METHODS: A total of 14 test-tubes containing Mueller-Hinton broth were used to determine the Minimum Inhibitory Concentration (MIC). The following concentrations of the Melaleuca sp. oil were added to the first 11 tubes: 8; 4; 2; 1; 0.5; 0.2; 0.1; 0.05; 0.025; 0,0125 and 0.00625%. The 12th and 13th tubes, with and without oil, were used as the positive and negative controls, respectively. The experimental study was carried out in triplicate at 37ºC for 18 hours. The Minimum Bactericidal Concentration (MBC), able of killing all the microorganisms, was also determined. Two S. aureus isolates were obtained from lower limb wounds of female patients and the identification of the microorganisms (Staphylococcus aureus) and the test for susceptibility to the antimicrobial agents were carried out by automation using the apparatus MicroScan(r). After identification, the isolates were preserved in liquid Trypticase Soy medium, and inoculated for determination of the MIC and MBC. RESULTS: The MIC was 0.2% and the MBC was 0.4%. CONCLUSION: The Melaleuca sp. oil showed antimicrobial properties in vitro against strains isolated from lower limb wounds which were resistant to multiple antibiotics. .

Atividade de nanoformulações de Melaleuca alternifolia e terpinen-4-ol em isolados de Rhodococcus equi / Melaleuca alternifolia activity in nanoformulations and terpinen-4-ol against Rhodococcus equi isolates

Rhodococcus equi é o agente etiológico da rodococose equina, importante doença respiratória de potros. Especialmente na última década, a emergência de cepas resistentes aos antimicrobianos empregados no tratamento da rodococose tem sido relatada. Nesse sentido, há a necessidade de estudos envolvendo terapias alternativas e novas tecnologias, incluindo o uso de plantas medicinais e nanotecnologia. Neste trabalho utilizou-se Melaleuca alternifolia nas seguintes formulações: óleo livre, nanocápsula, nanoemulsão e a combinação de óleo livre com nanocápsula e com nanoemulsão, além do seu composto majoritário, terpinen-4-ol, a fim de verificar a atividade antimicrobiana frente a isolados de R. equi de diferentes origens. Utilizou-se o método de microdiluição em caldo na determinação das concentrações inibitória mínima (CIM) e bactericida mínima (CBM) das diferentes formulações frente aos isolados (n=24). Verificou-se baixo potencial para atividade antibacteriana de M. alternifolia na formulação de óleo livre. Todavia, essa atividade foi potencializada quando se incorporou o óleo essencial às nanoformulações. O composto terpinen-4-ol demonstrou potencial atividade antibacteriana quando incorporado ao óleo essencial e quando utilizado isoladamente. Verificou-se que tanto M. alternifolia quanto terpinen-4-ol testados possuem atividade antimicrobiana contra isolados de R. equi, sugerindo seu emprego em estudos avaliando seu potencial para o tratamento da rodococose.

Rhodococcus equi causes rodococose in horses, characterized by bronchopneumonia in foals. Due to reports of antimicrobial resistance, it is important to develop studies involving alternative therapies and new technologies, including the use of medicinal plants and nanotechnology. In this work, the plant Melaleuca alternifolia in oil free formulations, nanocapsule, nanoemulsion and the combination of free and nanocapsule oil nanoemulsion, besides its major compound, terpinen-4-ol, were used in order to verify antimicrobial activity against isolates of R. equi. The broth microdilution method was employed to determine the minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations of different formulations against 24 isolates. There was low antibacterial activity of M. alternifolia in oil free formulation; however, it was observed that the activity was enhanced when incorporated as essential oil the nanoformulations. The major compound, terpinen-4-ol, showed bactericidal and bacteriostatic activity when used alone. It is suggested that M. alternifolia, in association with nanocarriers systems, as well as terpinen -4-ol, presents potential for future studies concerning the equine rodococosis therapy.

Avaliação da eficácia antimicrobiana de sabonetes contendo: óleo essencial de melaleuca alternifolia versus triclosan versus clorexidina e o impacto na adesão à higienização das mãos pelo efeito aromaterápico / Evaluation of the antimicrobial efficacy of soaps containing: melaleuca alternifolia essential oil versus chlorhexidine versus triclosan and the impact of adherence to hand hygiene by aromatherapeutic effect

Introdução: Os efeitos antimicrobianos de óleos essenciais têm sido relatados na literatura científica, sobretudo referentes ao óleo essencial de Melaleuca alternifolia, também denominado óleo essencial de Tea Tree (OTT). Tal óleo essencial apresenta propriedades antissépticas e pode representar uma alternativa de um produto natural para higienização das mãos (HM) nos estabelecimentos de assistência à saúde que atualmente utilizam predominantemente produtos à base de triclosan e clorexidina. Objetivo: Avaliar a eficácia antimicrobiana na higiene das mãos realizada com três diferentes formulações de sabonetes líquidos distintos, contendo: óleo essencial de Melaleuca alternifolia a 2,0%; sabonete com triclosan a 0,5%; sabonete com clorexidina a 2,0%, bem como compreender de que forma o uso de um sabonete com óleo essencial na higienização das mãos na prática assistencial é percebido por profissionais de saúde. Métodos: Para o experimento (etapa quantitativa) foram utilizadas as diretrizes da metodologia do Comitê Europeu de Padronização, EN1499 versão abril 2013 (phase2/step2), indicada para avaliar a eficácia de antissépticos para higienização das mãos. Foram contaminadas artificialmente as mãos de 15 voluntários sadios com Escherichia coli K12, seguida pela lavagem das mãos utilizando-se cada um dos produtos em avaliação ou um sabão de referência (soft soap). Realizou-se a contagem do número de microrganismos antes (pré-valores) e após (pós-valores) cada procedimento e foi estabelecida a redução logarítmica microbiana para cada um dos participantes em cada procedimento.Os dados foram analisados aplicando-se dois testes não paramétricos. Para a obtenção dos dados qualiquantitativos realizaram-se entrevistas cujos discursos foram analisados conforme metodologia proposta pelo discurso do sujeito coletivo (DSC). Resultados: ao ser aplicado o Teste de Wilcoxon, os três sabonetes testados obtiveram resultados superiores ao do sabão de referência (soft soap) e foram considerados antimicrobianos; constatou-se ainda a superioridade do sabonete contendo OTT e contendo triclosan em relação ao sabonete com clorexidina. Quando aplicado o Teste de Friedman, os sabonetes contendo triclosan e OTT, que apresentaram eficácias equivalentes, podem ser considerados antimicrobianos. A maior parte dos profissionais tinha algum conhecimento sobre Aromaterapia (65,21%), mas menos da metade conhecia as aplicações do OTT (43,47%). Profissionais mais jovens e menos experientes acharam o aroma do OTT agradável ou forte, mas não desagradável. Profissionais mais experientes e com mais idade o associaram ao aroma de pinho e levantaram a questão de o aroma ser incômodo para alérgicos. As principais diferenças observadas entre o sabonete com OTT e os demais sabonetes da prática assistencial foram em relação a aspectos físicos, como textura mais agradável, ao aroma e ao fato de ser menos agressivo à pele. A não agressão à pele foi considerada pelos participantes como o grande diferencial do sabonete contendo OTT, sobrepondo-se, inclusive, ao fator aroma, e que poderia contribuir para aumentar a adesão à HM. Conclusão: os sabonetes contendo OTT 2,0% e contendo triclosan 0,5% demonstraram desempenho superior em relação à clorexidina 2,0%. O não ressecamento da pele por produtos de HM é fundamental para aumentar a adesão dos profissionais de saúde. Além disso, a presença do aroma no sabonete pode ou não ser um fator de estímulo.

Introduction: The antimicrobial effects of essential oils have been reported in the scientific literature, especially regarding the essential oil of Melaleuca alternifolia, also known as tea tree essential oil (TTO). This essential oil has antiseptic properties and can represent a natural-product alternative for hand hygiene (HH) in health-care settings, which currently use mainly products based on triclosan and chlorhexidine. Objective: To evaluate the antimicrobial efficacy in HH performed using three distinct liquid soap formulations containing 2.0% Melaleuca alternifolia essential oil; 0.5% triclosan; 2.0% chlorhexidine and assess how using a soap with essential oil for HH in healthcare practice is perceived by health professionals. Methods: For the experiment (quantitative phase) we used the methodology guidelines of the European Committee for Standardization, EN1499 version April 2013 (phase2/step2), indicated to evaluate the efficacy of antiseptics for HH. The hands of 15 healthy volunteers were artificially contaminated with Escherichia coli K12 and then the hands were washed with each of the products being assessed or the reference soap (soft soap). The number of microorganisms was counted before (pre-values) and after (post-values) each procedure and microbial logarithmic reduction was performed for each of the participants in each procedure. Data were analyzed using two non-parametric tests. To obtain the qualiquantitative data, interviews were carried out, of which contents were analyzed according to the methodology proposed by the Collective Subject Discourse (CSD).Results: When the Wilcoxon test was applied, the three assessed soaps showed better results than the reference soap (soft soap) and were considered as exhibiting antimicrobial action; the soaps containing TTO and triclosan showed to be superior to the one containing chlorhexidine. When Friedmans test was applied, the soaps containing triclosan and TTO, which showed similar efficacy, were considered antimicrobials. Most of the professionals had some knowledge of aromatherapy (65.21%), but less than half knew about TTO uses (43.47%). Younger and less experienced professionals found the smell of TTO pleasant or strong, but not unpleasant. Older and more experienced professionals associated it to the smell of pine and raised the question of the smell being displeasing for allergic individuals. The main differences between the TTO soap and the other soaps used in health care practice were related to the physical aspects, such as a more pleasant texture, smell and the fact of its being less aggressive to the skin. The fact that it was less aggressive to the skin was perceived by participants as the great differential of the soap containing TTO, overriding even the scent factor, which could help to increase adherence to HH. Conclusion: The soaps containing 2.0% TTO and 0.5% triclosan showed superior performance when compared to the one with 2.0% chlorhexidine. The factthat a soap used in HH does not dry the skin is considered a critical point for adherence by health care professionals. Additionally, the soap smell may or may not be a stimulating factor for HH.

Cumulative mortality of Aedes aegypti larvae treated with compounds / Mortalidade acumulativa de larvas de Aedes aegypti tratadas com compostos

OBJECTIVE To evaluate the larvicidal activity of Azadirachta indica, Melaleuca alternifolia, carapa guianensis essential oils and fermented extract of Carica papaya against Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae). METHODS The larvicide test was performed in triplicate with 300 larvae for each experimental group using the third larval stage, which were exposed for 24h. The groups were: positive control with industrial larvicide (BTI) in concentrations of 0.37 ppm (PC1) and 0.06 ppm (PC2); treated with compounds of essential oils and fermented extract, 50.0% concentration (G1); treated with compounds of essential oils and fermented extract, 25.0% concentration (G2); treated with compounds of essential oils and fermented extract, 12.5% concentration (G3); and negative control group using water (NC1) and using dimethyl (NC2). The larvae were monitored every 60 min using direct visualization. RESULTS No mortality occurred in experimental groups NC1 and NC2 in the 24h exposure period, whereas there was 100% mortality in the PC1 and PC2 groups compared to NC1 and NC2. Mortality rates of 65.0%, 50.0% and 78.0% were observed in the groups G1, G2 and G3 respectively, compared with NC1 and NC2. CONCLUSIONS The association between three essential oils from Azadirachta indica, Melaleuca alternifolia, Carapa guianensis and fermented extract of Carica papaya was efficient at all concentrations. Therefore, it can be used in Aedes aegypti Liverpool third larvae stage control programs. .

OBJETIVO Avaliar a eficácia de composto de óleos essenciais de Azadirachta indica, Melaleuca alternifolia, Carapa guianensis e extrato fermentado de Carica papaya sobre larvas de Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae). MÉTODOS O ensaio larvicida foi realizado em triplicata com 300 larvas para cada grupo experimental utilizando larvas de terceiro estádio, as quais foram expostas por 24h, em 2013. Os grupos foram: controles positivos com larvicida industrial (BTI) nas concentrações de 0,37 ppm (CP1) e 0,06 ppm (CP2); tratado com composto de óleos essenciais e extrato fermentado na concentração de 50,0% (G1); tratado composto e óleos essenciais e extrato fermentado na concentração de 25,0% (G2); tratado com composto de óleos essenciais e um extrato fermentado na concentração de 12,5% (G3); controle negativo com água (CN1) e controle dimetil sulfóxido (CN2). As larvas foram monitoradas a cada 60 min através de visualização direta. RESULTADOS Larvas dos grupos CN1 e CN2 não tiveram mortalidade durante o período de 24h de exposição, mas os grupos CP1 e CP2 apresentaram taxa de mortalidade de 100% em relação a CN1 e CN2. Os tratamentos G1, G2 e G3 exerceram atividade larvicida de 65,0%, 50,0% e 78,0%, respectivamente, quando comparados a CN1 e CN2. CONCLUSÕES A associação entre os três óleos essenciais de Azadirachta indica, Melaleuca alternifolia, Carapa guianensis e extrato fermentado de Carica papaya foi eficiente em todas as concentrações testadas, podendo ser utilizado no controle de larvas de terceiro estádio de A. aegypti linhagem Liverpool. .

Substratos, concentrações de ácido indolbutírico e tipos de miniestacas no enraizamento de melaleuca (Melaleuca alternifolia Cheel) / Substrates, indolebutyric acid levels and types of minicuttings on the rooting of tea tree (Melaleuca alternifolia Cheel)

Melaleuca alternifolia tem como produto principal o óleo essencial extraído das folhas devido às propriedades antifúngicas e antibacterianas. Pouco se tem relatado sobre a propagação desta espécie, sendo a miniestaquia uma alternativa para a propagação vegetativa de clones superiores visando à implantação de campo de produção. Este trabalho teve como objetivo avaliar o efeito de diferentes substratos, concentrações de AIB, e tipo de miniestaca, no enraizamento de Melaleuca alternifolia. No primeiro experimento foram testados os substratos, areia de granulometria média, Plantmax HT®, Golden-Mix® e vermiculita. No segundo experimento foram avaliadas diferentes concentrações de AIB (0, 500, 1000 e 2000 mg L-1), em dois tipos de miniestacas (apical e mediana). As miniestacas foram confeccionadas com 5 cm de comprimento, mantidas em casa de vegetação com nebulização intermitente, e, após 45 dias do plantio, foram avaliadas as porcentagens de miniestacas enraizadas, com calos e não responsivas, o número de raízes formadas por miniestaca e o comprimento das três maiores raízes (cm). O substrato Golden-Mix® e as miniestacas coletadas da porção apical do ramo submetidas ao tratamento com 500 mg L-1 de AIB apresentaram maior porcentagem de enraizamento e melhor qualidade do sistema radicial.

Melaleuca alternifolia has as major product the essential oil extracted from its leaves due to its antifungal and antibacterial properties. There are scarce reports about the propagation of this species, and minicutting is an alternative for vegetative propagation of superior clones in order to establish a production field. This study aimed to evaluate the effect of different substrates, IBA levels and types of minicuttings on the rooting of Melaleuca alternifolia. In the first experiment, the following substrates were tested: medium sand, Plantmax HT®, Golden-Mix® and vermiculite. In the second experiment, different IBA levels (0, 500, 1000 and 2000 mg L-1) were tested for two minicutting types (apical and medium). Minicuttings were prepared with 5 cm length and were kept in a greenhouse with intermittent mist; then, at 45 days after planting, we evaluated: the percentages of rooted minicuttings, with callus and non-responsive, the number of roots per minicutting and the length of the three longest roots. The substrate Golden-Mix® and the minicuttings collected from the apical part of the branch and treated with 500 mg L-1 IBA presented the largest rooting percentage and the best root system quality.

Efeito inibitório de óleos essenciais sobre microrganismos do canal radicular / Inhibitory effect of essential oils against organisms from root canal

Introdução: os óleos essenciais apresentam propriedades biológicas, as quais devem ser estudadas de modo a investigar novas possibilidades de constituição de soluções irrigadoras. Objetivo: avaliar o efeito inibitóriode óleos essenciais extraídos de plantas sobre a atividade de microrganismos envolvidos na infecção do canal radicular. Material e método: foram selecionados os óleos essenciais de Melaleuca alternifolia (melaleuca), Cymbopogon winterianus (citronela), Thymus vulgaris (tomilho), Ocimum basilicum (manjericão), Cymbopogon martinii (palmarosa) e Cinnamomum cassia (canela-da-china). A atividade antimicrobiana sobre Candida albicans (ATCC 289065) e Enterococcus faecalis (ATCC 29212) foi avaliada por meio da triagem da atividade antimicrobiana e da determinação da Concentração Inibitória Mínima (CIM). As soluções de Digluconato de Clorexidina (0,12%) e Hipoclorito de Sódio (1%) serviram de controle. Resultado: os halos de inibição docrescimento para E. faecalis variaram entre 8,00 e 26,00 mm, enquanto que a variação para C. albicans foi entre 26,67 e > 35,00 mm. Os óleos essenciais de T. vulgaris, C. martinii e C. cassia apresentaram CIM na concentração 0,56 mg.mL­1 frente às cepas testadas. Menor atividade foi demonstrada por O. basilicum, que apresentou CIM nas concentrações 72,00 e 1,12 mg.mL­1 contra E. faecalis e C. albicans, respectivamente. Conclusão: os produtos testados apresentaram efeito inibitório satisfatório sobre E. faecalis e C. albicans, destacando-se os óleos essenciais de T. vulgaris, C. martinii e C. cassia.

Introduction: essential oils have biological properties that should be studied in order to investigate new possibilities for formulating irrigating solutions. Objective: the aim was to evaluate the inhibitory effect of essential oils extracted from plants on the activity of organisms involved in root canal infection. Material and method: the essential oils from Melaleuca alternifolia (tea tree), Cymbopogon winterianus (citronella), Thymus vulgaris (thyme), Ocimum basilicum (basil), Cymbopogon martinii (palmarosa) and Cinnamomum cassia (cinnamon) were selected.The antimicrobial activity against Candida albicans (ATCC 289065) and Enterococcus faecalis (ATCC 29212) was evaluated by screening for antimicrobial activity and determination of Minimum Inhibitory Concentration (MIC). The Chlorhexidine Digluconate (0.12%) and 1% Sodium Hypochlorite solutions served as control. Result: the zones of growth inhibition for E. faecalis varied between 8.00 and 26.00 mm, while the zones of inhibition for C. albicans ranged between 26.67 and > 35.00 mm. The essential oils from T. vulgaris, C. martinii and C. cassia showedMIC at concentration of 0.56 mg.mL­1 against the tested strains. Minor activity was demonstrated by the essential oil from O. basilicum, which presented MIC at concentrations of 72.00 and 1.12 mg.mL­1, against E. faecalis and C. albicans, respectively. Conclusion: the tested products presented satisfactory inhibitory effect against E. faecalisand C. albicans, with highlight to the essential oils from T. vulgaris, C. martinii and C. cassia.

Efecto antimicrobiano de hojas de Melaleuca leucadendron L, que crece en la Ciénaga de Zapata / Antimicrobial effect of the leaves of Melaleuca leucadendron L growing in Cienaga de Zapata

SUMARY Melaleuca leucadendron L is a tree commonly known as cayeput, being an invasive, undesirable species in Cienaga de Zapata, in the province of Matanzas. According to the referred usages, it might be exploited in a reasonable way as an antimicrobial agent. As our objective we pretended to determine antimicrobial activity in the fluid extract of the leaves of this tree wildly growing in the before mentioned territory. The extract was obtained by repercolation and the assay was carried out in vitro, using the methods of diffusion in agar and dilution in a liquid media. Different concentrations of the extract were used against bacteria, yeast, and filamentous fungi. The microbicidal effect of the extract was demonstrated for all the tested microorganisms, establishing values of minimal inhibitory, minimal bactericidal and minimal fungicidal effects of the concentration. The effect kept steady during four years. These results confirm the purpose of using as antimicrobial the raw vegetable material existing in excess in the region. It is recommended to take into account the matters discussed in the study according to the undesirable effects, so other studies are required to deepen in that sense. The evaluation risk-benefit should be observed to use the tree in the medical practice with the precautions also demanded by other well-known antimicrobials.

Dormência e germinação de sementes de Melaleuca alternifolia Cheel / Dormancy and germination of Melaleuca alternifolia Cheel. seeds

A Melaleuca alternifolia Cheel. é uma espécie aromática de expressivo interesse econômico, em função da presença de óleo essencial armazenado no tecido foliar. As sementes, entretanto, apresentam baixo poder germinativo, o que tem dificultado a obtenção de novos materiais genéticos e o avanço tecnológico para produção no Brasil. O presente trabalho teve por objetivo determinar uma metodologia adequada para avaliar o poder germinativo de sementes de melaleuca. Para tanto, foram realizados dois experimentos, um em condições de laboratório e outro em casa-de-vegetação, avaliando-se diferentes tratamentos para promover a germinação da semente. O delineamento experimental empregado foi o inteiramente casualizado, com quatro repetições, sendo nove tratamentos em laboratório e sete em casa de vegetação; a comparação de médias foi realizada pelo teste Tukey, a 5 por cento de probabilidade. Diante dos resultados obtidos, concluiu-se que a pré-embebição das sementes por 18h, em água, é o procedimento mais adequado, dentre os testados, para avaliar o poder germinativo da semente de melaleuca, sendo que em condições de casa de vegetação, o referido tratamento pode ser usado com os substratos areia ou Plantmax.

Melaleuca alternifolia Cheel. is an aromatic species of high economic interest due to the presence of essential oil in its leaf tissue. However, its seeds have low germinative potential, which has made difficult the obtaining of new genetic materials and the technological advance for production in Brazil. The present work aimed to determine a suitable methodology to evaluate the germinative potential of Narrow-leaved Paperbark seeds. Thus, two experiments were carried out, one under lab conditions and other in greenhouse, in order to evaluate different treatments to stimulate seed germination. Experimental design was completely randomized, with four replicates; nine treatments were used in the lab and other seven in greenhouse. Means were compared by the Tukey's test at 5 percent significance. The obtained results suggest that pre-imbibition of seeds for 18h in water is the most suitable procedure to evaluate the germinative potential of Narrow-leaved Paperbark seeds. Under greenhouse conditions, this treatment can be used with the substrates sand or Plantmax®.

In vitro anti-microbial activity of the Cuban medicinal plants Simarouba glauca DC, Melaleuca leucadendron L and Artemisia absinthium L

In the present study, an extensive in vitro antimicrobial profiling was performed for three medicinal plants grown in Cuba, namely Simarouba glauca, Melaleuca leucadendron and Artemisia absinthium. Ethanol extracts were tested for their antiprotozoal potential against Trypanosoma b. brucei, Trypanosoma cruzi, Leishmania infantum and Plasmodium falciparum. Antifungal activities were evaluated against Microsporum canis and Candida albicans whereas Escherichia coli and Staphylococcus aureus were used as test organisms for antibacterial activity. Cytotoxicity was assessed against human MRC-5 cells. Only M. leucadendron extract showed selective activity against microorganisms tested. Although S. glauca exhibited strong activity against all protozoa, it must be considered non-specific. The value of integrated evaluation of extracts with particular reference to selectivity is discussed.

The influence of the essential oil of Melaleuca alternifolia on the healing of infected dental alveoli: a histological study in rats

The plant Melaleuca alternifolia is native to Australia. The distillation of its leaves produces an essential oil, commonly known as oil of Melaleuca, or Tea tree oil, which present antimicrobial activity. This study investigates the action of this oil on the repair process of infected dental alveoli. 48 rats were used (Rattus novergicus albinus, Wistar). After tooth extraction and posterior infection of the dental alveoli with Staphylococcus aureus, the animals were separated into three groups: Group I: curettage and irrigation with physiologic saline solution; Group II: curettage and irrigation with physiologic saline solution and topical application of rifamycin diethylamide B 25 mg; and Group III: curettage and irrigation with physiologic saline solution and topical application of oil of Melaleuca 20 percent. The animals were sacrificed 24 hours, 7, 14 and 21 days after the treatment with powder and the repair process of the dental alveoli was analyzed using an optical microscope. The results were submitted to qualitative and quantitative analysis and it was concluded that tea tree oil at 20 percent caused a delay in the repair process of infected dental alveoli in rats, as demonstrated by the presence of more necrosis area and less osteogenesis.

A planta Melaleuca alternifolia é nativa da Austrália e a destilação de suas folhas produz um óleo essencial conhecido por óleo de Melaleuca, ou Tea tree oil, usado como antimicrobiano. Nesse estudo, foi verificado a atividade deste óleo no processo de reparo de alvéolos dentais infectados. 48 ratos foram utilizados (Rattus novergicus albinus, Wistar) e após a extração do dente e posterior infecção do alvéolo com Staphylococcus aureus, os animais foram separados em três grupos: Grupo I: curetagem e irrigação do alvéolo com soro fisiológico; Grupo II: curetagem e irrigação com soro fisiológico e tratamento com Rifocina 25 mg; e Grupo III: curetagem e irrigação com soro fisiológico e aplicação tópica de óleo de Melaleuca 20 por cento. Os animais foram sacrificados 24 horas, 7, 14 e 21 dias após o tratamento e o processo de reparo do alvéolo dental foi analisado por microscopia ótica. Os resultados foram submetidos à análise quantitativa e qualitativa e foi possível concluir que o óleo a 20 por cento causou um retardo no processo de reparo dos alvéolos dentais infectados dos ratos, demonstrado por maior área de necrose e menor osteogênese.

A preliminary study on the mosquito repellent effect of tea tree (Melaleuca alternifolia) oil

BACKGROUND: Dengue Fever (DF) and Dengue Hemorrhagic Fever (DHF) are now considered as major health problems in the Philippines. N,N,-dietyl-3-toluamide (DEET) is recognized as the most effective against Aedes aegypti. However, the concern about its use have underscored the need to find a safer alternative repellent.OBJECTIVES: This study aims to determine and compare the repellent activity of tea tree (Melaleuca alternifolia) oil against Aedes aegypti with 7% DEET using a double-blind controlled experimental trialMETHODOLOGY: Twenty healthy subjects were allocated systematically by alternate assignment into three treatment groups (Control vs. Tea Tree oil, control vs. 7 percent DEET, Tea Tree oil vs DEET). All subjects were exposed to Aedes aegypti for 5 minutes every hour for 8 hours and the number of mosquitoes biting/landing were recorded and compared for each treatment groupRESULTS: Fifty percent tea tree oil has a repellent activity against Aedes aegypti and its efficacy is comparable to 7% DEET. Both treatments were equally effective in repelling mosquitoes for 7 hours. No cutaneous reactions to both repellents were notedCONCLUSION: The efficacy of tea tree oil is comparable to 7% DEET and is recommended as an alternative natural mosquito repellent.