The antimicrobial activity of essential oils is discussed in this review taking in account studies which were published in the period of time from 2008 until September 2010. Furthermore, the most important methods to examine the antimicrobial efficiency of essential oils are presented. The studies are divided into the following two groups, namely antibacterial and antifungal active agents depending on the activity of the applied essential oil against the test microorganisms. Various interesting possible applications are revealed such as the use of essential oils instead of synthetic drugs to circumvent the increasing resistance of some pathogens. Moreover, they could not only be used for the therapy of infectious illnesses, but also as preservatives in the food industry. A further possibility is, among others, the application of essential oils in skin products in order to treat or avoid dermal infections. Additionally, the prevalent constituents of the individual antimicrobial active essential oils are elaborated. Copyright © 2011 John Wiley & Sons, Ltd.

A review on recent research results (2008–2010) on essential oils as antimicrobials and antifungals. A review.

A crescente demanda por produtos cosmeticos estaveis, seguros e eficazes tem exigido da comunidade cientifica estudos cada vez mais complexos e utilizacao de tecnicas mais eficientes para determinacao da estabilidade dos produtos O uso de ativos da biodiversidade brasileira levou ao desenvolvimento de inumeros produtos, nas mais diferentes formas cosmeticas, o que dificulta, ainda mais, a padronizacao de protocolos experimentais para atestar a estabilidade das preparacoes cosmeticas Embora nao exista no Brasil um protocolo que padronize os ensaios a serem realizados para se determinar a estabilidade dos produtos, varios estudos foram realizados nos meios academicos para determinacao da estabilidade de materias-primas especificas As caracteristicas reologicas sao propriedades importantes a serem consideradas na fabricacao, estocagem e aplicacao de produtos de uso topico Alem de ensaios comumente empregados, a determinacao do comportamento reologico da formulacao auxilia na avaliacao da natureza fisico-quimica do veiculo, de tal forma que torna possivel detectar sinais precoces de instabilidade fisica, possibilitando o controle de qualidade dos constituintes, das formulacoes teste e dos produtos finais A analise termica tambem e usada para auxiliar o estudo da estabilidade de produtos cosmeticos e, de modo geral, a calorimetria exploratoria diferencial para orientar o desenvolvimento de novos produtos Outras ferramentas, como a fluorimetria e a granulometria a laser podem auxiliar o estudo e o desenvolvimento de sistemas, emulsionados ou nao O objetivo deste estudo e o desenvolvimento de protocolo para o estudo da estabilidade fisico-quimica de fitocosmeticos - sistemas contendo ativos da biodiversidade brasileira

/pdf/protocolo-para-ensaios-fisico-quimicos-de-estabilidade-de-5gmguwvzhu.pdf

Protocolo para ensaios físico-químicos de estabilidade de fitocosméticos

Essential oil of Cymbopogon citratus collected from Brazil and Cuba was tested to a chemical characterization and then was tested on the post-embryonic development of Musca domestica. The chemical composition analysis by GC-MS of the oils from Brazil/Cuba allowed the identification of 13 and 12 major constituents respectively; nine of them common to both. In the both oils, the main components were the isomers geranial and neral, which together form the compound citral. This corresponds to a total of 97.92%/Brazil and 97.69%/Cuba of the compounds identified. The monoterpene myrcene, observed only in the sample of Cuba, presented a large relative abundance (6.52%). The essential oil of C. citratus (Brazil/Cuba) was dissolved in DMSO and tested at concentrations of 5, 10, 25, 50, 75 and 100% and citral was prepared by mixing 16.8 mg with 960 µL DMSO. Both essential oils and monoterpene citral were applied topically to newly-hatched larvae (1µL/larva). The results showed a lethal concentration (LC50) of 4.25 and 3.24% for the Brazilian and Cuban essential oils, respectively. Mortalities of larval and newly-hatched larvae to adult periods were dose-dependent for the two both oils as for monoterpene citral, reaching 90%. Both essential oils and citral caused morphological changes in adult specimens.

https://www.arca.fiocruz.br/bitstream/icict/11515/2/zeneida_pinto_etal_IOC-2015.pdf

Chemical composition and insecticidal activity of Cymbopogon citratus essential oil from Cuba and Brazil against housefly

Characterisation of the anti-inflammatory and antinociceptive activities of the Hyptis pectinata (L.) Poit essential oil.

Antimicrobial and antibiofilm action of Casbane Diterpene from Croton nepetaefolius against oral bacteria

The given data of the literature on the antimicrobial activity of the essential oils are treated from the experimental point of view, and they consider a possible clinical application of the oils. The purpose of this study is to analyze the factors that can influence on antimicrobial activity of essential oils, in vitro, based on preview data from literature. We noticed that the tests and evaluations of the antimicrobial activity of the essential oils can be hindered by the volatility of the oil, its insolubility in water and its chemistry complexity. These details make the results obtained on literature difficult to compare. The used methods differ broadly and important factors that influence the results are frequently neglectful. After a bibliographical rising, we concluded that a large attention should be given to some factors when we work with essential oils: the used technique, the growth medium, the inoculums density, the tested essential oil and the used emulsifying. Its necessary to define and follow a right and standard methodology to make antimicrobial activity testes of essential oils.

/pdf/atividade-antimicrobiana-dos-oleos-essenciais-uma-abordagem-1hy2g4bawe.pdf

Atividade antimicrobiana dos óleos essenciais: uma abordagem multifatorial dos métodos

Objectives: The aim of the present study was to evaluate the anti-Streptococcus mutans activity of Hyptis pectinata essential oil, and present its promising potential against oral diseases.



Materials and methods:  The essential oil of H. pectinata was obtained by hydrodistillation from dried leaves and analyzed by GC / MS. The effectiveness of this essential oil regarding the antimicrobial activity against several S. mutans strains was investigated by the agar diffusion and microdilution methods, and chlorohexidine was used as a standard control.



Results:  The H. pectinata essential oil exhibited considerable inhibitory effect against either all the clinical isolates obtained from patients’ saliva or the ATCC strains tested, with minimum inhibitory and bactericidal concentrations of 200 μg ml−1. The study also compared the efficiency of the emulsifying agents Tween 20, Tween 80, dimethyl sulfoxide and propylene glycol in H. pectinata essential oil when tested against S. mutans. The data obtained confirmed the better inhibitory effect of the oil when using all tested diluents, although Tween 80 seemed to be more suitable for emulsification.



Conclusion:  According to our results, H. pectinata essential oil can be considered a promising alternative to chlorhexidine for the control of oral bacteria-related diseases and hygiene.

Hyptis pectinata essential oil: chemical composition and anti-Streptococcus mutans activity.

Essential oil was extracted from leaves of Hyptis pectinata using hydrodistillation, and its composition determined using GC-FID and GC-MS. Chemical analysis showed that there was a predominance of sesquiterpenes, of which β-caryophyllene (18.34%), caryophyllene oxide (18.00%) and calamusenone (24.68%) were measured for the first time in the genus Hyptis. Twenty-one compounds were identified, and calamusenone was isolated using preparative thin layer chromatography with a silica gel plate (60 PF254). The minimal inhibitory concentration (MIC) and minimal microbicidal concentration (MMC) were determined for various pathogenic microorganisms. H. pectinata oil was most effective against Gram (+) bacteria and yeasts.

/pdf/chemical-composition-and-antimicrobial-activity-of-the-12gmr3pt74.pdf

Paula F. C. Nascimento

Papers

Atividade antimicrobiana dos óleos essenciais: uma abordagem multifatorial dos métodos

Hyptis pectinata essential oil: chemical composition and anti-Streptococcus mutans activity.

Chemical composition and antimicrobial activity of the essential oil of Hyptis pectinata (l.) Poit.