Vinicius Nogueira Trajano

Antimicrobial effectiveness of spices: an approach for use in food conservation systems

There has been constant an increasing the search alternative and efficient compounds for food conservation, aiming a partial or total replacement of antimicrobial chemical additives. Spices offer a promising alternative for food safety. Inhibitory activity of spices and derivatives on the growth of bacteria, yeasts, fungi and microbial toxins synthesis has been well reported, so they could be used in food conservation as main or as adjuvant antimicrobial compounds in order to assure the production of microbiologically stable foods.

Estudo da interferência de óleos essenciais sobre a atividade de alguns antibióticos usados na clínica

The aim of this study was to evaluate the interference of essential oils from Lippia sidoides Cham, Plectranthus amboinicus Lour Spr., Conyza bonariensis L. and Eucalyptus citriodora Hook on the antibacterial effect of clinically used antibiotics. The assays were carried out with ampicillin (10 µg/mL), cephalotin (30 µg/mL), chloraphenicol (30 µg/mL), gentamicin (10 µg/mL) and tetracyclin (30 µg/mL) isolated and associated with essential oils (4% v/v) by the solid medium diffusion procedure using filter paper discs. The results showed interference of some essential oils on the antibacterial activity of the assayed antibiotics. It was observed the development of growth inhibition halo with different diameters when the antibiotics were applied alone and associated with essential oils. Synergic or antagonic behavior was more prominent in interactions with S. aureus and S. epidermidis strains. On the other hand, it was observed a smaller interference of essential oils on the effect of the antibiotics against Gram negative strains, mainly P. aeruginosa. These results show that the use of plants by-products could some times interfere on the effectiveness of antibiotics used clinically.

Interference of Plectranthus amboinicus (Lour.) Spreng essential oil on the anti-Candida activity of some clinically used antifungals

Plants with medicinal properties have been applied for a long in the traditional health care, so that sometimes their use takes place concomitantly to the use of industrialized drugs. The aim of this study was to evaluate the interference of Plectranthus amboinicus essential oil on the anti-Candida activity of some clinically used antifungals by the solid medium diffusion procedure. Assayed antifungals were amphotericin B (100 µg/mL), ketoconazole (50 µg/mL) and itraconazole (50 µg/mL). C. albicans, C. tropicalis, C. guilliermondii, C. krusei and C. stellatoidea were used as test microorganisms. P. amboinicus essential oil showed MIC value for most assayed yeast strains. The essential oil when assayed in its MIC value showed some interference on the anti-Candida effectiveness of the assayed antifungals. It was noted yeast growth inhibition zones with different diameters when the antifungals were tested alone and combined with the essential oil. P. amboinicus essential oil showed prominent interference on the anti-yeast activity of itraconazole providing a synergic effect on C. albicans, C. tropicalis, C. krusei and C. stellatoidea. Also, the essential oil interfered on the anti-yeast activity of ketoconazole when interacting with C. albicans, C. guilliermondii and C. stellatoidea providing, respectively, an antagonic and synergic effect. On the other hand, it was found a small interference on the anti-yeast effect of amphotericin B. These data showed that combined use of medicinal plants and/or derivatives with industrialized drugs, particularly antimicrobials, could interfere on their expected therapeutic effects.As plantas com propriedades medicinais tem sido utilizadas por um longo tempo no cuidado tradicional de saude, de modo que algumas vezes seu uso ocorre concomitantemente ao uso de drogas industrializadas. O objetivo deste estudo foi avaliar a interferencia do oleo essencial de Plectranthus amboinicus sobre atividade anti-Candida de alguns antifungicos utilizados clinicamente atraves do metodo de difusao em meio solido. Os antifungicos ensaiados foram anfotericina B (100 µg/mL), cetoconazol (50 µg/mL) e itraconazol (50 µg/mL). C. albicans, C. tropicalis, C. guilliermondii, C. krusei e C. stellatoidea foram utilizadas como microrganismos testes. O oleo essencial de P. amboinicus mostrou um valor de CIM de 40 µL/mL para a maioria das cepas de leveduras ensaiadas. O oleo essencial quando ensaiado em sua CIM mostrou alguma interferencia sobre a efetividade anti-Candida dos antifungicos testados, sendo notada a formacao de zonas de inibicao do crescimento fungico com diferentes diâmetros quando os antifungicos foram testados isolados e em combinacao com o oleo essencial. O oleo essencial de P. amboinicus mostrou destacavel interferencia sobre a atividade antifungica de itraconazol, sendo observado um efeito sinergico sobre C. albicans, C. tropicalis, C. krusei e C. stellatoidea. Ademais, o oleo essencial interferiu na atividade antifungica de cetoconazol sobre C. albicans, C. guilliermondii e C. stellatoidea causando, respectivamente, efeito antagonico e sinergico. De outra forma, foi observada uma pequena interferencia do oleo essencial sobre o efeito antifungico de anfotericina B. Estes dados mostram que o uso combinado de plantas medicinais e/ou seus produtos derivados com drogas industrializadas, particularmente, antimicrobianos podem interferir sobre os efeitos terapeuticos esperados.

Propriedade antibacteriana de óleos essenciais de especiarias sobre bactérias contaminantes de alimentos

Spices are known for their stability against microbial action; that being so, they are included in the group of stable foods. This preservative property of spices is related to the presence of antibacterial compounds in their composition. Such compounds could be used to control the food contaminating bacteria. This study aimed to assess the antimicrobial property of the essential oils from Cinnamomum zeylanicum Blume, Coriandrum sativum L., Cuminum cyminum L., Mentha. piperita L., Ocimum basilicum L., Origanum majorana L., Pimpinella anisum L., Piper nigrum L., Rosmarinus officinalis L., and Zingiber officinalis Rosc. against food related bacteria. Therefore, 10 species of degenerating food bacteria were selected. The solid medium diffusion procedure was used to carry out the antimicrobial assays. The results showed that essential oils from E. caryophyllata and C. zeylanicum are efficient in inhibiting all assayed bacterial strains. The other assayed oils presented some antibacterial activity but with smaller action spectrum. The research of the antimicrobial activity of the essential oils is quite promising, and it is a possible alternative for replacing food additives.

Inhibitory effect of Cinnamomum zeylanicum Blume (Lauraceae) essential oil and beta-pinene on the growth of dematiaceous moulds

Os fungos dematiaceos sao microrganismos patogenicos capazes de agir como agentes etiologicos de micoses com diferentes graus de severidade. Este estudo avaliou a efetividade do oleo essencial de Cinnamomum zeylanicum Blume e b-pineno em inibir o crescimento de varias cepas de fungos dematiaceos (Alternaria brassicola, Cladosporium herbarium, C. resinae, C. cladosporioides, Chaetomum globosum, Curvularia, Fonsecaea compacta, Piedraia hortae). Os ensaios antimicrobianos foram conduzidos atraves da determinacao da Concentracao Inibitoria Minima-CIM utilizando-se da tecnica de difusao em meio solido, bem como atraves da observacao da interferencia dos valores de CIM sobre o crescimento micelial radial fungico ao longo de 14 dias. Os valores de CIM encontrados para o oleo essencial de C. zeylanicum oscilaram entre 63 e 125 µL/mL. b-pineno apresentou um valor de CIM de 125 µL/mL para a maioria das cepas fungicas, entretanto C. resinae e C. globosum mostraram-se resistentes a todas as concentracoes ensaiadas. Os valores de CIM encontrados para C. zeylanicum e b-pineno apresentaram intenso efeito fungicida notado por uma total inibicao do crescimento micelial de C. cladosporioides e F. compacta ao longo de 14 dias de exposicao. Estes resultados mostraram o intenso potencial antifungico do oleo essencial de C. zeylanicum e b-pineno, os quais poderiam ser considerados em um uso racional em formulacoes farmaceuticas utilizadas para a terapia de algumas micoses, particularmente, aquelas causadas por fungos dematiaceos.

Effectiveness of Origanum vulgare L. and Origanum majorana L. essential oils in inhibiting the growth of bacterial strains isolated from the patients with conjunctivitis.

This study aimed to evaluate the antibacterial activity of Origanum vulgare L. and O. majorana L. essential oils on Staphylococcus aureus, S. coagulase negative, Enterobacter spp., Proteus spp., Acinetobacter spp., Klebsiella spp. isolated from the patients with conjunctivitis. The results showed a prominent inhibitory effect of both the essential oils on all the bacterial strains, noted by the large bacterial growth inhibition zones (15-32mm). The Minimum Inhibitory Concentrations (MIC) values were between 5-20µL/mL and 2.5-10 µL/mL for O. vulgare and O. majorana essential oil, respectively. The MIC were able to cause significant (P<0.05) inhibitory effect on the cell viability of Klebsiella spp., Proteus spp. and S. aureus providing a total elimination of the bacterial inoculum in a maximum time of 24 h of exposure. These results showed the antibacterial effectiveness of O. vulgare and O. marjorana essential oils and supported the possibility of their use as the sources of alternative antimicrobial compounds.

Inhibitory effect of the essential oil from Cinnamomum zeylanicum Blume leaves on some food-related bacteria

Cinnamomum zeylanicum Blume, Lauraceae, e uma especie vegetal reconhecida, a longo tempo, como possuidora de muitas propriedades biologicas. Este estudo objetivou identificar os constituintes do oleo essencial das folhas de C. zeylanicum, utilizando CG-EM, e avaliar seu efeito inibitorio sobre Salmonella enterica, Escherichia coli, Staphylococcus aureus e Pseudomonas aeruginosa atraves da determinacao da CIM e CBM, bem como atraves da analise do tempo de morte bacteriana. Eugenol (73,27%) foi o composto mais prevalente no oleo essencial, seguido por trans-β-cariofileno (5,38%), linalol (3,31%) e alcool acetato cinâmico (2,53%). Os resultados mostraram uma interessante atividade antibacteriana do oleo essencial com CIM, variando de 1,25 a 10 µL.mL-1. Os valores de CBM oscilaram entre 20 e 80 µL.mL-1. O oleo essencial na concentracao de 10 e 40 µL.mL-1 causou uma rapida e constante diminuicao (2 a 5 ciclos logaritmicos) na contagem de celulas viaveis de todas as cepas ensaiadas ao longo de 24 horas. O oleo essencial na concentracao de 40 µL.mL-1 causou uma total eliminacao do inoculo inicial de S. aureus depois de 2 horas. Estes resultados mostram a possibilidade do uso do oleo essencial extraido das folhas de C. zeylanicum como uma fonte alternativa de compostos antimicrobianos para aplicacao em sistemas de conservacao de alimentos.

Inhibitory effect of the essential oil from Eugenia caryophyllata Thumb leaves on coalho cheese contaminating microorganisms

O queijo de coalho e amplamente produzido e consumido na regiao Nordeste do Brasil, sendo principalmente fabricado por pequenos produtores rurais. Este produto tem sido caracterizado por uma alta carga microbiana, significando um risco para a saude dos consumidores. Este estudo teve como objetivo identificar os compostos quimicos do oleo essencial extraido das folhas de Eugenia caryophyllata; avaliar o efeito inibitorio do oleo essencial sobre microrganismos contaminantes de queijo de coalho; e verificar sua eficacia em inibir a microflora autoctone do produto durante o armazenamento refrigerado. Eugenol (74%) apresentou-se como o composto mais prevalente no oleo essencial. Os valores de Concentracao Inibitoria Minima (CIM) e Concentracao Microbicida Minima (CMM) em meio sintetico variaram entre 2,5-5 e 5-20 µg.mL-1, respectivamente. As amostras de queijo de coalho embaladas a vacuo e adicionadas de 5, 10 e 20 µg.g-1 de oleo essencial apresentaram uma menor taxa de crescimento (efeito microstatico) de bacterias mesofilas ao longo dos intervalos avaliados. De outra forma, o oleo essencial em concentracoes variando entre 2,5 e 10 µg.g-1 causou consideravel reducao da contagem de fungos nas amostras de queijo ao longo do armazenamento. Estes resultados revelam a destacavel propriedade antimicrobiana do oleo essencial extraido das folhas de E. caryophyllata frente a uma variedade de microrganismos contaminantes de queijo de coalho em meio laboratorial e na matriz alimentar.

Antifungal Activity of the Essential Oil of Cinnamomum zeylanicum Blume and Eugenol on Aspergillus flavus

Abstract The genus Aspergillus includes filamentary fungi that can cause diseases in humans and animals, being the most common forms of allergic bronchopulmonary aspergillosis, pulmonary aspergilloma and invasive aspergillosis. Furthermore, A. flavus can contaminate foods of plant origin and produce toxic metabolites to humans and animals such as aflatoxins. This research aims to study the antifungal potential of the essential oil from leaves of Cinnamomum zeylanicum and its major compound, eugenol, on Aspergillus flavus. Results showed that the essential oil showed 650 μg/mL MIC and 2600 μg/mL MFC, the eugenol in turn, presented 337.5 μg/mL MIC and 1350 μg/mL MFC. In evaluating the effect of oil and eugenol on conidial germination at all concentrations tested, the oil and eugenol inhibited the germination of fungal structures. In relation to the effects of the essential oil and eugenol on the morphology of A. flavus, it was clearly observed a reduction in hyphae pigmentation, number of conidiophores and inhibition of the conidiation process, which is the formation of conidia on the conidiophore head. Given these results, the essential oil of C. zeylanicum has great potential as possible alternative in the treatment of aspergillosis caused by A. flavus.

Antimicrobial effectiveness of maleimides on fungal strains isolated from onychomycosis

This study aimed to analyze the effectiveness of maleimides as inhibitors on the growth of fungal strains isolated from onychomycosis by the solid medium diffusion procedure. The results showed a promising antifungical activity of the assayed maleimides with formation of fungal growth inhibition halos oscillating between diameter 10 and 23mm. MIC was 100µg/mL for 3,4-dichloro-N-phenyl-methyl-maleimide and 3,4-dichloro-N-phenyl-propil-maleimide and 200µg/mL for 3,4-dichloro-N-phenyl-maleimide, 3,4-dichloro-N-phenyl-ethyl-maleimide and 3,4-dichloro-N-phenyl-buthyl-maleimide.