Atividade antifúngica e potencial antibiofiome do extrato hidroetanólico de Spondias mombin L. e de suas frações frente a leveduras do gênero Candida / Antifungal activity and antibiofiome potential of the hydroethanolic extract of Spondias mombin L. and its fractions against yeasts of the genus Candida

A Candidose é uma patologia que pode ter manifestações locais e também sistêmicas e acontece pela proliferação de fungos do gênero Candida. O tratamento desta patologia é realizado com antifúngicos mas, devido a resistência dos fungos causadores desta enfermidade se faz necessário conhecer outros antifúngicos. A ação antimicrobiana do extrato hidroetanólico de Spondias mombin L. já é conhecida e é fundamental que seja pesquisado a atividade antibiofilme das substâncias, uma vez que estes fungos causam adoecimento quando se acumulam e proliferam. Sabendo disso é que o presente estudo teve por objetivo principal investigar a ação antifúngica e antibiofilme do extrato hidroetanólico (EH) de Spondias mombin L. e das frações de taninos, flavonoides e ácidos fenólicos, frente a fungos do gênero Candida, de importância clínica. Para isto, determinou-se a concentração inibitória mínima por meio do uso de discos e pela técnica da microdiluição em caldo, concentração inibitória mínima de aderência, determinação da curva de morte dos fungos e atividade antibiofilme das frações de ácidos fenólicos, flavonoides e tanino, frente aos fungos Candida albicans, Candida tropicalis, Candida Krusei e Candida Glabrata, utilizando como controle positivo a Nistatina (100.000 UI), em triplicata. Foi visto que, a atividade antifúngica e antibiofilme do EH e de suas frações analisadas existe, porém, quando comparamos as frações com o EH este último apresentou melhor atividade em suas maiores concentrações (500 µg/mL e 250 µg/mL) e quando traçamos o comparativo entre a ação antifúngica e antibiofilme das substâncias testadas e do grupo controle, tivemos melhores resultados do grupo controle frente aos fungos testados. Desta forma foi possível concluir que o extrato hidroetanólico apresentam resultados superiores de atividade antifúngica frente a todos os microrganismos testados, exceto C. krusei e antibiofilme frente a, pelo menos, uma das espécies de Candida e que este extrato teve resultados muito semelhantes e, por vezes, superior ao grupo controle (AU).

Candidosis is a pathology that can have local as well as systemic manifestations and happens due to the proliferation of fungi of the Candida genus. The treatment of this pathology is carried out with antifungal agents, but due to the resistance of the fungi that cause this disease, it is necessary to know other antifungal agents. The antimicrobial action of the hydroethanolic extract of Spondias mombin L. is already known and it is essential that the antibiofilm activity of the substances be researched, since these fungi cause illness when they accumulate and proliferate. Knowing that, this study aimed to investigate the antifungal and antibiofilm action of the hydroethanolic extract (EH) of Spondias mombin L. and its fractions, against fungi of the genus Candida, of clinical importance. For this, the minimum inhibitory concentration was determined through the use of disks and the technique of microdilution in broth, minimum inhibitory concentration of adhesion, determination of the fungal death curve and antibiofilm activity of the fractions of phenolic acids, flavonoids and tannin, against the fungi Candida albicans, Candida tropicalis, Candida Krusei and Candida Glabrata, using nystatin (100,000 IU) as a positive control, in triplicate. It was seen that the antifungal and antibiofilm activity of EH and its analyzed fractions exists, however, when we compare the fractions with EH, the latter showed better activity at its highest concentrations (500 µg/mL e 250 µg/mL) and when we draw the comparison between the antifungal and antibiofilm action of the tested substances and the control group, we had better results than the control group against the tested fungi. Thus, it was possible to conclude that the hydroethanolic extract presented superior results of antifungal activity against all tested microorganisms, except C. krusei and antibiofilm against at least one of the Candida species and that this extract had very similar results and, for times higher than the control group (AU).

Muscodor brasiliensis sp. nov. produces volatile organic compounds with activity against Penicillium digitatum.

Endophytic fungi belonging to Muscodor genus are considered as promising alternatives to be used in biological control due to the production of volatile organic compounds (VOCs). The strains LGMF1255 and LGMF1256 were isolated from the medicinal plant Schinus terebinthifolius and, by morphological data and phylogenetic analysis, identified as belonging to Muscodor genus. Phylogenetic analysis suggests that strain LGMF1256 is a new species, which is herein introduced as Muscodor brasiliensis sp. nov. The analysis of VOCs production revealed that compounds phenylethyl alcohol, α-curcumene, and E (ß) farnesene until now has been reported only from M. brasiliensis, data that supports the classification of strain LGMF1256 as a new species. M. brasiliensis completely inhibited the phytopathogen P. digitatum in vitro. We also evaluated the ability of VOCs from LGMF1256 to inhibit the development of green mold symptoms by inoculation of P. digitatum in detached oranges. M. brasiliensis reduced the severity of diseases in 77%, and showed potential to be used for fruits storage and transportation to prevent the green mold symptoms development, eventually reducing the use of fungicides.

Antibacterial activity of Aroeira honeys produced in Minas-Gerais against bacteria of clinical importance / Atividade antibacteriana de méis de Aroeira produzidos em Minas-Gerais frente a bactérias de importância clínica

The biological activity of honey has been the subject of great scientific investigation. Bee products are widely used in folk medicine to treat human diseases due to their antibacterial and inhibitory potential action on different human pathogens. Ten honey samples produced by Apis mellifera in the northern of Minas Gerais state were tested against pathogenic microorganisms Staphylococcus aureus TSST (clinical isolated) and enterohaemorrhagic Escherichia coli ATCC 43895 for determination of their minimum inhibitory concentrations. The microdilution technique in broth Mueller-Hinton broth (MHB) was used in four concentrations (25, 12.5, 6.25 and 3.125%). There was a reduction of bacterial growth for the two target species at all concentrations tested. The optimal concentration for inhibition of S. aureus and E. coli were 3.125% (w/v). Therefore, the antibacterial activity of the tested samples evidences the potential of Aroeira honey produced in the north of Minas Gerais for therapeutic use, thus contributing to the aggregation value and commercialization of this type of honey.

A atividade biológica do mel tem sido objeto de relevante investigação científica. Produtos apícolas são amplamente utilizados na medicina popular para tratar doenças humanas por causa de sua potencial ação antibacteriana e inibitória a diferentes patógenos humanos. Dez amostras de mel produzidas por Apis mellifera, no norte do Estado de Minas Gerais, foram testadas contra os micro-organismos patogênicos Staphylococcus aureus TSST (isolado clínico) e Escherichia coli enterohemorrágica ATCC 43895 para determinação de suas concentrações inibitórias mínimas. A técnica de microdiluição em caldo Mueller-Hinton (CMH) foi utilizada em quatro concentrações (25, 12,5, 6,25 e 3,125%). Houve uma redução do crescimento bacteriano para as duas espécies alvo em todas as concentrações testadas. A concentração ótima para a inibição de S. aureus e E. coli foi de 3,125% (p/v). Portanto, a atividade antibacteriana das amostras testadas evidencia o potencial do mel de Aroeira produzido no norte de Minas Gerais para uso terapêutico, contribuindo para a agregação de valor e comercialização deste tipo de mel.

Influence of Culturing Conditions on Bioprospecting and the Antimicrobial Potential of Endophytic Fungi from Schinus terebinthifolius.

In this study, we analyzed the antimicrobial activity of extracts harvested from 17 endophytic fungi isolated from the medicinal plant Schinus terebinthifolius. Morphological and molecular analyses indicated that these fungal species belonged to the genera Alternaria, Bjerkandera, Colletotrichum, Diaporthe, Penicillium, and Xylaria. Of the endophytes analyzed, 64.7 % produced antimicrobial compounds under at least one of the fermentation conditions tested. Nine isolates produced compounds that inhibited growth of Staphylococcus aureus, four produced compounds that inhibited Candida albicans, and two that inhibited Pseudomonas aeruginosa. The fermentation conditions of the following endophytes were optimized: Alternaria sp. Sect. Alternata-LGMF626, Xylaria sp.-LGMF673, and Bjerkandera sp.-LGMF713. Specifically, the carbon and nitrogen sources, initial pH, temperature, and length of incubation were varied. In general, production of antimicrobial compounds was greatest when galactose was used as a carbon source, and acidification of the growth medium enhanced the production of compounds that inhibited C. albicans. Upon large-scale fermentation, Alternaria sp. Sect. Alternata-LGMF626 produced an extract containing two fractions that were active against methicillin-resistant S. aureus. One of the extracts exhibited high activity (minimum inhibitory concentration of 18.52 µg/mL), and the other exhibited moderate activity (minimum inhibitory concentration of 55.55 µg/mL). The compounds E-2-hexyl-cinnamaldehyde and two compounds of the pyrrolopyrazine alkaloids class were identified in the active fractions by gas chromatography-mass spectrometry.

Efeito modulador do extrato de plantas medicinais do gênero Spondias sobre a resistência de cepas de Staphylococcus aureus à Eritromicina / Modulatory effect of the extract of medicinal plants of Spondias genus on resistance of Staphylococcus aureus to Erythromycin

A acentuada resistência bacteriana gera uma necessidade de desenvolver novos fármacos e a pesquisa com plantas medicinais, como fontes de substâncias bioativas vêm sendo um indicativo para descoberta de eficientes agentes terapêuticos. Microrganismos do gênero Staphylococcus são cocos Gram positivos, que podem causar supurações, abscessos e diversas infecções piogênicas em humanos e animais. Assim, o objetivo deste trabalho foi analisar a atividade moduladora de extratos de plantas medicinais do gênero Spondias frente à Staphylococcus aureus resistentes a eritromicina. A concentração inibitória mínima e a capacidade de modular a resistência das cepas de S. aureus à Eritromicina foram avaliadas pelo método de microduluição. Os resultados mostraram que a associação de eritromicina com Spondias purpurea apresentou efeito sinérgico sobre as cepas SA04 e SA05. Enquanto que a Spondias mombin apresentou sinergismos sobre a ATCC, SA01, SA03 e SA05. O bioensaio com A. salina demonstrou que S. purpurea e S. mombin, apresentaram em CL 50 1000 e 482,5 ?g/ mL, respectivamente. Os resultados são promissores e sugerem que os extratos de espécies do gênero Spondias possuem potencial como agentes moduladores de resistência bacteriana.(AU)

The marked bacterial resistance generates a need to develop new drugs and research on medicinal plants as sources of bioactive substances has been an indication for efficient discovery of therapeutic agents. Microorganisms of the genus Staphylococcus are Gram positive coccus, which can cause suppuration, abscesses and various pyogenic infections in humans and animals. Thus, the objective of this study was to evaluate the modulatory activity of extracts of medicinal plants of genus Spondias against Staphylococcus aureus resistant to erythromycin. The minimum inhibitory concentration and modulating activity of the plant extracts studied and erythromycin were evaluated by the microdilution method. The results showed that the association of erythromycin with Spondias purpurea showed synergistic effect on the strains SA04 and SA05. While Spondias mombin showed synergism on the ATCC, SA01, SA03 and SA05 strain. The bioassay with A. saline showed that S. purpurea and S. mombin presented a LC50 1000 and 482.5 mg/ mL, respectively. The results are promising and suggest that that the extracts species of the genus Spondias agents have potential as modulator agents of bacterial resistance.(AU)

Antimicrobial evaluation of fungal extracts produced by endophytic strains of Phomopsis sp.

Crude extract of cultures of 13 fungal strains identified as Phomopsis sp. and isolated as endophytes from the leaves of Aspidosperma tomentosum and twigs of Spondias mombin were examined for their antibacterial and antifungal activities. The screening was conducted using the bioautographic TLC agar-overlay technique against bacteria (E. coli, P. aeruginosa, S. aureus), yeast (C. albicans, S. cerevisiae), and readily adapted for use with filamentous fungi (A. niger, F. oxysporum). Three of the 13 extracts effectively inhibited the growth of all test-organisms, indicating that they may represent a potential for pharmaceutical and/or agricultural applications and are worthy of further study.