Atividade in vitro do óleo essencial de Origanum vulgare L. em isolados clínicos de Aspergillus spp / In vitro activity of essential oil of Origanum vulgare L. in clinical isolates from Aspergillus spp

Aspergillus fumigatus, A. flavus e A. niger são os mais importantes agentes etiológicos da aspergilose, relevante micose aviária, com tratamento ineficaz e altas taxas de mortalidade. Em vista da importância da aspergilose, da necessidade de prospectar novos fármacos e do potencial terapêutico do óleo essencial de Origanum vulgare L. (OEO), o orégano, objetivou-se avaliar a sensibilidade in vitro de isolados clínicos de Aspergillus spp. em relação ao OEO. O óleo foi obtido por hidrodestilação em Clevenger, e a análise química realizada por cromatografia de massa (GC/MS). Observaram-se 15 diferentes compostos ativos, sendo 4-terpineol, hidrato de sabinene e timol os majoritários. Nos testes de microdiluição em caldo (Reference..., 2008), todos os isolados (n= 23) foram sensíveis ao OEO: A. fumigatus teve CIM entre 28,125mg/mL (0,1875%) e 450mg/mL (3,0%), A. flavus entre 112,5mg/mL (0,75%) e 450mg/mL, e A. niger 112,5mg/mL. CFM variou de 112,5mg/mL a 450mg/mL nos isolados de A. fumigatus, de 225mg/mL (1,5%) a 450mg/mL em A. flavus, e foi de 450mg/mL em A. niger. CIM e CFM foram idênticos em 6/14 isolados, o que demonstra que o óleo com a mesma concentração pode ter capacidade fungistática e fungicida. CIM 90 correspondeu à CIM máxima. Os resultados demonstram a atividade anti-Aspergillus do OEO, com CIM 90 de 450mg/mL (3%).(AU)

Aspergillus fumigatus, A. flavus and A. niger are the most important etiological agents of aspergillosis, a relevant avian mycosis, with innefective treatment and high mortality rates. Due the importance of aspergillosis, the necessity of prospection of new drugs and the therapeutic potential of the essential oil of Origanum vulgare L. (OEO), popularly known as oregano, aims to evaluate the in vitro sensitivity of Aspergillus spp. opposing to OEO. The oil was obtained by hydrodistillation in Clevenger, and the chemical analysis performed by mass chromatography (GC/MS). 15 different active compounds were observed, being 4-terpineol (18.4%), sabinene hydrate (15.6%) and thymol (13.6%), the majority components. In the in vitro susceptibility test, all strains showed sensitivity to OEO, MIC of Aspergillus fumigatus ranged from 28,125mg/mL (0,1875%) to 450mg/mL (3,0%), A. flavus 112,5mg/mL (0,75%) to 450mg/mL, and A. niger 112,5mg/mL. MFC ranged from 112,5mg/mL to 450mg/mL in the A. fumigatus isolates, 225mg/mL (1,5%) to 450mg/mL in A. flavus, and 450mg/mL for A. niger. The MIC and FMC values were identical in 6/14 of the isolated subjects, demonstrating that the oil with the same concentration can have fungistatic and fungicidal capacity. The results demonstrates anti-Aspergillus activities of OEO with CIM90 de 450mg/mL (3%).(AU)

Effects of transcranial direct current stimulation on working memory and negative symptoms in schizophrenia: a phase II randomized sham-controlled trial.

BACKGROUND: The lack of efficacy of pharmacological treatments for cognitive and negative symptoms in schizophrenia highlights the need for new interventions. We investigated the effects of tDCS on working memory and negative symptoms in patients with schizophrenia. METHOD: Double-blinded, randomized, sham-controlled clinical trial, investigating the effects of 10 sessions of tDCS in schizophrenia subjects. Stimulation used 2 mA, for 20 min, with electrodes of 25 cm2 wrapped in cotton material soaked in saline solution. Anode was positioned over the left DLPFC and the cathode in the contralateral area. Twenty-four participants were assessed at baseline, after intervention and in a three-months follow-up. The primary outcome was the working memory score from MATRICS and the secondary outcome the negative score from PANSS. Data were analyzed using generalized estimating equations. RESULTS: We did not find group ∗ time interaction for the working memory (p = 0.720) score or any other cognitive variable (p > 0.05). We found a significant group ∗ time interaction for PANSS negative (p < 0.001, d = 0.23, CI.95 = -0.59-1.02), general (p = 0.011) and total scores (p < 0.001). Exploratory analysis of PANSS 5 factors suggests tDCS effect on PANSS negative (p = 0.012), cognitive (p = 0.016) and depression factors (p = 0.029). CONCLUSION: The results from this trial highlight the therapeutic effects of tDCS for treatment of persistent symptoms in schizophrenia, with reduction of negative symptoms. We were not able to confirm the superiority of active tDCS over sham to improve working memory performance. Larger sample size studies are needed to confirm these findings.

In vitro activity of antifungals in combination with essential oils against the oomycete Pythium insidiosum.

AIMS: The aim of this study was to investigate the in vitro susceptibility of Pythium insidiosum to combinations of the antifungal drugs terbinafine or itraconazole with Melaleuca alternifolia, Mentha piperita and Origanum vulgare essential oils (EOs). METHODS AND RESULTS: In vitro combinations of antifungal drugs with EOs were evaluated by checkerboard microdilution method against 20 Brazilian isolates of P. insidiosum. The tests were performed according to protocol M38-A2, and the interpretation of each combination result was based on the values of the fractional inhibitory concentration index. The combinations of itraconazole with EOs presented prominent synergistic effects against P. insidiosum isolates, and no antagonism was observed with these combinations. However, the combinations of terbinafine with EOs resulted in indifferent or antagonistic effects. CONCLUSIONS: The combination of plant-derived bioactive compounds with antifungal drugs may be an alternative therapy for the control of infections caused by P. insidiosum. Studies of new therapeutic protocols involving these proposed combinations are needed. SIGNIFICANCE AND IMPACT OF THE STUDY: The antimicrobial combinations using EOs with terbinafine or itraconazole can be an attractive therapeutic option for controlling P. insidiosum infections.

In vitro susceptibility of Brazilian Pythium insidiosum isolates to essential oils of some Lamiaceae family species.

The present study aimed to evaluate the in vitro antimicrobial action of Origanum vulgare, Origanum majorana, Mentha piperita and Rosmarinus officinalis on Pythium insidiosum oomycete zoospores. The antimicrobial activity evaluation was performed by the broth microdilution method according to CSLI M38-A2 documentation adapted to phytopharmaceuticals. Twenty-two P. insidiosum isolates were evaluated, and the minimum inhibitory concentration was determined at 100% growth inhibition. All P. insidiosum isolates evaluated showed a minimum inhibitory concentration ranging from 0.05 to 1.75 mg/mL when O. vulgare oil was used and from 0.11 to 3.5 mg/mL for O. majorana, M. piperita and R. officinalis oils. The results obtained indicate that the essential oils tested showed antimicrobial activity on P. insidiosum, with O. vulgare essential oil showing the best performance. These findings emphasize the potential use of plant essential oils as control agents in P. insidiosum infections; further research, however, is needed so as the in vivo activity of these oils can also be evaluated.

In vitro susceptibility of zoospores and hyphae of Pythium insidiosum to antifungals.

OBJECTIVES: The purpose of this study was to compare the in vitro susceptibilities of 22 Brazilian isolates of Pythium insidiosum to antifungals using a standardized inoculum of zoospores and a proposed novel inoculum prepared from cultured mycelia (hyphae) of P. insidiosum. METHODS: A zoospore suspension of P. insidiosum was obtained by the zoosporogenesis technique. The hyphal inoculum was prepared from a suspension of P. insidiosum mycelium. Susceptibility to each drug was evaluated using the CLSI M38-A2 method. RESULTS: Of the 88 MIC comparisons performed, 36 (41%) showed the same MIC value for the two inocula. The agreement (differences not greater than one dilution) between MICs obtained with both types of inocula was 39.8% (35/88). In other MIC comparisons analysed, 17 (19.3%) showed differences of two or three dilutions. CONCLUSIONS: We conclude that the use of hyphal inocula of P. insidiosum for in vitro susceptibility tests could be a suitable method for evaluating antimicrobial susceptibility, particularly when it is not possible to obtain a standardized zoospore inoculum.

Perfil de suscetibilidade de leveduras do gênero Candida isoladas de animais ao óleo essencial de Rosmarinus officinalis L / Susceptibility profile of Candida spp. isolated from animals to the essential oil of Rosmarinus officinalis L

Neste trabalho foram avaliadas a atividade antifúngica e composição química do óleo essencial de Rosmarinus officinalis (alecrim). O óleo essencial foi obtido, através da hidrodestilação, das partes aéreas da planta, o qual foi analisado por cromatografia gasosa com detectores de ionização em chama (GC/FID) e espectrometria de massas (GC/MS). Esse óleo foi testado em isolados de C. albicans da mucosa vaginal de fêmeas caninas, casos clínicos de candidíase em animais cepas padrões e espécies não-albicans, usando a técnica de microdiluição em caldo (CLSI-M27A2). A análise cromatográfica do óleo permitiu identificar como principais compostos cânfora, verbenona e 1,8-cineol. Os valores de CIM do óleo para os isolados padrões de C. albicans variaram entre 1,25 e 2,5 µL mL-1 e de 2,5 a 5,0 µL mL-1 para CFM, enquanto que para os isolados não-albicans observou-se CIM entre 1,25 e 5,0 µL mL-1 e CFM de 2,5 a 10,0 µL mL-1. C. albicans isolada de animais apresentou valores de 2,5 a >10,0 µL mL-1 para CIM e de 5,0 a >10,0 µL mL-1 para CFM. Os resultados demonstraram atividade fungicida e fungistática do óleo essencial de alecrim em isolados de Candida spp. provenientes de animais.

In this work the antifungal activity and chemical composition of the Rosmarinus officinalis (rosemary) essential oil against Candida spp. were evaluated. The essential oil was obtained by hydrodistillation of aerial parts, and analyzed by gas chromatography with a flame ionization detector (GC/FID) and gas chromatography coupled with mass spectrometry (GC/MS). This oil was tested against fourteen isolates of Candida sp. (ten C. albicans and four no-albicans species) by the microdillution broth assay (CLSI-M27A2). Chromatography analyses of the essential oil showed compounds, as camphor, verbenone and 1,8-cineole as major constituents. MIC and MFC values for C. albicans standard strains were 1.25 - 2.5 µL mL-1 and 2.5 - 5.0 µL mL-1, respectively. MIC and MFC for the non-albicans species were 1.25 - 5.0 µL mL-1 and 2.5 - 10.0 µL mL-1, respectively. C. albicans isolates obtained from animals exhibited MIC and MFC values of 2.5 - > 10.0 µL mL-1 and 5.0 - > 10.0 µL mL-1, respectively. According to the results, the essential oil of rosemary presented fungicidal and fungistatic activities against Candida spp.