Evaluation of polymeric PLGA nanoparticles conjugated to curcumin for use in aPDT

ABSTRACT Antimicrobial photodynamic therapy (aPDT) involves the association of a photosensitizing agent with a light source with the goal of causing apoptosis or microbial lysing. The use of compounds with natural active principles is gaining prominence throughout the world. Several studies from groups that are linked to the development of innovations in the pharmaceutical market have used natural dyes, such as curcumin, the efficacy of which has been demonstrated in aPDT trials. Difficulties related to physicochemical stability, solubility and cell penetration are some of the challenges associated with this field. The present work aimed to prepare, investigate the characteristics and improve the photodynamic activity of PLGA-based nanoparticles loaded with curcumin for use in aPDT therapy. Using the simple technique of emulsion during the evaporation of a solvent, the particles were built, characterized and tested against microorganisms with importance for medicine and dentistry. The results revealed that the particles were able to protect the curcumin against degradation and eliminate some microorganism species at nanomolar concentrations.

The antimicrobial activity of lapachol and its thiosemicarbazone and semicarbazone derivatives

Lapachol was chemically modified to obtain its thiosemicarbazone and semicarbazone derivatives. These compounds were tested for antimicrobial activity against several bacteria and fungi by the broth microdilution method. The thiosemicarbazone and semicarbazone derivatives of lapachol exhibited antimicrobial activity against the bacteria Enterococcus faecalis and Staphylococcus aureus with minimal inhibitory concentrations (MICs) of 0.05 and 0.10 µmol/mL, respectively. The thiosemicarbazone and semicarbazone derivatives were also active against the pathogenic yeast Cryptococcus gattii (MICs of 0.10 and 0.20 µmol/mL, respectively). In addition, the lapachol thiosemicarbazone derivative was active against 11 clinical isolates of Paracoccidioides brasiliensis, with MICs ranging from 0.01-0.10 µmol/mL. The lapachol-derived thiosemicarbazone was not cytotoxic to normal cells at the concentrations that were active against fungi and bacteria. We synthesised, for the first time, thiosemicarbazone and semicarbazone derivatives of lapachol. The MICs for the lapachol-derived thiosemicarbazone against S. aureus, E. faecalis, C. gattii and several isolates of P. brasiliensis indicated that this compound has the potential to be developed into novel drugs to treat infections caused these microbes.

In vitro antifungal activity of fatty acid methyl esters of the seeds of Annona cornifolia A.St.-Hil. (Annonaceae) against pathogenic fungus Paracoccidioides brasiliensis / Atividade antifúngica in vitro dos ésteres metílicos de ácidos graxos das sementes de Annona cornifolia A.St.-Hil. (Annonaceae) sobre o fungo patogênico Paracoccidioides brasiliensis

INTRODUCTION: Fatty acids are abundant in vegetable oils. They are known to have antibacterial and antifungal properties. METHODS: Antifungal susceptibility was evaluated by broth microdilution assay following CLSI (formerly the NCCLS) guidelines against 16 fungal strains of clinical interest. RESULTS: In this work, fatty acid methyl esters (FAME) was able to inhibit 12 clinical strains of the pathogenic fungus Paracoccidioides brasiliensis and were also active in the bioautographic assay against Cladosporium sphaerospermum. CONCLUSIONS: FAME was a more potent antifungal than trimethoprim-sulfamethoxazole against P. brasiliensis under the experimental conditions tested.

INTRODUÇÃO: Os ácidos graxos são abundantes em óleos vegetais. Eles são conhecidos por suas propriedades antibacterianas e antifúngicas. MÉTODOS: A suscetibilidade a antifúngicos foi avaliada pelo ensaio de microdiluição em caldo de acordo com CLSI (anteriormente NCCLS) sobre 16 isolados de interesse clínico. RESULTADOS: Nesse trabalho, os ésteres metílicos de ácidos graxos (FAME) inibiram doze isolados clínicos do fungo patogênico Paracoccidioides brasiliensis, e também foi muito ativo no ensaio de bioautografia sobre o fungo Cladosporium sphaerospermum. CONCLUSÕES: FAME foi um antifúngico mais potente do que sulfametoxazol-trimetoprim contra P. brasiliensis, nas condições utilizadas no presente trabalho.

Comparison between two selected Saccharomyces cerevisiae strains as fermentation starters in the production of traditional cachaça

Two Saccharomyces cerevisiae strains were tested as the starter yeasts in a traditional cachaça distillery. The strains used were S. cerevisiae UFMG-A829, isolated from a cachaça fermentation process, and S. cerevisiae K1-V1116, obtained from the wine industry. The permanence of each strain in the fermentation must was determined by RAPD (Random Amplified Polymorphic DNA)-PCR, with primer M13. Both yeast strains were prevalent in the vats for approximately 30 days. Indigenous non-Saccharomyces and indigenous S. cerevisiae strains were isolated in lower counts during the fermentation period. Indigenous S. cerevisiae strains were molecularly distinct when compared to the starter yeasts. The two yeasts appeared promising starter yeasts in the fermentation process to produce traditional cachaça.

Duas linhagens de Saccharomyces cerevisiae foram testadas como iniciadoras em uma destilaria de cachaça. Foram utilizadas as linhagens de S. cerevisiae UFMG-A829, isolada de fermentação de cachaça, e S. cerevisiae K1-V1116, de origem vinícola. A permanência de cada linhagem durante a fermentação foi determinada por RAPD (Random Amplified Polymorphic DNA)-PCR, utilizando o iniciador M13. As duas linhagens predominaram nas dornas de fermentação por aproximadamente 30 dias. Leveduras não-Saccharomyces e S. cerevisiae indígenas foram isoladas em menor proporção durante o experimento. As linhagens de S. cerevisiae indígenas apresentaram perfis moleculares distintos em relação às linhagens iniciadoras. As duas linhagens foram promissoras para serem utilizadas como iniciadoras do processo fermentativo para a produção da cachaça.

Aspectos laboratoriais evolutivos de crianças em tratamento da paracoccidioidomicose / Laboratory evolutive aspects of children under paracoccidioidomycosis treatment

Estudo de 38 crianças com paracoccidioidomicose, até 14 anos de idade, tratados por 24-30 meses, com um derivado sulfamídico ou cetoconazol, desde o início do tratamento ou em seguida ao uso da anfotericina B. Dados laboratoriais à admissão foram analisados e comparados com exames seqüenciais até 30 meses de acompanhamento. Anemia, eosinofilia e bilirrubinas e aminotransferases elevadas normalizaram-se, na maioria, até os três meses de tratamento e, hipoalbuminemia, até os seis meses, sugerindo que esses achados sejam bons parâmetros para o monitoramento da resposta terapêutica inicial. Leucócitos periféricos, velocidade de hemossedimentação, IgG e títulos sorológicos para o Paracoccidioides brasiliensis estavam elevados e normalizaram-se, freqüentemente, após nove a 12 meses de tratamento, o que sugere utilidade desses exames no monitoramento de todo o tratamento e enfatiza a necessidade de curso terapêutico prolongado da paracoccidioidomicose na infância.

The study of 38 children with paracoccidioidomycosis, aged up to 14, treated for 24 to 30 months with either a sulfonamide derivative or ketoconazole either alone or, after the use of amphotericin B. Laboratory data at admission were analyzed and compared with those of sequential tests after up to 30 months follow-up. Anemia, eosinophilia, increased bilirubin and aminotransferases normalized, in most patients, after three months treatment and hypoalbuminemia normalized after six months, suggesting that these laboratory findings are useful for monitoring early therapeutic response. Peripheral leucocytes, erythrocyte sedimentation rate, IgG, and serological titers for Paracoccidioides brasiliensis were increased and frequently normalized after nine to 12 months of treatment. They may be useful for monitoring the entire treatment and emphasize the need for long term treatment of paracoccidioidomycosis in children.

Microscopia de escamas cutâneas em dermatomicoses humanas / Microscopy of cutaneous scales in human dermatomycosis

Avalia-se comparativamente a eficiência diagnóstica da microscopia de escamas cutâneas após clarificaçäo com KOH (40 por cento) e de escamas colhidas com fita adesiva em 102 casos de dermatomicoses humanas, adotando como parâmetros: a positividade, a intensidade (número e nitidez das estruturas fúngicas) e o tempo médio de leitura de lâminas por ambas as técnicas. Verifica-se para a fita adesiva um índice de positivaçäo de 48,04 por cento, quando 100 por cento dos casos säo positivos através do procedimento tradicional, bem como tempo excessivo para leitura e baixa acuidade resolutiva no discernimento de estruturas fúngicas, configurando-se inadequado o seu emprego rotineiro em diagnóstico por exame direto de casos de dermatomicose.