In Silico and In Vitro Investigation of the Antifungal Activity of Isoeugenol against Penicillium citrinum.

INTRODUCTION: This increase in the prevalence of drug-resistant pathogens occurs at a time when the discovery and development of new antimicrobial agents occur slowly. In this context, the objective of this study was to investigate the antifungal activity of isoeugenol, a phenylpropanoid, by in vitro and in silico assays against Penicillium citrinum strains. MATERIAL AND METHOD: For in silico analysis, the software PASS online, Molinspiration and Osíris were used. For the determination of Minimum Inhibitory Concentration (MIC) and Minimal Fungicide Concentration (MFC) of isoeugenol and voriconazole were carried out using the broth microdilution technique. PASS online has shown that isoeugenol has the opportunity to present antiseptic, antifungal, antibacterial, antimycobacterial activities. Molinspiration showed that the phytoconstituent has good potential for oral bioavailability. CONCLUSION: In the analysis with the Osiris program, it was demonstrated that isoeugenol has low irritant and tumorigenic risk. The MIC of isoeugenol varied between 256 and 32 µg/mL, MIC50 of 64 µg/mL and MIC90 was 128 µg/mL. The MFC50, MFC90 and MFC of the isoeugenol for P. citrinum species were 64, 256 and 518 µg/mL, respectively. After analysis, it was verified that the isoeugenol have bactericidal effect against the strains of P. citrinum. After these results, it is important to discover the mechanism of action involved in the antifungal action of the compound, as well as in vitro and in vivo toxicity tests.

Contaminação fúngica de plantas medicinais utilizadas em chás / Fungal contamination of medicinal plants used in teas

Este trabalho teve como objetivo avaliar a qualidade microbiológica quanto à presença de fungos filamentosos em ervas do tipo Peumus boldus Molina (Boldo), Pimpinella anisum L. (erva-doce) e Matricaria chamomilla L. (Camomila) comercializadas na cidade de Campina Grande (Paraíba). Nove amostras de cada planta foram analisadas, totalizando 27 amostras, obtidas aleatoriamente nas feiras livres e barracas informais da cidade. Cada 10 g de amostra foram suspensas em 90 mL de solução salina 0,89% estéril, obtendo-se o concentrado, a partir do qual foram realizadas diluições sucessivas. A seguir, uma alíquota de 0,1mL de cada diluição foi semeada em placas de Petri contendo Ágar Sabouraud Dextrose, as quais foram incubadas à temperatura ambiente por cinco a dez dias. Após este período foram contadas as colônias fúngicas presentes e realizados seus respectivos microcultivos para identificação através de microscópio óptico. Foram encontrados fungos toxigênicos como Aspergillus sp., Penicillium sp. e Fusarium sp., estando o primeiro presente em todas as amostras avaliadas. Também foram identificados os fungos Exophiala sp. E Fonsecaea sp., que possuem importância clínica, podendo causar micose. A forma como estas plantas são armazenadas para comercialização e a falta de fiscalização torna questionável a qualidade das plantas comercializadas para obtenção de chás, o que pode comprometer a saúde do consumidor ao utilizar esses produtos na forma de Chá.

The aim of this study was to assess the microbiological quality, with regard to the presence of filamentous fungi, of the tea herbs Peumus boldus Molina (boldo leaf), Pimpinella anisum L. (anise) and Matricaria chamomilla L. (wild chamomile) marketed in the city of Campina Grande (Paraiba State, Brazil). Nine samples of each plant, totaling 27 samples, were randomly collected in street markets and informal stalls in the city. In the laboratory, 10 g of each sample was ground and suspended in 90 mL of 0.89% sterile saline solution, affording the concentrate from which serial dilutions were obtained. Aliquots of 0.1 mL of each dilution were spread on plates of Sabouraud Dextrose Agar, which were then incubated at room temperature for five to ten days. After this period, the fungal colonies were counted, their morphology was analyzed and subcultures were made on slides for identification by optical microscope. Toxigenic fungi such as Aspergillus sp., Penicillium sp. and Fusarium sp. were found, the first being present in all plant samples. The fungi Exophiala sp. and Fonsecaea sp., which are clinically significant as they can cause mycoses, were also identified. The method of storing these plants before sale and the lack of inspection raise questions about the quality of the marketed herbs, suggesting that the health of the consumer who uses these products to make tea could be harmed.