ABSTRACT
SUMMARY Introduction: invasive candidiasis is related to high rates of morbidity and mortality. There are few classes of drugs available for the treatment of this type of infection and the index of resistant strains is increasing. Such circumstances highlight that the search for new pharmacotherapeutic alternatives is increasingly necessary. This study investigated 2-Bromo-N-phenylacetamide, a substance whose antifungal activity has not yet been reported. Objective: to evaluate its activity against invasive candidiasis isolates, by determining the minimum inhibitory and fungicide concentrations. Methodology: molecular docking was performed to investigate the possible mechanism of action of the substance. The substance was also associated with fluconazole, to assess the viability of the combination in clinical practice. The minimum inhibitory concen trations ranged between 4 to 32 jig/mL, and it acts in a fungicidal way. Results: molec ular docking suggests that 2-Bromo-N-phenylacetamide possibly acts on the fungal plasma membrane. And the association of 2-Bromo-N-phenylacetamide with flucon azole against resistant strains showed an indifferent effect. Conclusion: further studies should be carried out to elucidate the potential of this substance, which may become a future drug candidate to treat invasive candidiasis and other fungal infections.
Introducción: la candidiasis invasiva está relacionada con altas tasas de morbilidad y mortalidad. Hay pocas clases de medicamentos disponibles para el tratamiento de este tipo de infección y el índice de cepas resistentes está aumentando. Tales circunstancias ponen de relieve que la búsqueda de nuevas alternativas farmacoterapéuticas es cada vez más necesaria. Este estudio investigó la 2-Bromo-N-fenilacetamida, una sustancia cuya actividad antifúngica aún no se ha informado. Objetivo: evaluar su actividad frente a aislados de candidiasis invasiva, mediante la determinación de las concentra ciones mínimas inhibitorias y fungicidas. Metodología: se realizó un acoplamiento molecular para investigar el posible mecanismo de acción de la sustancia. La sustancia también se asoció con fluconazol, para evaluar la viabilidad de la combinación en la práctica clínica. Las concentraciones mínimas inhibidoras oscilaron entre 4 a 32 µg/mL y actúa de forma fungicida. Resultados: el acoplamiento molecular sugiere que la 2-Bromo-N-fenilacetamida posiblemente actúa sobre la membrana plasmática de los hongos. Y la asociación de 2-Brorno-Ar-fenilacetamida con fluconazol contra cepas resistentes mostró un efecto indiferente. Conclusión: deben realizarse más estudios para dilucidar el potencial de esta sustancia, que puede convertirse en un futuro candi dato a fármaco para tratar la candidiasis invasiva y otras infecciones fúngicas.
Introdução: a candidíase invasiva está relacionada a altas taxas de morbidade e morta lidade. Existem poucas classes de medicamentos disponíveis para o tratamento desse tipo de infecção e o índice de cepas resistentes está aumentando. Tais circunstâncias evidenciam que a busca por novas alternativas farmacoterapêuticas é cada vez mais necessária. Este estudo investigou a 2-Bromo-N-fenilacetamida, uma substância cuja atividade antifúngica ainda não foi relatada. Objetivo: avaliar sua atividade contra isolados de candidíase invasiva, por meio da determinação das concentrações mínimas inibitórias e fungicidas. Metodologia: o docking molecular foi realizado para inve stigar o possível mecanismo de ação da substância. A substância também foi associada ao fluconazol, para avaliar a viabilidade da associação na prática clínica. As concen trações inibitórias mínimas variaram entre 4 a 32 µg/Ml e atuam de forma fungicida. Resultados: o docking molecular sugere que a 2-Bromo-N-fenilacetamida possivel mente atua na membrana plasmática do fungo. E a associação de 2-Bromo-N-fenilace-tamida com fluconazol contra cepas resistentes mostrou efeito indiferente. Conclusão: Novos estudos devem ser realizados para elucidar o potencial dessa substância, que pode se tornar uma futura droga candidata ao tratamento de candidíase invasiva e outras infecções fúngicas.
ABSTRACT
In this work, we report the synthesis of a new 1,3-thiazolium-5-thiolate derivative of a mesoionic compound (MIH 2.4Bl) and the characterization of its selective cytotoxicity on a panel of breast cancer cells lines. The cytotoxic effect of MIH 2.4Bl on breast cancer cell lines was determined by XTT and crystal violet assays, flow cytometry analysis, electron microscopy characterization, and terminal deoxynucleotidyl transferase (TdT) deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) apoptosis assays. As determined using XTT cell growth and survival assays, MIH 2.4Bl exhibited growth inhibition activity on most breast cancer cell lines tested, compared with normal human mammary epithelial cells. Three breast cancer cell lines (MCF-7, T-47D, and ZR-75-1) showed a more potent sensitivity index to growth inhibition by MIH 2.4Bl than the other breast cancer cell lines. Interestingly, these 3 cell lines were derived from tumors of Luminal A origin and have ER (estrogen receptor), PR (progesterone receptor), and HER2 (human epidermal growth factor receptor 2) positive expression. Additional analysis of cytotoxicity mediated by MIH 2.4Bl was performed using the MCF-7 cell line. MCF-7 cells displayed both time- and dose-dependent decreases in cell growth and survival, with a maximum cytotoxic effect observed at 72 and 96 hours. The MCF-7 cells were also characterized for cell cycle changes upon treatment with MIH 2.4Bl. Using flow cytometry analysis of cell cycle distribution, a treatment-dependent effect was observed; treatment of cells with MIH 2.4Bl increased the G2/M population to 34.2% compared with 0.1% in untreated (control) cells. Ultrastructural analysis of MFC-7 cells treated with MIH 2.4Bl at 2 different concentrations (37.5 and 75 µM) was performed by transmission electron microscopy. Cells treated with 37.5 µM MIH 2.4Bl showed morphologic changes beginning at 6 hours after treatment, while cells treated with 75 µM showed changes beginning at 3 hours after treatment. These changes were characterized by an alteration of nuclear morphology and mitochondrial degeneration consistent with apoptotic cell death. Results of a TUNEL assay performed on cells treated for 96 hours with MIH 2.4Bl supported the observation of apoptosis. Together, these results suggest that MIH 2.4Bl is a promising candidate for treating breast cancer and support further in vitro and in vivo investigation.
