Coumarin (2H-1-Benzopyran-2-one) act against planktonic and biofilm forms of Staphylococcus aureus, Klebsiellapneumoniae and Pseudomonas aeruginosa

SUMMARY Introduction: biofilm-related infections caused by Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa are difficult to treat and few effective pharmacological options are currently available for this purpose. In this context, coumarin (2H-1-Benzopyran-2-one) has been reported to have antibacterial and antibiofilm activity, but this potential remains poorly understood. Aim: to investigate the action of coumarin on planktonic and biofilm forms of S. aureus, K. pneumoniae and P. aeruginosa. Results: a minimum inhibitory concentration (MIC) of coumarin ranging from 256 to 1024 fig/mL was observed, with a remarkable ability to inhibit the formation of biofilms and to act on mature biofilms in concentrations close to MIC. Conclusion: coumarin has strong activity against planktonic and biofilm forms on the three species of great relevance in the clinical scenario. These results are interesting to enable a pharmacological alternative for the treatment of these infections.

Introducción: las infecciones relacionadas con la biopelícula causadas por Staphylococcus aureus, Klebsiella pneumoniae y Pseudomonas aeruginosa son difíciles de tratar y actualmente existen pocas opciones farmacológicas eficaces para este propósito. En este contexto, se ha informado que la cumarina (2H-1-Benzopiran-2-ona) tiene actividad antibacteriana y antibiofilm, pero este potencial sigue siendo poco conocido. Objetivo: investigar la acción de la cumarina sobre formas planctónicas y de biopelículas de S. aureus, K. pneumoniae y P. aeruginosa. Resultados: se observó una concentración inhibitoria mínima (CMI) de cumarina en el rango de 256 a 1024 µg/mL, con una notable capacidad para inhibir la formación de biofilms y actuar sobre biofilms maduros en concentraciones cercanas a la CMI. Conclusión: la cumarina tiene una fuerte actividad contra las formas planctónicas y biofilm sobre las tres especies de gran relevancia en el escenario clínico. Estos resultados son interesantes para habilitar una alternativa farmacológica para el tratamiento de estas infecciones.

Introdução: as infecções relacionadas ao biofilme causadas por Staphylococcus aureus, Klebsiella pneumoniae e Pseudomonas aeruginosa são difíceis de tratar e poucas opções farmacológicas eficazes estão disponíveis atualmente para esse propósito. Nesse contexto, foi relatado que a cumarina (2H-1-benzopirano-2-ona) tem atividade antibacteriana e antibiofilme, mas esse potencial permanece pouco conhecido. Objetivo: investigar a ação da cumarina sobre as formas planctónicas e de biofilme de S. aureus, K. pneumoniae e P. aeruginosa. Resultados: observou-se uma concentração inibitória mínima (CIM) de cumarina variando de 256 a 1024 µg/mL, com notável capacidade de inibir a formação de biofilmes e de atuar sobre biofilmes maduros em concentrações próximas à CIM. Conclusão: a cumarina possui forte atividade contra as formas planctónicas e de biofilme sobre as três espécies de grande relevância no cenário clínico. Esses resultados são interessantes para possibilitar uma alternativa farmacológica para o tratamento dessas infecções.

Virtual screening and assessment of anticancer potential of selenium-based compounds against HL-60 and MCF7 cells.

Aim: Selenium-based compounds have antitumor potential. We used a ligand-based virtual screening analysis to identify selenoglycolicamides with potential antitumor activity. Results & Conclusion: Compounds 3, 6, 7 and 8 were selected for in vitro cytotoxicity tests against various cell lines, according to spectrophotometry results. Compound 3 presented the best cytotoxicity results against a promyelocytic leukemia line (HL-60) and was able to induce cell death at a frequency similar to that observed for doxorubicin. The docking study showed that compound 3 has good interaction energies with the targets caspase-3, 7 and 8, which are components of the apoptotic pathway. These results suggested that selenium has significant pharmacological potential for the selective targeting of tumor cells, inducing molecular and cellular events that culminate in tumor cell death.

Mechanistic studies of cytotoxic activity of the mesoionic compound MIH 2.4Bl in MCF-7 breast cancer cells.

In the present study, the cytotoxic effects of a 1,3-thiazolium-5-thiolate derivative of a mesoionic compound, MIH 2.4Bl, were assessed in the MCF-7 breast cancer cell line. The cytotoxic effects of MIH 2.4Bl were determined using a crystal violet assay. Using a dose-response curve, the IC50 value of MIH 2.4Bl was determined to be 45.8±0.8 µM. Additionally, the effects of MIH 2.4Bl on mitochondrial respiration were characterized using oxygen consumption rate analysis. Treating MCF-7 cells with increasing concentrations of MIH 2.4Bl resulted in a significant reduction in all mitochondrial respiratory parameters compared with the control cells, indicative of an overall decrease in mitochondrial membrane potential. The induction of autophagy by MIH 2.4Bl was also examined by measuring changes in the expression of protein markers of autophagy. As shown by western blot analysis, treatment of MCF-7 cells with MIH 2.4Bl resulted in increased protein expression levels of Beclin-1 and ATG5, as well as an increase in the microtubule-associated protein 1A/1B light chain 3B (LC3B)-II to LC3B-I ratio compared with the control cells. Microarray analysis of changes in gene expression following MIH 2.4Bl treatment demonstrated 3,659 genes exhibited a fold-change ≥2. Among these genes, 779 were up-regulated, and 2,880 were down-regulated in cells treated with MIH 2.4Bl compared with the control cells. Based on the identity of the transcripts and fold-change of expression, six genes were selected for verification by reverse transcription-quantitative (RT-q)PCR; activating transcription factor 3, acidic repeat-containing protein, heparin-binding EGF-like growth factor, regulator of G-protein signaling 2, Dickkopf WNT signaling pathway inhibitor 1 and adhesion molecule with Ig like domain 2. The results of RT-qPCR analysis of RNA isolated from control and MIH 2.4Bl treated cells were consistent with the expression changes identified by microarray analysis. Together, these results suggest that MIH 2.4Bl may be a promising candidate for treating breast cancer and warrants further in vitro and in vivo investigation.