scholarly journals Antifungal Activity of N-(4-Halobenzyl)amides against Candida spp. and Molecular Modeling Studies

2021 ◽  
Vol 23 (1) ◽  
pp. 419
Author(s):  
Yunierkis Perez-Castillo ◽  
Ricardo Carneiro Montes ◽  
Cecília Rocha da Silva ◽  
João Batista de Andrade Neto ◽  
Celidarque da Silva Dias ◽  
...  

Fungal infections remain a high-incidence worldwide health problem that is aggravated by limited therapeutic options and the emergence of drug-resistant strains. Cinnamic and benzoic acid amides have previously shown bioactivity against different species belonging to the Candida genus. Here, 20 cinnamic and benzoic acid amides were synthesized and tested for inhibition of C. krusei ATCC 14243 and C. parapsilosis ATCC 22019. Five compounds inhibited the Candida strains tested, with compound 16 (MIC = 7.8 µg/mL) producing stronger antifungal activity than fluconazole (MIC = 16 µg/mL) against C. krusei ATCC 14243. It was also tested against eight Candida strains, including five clinical strains resistant to fluconazole, and showed an inhibitory effect against all strains tested (MIC = 85.3–341.3 µg/mL). The MIC value against C. krusei ATCC 6258 was 85.3 mcg/mL, while against C. krusei ATCC 14243, it was 10.9 times smaller. This strain had greater sensitivity to the antifungal action of compound 16. The inhibition of C. krusei ATCC 14243 and C. parapsilosis ATCC 22019 was also achieved by compounds 2, 9, 12, 14 and 15. Computational experiments combining target fishing, molecular docking and molecular dynamics simulations were performed to study the potential mechanism of action of compound 16 against C. krusei. From these, a multi-target mechanism of action is proposed for this compound that involves proteins related to critical cellular processes such as the redox balance, kinases-mediated signaling, protein folding and cell wall synthesis. The modeling results might guide future experiments focusing on the wet-lab investigation of the mechanism of action of this series of compounds, as well as on the optimization of their inhibitory potency.

Antibiotics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 394
Author(s):  
Mayara Nunes Vitor Anjos ◽  
Luiz Nascimento de Araújo-Neto ◽  
Maria Daniela Silva Buonafina ◽  
Rejane Pereira Neves ◽  
Edson Rubhens de Souza ◽  
...  

Background: Opportunistic fungal infections are increasingly common, with Candida albicans being the most common etiological agent; however, in recent years, episodes of candidiasis caused by non-albicans Candida species have emerged. Plants belonging to the Lauraceae family have shown remarkable antifungal effects. This study assessed the anti-Candida activity of Ocotea glomerata extracts and fractions, time of death and the synergistic effects with conventional antifungals. The possible mechanism of action was also addressed. Methods: Minimal inhibitory concentrations (MIC) were determined by broth microdilution technique, and the mechanism of action was assessed by ergosterol, sorbitol, cell viability, reactive oxygen species (ROS) generation and phosphatidylserine externalization tests. Results: All the tested extracts evidenced antifungal activity, but the methanol extract was revealed to be the most effective (MIC = 3.12 μg/mL) on C. krusei. The combination of methanol extract with ketoconazole and fluconazole revealed a synergistic effect for C. krusei and C. albicans, respectively. Fractions 1 and 5 obtained from the methanol extract had fungicidal activity, mainly against C. krusei. Methanol extract did not reveal effects by ergosterol and sorbitol assays; however, it led to an increase in intracellular ROS levels, decreased cell viability, and consequently, cell death. Conclusion: O. glomerata methanol extract may be viewed as a rich source of biomolecules with antifungal activity against Candida spp.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4087
Author(s):  
Marta Szekalska ◽  
Aleksandra Citkowska ◽  
Magdalena Wróblewska ◽  
Katarzyna Winnicka

Fungal infections and invasive mycoses, despite the continuous medicine progress, are an important globally therapeutic problem. Multicompartment dosage formulations (e.g., microparticles) ensure a short drug diffusion way and high surface area of drug release, which as a consequence can provide improvement of therapeutic efficiency compared to the traditional drug dosage forms. As fucoidan is promising component with wide biological activity per se, the aim of this study was to prepare fucospheres (fucoidan microparticles) and fucoidan/gelatin microparticles with posaconazole using the one-step spray-drying technique. Pharmaceutical properties of designed fucospheres and the impact of the gelatin addition on their characteristics were evaluated. An important stage of this research was in vitro evaluation of antifungal activity of developed microparticles using different Candida species. It was observed that gelatin presence in microparticles significantly improved swelling capacity and mucoadhesiveness, and provided a sustained POS release. Furthermore, it was shown that gelatin addition enhanced antifungal activity of microparticles against tested Candida spp. strains. Microparticles formulation GF6, prepared by the spray drying of 20% fucoidan, 5% gelatin and 10% Posaconazole, were characterized by optimal mucoadhesive properties, high drug loading and the most sustained drug release (after 8 h 65.34 ± 4.10% and 33.81 ± 5.58% of posaconazole was dissolved in simulated vaginal fluid pH 4.2 or 0.1 M HCl pH 1.2, respectively).


Author(s):  
Letícia S. Sampaio ◽  
Cecília R. da Silva ◽  
Rosana S. Campos ◽  
Francisca B.S.A. do Nascimento ◽  
João B.A. Neto ◽  
...  

2018 ◽  
Vol 4 (2) ◽  
pp. 70 ◽  
Author(s):  
Flávia Lassie ◽  
Janaina Emiliano ◽  
Ane Simionato ◽  
Miguel Navarro ◽  
Bárbara Gionco ◽  
...  

Yeasts of the genus Candida are commensals, colonizing the gastrointestinal and genital tract. Accounting for 15% of hospital acquired infections, they are considered a pathogen of clinical importance. The emergence of fungal infections and the occurrence of intrinsic and acquired resistance have reflected in the increased search for new antimicrobials. The objective of this study was to evaluate the antifungal activity of extracellular substances produced by Burkholderia sp. strain RV7S3, for yeast control of the genus Candida. The substance responsible for the antifungal activity was identified and characterized biochemically, its activity was evaluated by agar diffusion tests, minimum inhibitory concentration (MIC), action effect on biofilm formation, and hemolytic activity. The data suggested that the antifungal substance is a hydrolase that exhibits lipolytic activity. The lowest concentration of this enzyme, capable of inhibiting 90% of fungal growth, was 0.38 µg.mL-1. The agar diffusion test showed inhibition halo formation of fungal growth with a diameter of 10 mm or greater, presenting 17.5 ± 0.5 mm. The substance showed low hemolytic activity and reduced biofilm cell viability, demonstrating its potential as an antifungal agent.


2019 ◽  
Author(s):  
Marhiah C. Montoya ◽  
Sarah Beattie ◽  
Kathryn M. Alden ◽  
Damian J. Krysan

ABSTRACTThe antifungal pharmacopeia is critically small, particularly in light of the recent emergence of multi-drug-resistant pathogens such as Candida auris. Herein, we report that derivatives of the anti-malarial drug mefloquine have broad spectrum antifungal activity against pathogenic yeasts and molds. In addition, the mefloquine derivatives have activity against clinical isolates that are resistant to one or more of the three classes of drugs currently used to treat invasive fungal infections, indicating that they have a novel mechanism of action. Importantly, the in vitro toxicity profiles using human cell lines indicate that the mefloquine derivatives are very similar to the parent mefloquine despite being up to 64-fold more active against fungal cells. In addition to direct antifungal activity, sub-inhibitory concentrations of the mefloquine derivatives inhibit the expression of virulence traits including filamentation in C. albicans and capsule formation/melanization in C. neoformans. Mode/mechanism of action experiments indicate that the mefloquine derivatives interfere with both mitochondrial and vacuolar function as part of a multi-target mechanism of action. The broad-spectrum scope of activity, blood-brain-barrier penetration, and large number of previously synthesized analogs available combine to support the further optimization and development of the antifungal activity of this general class of drug-like molecules.


2016 ◽  
Vol 60 (6) ◽  
pp. 3551-3557 ◽  
Author(s):  
Anderson Ramos da Silva ◽  
João Batista de Andrade Neto ◽  
Cecília Rocha da Silva ◽  
Rosana de Sousa Campos ◽  
Rose Anny Costa Silva ◽  
...  

The incidence of fungal infections and, in particular, the incidence of fungal antibiotic resistance, which is associated with biofilm formation, have significantly increased, contributing to morbidity and mortality. Thus, new therapeutic strategies need to be developed. In this context, natural products have emerged as a major source of possible antifungal agents. Berberine is a protoberberine-type isoquinoline alkaloid isolated from the roots, rhizomes, and stem bark of natural herbs, such asBerberis aquifolium,Berberis vulgaris,Berberis aristata, andHydrastis canadensis, and ofPhellodendron amurense. Berberine has been proven to have broad antibacterial and antifungal activity. In the present study, the potential antifungal effect of berberine against fluconazole-resistantCandidaandCryptococcus neoformansstrains, as well as against the biofilm form ofCandidaspp., was assessed. The antifungal effect of berberine was determined by a broth microdilution method (the M27-A3 method of the Clinical and Laboratory Standards Institute) and flow cytometry techniques, in which the probable mechanism of action of the compound was also assessed. For biofilm assessment, a colorimetric 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used to determine the susceptibility of sessile cells. The isolates used in the study belonged to the Laboratory of Bioprospection and Experiments in Yeast (LABEL) of the Federal University of Ceará. After 24 and 72 h, fluconazole-resistantCandidaandCryptococcus neoformansstrains showed berberine MICs equal to 8 μg/ml and 16 μg/ml, respectively. Cytometric analysis showed that treatment with berberine caused alterations to the integrity of the plasma and mitochondrial membranes and DNA damage, which led to cell death, probably by apoptosis. Assessment of biofilm-forming isolates after treatment showed statistically significant reductions in biofilm cell activity (P< 0.001).


2020 ◽  
Vol 64 (3) ◽  
Author(s):  
Marhiah C. Montoya ◽  
Sarah Beattie ◽  
Kathryn M. Alden ◽  
Damian J. Krysan

ABSTRACT The antifungal pharmacopeia is critically small, particularly in light of the recent emergence of multidrug-resistant pathogens, such as Candida auris. Here, we report that derivatives of the antimalarial drug mefloquine have broad-spectrum antifungal activity against pathogenic yeasts and molds. In addition, the mefloquine derivatives have activity against clinical isolates that are resistant to one or more of the three classes of antifungal drugs currently used to treat invasive fungal infections, indicating that they have a novel mechanism of action. Importantly, the in vitro toxicity profiles obtained using human cell lines indicated that the toxicity profiles of the mefloquine derivatives are very similar to those of the parent mefloquine, despite being up to 64-fold more active against fungal cells. In addition to direct antifungal activity, subinhibitory concentrations of the mefloquine derivatives inhibited the expression of virulence traits, including filamentation in Candida albicans and capsule formation/melanization in Cryptococcus neoformans. Mode/mechanism-of-action experiments indicated that the mefloquine derivatives interfere with both mitochondrial and vacuolar function as part of a multitarget mechanism of action. The broad-spectrum scope of activity, blood-brain barrier penetration, and large number of previously synthesized analogs available combine to support the further optimization and development of the antifungal activity of this general class of drug-like molecules.


2010 ◽  
Vol 82 (1) ◽  
pp. 219-226 ◽  
Author(s):  
Woo Sang Sung ◽  
Dong Gun Lee

Chlorogenic acid is a polyphenol compound, derived from several fruit and plants. The aim of this study was to assess the in vitro antifungal activity of chlorogenic acid and its mode of action. The results indicate that chlorogenic acid exhibits antifungal activities against certain pathogenic fungi in an energy-independent manner, without any hemolytic effect on human erythrocytes. To elucidate the antifungal mode of action of chlorogenic acid, flow cytometry analysis by using DiBAC4(3) and changes in membrane dynamics using 1,6-diphenyl-1,3,5-hexatriene (DPH) were performed with Candida albicans. The results suggest that chlorogenic acid may exert antifungal activity by disrupting the structure of the cell membrane. It is demonstrated that chlorogenic acid is a valid lead compound for the development of bioactive alternatives for treatment of fungal infections.


Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3853 ◽  
Author(s):  
Eftichia Kritsi ◽  
Minos-Timotheos Matsoukas ◽  
Constantinos Potamitis ◽  
Anastasia Detsi ◽  
Marija Ivanov ◽  
...  

The prevalence of invasive fungal infections has been dramatically increased as the size of the immunocompromised population worldwide has grown. Aspergillus fumigatus is characterized as one of the most widespread and ubiquitous fungal pathogens. Among antifungal drugs, azoles have been the most widely used category for the treatment of fungal infections. However, increasingly, azole-resistant strains constitute a major problem to be faced. Towards this direction, our study focused on the identification of compounds bearing novel structural motifs which may evolve as a new class of antifungals. To fulfil this scope, a combination of in silico techniques and in vitro assays were implemented. Specifically, a ligand-based pharmacophore model was created and served as a 3D search query to screen the ZINC chemical database. Additionally, molecular docking and molecular dynamics simulations were used to improve the reliability and accuracy of virtual screening results. In total, eight compounds, bearing completely different chemical scaffolds from the commercially available azoles, were proposed and their antifungal activity was evaluated using in vitro assays. Results indicated that all tested compounds exhibit antifungal activity, especially compounds 1, 2, and 4, which presented the most promising minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values and, therefore, could be subjected to further hit to lead optimization.


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