scholarly journals In Vitro Confirmation of Siramesine as a Novel Antifungal Agent with In Silico Lead Proposals of Structurally Related Antifungals

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3504
Author(s):  
Josipa Vlainić ◽  
Ozren Jović ◽  
Ivan Kosalec ◽  
Oliver Vugrek ◽  
Rozelindra Čož-Rakovac ◽  
...  

The limited number of medicinal products available to treat of fungal infections makes control of fungal pathogens problematic, especially since the number of fungal resistance incidents increases. Given the high costs and slow development of new antifungal treatment options, repurposing of already known compounds is one of the proposed strategies. The objective of this study was to perform in vitro experimental tests of already identified lead compounds in our previous in silico drug repurposing study, which had been conducted on the known Drugbank database using a seven-step procedure which includes machine learning and molecular docking. This study identifies siramesine as a novel antifungal agent. This novel indication was confirmed through in vitro testing using several yeast species and one mold. The results showed susceptibility of Candida species to siramesine with MIC at concentration 12.5 µg/mL, whereas other candidates had no antifungal activity. Siramesine was also effective against in vitro biofilm formation and already formed biofilm was reduced following 24 h treatment with a MBEC range of 50–62.5 µg/mL. Siramesine is involved in modulation of ergosterol biosynthesis in vitro, which indicates it is a potential target for its antifungal activity. This implicates the possibility of siramesine repurposing, especially since there are already published data about nontoxicity. Following our in vitro results, we provide additional in depth in silico analysis of siramesine and compounds structurally similar to siramesine, providing an extended lead set for further preclinical and clinical investigation, which is needed to clearly define molecular targets and to elucidate its in vivo effectiveness as well.

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0258465
Author(s):  
Mohamed Hagras ◽  
Nader S. Abutaleb ◽  
Ahmed M. Sayed ◽  
Ehab A. Salama ◽  
Mohamed N. Seleem ◽  
...  

To minimize the intrinsic toxicity of the antibacterial agent hydrazinyloxadiazole 1, the hydrazine moiety was replaced with ethylenediamine (compound 7). This replacement generated a potent antifungal agent with no antibacterial activity. Notably, use of a 1,2-diaminocyclohexane moiety, as a conformationally-restricted isostere for ethylenediamine, potentiated the antifungal activity in both the cis and trans forms of N-(5-(2-([1,1’-biphenyl]-4-yl)-4-methylthiazol-5-yl)-1,3,4-oxadiazol-2-yl)cyclohexane-1,2-diamine (compounds 16 and 17). Both compounds 16 and 17 were void of any antibacterial activity; nonetheless, they showed equipotent antifungal activity in vitro to that of the most potent approved antifungal agent, amphotericin B. The promising antifungal effects of compounds 16 and 17 were maintained when assessed against an additional panel of 26 yeast and mold clinical isolates, including the Candida auris and C. krusei. Furthermore, compound 17 showed superior activity to amphotericin B in vitro against Candida glabrata and Cryptococcus gattii. Additionally, neither compound inhibited the normal human microbiota, and both possessed excellent safety profiles and were 16 times more tolerable than amphotericin B.


2019 ◽  
Vol 15 (6) ◽  
pp. 648-658 ◽  
Author(s):  
Manzoor Ahmad Malik ◽  
Shabir Ahmad Lone ◽  
Parveez Gull ◽  
Ovas Ahmad Dar ◽  
Mohmmad Younus Wani ◽  
...  

Background: The increasing incidence of fungal infections, especially caused by Candida albicans, and their increasing drug resistance has drastically increased in recent years. Therefore, not only new drugs but also alternative treatment strategies are promptly required. Methods: We previously reported on the synergistic interaction of some azole and non-azole compounds with fluconazole for combination antifungal therapy. In this study, we synthesized some non-azole Schiff-base derivatives and evaluated their antifungal activity profile alone and in combination with the most commonly used antifungal drugs- fluconazole (FLC) and amphotericin B (AmB) against four drug susceptible, three FLC resistant and three AmB resistant clinically isolated Candida albicans strains. To further analyze the mechanism of antifungal action of these compounds, we quantified total sterol contents in FLC-susceptible and resistant C. albicans isolates. Results: A pyrimidine ring-containing derivative SB5 showed the most potent antifungal activity against all the tested strains. After combining these compounds with FLC and AmB, 76% combinations were either synergistic or additive while as the rest of the combinations were indifferent. Interestingly, none of the combinations was antagonistic, either with FLC or AmB. Results interpreted from fractional inhibitory concentration index (FICI) and isobolograms revealed 4-10-fold reduction in MIC values for synergistic combinations. These compounds also inhibit ergosterol biosynthesis in a concentration-dependent manner, supported by the results from docking studies. Conclusion: The results of the studies conducted advocate the potential of these compounds as new antifungal drugs. However, further studies are required to understand the other mechanisms and in vivo efficacy and toxicity of these compounds.


2019 ◽  
Vol 9 (1) ◽  
pp. 21-28
Author(s):  
Nisha Sharma ◽  
Shashikiran Misra

Background and Objectives: Dermatophytosis (topical fungal infection) is the 4th common disease in the last decade, affecting 20-25% world’s population. Patients of AIDS, cancer, old age senescence, diabetes, cystic fibrosis become more vulnerable to dermatophytosis. The conventional topical dosage proves effective as prophylactic in preliminary stage. In the advanced stage, the therapeutics interacts with healthy tissues before reaching the pathogen site, showing undesirable effects, thus resulting in pitiable patient compliance. The youngest carbon nano-trope “Graphene” is recently used to manipulate bioactive agents for therapeutic purposes. Here, we explore graphene via smart engineering by virtue of high surface area and high payload for therapeutics and developed graphene–ketoconazole nanohybrid (Gn-keto) for potent efficacy towards dermatophytes in a controlled manner. </P><P> Methods: Polymethacrylate derivative Eudragit (ERL100 and ERS 100) microspheres embedded with keto and Gn-keto nanohybrid were formulated and characterized through FTIR, TGA, and SEM. In vitro drug release and antifungal activity of formulated Gn-keto microspheres were assessed for controlled release and better efficacy against selected dermatophytes. </P><P> Results: Presence of numerous pores within the surface of ERL100 microspheres advocated enhanced solubility and diffusion at the site of action. Controlled diffusion across the dialysis membrane was observed with ERS100 microspheres owing to the nonporous surface and poor permeability. Antifungal activity against T. rubrum and M. canis using microdilution method focused on a preeminent activity (99.785 % growth inhibition) of developed nanohybrid loaded microspheres as compared to 80.876% of keto loaded microspheres for T. rubrum. The culture of M. canis was found to be less susceptible to formulated microspheres. Conclusion: Synergistic antifungal activity was achieved by nanohybrid Gn-Keto loaded microspheres against selected topical fungal infections suggesting a vital role of graphene towards fungi.


2021 ◽  
Vol 7 (2) ◽  
pp. 130
Author(s):  
Nathan P. Wiederhold

Invasive infections caused by Candida that are resistant to clinically available antifungals are of increasing concern. Increasing rates of fluconazole resistance in non-albicans Candida species have been documented in multiple countries on several continents. This situation has been further exacerbated over the last several years by Candida auris, as isolates of this emerging pathogen that are often resistant to multiple antifungals. T-2307 is an aromatic diamidine currently in development for the treatment of invasive fungal infections. This agent has been shown to selectively cause the collapse of the mitochondrial membrane potential in yeasts when compared to mammalian cells. In vitro activity has been demonstrated against Candida species, including C. albicans, C. glabrata, and C. auris strains, which are resistant to azole and echinocandin antifungals. Activity has also been reported against Cryptococcus species, and this has translated into in vivo efficacy in experimental models of invasive candidiasis and cryptococcosis. However, little is known regarding the clinical efficacy and safety of this agent, as published data from studies involving humans are not currently available.


2015 ◽  
Vol 119 (4) ◽  
pp. 962-969 ◽  
Author(s):  
R.S.N. Brilhante ◽  
E.P. Caetano ◽  
R.A.C. Lima ◽  
D.S.C.M. Castelo Branco ◽  
R. Serpa ◽  
...  

2019 ◽  
Vol 16 (32) ◽  
pp. 894-898
Author(s):  
D. F. SILVA ◽  
H. D. NETO ◽  
M. D. L. FERREIRA ◽  
A. A. O. FILHO ◽  
E. O. LIMA

β-citronellol (3,7-dimethyl-6-octen-1-ol) has been exhibiting a number of pharmacological effects that creates interest about its antimicrobial potential, since several substances of the monoterpene class have already demonstrated to possess activity in this profile. In addition, the emergence of fungal species resistant to current pharmacotherapy poses a serious challenge to health systems, making it necessary to search for new effective therapeutic alternatives to deal with this problem. In this study, the antimicrobial profile of β-citronellol was analyzed. The Prediction of Activity Spectra for Substances (PASS) online software was used to study the antimicrobial activity of the β-citronellol molecule by the use of in silico analysis. In contrast, an in vitro antifungal study of this monoterpene was carried out. For this purpose, the Minimum Inhibitory Concentration (MIC) was determined by the microdilution technique in 96-well plates in Saboraud Dextrose Broth/RPMI against sensitive strains of Candida albicans, and this assay was performed in duplicate. In the in silico analysis of the antimicrobial profile, it was revealed that the monoterpene β-citronellol had a diverse antimicrobial bioactivity profile. For the antifungal activity, it presented a percentage value with Pa: 58.4% (predominant) and its MIC of 128 μg/mL, which was equivalent for all strains tested. The in silico study of the β-citronellol molecule allowed us to consider that the monoterpenoid is very likely to be bioactive against agents that cause fungal infections.


2021 ◽  
Author(s):  
Belén Casas ◽  
Liisa Vilén ◽  
Sophie Bauer ◽  
Kajsa Kanebratt ◽  
Charlotte Wennberg Huldt ◽  
...  

Microphysiological systems (MPS) are powerful tools for emulating human physiology and replicating disease progression in vitro. MPS could be better predictors of human outcome than current animal models, but mechanistic interpretation and in vivo extrapolation of the experimental results remain significant challenges. Here, we address these challenges using an integrated experimental-computational approach. This approach allows for in silico representation and predictions of glucose metabolism in a previously reported MPS with two organ compartments (liver and pancreas) connected in a closed loop with circulating medium. We developed a computational model describing glucose metabolism over 15 days of culture in the MPS. The model was calibrated on an experiment-specific basis using data from seven experiments, where single-liver or liver-islet cultures were exposed to both normal and hyperglycemic conditions resembling high blood glucose levels in diabetes. The calibrated models reproduced the fast (i.e. hourly) variations in glucose and insulin observed in the MPS experiments, as well as the long-term (i.e. over weeks) decline in both glucose tolerance and insulin secretion. We also investigated the behavior of the system under hypoglycemia by simulating this condition in silico, and the model could correctly predict the glucose and insulin responses measured in new MPS experiments. Last, we used the computational model to translate the experimental results to humans, showing good agreement with published data of the glucose response to a meal in healthy subjects. The integrated experimental-computational framework opens new avenues for future investigations toward disease mechanisms and the development of new therapies for metabolic disorders.


2013 ◽  
Vol 66 ◽  
pp. 480-488 ◽  
Author(s):  
Saeed Emami ◽  
Shahaboddin Shojapour ◽  
Mohammad Ali Faramarzi ◽  
Nasrin Samadi ◽  
Hamid Irannejad

2015 ◽  
Vol 59 (10) ◽  
pp. 6296-6307 ◽  
Author(s):  
Petra Keller ◽  
Christoph Müller ◽  
Isabel Engelhardt ◽  
Ekkehard Hiller ◽  
Karin Lemuth ◽  
...  

ABSTRACTFungal infections are a leading cause of morbidity and death for hospitalized patients, mainly because they remain difficult to diagnose and to treat. Diseases range from widespread superficial infections such as vulvovaginal infections to life-threatening systemic candidiasis. For systemic mycoses, only a restricted arsenal of antifungal agents is available. Commonly used classes of antifungal compounds include azoles, polyenes, and echinocandins. Due to emerging resistance to standard therapies, significant side effects, and high costs for several antifungals, there is a need for new antifungals in the clinic. In order to expand the arsenal of compounds with antifungal activity, we previously screened a compound library using a cell-based screening assay. A set of novel benzimidazole derivatives, including (S)-2-(1-aminoisobutyl)-1-(3-chlorobenzyl)benzimidazole (EMC120B12), showed high antifungal activity against several species of pathogenic yeasts, includingCandida glabrataandCandida krusei(species that are highly resistant to antifungals). In this study, comparative analysis of EMC120B12 versus fluconazole and nocodazole, using transcriptional profiling and sterol analysis, strongly suggested that EMC120B12 targets Erg11p in the ergosterol biosynthesis pathway and not microtubules, like other benzimidazoles. In addition to the marker sterol 14-methylergosta-8,24(28)-dien-3β,6α-diol, indicating Erg11p inhibition, related sterols that were hitherto unknown accumulated in the cells during EMC120B12 treatment. The novel sterols have a 3β,6α-diol structure. In addition to the identification of novel sterols, this is the first time that a benzimidazole structure has been shown to result in a block of the ergosterol pathway.


2018 ◽  
Vol 62 (5) ◽  
Author(s):  
Cristina Lazzarini ◽  
Krupanandan Haranahalli ◽  
Robert Rieger ◽  
Hari Krishna Ananthula ◽  
Pankaj B. Desai ◽  
...  

ABSTRACTThe incidence of invasive fungal infections has risen dramatically in recent decades. Current antifungal drugs are either toxic, likely to interact with other drugs, have a narrow spectrum of activity, or induce fungal resistance. Hence, there is a great need for new antifungals, possibly with novel mechanisms of action. Previously our group reported an acylhydrazone called BHBM that targeted the sphingolipid pathway and showed strong antifungal activity against several fungi. In this study, we screened 19 derivatives of BHBM. Three out of 19 derivatives were highly active againstCryptococcus neoformansin vitroand had low toxicity in mammalian cells. In particular, one of them, called D13, had a high selectivity index and showed better activity in an animal model of cryptococcosis, candidiasis, and pulmonary aspergillosis. D13 also displayed suitable pharmacokinetic properties and was able to pass through the blood-brain barrier. These results suggest that acylhydrazones are promising molecules for the research and development of new antifungal agents.


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