scholarly journals Activities ofN,N′-Diarylurea MMV665852 Analogs against Schistosoma mansoni

2015 ◽  
Vol 59 (4) ◽  
pp. 1935-1941 ◽  
Author(s):  
Noemi Cowan ◽  
Philipp Dätwyler ◽  
Beat Ernst ◽  
Chunkai Wang ◽  
Jonathan L. Vennerstrom ◽  
...  

ABSTRACTThere is an unmet need to discover and develop novel antischistosomal drugs. As exemplified by MMV665852,N,N′-diarylureas have recently emerged as a promising antischistosomal chemotype. In this study, we evaluated the structure-activity relationships of 46 commercially available analogs of MMV665852 on newly transformed schistosomula (NTS) and adultSchistosoma mansoniwormsin vitro. Active compounds were evaluated with a cytotoxicity assay,in silicocalculations, metabolic stability studies, and anin vivoassay with mice harboring adultS. mansoniworms. Of the 46 compounds tested at 33.3 μM, 13 and 14 compounds killed NTS and adult worms, respectively, within 72 h. Nine compounds had 90% inhibitory concentrations (IC90s) of ≤10 μM against adult worms, with selectivity indexes of ≥2.8. Their physicochemical properties and permeation through an artificial membrane indicated good to moderate intestinal absorption. Their metabolic stabilities ranged from low to high. Despite satisfactoryin vitroresults andin silicopredictions, only one compound resulted in a statistically significant worm burden reduction (66%) after administration of a single oral dose of 400 mg/kg of body weight toS. mansoni-infected mice. Worm burden reductions of 0 to 43% were observed for the remaining eight compounds tested. In conclusion, several analogs of theN,N′-diarylurea MMV665852 had high efficacy againstS. mansoniin vitroand favorable physicochemical properties for permeation through the intestinal wall. To counteract the low efficacy observed in the mouse model, further investigations should focus on identifying compounds with improved solubility and pharmacokinetic properties.

2014 ◽  
Vol 58 (9) ◽  
pp. 5466-5472 ◽  
Author(s):  
Isabel Meister ◽  
Katrin Ingram-Sieber ◽  
Noemi Cowan ◽  
Matthew Todd ◽  
Murray N. Robertson ◽  
...  

ABSTRACTA racemic mixture ofRandSenantiomers of praziquantel (PZQ) is currently the treatment of choice for schistosomiasis. Though theSenantiomer and the metabolites are presumed to contribute only a little to the activity of the drug, in-depth side-by-side studies are lacking. The aim of this study was to investigate thein vitroactivities of PZQ and its main metabolites, namely,R- andS-cis- andR- andS-trans-4′-hydroxypraziquantel, against adult worms and newly transformed schistosomula (NTS). Additionally, we explored thein vivoactivity and hepatic shift (i.e., the migration of the worms to the liver) produced by each PZQ enantiomer in mice. Fifty percent inhibitory concentrations ofR-PZQ,S-PZQ, andR-trans- andR-cis-4′-hydroxypraziquantel of 0.02, 5.85, 4.08, and 2.42 μg/ml, respectively, for adultS. mansoniwere determinedin vitro. S-trans- andS-cis-4′-hydroxypraziquantel were not active at 100 μg/ml. These results are consistent with microcalorimetry data and studies with NTS.In vivo, single 400-mg/kg oral doses ofR-PZQ andS-PZQ achieved worm burden reductions of 100 and 19%, respectively. Moreover, worms treatedin vivowithS-PZQ displayed an only transient hepatic shift and returned to the mesenteric veins within 24 h. Our data confirm thatR-PZQ is the main effector molecule, whileS-PZQ and the metabolites do not play a significant role in the antischistosomal properties of PZQ.


Author(s):  
Stefan L. Debbert ◽  
Mikaela J. Hintz ◽  
Christian J. Bell ◽  
Kenya R. Earl ◽  
Grant E. Forsythe ◽  
...  

The reliance on one drug, praziquantel, to treat the parasitic disease schistosomiasis in millions of people a year shows the need to further develop a pipeline of new drugs to treat this disease. Recently, an antimalarial quinoxaline derivative (MMV007204) from the Medicines for Malaria Venture (MMV) Malaria Box demonstrated promise against Schistosoma mansoni. In this study, 47 synthesized compounds containing quinoxaline moieties were first assayed against the larval stage of this parasite, newly transformed schistosomula (NTS); of these, 16 killed over 70% NTS at 10 μM. Further testing against NTS and adult S. mansoni yielded three compounds with 50% inhibitory concentrations (IC50s) of ≤ 0.31 μM against adult S. mansoni and selectivity indices of ≥ 8.9. Administration of these compounds as a single oral dose of 400 mg/kg of body weight to S. mansoni-infected mice yielded only moderate worm burden reduction (WBR) (9.3% – 46.3%). The discrepancy between these compounds’ good in vitro activities and their poor in vivo activities indicates that optimization of their pharmacokinetic properties may yield compounds with greater bioavailabilities and better antischistosomiasis activities in vivo.


2011 ◽  
Vol 56 (2) ◽  
pp. 1090-1092 ◽  
Author(s):  
Jennifer Keiser ◽  
Katrin Ingram ◽  
Mireille Vargas ◽  
Jacques Chollet ◽  
Xiaofang Wang ◽  
...  

ABSTRACTWe evaluated thein vivoantischistosomal activities of 11 structurally diverse synthetic peroxides. Of all compounds tested, ozonide (1,2,4-trioxolane) OZ418 had the highest activity against adultSchistosoma mansoni, with total and female worm burden reductions of 80 and 90% (P< 0.05), respectively. Furthermore, treatment ofS. haematobium-infected mice with OZ418 reduced the total worm burden by 86%. In conclusion, OZ418 is a promising antischistosomal lead compound.


2020 ◽  
Vol 64 (9) ◽  
Author(s):  
Letícia Tiburcio Ferreira ◽  
Juliana Rodrigues ◽  
Gustavo Capatti Cassiano ◽  
Tatyana Almeida Tavella ◽  
Kaira Cristina Peralis Tomaz ◽  
...  

ABSTRACT Widespread resistance against antimalarial drugs thwarts current efforts for controlling the disease and urges the discovery of new effective treatments. Drug repositioning is increasingly becoming an attractive strategy since it can reduce costs, risks, and time-to-market. Herein, we have used this strategy to identify novel antimalarial hits. We used a comparative in silico chemogenomics approach to select Plasmodium falciparum and Plasmodium vivax proteins as potential drug targets and analyzed them using a computer-assisted drug repositioning pipeline to identify approved drugs with potential antimalarial activity. Among the seven drugs identified as promising antimalarial candidates, the anthracycline epirubicin was selected for further experimental validation. Epirubicin was shown to be potent in vitro against sensitive and multidrug-resistant P. falciparum strains and P. vivax field isolates in the nanomolar range, as well as being effective against an in vivo murine model of Plasmodium yoelii. Transmission-blocking activity was observed for epirubicin in vitro and in vivo. Finally, using yeast-based haploinsufficiency chemical genomic profiling, we aimed to get insights into the mechanism of action of epirubicin. Beyond the target predicted in silico (a DNA gyrase in the apicoplast), functional assays suggested a GlcNac-1-P-transferase (GPT) enzyme as a potential target. Docking calculations predicted the binding mode of epirubicin with DNA gyrase and GPT proteins. Epirubicin is originally an antitumoral agent and presents associated toxicity. However, its antiplasmodial activity against not only P. falciparum but also P. vivax in different stages of the parasite life cycle supports the use of this drug as a scaffold for hit-to-lead optimization in malaria drug discovery.


2012 ◽  
Vol 56 (6) ◽  
pp. 3207-3215 ◽  
Author(s):  
Katrin Ingram ◽  
William Ellis ◽  
Jennifer Keiser

ABSTRACTInteresting antischistosomal properties have been documented for the antimalarial mefloquine, a 4-quinolinemethanol. We evaluated the antischistosomal activities of nine mefloquine-related compounds belonging to the 4-pyridinemethanols, 9-phenanthrenmethanols, and 4-quinolinemethanols. Eight compounds revealed high activities againstSchistosoma mansoni in vitro, with two drugs (the 4-quinolinemethanols WR7573 and WR7930) characterized by significantly lower half-maximal inhibitory concentrations (IC50s) (2.7 and 3.5 μM, respectively) compared to mefloquine (11.4 μM). Mefloquine and WR7930 showed significantly decreased IC50s when incubated in the presence of hemoglobin. High worm burden reductions (WBR) were obtained with enpiroline (WBR, 82.7%; dosage, 200 mg/kg of body weight) and itsthreoisomers (+)-threo(WBR, 100%) and (−)-threo(WBR, 89%) and with WR7930 (WBR, 87%; dosage, 100 mg/kg) against adultS. mansoniin mice. Furthermore, excellentin vitroandin vivoantischistosomal activity was observed for two WR7930-related structures (WR29252 and WR7524). In addition, mefloquine (WBR, 81%), enpiroline (WBR, 77%), and WR7930 (WBR, 100%) showed high activities againstS. haematobiumharbored in mice following single oral doses of 200 mg/kg. These results provide a deeper insight into the structural features of the arylmethanols that rule antischistosomal activity. Further studies should be launched with enpiroline and WR7930.


2015 ◽  
Vol 59 (6) ◽  
pp. 3645-3647 ◽  
Author(s):  
Carolina B. Moraes ◽  
Karen L. White ◽  
Stéphanie Braillard ◽  
Catherine Perez ◽  
Junghyun Goo ◽  
...  

ABSTRACTWith the aim of improving the available drugs for the treatment of Chagas disease, individual enantiomers of nifurtimox were characterized. The results indicate that the enantiomers are equivalent in theirin vitroactivity against a panel ofTrypanosoma cruzistrains;in vivoefficacy in a murine model of Chagas disease;in vitrotoxicity and absorption, distribution, metabolism, and excretion characteristics; andin vivopharmacokinetic properties. There is unlikely to be any therapeutic benefit of an individual nifurtimox enantiomer over the racemic mixture.


2016 ◽  
Vol 61 (2) ◽  
Author(s):  
Kenneth D. James ◽  
Christopher P. Laudeman ◽  
Navdeep B. Malkar ◽  
Radha Krishnan ◽  
Karen Polowy

ABSTRACT Echinocandins are a first-line therapy for candidemia and invasive candidiasis. They are generally safe with few drug interactions, but the stability and pharmacokinetic properties of currently approved echinocandins are such that each was developed for daily intravenous infusion. We sought to discover a novel echinocandin with properties that would enable more flexible dosing regimens, alternate routes of delivery, and expanded utility. Derivatives of known echinocandin scaffolds were generated, and an iterative process of design and screening led to the discovery of CD101, a novel echinocandin that has since demonstrated improved chemical stability and pharmacokinetics. Here, we report the structure-activity relationships (including preclinical efficacy and pharmacokinetic data) for the series of echinocandin analogs from which CD101 was selected. In a mouse model of disseminated candidiasis, the test compounds displayed clear dose responses and were generally associated with lower fungal burdens than that of anidulafungin. Single-dose pharmacokinetic studies in beagle dogs revealed a wide disparity in the half-lives and volumes of distribution, with one compound (now known as CD101) displaying a half-life that is nearly 5-fold longer than that of anidulafungin (53.1 h versus 11.6 h, respectively). In vitro activity data against panels of Candida spp. and Aspergillus spp. demonstrated that CD101 behaved similarly to approved echinocandins in terms of potency and spectrum of activity, suggesting that the improved efficacy observed in vivo for CD101 is a result of features beyond the antifungal potency inherent to the molecule. Factors that potentially contribute to the improved in vivo efficacy of CD101 are discussed.


2020 ◽  
Author(s):  
Mustafa Alhaji Isa ◽  
Muhammad M Ibrahim

The 3-hydroquinate synthase (DHQase) is an enzyme that catalyzes the third step of the shikimate pathway in <i>Mycobacterium tuberculosis</i> (MTB), by converting 3-dehydroquinate into 3-dehydroshikimate. In this study, the novel inhibitors of DHQase from MTB was identified using in silico approach. The crystal structure of DHQase bound to 1,3,4-trihydroxy-5-(3-phenoxypropyl)-cyclohexane-1-carboxylic acid (CA) obtained from the Protein Data Bank (PDB ID: 3N76). The structure prepared through energy minimization and structure optimization. A total of 9699 compounds obtained from Zinc and PubChem databases capable of binding to DHQase and subjected to virtual screening through Lipinski’s rule of five and molecular docking analysis. Eight (8) compounds with good binding energies, ranged between ─8.99 to ─8.39kcal/mol were selected, better than the binding energy of ─4.93kcal/mol for CA and further filtered for pharmacokinetic properties (Absorption, Distribution, Metabolism, Excretion, and Toxicity or ADMET). Five compounds (ZINC14981770, ZINC14741224, ZINC14743698, ZINC13165465, and ZINC8442077) which had desirable pharmacokinetic properties selected for molecular dynamic (MD) simulation and molecular generalized born surface area (MM-GBSA) analyses. The results of the analyses showed that all the compounds formed stable and rigid complexes after the 50ns MD simulation and also had a lower binding as compared to CA. Therefore, these compounds considered as good inhibitors of MTB after in vitro and in vivo validation.”


2019 ◽  
Vol 85 (9) ◽  
Author(s):  
Jongsoo Jeon ◽  
Dongeun Yong

ABSTRACT Extensively drug-resistant Pseudomonas aeruginosa (XDR-PA) is a life-threatening pathogen that causes serious global problems. Here, we investigated two novel P. aeruginosa bacteriophages (phages), Bϕ-R656 and Bϕ-R1836, in vitro, in silico, and in vivo to evaluate the potential of phage therapy to control XDR-PA clinical strains. Bϕ-R656 and Bϕ-R1836 belong to the Siphoviridae family and exhibited broad host ranges which could lyse 18 (64%) and 14 (50%) of the 28 XDR-PA strains. In addition, the two phages showed strong bacteriolytic activity against XDR-PA host strains from pneumonia patients. The whole genomes of Bϕ-R656 and Bϕ-R1836 have linear double-stranded DNA of 60,919 and 37,714 bp, respectively. The complete sequence of Bϕ-R656 had very low similarity to the previously discovered P. aeruginosa phages in GenBank, but phage Bϕ-R1836 exhibited 98% and 91% nucleotide similarity to Pseudomonas phages YMC12/01/R24 and PA1/KOR/2010, respectively. In the two in vivo infection models, treatment with Bϕ-R656 and Bϕ-R1836 enhanced the survival of Galleria mellonella larvae (50% and 60%, respectively) at 72 h postinfection and pneumonia-model mice (66% and 83%, respectively) at 12 days postinfection compared with untreated controls. Treatment with Bϕ-R656 or Bϕ-R1836 also significantly decreased the bacterial load in the lungs of the mouse pneumonia model (>6 log10 CFU and >4 log10 CFU, respectively) on day 5. IMPORTANCE In this study, two novel P. aeruginosa phages, Bϕ-R656 and Bϕ-R1836, were evaluated in vitro, in silico, and in vivo for therapeutic efficacy and safety as an alternative antibacterial agent to control XDR-PA strains collected from pneumonia patients. Both phages exhibited potent bacteriolytic activity and greatly improved survival in G. mellonella larva infection and a mouse acute pneumonia model. Based on these results, we strongly predict that these two new phages could be used as fast-acting and safe alternative biological weapons against XDR-PA infections.


2020 ◽  
Vol 64 (11) ◽  
Author(s):  
Mariana G. de Brito ◽  
Ana C. Mengarda ◽  
George L. Oliveira ◽  
Maria E. Cirino ◽  
Tais C. Silva ◽  
...  

ABSTRACT Praziquantel is currently the only drug available to treat schistosomiasis, a disease of enormous public health significance caused by a blood fluke of the genus Schistosoma. Diminazene, a drug approved by the FDA, has been successfully used to treat diseases caused by blood protozoan parasites. In this study, we evaluated the antiparasitic properties of diminazene against Schistosoma mansoni ex vivo and in mice harboring either chronic or early S. mansoni infections. In vitro, we monitored phenotypic and tegumental changes as well as the effects of the drug on pairing and egg production. In mice infected with either adult (chronic infection) or immature (early infection) worms, diminazene was administered intraperitoneally (10 to 100 mg/kg of body weight) or by oral gavage (100 to 400 mg/kg), and we studied the influence of the drug on worm burden and egg production. Liver and spleen pathologies and serum aminotransferase levels were also analyzed. In vitro, 50% effective concentrations (EC50) and EC90 revealed that diminazene is able to kill both immature and adult parasites, and its effect was time and concentration dependent. In addition, confocal laser scanning microscopy showed morphological alterations in the teguments of schistosomes. In an animal model, the influence of the drug on worm burden, egg production, hepatomegaly, and splenomegaly depended on the dosing regimen applied and the route of administration. Diminazene also caused a significant reduction in aminotransferase levels. Comparatively, diminazene treatment was more effective in chronic infection than in early infection. In tandem, our study revealed that diminazene possesses anthelmintic properties and inhibits liver injury caused by Schistosoma eggs.


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