scholarly journals Novel Dihydroorotate Dehydrogenase Inhibitors with Potent Interferon-Independent Antiviral Activity against Mammarenaviruses In Vitro

Viruses ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 821 ◽  
Author(s):  
Yu-Jin Kim ◽  
Beatrice Cubitt ◽  
Yingyun Cai ◽  
Jens H. Kuhn ◽  
Daniel Vitt ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
De Novo ◽  
Lymphocytic Choriomeningitis ◽  
Human Infection ◽  
Cell Entry ◽  
Dihydroorotate Dehydrogenase ◽  
Chronic Infections ◽  
Natural Hosts ◽  
Nanomolar Range

Mammarenaviruses cause chronic infections in rodents, which are their predominant natural hosts. Human infection with some of these viruses causes high-consequence disease, posing significant issues in public health. Currently, no FDA-licensed mammarenavirus vaccines are available, and anti-mammarenavirus drugs are limited to an off-label use of ribavirin, which is only partially efficacious and associated with severe side effects. Dihydroorotate dehydrogenase (DHODH) inhibitors, which block de novo pyrimidine biosynthesis, have antiviral activity against viruses from different families, including Arenaviridae, the taxonomic home of mammarenaviruses. Here, we evaluate five novel DHODH inhibitors for their antiviral activity against mammarenaviruses. All tested DHODH inhibitors were potently active against lymphocytic choriomeningitis virus (LCMV) (half-maximal effective concentrations [EC50] in the low nanomolar range, selectivity index [SI] > 1000). The tested DHODH inhibitors did not affect virion cell entry or budding, but rather interfered with viral RNA synthesis. This interference resulted in a potent interferon-independent inhibition of mammarenavirus multiplication in vitro, including the highly virulent Lassa and Junín viruses.

The new generation hDHODH inhibitor MEDS433 hinders the in vitro replication of SARS-CoV-2

2020 ◽  
Author(s):  
Arianna Calistri ◽  
Anna Luganini ◽  
Valeria Conciatori ◽  
Claudia Del Vecchio ◽  
Stefano Sainas ◽  
...  
Keyword(s):  
Virus Replication ◽  
De Novo ◽  
Dihydroorotate Dehydrogenase ◽  
In Vitro Replication ◽  
Attractive Candidate ◽  
New Generation ◽  
Effective Drugs ◽  
Nanomolar Range

AbstractIdentification and development of effective drugs active against SARS-CoV-2 are urgently needed. Here, we report on the anti-SARS-CoV-2 activity of MEDS433, a novel inhibitor of human dihydroorotate dehydrogenase (hDHODH), a key cellular enzyme of the de novo pyrimidines biosynthesis. MEDS433 inhibits in vitro virus replication in the low nanomolar range, and through a mechanism that stems from its ability to block hDHODH activity. MEDS433 thus represents an attractive candidate to develop novel anti-SARS-CoV-2 agents.

scholarly journals Ribavirin InhibitsIn VitroHepatitis E Virus Replication through Depletion of Cellular GTP Pools and Is Moderately Synergistic with Alpha Interferon

2013 ◽  
Vol 58 (1) ◽  
pp. 267-273 ◽  
Author(s):  
Yannick Debing ◽  
Suzanne U. Emerson ◽  
Yijin Wang ◽  
Qiuwei Pan ◽  
Jan Balzarini ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Hepatitis E Virus ◽  
Clinical Effectiveness ◽  
Hepatitis E ◽  
Alpha Interferon ◽  
Chronic Infections ◽  
Genotype 3 ◽  
Subgenomic Replicon ◽  
First Time

ABSTRACTHepatitis E virus (HEV) is a common cause of acute hepatitis that results in high mortality in pregnant women and may establish chronic infections in immunocompromised patients. We demonstrate for the first time that alpha interferon (IFN-α) and ribavirin inhibitin vitroHEV replication in both a subgenomic replicon and an infectious culture system based on a genotype 3 strain. IFN-α showed a moderate but significant synergism with ribavirin. These findings corroborate the reported clinical effectiveness of both drugs. In addition, the antiviral activity of ribavirin against wild-type genotype 1, 2, and 3 strains was confirmed by immunofluorescence staining. Furthermore, thein vitroactivity of ribavirin depends on depletion of intracellular GTP pools, which is evident from the facts that (i) other GTP-depleting agents (5-ethynyl-1-β-d-ribofuranosylimidazole-4-carboxamide [EICAR] and mycophenolic acid) inhibit viral replication, (ii) exogenously added guanosine reverses the antiviral effects, and (iii) a strong correlation (R2= 0.9998) exists between the antiviral activity and GTP depletion of ribavirin and other GTP-depleting agents.

scholarly journals In Vitro Inhibition of Zika Virus Replication with Amantadine and Rimantadine Hydrochlorides

2021 ◽  
Vol 12 (3) ◽  
pp. 727-738
Author(s):  
Jorge L. Arias-Arias ◽  
Francisco Vega-Aguilar ◽  
Dihalá Picado-Soto ◽  
Eugenia Corrales-Aguilar ◽  
Gilbert D. Loría
Keyword(s):  
Antiviral Activity ◽  
Zika Virus ◽  
Influenza A ◽  
Yellow Fever Virus ◽  
Human Infection ◽  
Virus Infections ◽  
Drug Concentrations ◽  
Dose Dependent ◽  
Reference Strains

Zika virus (ZIKV) is a mosquito-borne flavivirus in which human infection became relevant during recent outbreaks in Latin America due to its unrecognized association with fetal neurological disorders. Currently, there are no approved effective antivirals or vaccines for the treatment or prevention of ZIKV infections. Amantadine and rimantadine are approved antivirals used against susceptible influenza A virus infections that have been shown to have antiviral activity against other viruses, such as dengue virus (DENV). Here, we report the in vitro effectiveness of both amantadine and rimantadine hydrochlorides against ZIKV replication, resulting in a dose-dependent reduction in viral titers of a ZIKV clinical isolate and two different ZIKV reference strains. Additionally, we demonstrate similar in vitro antiviral activity of these drugs against DENV-1 and yellow fever virus (YFV), although at higher drug concentrations for the latter. ZIKV replication was inhibited at drug concentrations well below cytotoxic levels of both compounds, as denoted by the high selectivity indexes obtained with the tested strains. Further work is absolutely needed to determine the potential clinical use of these antivirals against ZIKV infections, but our results suggest the existence of a highly conserved mechanism across flavivirus, susceptible to be blocked by modified more specific adamantane compounds.

scholarly journals Recombinant production, crystallization and crystal structure determination of dihydroorotate dehydrogenase fromLeishmania (Viannia) braziliensis

2015 ◽  
Vol 71 (5) ◽  
pp. 547-552 ◽  
Author(s):  
Renata Almeida Garcia Reis ◽  
Eder Lorenzato ◽  
Valeria Cristina Silva ◽  
Maria Cristina Nonato
Keyword(s):  
Crystal Structure ◽  
De Novo ◽  
Cell Metabolism ◽  
Dihydroorotate Dehydrogenase ◽  
Recombinant Production ◽  
High Degree ◽  
Respective Host

The enzyme dihydroorotate dehydrogenase (DHODH) is a flavoenzyme that catalyses the oxidation of dihydroorotate to orotate in thede novopyrimidine-biosynthesis pathway. In this study, a reproducible protocol for the heterologous expression of active dihydroorotate dehydrogenase fromLeishmania (Viannia) braziliensis(LbDHODH) was developed and its crystal structure was determined at 2.12 Å resolution.L. (V.) braziliensisis the species responsible for the mucosal form of leishmaniasis, a neglected disease for which no cure or effective therapy is available. Analyses of sequence, structural and kinetic features classifyLbDHODH as a member of the class 1A DHODHs and reveal a very high degree of structural conservation with the previously reported structures of orthologous trypanosomatid enzymes. The relevance of nucleotide-biosynthetic pathways for cell metabolism together with structural and functional differences from the respective host enzyme suggests that inhibition ofLbDHODH could be exploited for antileishmanicidal drug development. The present work provides the framework for further integratedin vitro,in silicoandin vivostudies as a new tool to evaluate DHODH as a drug target against trypanosomatid-related diseases.

scholarly journals Preclinical Profile of AB-423, an Inhibitor of Hepatitis B Virus Pregenomic RNA Encapsidation

2018 ◽  
Vol 62 (6) ◽  
Author(s):  
Nagraj Mani ◽  
Andrew G. Cole ◽  
Janet R. Phelps ◽  
Andrzej Ardzinski ◽  
Kyle D. Cobarrubias ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Antiviral Activity ◽  
De Novo ◽  
Infection Model ◽  
Pharmacokinetic Studies ◽  
Circular Dna ◽  
B Virus ◽  
Combination Studies

ABSTRACTAB-423 is a member of the sulfamoylbenzamide (SBA) class of hepatitis B virus (HBV) capsid inhibitors in phase 1 clinical trials. In cell culture models, AB-423 showed potent inhibition of HBV replication (50% effective concentration [EC50] = 0.08 to 0.27 μM; EC90= 0.33 to 1.32 μM) with no significant cytotoxicity (50% cytotoxic concentration > 10 μM). Addition of 40% human serum resulted in a 5-fold increase in the EC50s. AB-423 inhibited HBV genotypes A through D and nucleos(t)ide-resistant variantsin vitro. Treatment of HepDES19 cells with AB-423 resulted in capsid particles devoid of encapsidated pregenomic RNA and relaxed circular DNA (rcDNA), indicating that it is a class II capsid inhibitor. In ade novoinfection model, AB-423 prevented the conversion of encapsidated rcDNA to covalently closed circular DNA, presumably by interfering with the capsid uncoating process. Molecular docking of AB-423 into crystal structures of heteroaryldihydropyrimidines and an SBA and biochemical studies suggest that AB-423 likely also binds to the dimer-dimer interface of core protein.In vitrodual combination studies with AB-423 and anti-HBV agents, such as nucleos(t)ide analogs, RNA interference agents, or interferon alpha, resulted in additive to synergistic antiviral activity. Pharmacokinetic studies with AB-423 in CD-1 mice showed significant systemic exposures and higher levels of accumulation in the liver. A 7-day twice-daily administration of AB-423 in a hydrodynamic injection mouse model of HBV infection resulted in a dose-dependent reduction in serum HBV DNA levels, and combination with entecavir or ARB-1467 resulted in a trend toward antiviral activity greater than that of either agent alone, consistent with the results of thein vitrocombination studies. The overall preclinical profile of AB-423 supports its further evaluation for safety, pharmacokinetics, and antiviral activity in patients with chronic hepatitis B.

scholarly journals Antiviral Activity of Inhibitors of Pyrimidine De-Novo Biosynthesis

1996 ◽  
Vol 7 (1) ◽  
pp. 7-13 ◽  
Author(s):  
M. Wachsman ◽  
F. M. Hamzeh ◽  
N. B. Assadi ◽  
P. S. Lietman
Keyword(s):  
Antiviral Activity ◽  
Human Cytomegalovirus ◽  
Hcmv Infection ◽  
De Novo ◽  
Antiviral Effect ◽  
Pyrimidine Biosynthesis ◽  
Dihydroorotate Dehydrogenase ◽  
Dot Blot ◽  
De Novo Biosynthesis ◽  
Biosynthesis Inhibitors

Evaluation of the elevation of host cell biosynthesis of deoxynucleoside triphosphates (dNTP's) induced by human cytomegalovirus (HCMV) infection as a target for antiviral therapeutics was carried out. The concentrations of all four intracellular dNTP's rose rapidly following HCMV infection, and were markedly above baseline by 8 h post infection (p.i.). All four deoxynucleoside triphosphates remained elevated above baseline for at least 72 h p.i. The effects of inhibitors of the de-novo pathway of pyrimidine biosynthesis on HCMV viral replication-were quantified by DNA dot blot. All pyrimidine biosynthesis inhibitors examined inhibited the HCMV DNA replication at concentrations that were non-toxic to the cell. These drugs were also more effective against HCMV, which is highly dependent on host denovo synthesis, than against HSV-1 which encodes enzymes capable of increasing the supply of dNTP's. The antiviral effect of brequinar, an inhibitor of one of the enzymes of the de-novo pathway (dihydroorotate dehydrogenase), was examined to determine if it coincided with a decrease in dNTP's. HCMV-infected fibroblasts and uninfected control cells were treated with a concentration of brequinar able to inhibit HCMV DNA levels 90%. It was found that brequinar markedly lowered the levels of dTTP found in treated cells compared to untreated cells in both HCMV-infected and uninfected cells.

scholarly journals In Vitro Antiviral Profile of Ruzasvir, a Potent and Pangenotype Inhibitor of Hepatitis C Virus NS5A

2018 ◽  
Vol 62 (11) ◽  
Author(s):  
Ernest Asante-Appiah ◽  
Rong Liu ◽  
Stephanie Curry ◽  
Patricia McMonagle ◽  
Sony Agrawal ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Antiviral Activity ◽  
De Novo ◽  
Antiviral Agents ◽  
Cross Resistance ◽  
Hcv Rna ◽  
Direct Acting Antiviral ◽  
Direct Acting

ABSTRACT Inhibition of NS5A has emerged as an attractive strategy to intervene in hepatitis C virus (HCV) replication. Ruzasvir (formerly MK-8408) was developed as a novel NS5A inhibitor to improve upon the potency and barrier to resistance of early compounds. Ruzasvir inhibited HCV RNA replication with 50% effective concentrations (EC50s) of 1 to 4 pM in Huh7 or Huh7.5 cells bearing replicons for HCV genotype 1 (GT1) to GT7. The antiviral activity was modestly (10-fold) reduced in the presence of 40% normal human serum. The picomolar potency in replicon cells extended to sequences of clinical isolates available in public databases that were synthesized and tested as replicons. In GT1a, ruzasvir inhibited common NS5A resistance-associated substitutions (RASs), with the exception of M28G. De novo resistance selection studies identified pathways with certain amino acid substitutions at residues 28, 30, 31, and 93 across genotypes. Substitutions at position 93 were more common in GT1 to -4, while changes at position 31 emerged frequently in GT5 and -6. With the exception of GT4, the reintroduction of selected RASs conferred a ≥100-fold potency reduction in the antiviral activity of ruzasvir. Common RASs from other classes of direct-acting antiviral agents (DAAs) did not confer cross-resistance to ruzasvir. The interaction of ruzasvir with an NS3/4A protease inhibitor (grazoprevir) and an NS5B polymerase prodrug (uprifosbuvir) was additive to synergistic, with no evidence of antagonism or cytotoxicity. The antiviral profile of ruzasvir supported its further evaluation in human trials in combination with grazoprevir and uprifosbuvir.

scholarly journals In Vitro Inhibition of Zika Virus Replication with Amantadine and Rimantadine Hydrochlorides

2021 ◽  
Author(s):  
Jorge L. Arias-Arias ◽  
Francisco Vega-Aguilar ◽  
Dihalá Picado-Soto ◽  
Eugenia Corrales-Aguilar ◽  
Gilbert D. Loría
Keyword(s):  
Antiviral Activity ◽  
Zika Virus ◽  
Influenza A ◽  
High Selectivity ◽  
Yellow Fever Virus ◽  
Human Infection ◽  
Virus Infections ◽  
Drug Concentrations ◽  
Dose Dependent

Zika virus (ZIKV) is a mosquito-born flavivirus which human infection became relevant dur-ing recent outbreaks in Latin America, due to its unrecognized association with fetal neurologi-cal disorders. Currently there are no approved effective antivirals or vaccines for treatment or prevention of ZIKV infections. Amantadine and rimantadine are approved antivirals used against susceptible influenza A virus infections, that have been shown to have antiviral activity against other viruses, such as dengue virus (DENV). Here, we report the in vitro effectiveness of both amantadine and rimantadine hydrochlorides against ZIKV replication, resulting in a dose-dependent reduction in viral titers of a ZIKV clinical isolate and two different ZIKV refer-ence strains. Additionally, we demonstrate similar in vitro antiviral activity of these drugs against DENV-1 and yellow fever virus (YFV), although at higher drug concentrations for the later. ZIKV replication was inhibited at drug concentrations well below cytotoxic levels of both compounds, as denoted by the high selectivity indexes obtained with the tested strains. Further work is absolutely needed to determine a potential clinical use of these antivirals against ZIKV infections, but our results suggest the existence of a highly conserved mechanism across fla-vivirus, susceptible to be blocked by modified more specific adamantane compounds.

Potent in vitro anti-SARS-CoV-2 activity by gallinamide A and analogues via inhibition of cathepsin L

2020 ◽  
Author(s):  
Anneliese S. Ashhurst ◽  
Arthur H. Tang ◽  
Pavla Fajtová ◽  
Michael Yoon ◽  
Anupriya Aggarwal ◽  
...  
Keyword(s):  
Drug Target ◽  
Cathepsin L ◽  
Antiviral Drug ◽  
Cell Entry ◽  
Marine Natural Product ◽  
Viral Proteases ◽  
Cathepsin Proteases ◽  
Human Cathepsin ◽  
Nanomolar Range

AbstractThe emergence of SARS-CoV-2 in late 2019, and the subsequent COVID-19 pandemic, has led to substantial mortality, together with mass global disruption. There is an urgent need for novel antiviral drugs for therapeutic or prophylactic application. Cathepsin L is a key host cysteine protease utilized by coronaviruses for cell entry and is recognized as a promising drug target. The marine natural product, gallinamide A and several synthetic analogues, were identified as potent inhibitors of cathepsin L activity with IC50 values in the picomolar range. Lead molecules possessed selectivity over cathepsin B and other related human cathepsin proteases and did not exhibit inhibitory activity against viral proteases Mpro and PLpro. We demonstrate that gallinamide A and two lead analogues potently inhibit SARS-CoV-2 infection in vitro, with EC50 values in the nanomolar range, thus further highlighting the potential of cathepsin L as a COVID-19 antiviral drug target.

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