scholarly journals Adenosine Analog NITD008 Is a Potent Inhibitor of Zika Virus

2016 ◽  
Vol 3 (4) ◽  
Author(s):  
Yong-Qiang Deng ◽  
Na-Na Zhang ◽  
Chun-Feng Li ◽  
Min Tian ◽  
Jia-Nan Hao ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Zika Virus ◽  
Potent Inhibitor ◽  
Antiviral Drug ◽  
Clinical Manifestations ◽  
Drug Screen ◽  
Adenosine Analog

Abstract The ongoing Zika virus (ZIKV) outbreaks have raised global concerns due to its unexpected clinical manifestations. Antiviral development is of high priority in response to the ZIKV emergency. In this study, we report that an adenosine analog NITD008 has potent in vitro and in vivo antiviral activity against ZIKV. The compound can effectively inhibit the historical and contemporary ZIKV strains in cultures as well as significantly reduce viremia and prevent mortality in A129 mice. Our results have demonstrated that NITD008 is potent inhibitor of ZIKV and can be used as reference inhibitor for future ZIKV antiviral drug screen and discovery.

scholarly journals Dual Inhibition of Human Rhinovirus 2A and 3C Proteases by Homophthalimides

1998 ◽  
Vol 42 (4) ◽  
pp. 916-920 ◽  
Author(s):  
Q. May Wang ◽  
Robert B. Johnson ◽  
Louis N. Jungheim ◽  
Jeffrey D. Cohen ◽  
Elcira C. Villarreal
Keyword(s):  
Antiviral Activity ◽  
Viral Replication ◽  
Enzyme Inhibitor ◽  
Antiviral Drug ◽  
3C Protease ◽  
Dependent Inhibition ◽  
Dual Inhibition ◽  
2A Protease

ABSTRACT The 2A and 3C proteases encoded by human rhinoviruses (HRVs) are attractive targets for antiviral drug development due to their important roles in viral replication. Homophthalimides were originally identified as inhibitors of rhinovirus 3C protease through our screening effort. Previous studies have indicated that the antiviral activity of certain homophthalimides exceeded their in vitro inhibitory activity against the viral 3C protease, suggesting that an additional mechanism might be involved. Reported here is the identification of homophthalimides as potent inhibitors for another rhinovirus protease, designated 2A. Several homophthalimides exhibit time-dependent inhibition of the 2A protease in the low-micromolar range, and enzyme-inhibitor complexes were identified by mass spectrometry. Compound LY343814, one of the most potent inhibitors against HRV14 2A protease, had an antiviral 50% inhibitory concentration of 4.2 μM in the cell-based assay. Our data reveal that homophthalimides are not only 3C but also 2A protease inhibitors in vitro, implying that the antiviral activity associated with these compounds might result from inactivation of both 2A and 3C proteases in vivo. Since the processing of the viral polyprotein is hierarchical, dual inhibition of the two enzymes may result in cooperative inhibition of viral replication. On the basis of the current understanding of their enzyme inhibitory mechanism, homophthalimides, as a group of novel nonpeptidic antirhinovirus agents, merit further structure-action relationship studies.

scholarly journals Illustrating and homology modeling the proteins of the Zika virus

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 275 ◽  
Author(s):  
Sean Ekins ◽  
John Liebler ◽  
Bruno J. Neves ◽  
Warren G. Lewis ◽  
Megan Coffee ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Crystal Structures ◽  
Zika Virus ◽  
Antiviral Drug ◽  
Homology Model ◽  
Glycoprotein E ◽  
Starting Point ◽  
Homology Models

The Zika virus (ZIKV) is a flavivirus of the familyFlaviviridae, which is similar to dengue virus, yellow fever and West Nile virus. Recent outbreaks in South America, Latin America, the Caribbean and in particular Brazil have led to concern for the spread of the disease and potential to cause Guillain-Barré syndrome and microcephaly. Although ZIKV has been known of for over 60 years there is very little in the way of knowledge of the virus with few publications and no crystal structures. No antivirals have been tested against it eitherin vitroorin vivo. ZIKV therefore epitomizes a neglected disease. Several suggested steps have been proposed which could be taken to initiate ZIKV antiviral drug discovery using both high throughput screens as well as structure-based design based on homology models for the key proteins. We now describe preliminary homology models created for NS5, FtsJ, NS4B, NS4A, HELICc, DEXDc, peptidase S7, NS2B, NS2A, NS1, E stem, glycoprotein M, propeptide, capsid and glycoprotein E using SWISS-MODEL. Eleven out of 15 models pass our criteria for selection. While a ZIKV glycoprotein E homology model was initially described in the immature conformation as a trimer, we now describe the mature dimer conformer which allowed the construction of an illustration of the complete virion. By comparing illustrations of ZIKV based on this new homology model and the dengue virus crystal structure we propose potential differences that could be exploited for antiviral and vaccine design. The prediction of sites for glycosylation on this protein may also be useful in this regard. While we await a cryo-EM structure of ZIKV and eventual crystal structures of the individual proteins, these homology models provide the community with a starting point for structure-based design of drugs and vaccines as well as a for computational virtual screening.

scholarly journals Antiviral activity of lycorine against Zika virus in vivo and in vitro

Virology ◽  
2020 ◽  
Vol 546 ◽  
pp. 88-97 ◽  
Author(s):  
Huini Chen ◽  
Zizhao Lao ◽  
Jiangtao Xu ◽  
Zhaoxin Li ◽  
Haishan Long ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Zika Virus

scholarly journals The citrus flavonoid naringenin impairs the in vitro infection of human cells by Zika virus

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Allan Henrique Depieri Cataneo ◽  
Diogo Kuczera ◽  
Andrea Cristine Koishi ◽  
Camila Zanluca ◽  
Guilherme Ferreira Silveira ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Zika Virus ◽  
Fruits And Vegetables ◽  
Antiviral Treatment ◽  
Clinical Manifestations ◽  
A549 Cells ◽  
Human Monocyte ◽  
Zikv Infection ◽  
Independent Manner

Abstract The Zika virus (ZIKV) is an arthropod-borne virus that belongs to the Flaviviridae family. The ZIKV infection is usually asymptomatic or is associated with mild clinical manifestations; however, increased numbers of cases of microcephaly and birth defects have been recently reported. To date, neither a vaccine nor an antiviral treatment has become available to control ZIKV replication. Among the natural compounds recognized for their medical properties, flavonoids, which can be found in fruits and vegetables, have been found to possess biological activity against a variety of viruses. Here, we demonstrate that the citrus flavanone naringenin (NAR) prevented ZIKV infection in human A549 cells in a concentration-dependent and ZIKV-lineage independent manner. NAR antiviral activity was also observed when primary human monocyte-derived dendritic cells were infected by ZIKV. NAR displayed its antiviral activity when the cells were treated after infection, suggesting that NAR acts on the viral replication or assembly of viral particles. Moreover, a molecular docking analysis suggests a potential interaction between NAR and the protease domain of the NS2B-NS3 protein of ZIKV which could explain the anti-ZIKV activity of NAR. Finally, the results support the potential of NAR as a suitable candidate molecule for developing anti-ZIKV treatments.

scholarly journals In Vitro and in Vivo Antiviral Activity of Mizoribine Against Foot-And-Mouth Disease Virus

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1723 ◽  
Author(s):  
Shi-Fang Li ◽  
Mei-Jiao Gong ◽  
Yue-Feng Sun ◽  
Jun-Jun Shao ◽  
Yong-Guang Zhang ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Early Stage ◽  
Antiviral Agents ◽  
Antiviral Drug ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Mouth Disease Virus ◽  
Foot And Mouth

Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals, which has significant economic consequences in affected countries. As the currently available vaccines against FMD provide no protection until 4–7 days post-vaccination, the only alternative method to control the spread of FMD virus (FMDV) during outbreaks is the application of antiviral agents. Hence, it is important to identify effective antiviral agents against FMDV infection. In this study, we found that mizoribine has potent antiviral activity against FMDV replication in IBRS-2 cells. A time-of-drug-addition assay demonstrated that mizoribine functions at the early stage of replication. Moreover, mizoribine also showed antiviral effect on FMDV in vivo. In summary, these results revealed that mizoribine could be a potential antiviral drug against FMDV.

scholarly journals Filociclovir Is a Potent In Vitro and In Vivo Inhibitor of Human Adenoviruses

2020 ◽  
Vol 64 (11) ◽  
Author(s):  
Karoly Toth ◽  
Islam T. M. Hussein ◽  
Ann E. Tollefson ◽  
Baoling Ying ◽  
Jacqueline F. Spencer ◽  
...  
Keyword(s):  
Body Weight ◽  
Virus Replication ◽  
Antiviral Drug ◽  
Clinical Manifestations ◽  
Body Weight Loss ◽  
Human Adenovirus ◽  
Clinical Safety ◽  
Virus Challenge

ABSTRACT Human adenovirus (HAdV) infection is common in the general population and can cause a range of clinical manifestations, among which pneumonia and keratoconjunctivitis are the most common. Although HAdV infections are mostly self-limiting, infections in immunocompromised individuals can be severe. No antiviral drug has been approved for treating adenoviruses. Filociclovir (FCV) is a nucleoside analogue which has successfully completed phase I human clinical safety studies and is now being developed for treatment of human cytomegalovirus (HCMV)-related disease in immunocompromised patients. In this report, we show that FCV is a potent broad-spectrum inhibitor of HAdV types 4 to 8, with 50% effective concentrations (EC50s) ranging between 1.24 and 3.6 μM and a 50% cytotoxic concentration (CC50) of 100 to 150 μM in human foreskin fibroblasts (HFFs). We also show that the prophylactic oral administration of FCV (10 mg/kg of body weight) 1 day prior to virus challenge and then daily for 14 days to immunosuppressed Syrian hamsters infected intravenously with HAdV6 was sufficient to prevent morbidity and mortality. FCV also mitigated tissue damage and inhibited virus replication in the liver. The 10-mg/kg dose had similar effects even when the treatment was started on day 4 after virus challenge. Furthermore, FCV administered at the same dose after intranasal challenge with HAdV6 partially mitigated body weight loss but significantly reduced pathology and virus replication in the lung. These findings suggest that FCV could potentially be developed as a pan-adenoviral inhibitor.

Design, Synthesis, and Pharmacokinetic Evaluation of O-Carbamoyl Tizoxanide Prodrugs

2020 ◽  
Vol 16 ◽  
Author(s):  
Xi He ◽  
Wenjun Hu ◽  
Fanhua Meng ◽  
Xingzhou Li
Keyword(s):  
Plasma Concentration ◽  
Broad Spectrum ◽  
Plasma Concentrations ◽  
Antiviral Drug ◽  
Systemic Exposure ◽  
Pharmacokinetic Profile ◽  
Hydroxyl Group ◽  
First Pass

Background: The broad-spectrum antiparasitic drug nitazoxanide (N) has been repositioned as a broad-spectrum antiviral drug. Nitazoxanide’s in vivo antiviral activities are mainly attributed to its metabolitetizoxanide, the deacetylation product of nitazoxanide. In reference to the pharmacokinetic profile of nitazoxanide, we proposed the hypotheses that the low plasma concentrations and the low system exposure of tizoxanide after dosing with nitazoxanide result from significant first pass effects in the liver. It was thought that this may be due to the unstable acyloxy bond of nitazoxanide. Objective: Tizoxanide prodrugs, with the more stable formamyl substituent attached to the hydroxyl group rather than the acetyl group of nitazoxanide, were designed with the thought that they might be more stable in plasma. It was anticipated that these prodrugs might be less affected by the first pass effect, which would improve plasma concentrations and system exposure of tizoxanide. Method: These O-carbamoyl tizoxanide prodrugs were synthesized and evaluated in a mouse model for pharmacokinetic (PK) properties and in an in vitro model for plasma stabilities. Results: The results indicated that the plasma concentration and the systemic exposure of tizoxanide (T) after oral administration of O-carbamoyl tizoxanide prodrugs were much greater than that produced by equimolar dosage of nitazoxanide. It was also found that the plasma concentration and the systemic exposure of tizoxanide glucuronide (TG) were much lower than that produced by nitazoxanide. Conclusion: Further analysis showed that the suitable plasma stability of O-carbamoyl tizoxanide prodrugs is the key factor in maximizing the plasma concentration and the systemic exposure of the active ingredient tizoxanide.

scholarly journals Pan-American Lancehead Pit-Vipers: Coagulotoxic Venom Effects and Antivenom Neutralisation of Bothrops asper and B. atrox Geographical Variants

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 78
Author(s):  
Lachlan A. Bourke ◽  
Christina N. Zdenek ◽  
Edgar Neri-Castro ◽  
Melisa Bénard-Valle ◽  
Alejandro Alagón ◽  
...  
Keyword(s):  
Evolutionary Biology ◽  
Current Knowledge ◽  
Clinical Manifestations ◽  
In Vivo Studies ◽  
Factor X ◽  
Clotting Factors ◽  
Bothrops Asper ◽  
Species Specific

The toxin composition of snake venoms and, thus, their functional activity, can vary between and within species. Intraspecific venom variation across a species’ geographic range is a major concern for antivenom treatment of envenomations, particularly for countries like French Guiana that lack a locally produced antivenom. Bothrops asper and Bothrops atrox are the most medically significant species of snakes in Latin America, both producing a variety of clinical manifestations, including systemic bleeding. These pathophysiological actions are due to the activation by the venom of the blood clotting factors Factor X and prothrombin, thereby causing severe consumptive coagulopathy. Both species are extremely wide-ranging, and previous studies have shown their venoms to exhibit regional venom variation. In this study, we investigate the differential coagulotoxic effects on human plasma of six venoms (four B. asper and two B. atrox samples) from different geographic locations, spanning from Mexico to Peru. We assessed how the venom variation of these venom samples affects neutralisation by five regionally available antivenoms: Antivipmyn, Antivipmyn-Tri, PoliVal-ICP, Bothrofav, and Soro Antibotrópico (SAB). The results revealed both inter- and intraspecific variations in the clotting activity of the venoms. These variations in turn resulted in significant variation in antivenom efficacy against the coagulotoxic effects of these venoms. Due to variations in the venoms used in the antivenom production process, antivenoms differed in their species-specific or geographical neutralisation capacity. Some antivenoms (PoliVal-ICP, Bothrofav, and SAB) showed species-specific patterns of neutralisation, while another antivenom (Antivipmyn) showed geographic-specific patterns of neutralisation. This study adds to current knowledge of Bothrops venoms and also illustrates the importance of considering evolutionary biology when developing antivenoms. Therefore, these results have tangible, real-world implications by aiding evidence-based design of antivenoms for treatment of the envenomed patient. We stress that these in vitro studies must be backed by future in vivo studies and clinical trials before therapeutic guidelines are issued regarding specific antivenom use in a clinical setting.

scholarly journals A Biochemical and Pharmacological Characterization of Phospholipase A2 and Metalloproteinase Fractions from Eastern Russell’s Viper (Daboia siamensis) Venom: Two Major Components Associated with Acute Kidney Injury

Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 521
Author(s):  
Janeyuth Chaisakul ◽  
Orawan Khow ◽  
Kulachet Wiwatwarayos ◽  
Muhamad Rusdi Ahmad Rusmili ◽  
Watcharamon Prasert ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Phospholipase A2 ◽  
Protein Identification ◽  
Clinical Manifestations ◽  
Kidney Injury ◽  
Factor X ◽  
Pharmacological Characterization ◽  
Russell’S Viper

Acute kidney injury (AKI) following Eastern Russell’s viper (Daboia siamensis) envenoming is a significant symptom in systemically envenomed victims. A number of venom components have been identified as causing the nephrotoxicity which leads to AKI. However, the precise mechanism of nephrotoxicity caused by these toxins is still unclear. In the present study, we purified two proteins from D. siamensis venom, namely RvPLA2 and RvMP. Protein identification using LCMS/MS confirmed the identity of RvPLA2 to be snake venom phospholipase A2 (SVPLA2) from Thai D. siamensis venom, whereas RvMP exhibited the presence of a factor X activator with two subunits. In vitro and in vivo pharmacological studies demonstrated myotoxicity and histopathological changes of kidney, heart, and spleen. RvPLA2 (3–10 µg/mL) caused inhibition of direct twitches of the chick biventer cervicis muscle preparation. After administration of RvPLA2 or RvMP (300 µg/kg, i.p.) for 24 h, diffuse glomerular congestion and tubular injury with minor loss of brush border were detected in envenomed mice. RvPLA2 and RvMP (300 µg/kg; i.p.) also induced congestion and tissue inflammation of heart muscle as well as diffuse congestion of mouse spleen. This study showed the significant roles of PLA2 and SVMP in snake bite envenoming caused by Thai D. siamensis and their similarities with observed clinical manifestations in envenomed victims. This study also indicated that there is a need to reevaluate the current treatment strategies for Thai D. siamensis envenoming, given the potential for irreversible nephrotoxicity.

Antiviral activity of Mulberroside C against enterovirus A71 in vitro and in vivo

2021 ◽  
pp. 174204
Author(s):  
Yiming Cao ◽  
En Lei ◽  
Lei Li ◽  
Jin Ren ◽  
Xiaoyang He ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Enterovirus A71
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