Utilization of pulse oximetry for the study of the inhibitory effects of antiviral agents on influenza virus in mice.

ABSTRACT The cyclopentane influenza virus neuraminidase inhibitor RWJ-270201 was evaluated against influenza A/NWS/33 (H1N1), A/Shangdong/09/93 (H3N2), A/Victoria/3/75 (H3N2), and B/Hong Kong/05/72 virus infections in mice. Treatment was by oral gavage twice daily for 5 days beginning 4 h pre-virus exposure. The influenza virus inhibitor oseltamivir was run in parallel, and ribavirin was included in studies with the A/Shangdong and B/Hong Kong viruses. RWJ-270201 was inhibitory to all infections using doses as low as 1 mg/kg/day. Oseltamivir was generally up to 10-fold less effective than RWJ-270201. Ribavirin was also inhibitory but was less tolerated by the mice at the 75-mg/kg/day dose used. Disease-inhibitory effects included prevention of death, lessening of decline of arterial oxygen saturation, inhibition of lung consolidation, and reduction in lung virus titers. RWJ-270201 and oseltamivir, at doses of 10 and 1 mg/kg/day each, were compared with regard to their effects on daily lung parameters in influenza A/Shangdong/09/93 virus-infected mice. Maximum virus titer inhibition was seen on day 1, with RWJ-270201 exhibiting the greater inhibitory effect, a titer reduction of >104 cell culture 50% infective doses (CCID50)/g. By day 8, the lung virus titers in mice treated with RWJ-270201 had declined to 101.2 CCID50/g, whereas titers from oseltamivir-treated animals were >103CCID50/g. Mean lung consolidation was also higher in the oseltamivir-treated animals on day 8. Both neuraminidase inhibitors were well tolerated by the mice. RWJ-270201 was nontoxic at doses as high as 1,000 mg/kg/day. These data indicate potential for the oral use of RWJ-270201 in the treatment of influenza virus infections in humans.

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Identification and Evaluation of Potential SARS-CoV-2 Antiviral Agents Targeting mRNA Cap Guanine N7-Methyltransferase

10.26434/chemrxiv.14484933.v1 ◽

2021 ◽

Author(s):

Renata Kasprzyk ◽

Tomasz J. Spiewla ◽

miroslaw smietanski ◽

Sebastian Golojuch ◽

Laura Vangeel ◽

...

Keyword(s):

Antiviral Agents ◽

Therapeutic Interventions ◽

Binding Assays ◽

Inhibitory Effects ◽

Dot Blot ◽

Rp Hplc ◽

Structure Activity ◽

Mrna Capping ◽

New Ideas ◽

A Cell

SARS-CoV-2, the cause of the currently ongoing COVID-19 pandemic, encodes its own mRNA capping machinery. Insights into this capping system may provide new ideas for therapeutic interventions and drug discovery. In this work, we employ a previously developed Py-FLINT screening approach to study the inhibitory effects of compounds against the cap guanine N7-methyltransferase enzyme, which is involved in SARS-CoV-2 mRNA capping. We screened five commercially available libraries (7039 compounds in total) to identify 83 inhibitors with IC50 < 50 μM, which were further validated using RP HPLC and dot blot assays. Novel fluorescence anisotropy binding assays were developed to examine the targeted binding site. The inhibitor structures were analyzed for structure-activity relationships in order to define common structural patterns. Finally, the most potent inhibitors were tested for antiviral activity on SARS-CoV-2 in a cell based assay<br>

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Screening and Purification of NanB Sialidase From Pasteurella Multocida With Activity in Hydrolyzing Sialic Acid Neu5Acα(2-6)Gal

10.21203/rs.3.rs-810816/v2 ◽

2021 ◽

Author(s):

Christian Marco Hadi Nugroho ◽

Ryan Septa Kurnia ◽

Simson Tarigan ◽

Otto Sahat Martua Silaen ◽

Silvia Tri Widyaningtyas ◽

...

Keyword(s):

Influenza Virus ◽

Antiviral Activity ◽

Red Blood Cells ◽

Blood Cells ◽

In Silico ◽

Pasteurella Multocida ◽

Antiviral Agents ◽

Influenza Virus Infection ◽

Ligand Complex ◽

In Silico Studies

Abstract Study on sialidases as antiviral agents has been widely performed, but many types of sialidase had not been tested for their antiviral activity. One of such sialidase is the NanB sialidase of Pasteurella multocida, which has never been isolated for further study. In this study, the activity of NanB sialidase was investigated in silico by docking the NanB sialidase of Pasteurella multocida to the Neu5Acα(2-6)Gal ligand. Additionally, some local isolates of Pasteurella multocida, which had the NanB gene were screened, and the proteins were isolated for further testing regarding their activity in hydrolyzing Neu5Acα(2-6)Gal. In silico studies showed that the NanB sialidase possesses an exceptional affinity towards forming a protein-ligand complex with Neu5Acα(2-6)Gal. This was further confirmed by showing that a dose of 0.258 U/ml (100%) NanB sialidase of Pasteurella multocida B018 can hydrolyze up to 44.28% of Neu5Acα(2-6)Gal in chicken red blood cells and 81.95% in rabbit red blood cells. This study suggested that the NanB sialidase of Pasteurella multocida B018 has a potent antiviral activity that can inhibit avian influenza virus infection.

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Man-Specific, GalNAc/T/Tn-Specific and Neu5Ac-Specific Seaweed Lectins as Glycan Probes for the SARS-CoV-2 (COVID-19) Coronavirus

Marine Drugs ◽

10.3390/md18110543 ◽

2020 ◽

Vol 18 (11) ◽

pp. 543

Author(s):

Annick Barre ◽

Els J.M. Van Damme ◽

Mathias Simplicien ◽

Hervé Benoist ◽

Pierre Rougé

Keyword(s):

Influenza Virus ◽

Antiviral Agents ◽

Host Cells ◽

Carbohydrate Binding ◽

Complex Type ◽

Enveloped Viruses ◽

High Mannose ◽

Hiv 1 ◽

Biomedical Interest

Seaweed lectins, especially high-mannose-specific lectins from red algae, have been identified as potential antiviral agents that are capable of blocking the replication of various enveloped viruses like influenza virus, herpes virus, and HIV-1 in vitro. Their antiviral activity depends on the recognition of glycoprotein receptors on the surface of sensitive host cells—in particular, hemagglutinin for influenza virus or gp120 for HIV-1, which in turn triggers fusion events, allowing the entry of the viral genome into the cells and its subsequent replication. The diversity of glycans present on the S-glycoproteins forming the spikes covering the SARS-CoV-2 envelope, essentially complex type N-glycans and high-mannose type N-glycans, suggests that high-mannose-specific seaweed lectins are particularly well adapted as glycan probes for coronaviruses. This review presents a detailed study of the carbohydrate-binding specificity of high-mannose-specific seaweed lectins, demonstrating their potential to be used as specific glycan probes for coronaviruses, as well as the biomedical interest for both the detection and immobilization of SARS-CoV-2 to avoid shedding of the virus into the environment. The use of these seaweed lectins as replication blockers for SARS-CoV-2 is also discussed.

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Recombinant Green Fluorescent Protein-Expressing Human Cytomegalovirus as a Tool for Screening Antiviral Agents

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.44.6.1588-1597.2000 ◽

2000 ◽

Vol 44 (6) ◽

pp. 1588-1597 ◽

Cited By ~ 101

Author(s):

Manfred Marschall ◽

Martina Freitag ◽

Sigrid Weiler ◽

Gabriele Sorg ◽

Thomas Stamminger

Keyword(s):

Green Fluorescent Protein ◽

Human Cytomegalovirus ◽

Fluorescent Protein ◽

Antiviral Agents ◽

Inhibitory Effects ◽

Plaque Reduction Assay ◽

Human Fibroblast Cultures ◽

Antiviral Activities ◽

Green Fluorescent

ABSTRACT A recombinant human cytomegalovirus (AD169-GFP) expressing green fluorescent protein was generated by homologous recombination. Infection of human fibroblast cultures with AD169-GFP virus produced stable and readily detectable amounts of GFP signals which were quantitated by automated fluorometry. Hereby, high levels of sensitivity and reproducibility could be achieved, compared to those with the conventional plaque reduction assay. Antiviral activities were determined for four reference compounds as well as a set of putative novel cytomegalovirus inhibitors. The results obtained were exactly in line with the known characteristics of reference compounds and furthermore revealed distinct antiviral activities of novel in vitro inhibitors. The fluorometric data could be confirmed by GFP-based flow cytometry and fluorescence microscopy. In addition, laboratory virus variants derived from the recombinant AD169-GFP virus provided further possibilities for study of the characteristics of drug resistance. The GFP-based antiviral assay appeared to be very reliable for measuring virus-inhibitory effects in concentration- and time-dependent fashions and might also be adaptable for high-throughput screenings of cytomegalovirus-specific antiviral agents.

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Inhibitory Effects of Amentoflavone and Orobol on Daclatasvir-Induced Resistance-Associated Variants of Hepatitis C Virus

The American Journal of Chinese Medicine ◽

10.1142/s0192415x18500441 ◽

2018 ◽

Vol 46 (04) ◽

pp. 835-852 ◽

Cited By ~ 5

Author(s):

Wei-Ping Lee ◽

Keng-Li Lan ◽

Shi-Xian Liao ◽

Yi-Hsiang Huang ◽

Ming-Chih Hou ◽

...

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

Viral Entry ◽

Antiviral Agents ◽

Cost Effective ◽

Pegylated Interferon ◽

Chinese Herbs ◽

Inhibitory Effects ◽

Direct Acting Antiviral ◽

Direct Acting

Hepatitis C virus (HCV) is recognized as a major causative agent of chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Despite rapid progress in the development of direct-acting antivirals (DAA) against HCV infection in recent years, cost-effective antiviral drugs with more affordable prices still need to be developed. In this study, we screened a library of natural compounds to identify natural HCV inhibitors. The library of the pure compounds extracted from Chinese herbs deposited in the chemical bank of National Research Institute of Chinese Medicine (NRICM), Taiwan was screened in the cell culture-derived HCV (HCVcc) system. We identified the flavone or flavan-based compounds amentoflavone, 7,4[Formula: see text]-dihydroxyflavanone, and orobol with the inhibition of viral entry, replication, and translation of the HCV life cycle. Amentoflavone and orobol also showed inhibitory effects on resistant-associated variants to the NS5A inhibitor daclatasvir. The results of this study have the potential to benefit patients who are intolerant to the adverse effect of pegylated interferon or who harbor resistant strains refractory to treatment by current direct-acting antiviral agents.

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Comparative Inhibitory Effects of Various Nucleoside and Nonnucleoside Analogues on Replication of Influenza Virus Types A and B In Vitro and In Ovo

The Journal of Infectious Diseases ◽

10.1093/infdis/168.3.641 ◽

1993 ◽

Vol 168 (3) ◽

pp. 641-646 ◽

Cited By ~ 30

Author(s):

M. Hosoya ◽

S. Shigeta ◽

T. Ishii ◽

H. Suzuki ◽

E. D. Clercq

Keyword(s):

Influenza Virus ◽

Inhibitory Effects ◽

In Ovo

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Inhibitory effects of carbocisteine on type A seasonal influenza virus infection in human airway epithelial cells

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00376.2009 ◽

2010 ◽

Vol 299 (2) ◽

pp. L160-L168 ◽

Cited By ~ 11

Author(s):

Mutsuo Yamaya ◽

Hidekazu Nishimura ◽

Kyoko Shinya ◽

Yukimasa Hatachi ◽

Takahiko Sasaki ◽

...

Keyword(s):

Influenza Virus ◽

Epithelial Cells ◽

Virus Infection ◽

Seasonal Influenza ◽

Influenza Virus Infection ◽

Airway Epithelial Cells ◽

Airway Epithelial ◽

Human Influenza ◽

Inhibitory Effects ◽

Human Influenza Virus

Type A human seasonal influenza (FluA) virus infection causes exacerbations of bronchial asthma and chronic obstructive pulmonary disease (COPD). l-carbocisteine, a mucolytic agent, reduces the frequency of common colds and exacerbations in COPD. However, the inhibitory effects of l-carbocisteine on FluA virus infection are uncertain. We studied the effects of l-carbocisteine on FluA virus infection in airway epithelial cells. Human tracheal epithelial cells were pretreated with l-carbocisteine and infected with FluA virus (H3N2). Viral titers in supernatant fluids, RNA of FluA virus in the cells, and concentrations of proinflammatory cytokines in supernatant fluids, including IL-6, increased with time after infection. l-carbocisteine reduced viral titers in supernatant fluids, RNA of FluA virus in the cells, the susceptibility to FluA virus infection, and concentrations of cytokines induced by virus infection. The epithelial cells expressed sialic acid with an α2,6-linkage (SAα2,6Gal), a receptor for human influenza virus on the cells, and l-carbocisteine reduced the expression of SAα2,6Gal. l-carbocisteine reduced the number of acidic endosomes from which FluA viral RNA enters into the cytoplasm and reduced the fluorescence intensity from acidic endosomes. Furthermore, l-carbocisteine reduced NF-κB proteins including p50 and p65 in the nuclear extracts of the cells. These findings suggest that l-carbocisteine may inhibit FluA virus infection, partly through the reduced expression of the receptor for human influenza virus in the human airway epithelial cells via the inhibition of NF-κB and through increasing pH in endosomes. l-carbocisteine may reduce airway inflammation in influenza virus infection.

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Screening and Purification of NanB Sialidase from Pasteurella Multocida with Activity in Hydrolyzing Sialic Acid Neu5Acα(2-6)Gal

10.21203/rs.3.rs-810816/v1 ◽

2021 ◽

Author(s):

Christian Marco Hadi Nugroho ◽

Ryan Septa Kurnia ◽

Simson Tarigan ◽

Otto Sahat Martua Silaen ◽

Silvia Tri Widyaningtyas ◽

...

Keyword(s):

Influenza Virus ◽

Antiviral Activity ◽

Red Blood Cells ◽

Blood Cells ◽

In Silico ◽

Pasteurella Multocida ◽

Antiviral Agents ◽

Influenza Virus Infection ◽

Ligand Complex ◽

In Silico Studies

Abstract Study on sialidases as antiviral agents has been widely performed, but many types of sialidase had not been tested for their antiviral activity. One of such sialidase is the NanB sialidase of Pasteurella multocida, which has never been isolated for further study. In this study, the activity of NanB sialidase was investigated in silico by docking the NanB sialidase of Pasteurella multocida to the Neu5Acα(2-6)Gal ligand. Additionally, some local isolates of Pasteurella multocida, which had the NanB gene were screened, and the proteins were isolated for further testing regarding their activity in hydrolyzing Neu5Acα(2-6)Gal. In silico studies showed that the NanB sialidase possesses an exceptional affinity towards forming a protein-ligand complex with Neu5Acα(2-6)Gal. This was further confirmed by showing that a dose of 0.258 U/ml (100%) NanB sialidase of Pasteurella multocida B018 can hydrolyze up to 44.28% of Neu5Acα(2-6)Gal in chicken red blood cells and 81.95% in rabbit red blood cells. This study suggested that the NanB sialidase of Pasteurella multocida B018 has a potent antiviral activity that can inhibit avian influenza virus infection.

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