scholarly journals Antiviral Activity and Underlying Action Mechanism of Euglena Extract against Influenza Virus

Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 3911
Author(s):  
Ayaka Nakashima ◽  
Yuka Horio ◽  
Kengo Suzuki ◽  
Yuji Isegawa
Keyword(s):  
Influenza Virus ◽  
Antiviral Activity ◽  
Defense Mechanisms ◽  
Mdck Cells ◽  
Influenza Virus Infection ◽  
Virus Titer ◽  
Prolonged Treatment ◽  
Action Mechanism ◽  
Cell Defense ◽  
Infected Cells

It is difficult to match annual vaccines against the exact influenza strain that is spreading in any given flu season. Owing to the emergence of drug-resistant viral strains, new approaches for treating influenza are needed. Euglena gracilis (hereinafter Euglena), microalga, used as functional foods and supplements, have been shown to alleviate symptoms of influenza virus infection in mice. However, the mechanism underlying the inhibitory action of microalgae against the influenza virus is unknown. Here, we aimed to study the antiviral activity of Euglena extract against the influenza virus and the underlying action mechanism using Madin–Darby canine kidney (MDCK) cells. Euglena extract strongly inhibited infection by all influenza virus strains examined, including those resistant to the anti-influenza drugs oseltamivir and amantadine. A time-of-addition assay revealed that Euglena extract did not affect the cycle of virus replication, and cell pretreatment or prolonged treatment of infected cells reduced the virus titer. Thus, Euglena extract may activate the host cell defense mechanisms, rather than directly acting on the influenza virus. Moreover, various minerals, mainly zinc, in Euglena extract were found to be involved in the antiviral activity of the extract. In conclusion, Euglena extract could be a potent agent for preventing and treating influenza.

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

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.

scholarly journals Ultrastructural Aspects of Photodynamic Inactivation of Highly Pathogenic Avian H5N8 Influenza Virus

Viruses ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 955 ◽  
Author(s):  
Korneev ◽  
Kurskaya ◽  
Sharshov ◽  
Eastwood ◽  
Strakhovskaya
Keyword(s):  
Influenza Virus ◽  
Lipid Membranes ◽  
Structural Integrity ◽  
Mdck Cells ◽  
Virus Titer ◽  
Surface Protein ◽  
Zinc Phthalocyanine ◽  
Photodynamic Inactivation ◽  
Photodynamic Treatment ◽  
Ultrastructural Studies

Ultrastructural studies revealing morphological differences between intact and photodynamically inactivated virions can point to inactivation mechanisms and molecular targets. Using influenza as a model system, we show that photodynamic virus inactivation is possible without total virion destruction. Indeed, irradiation with a relatively low concentration of the photosensitizer (octacationic octakis(cholinyl) zinc phthalocyanine) inactivated viral particles (the virus titer was determined in Madin Darby Canine Kidney (MDCK) cells) but did not destroy them. Transmission electron microscopy (TEM) revealed that virion membranes kept structural integrity but lost their surface glycoproteins. Such structures are known as “bald” virions, which were first described as a result of protease treatment. At a higher photosensitizer concentration, the lipid membranes were also destroyed. Therefore, photodynamic inactivation of influenza virus initially results from surface protein removal, followed by complete virion destruction. This study suggests that photodynamic treatment can be used to manufacture “bald” virions for experimental purposes. Photodynamic inactivation is based on the production of reactive oxygen species which attack and destroy biomolecules. Thus, the results of this study can potentially apply to other enveloped viruses and sources of singlet oxygen.

scholarly journals Caffeoylquinic Acids Are Major Constituents with Potent Anti-Influenza Effects in Brazilian Green Propolis Water Extract

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Tomohiko Urushisaki ◽  
Tomoaki Takemura ◽  
Shigemi Tazawa ◽  
Mayuko Fukuoka ◽  
Junji Hosokawa-Muto ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Viral Infections ◽  
Influenza Virus Infection ◽  
Water Extract ◽  
H1n1 Influenza ◽  
Caffeoylquinic Acids ◽  
Cytoprotective Activity ◽  
Infected Cells ◽  
Brazilian Green Propolis

Influenza A viral infections reached pandemic levels in 1918, 1957, 1968, and, most recently, in 2009 with the emergence of the swine-origin H1N1 influenza virus. The development of novel therapeutics or prophylactics for influenza virus infection is urgently needed. We examined the evaluation of the anti-influenza virus (A/WSN/33 (H1N1)) activity of Brazilian green propolis water extract (PWE) and its constituents by cell viability and real-time PCR assays. Our findings showed strong evidence that PWE has an anti-influenza effect and demonstrate that caffeoylquinic acids are the active anti-influenza components of PWE. Furthermore, we have found that the amount of viral RNA per cell remained unchanged even in the presence of PWE, suggesting that PWE has no direct impact on the influenza virus but may have a cytoprotective activity by affecting internal cellular process. These findings indicate that caffeoylquinic acids are the active anti-influenza components of PWE. Above findings might facilitate the prophylactic application of natural products and the realization of novel anti-influenza drugs based on caffeoylquinic acids, as well as further the understanding of cytoprotective intracellular mechanisms in influenza virus-infected cells.

scholarly journals Mouse Saliva Inhibits Transit of Influenza Virus to the Lower Respiratory Tract by Efficiently Blocking Influenza Virus Neuraminidase Activity

2017 ◽  
Vol 91 (14) ◽  
Author(s):  
Brad Gilbertson ◽  
Wy Ching Ng ◽  
Simon Crawford ◽  
Jenny L. McKimm-Breschkin ◽  
Lorena E. Brown
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Respiratory Tract ◽  
Active Site ◽  
Lower Respiratory Tract ◽  
Mdck Cells ◽  
Influenza Virus Infection ◽  
Natural Form ◽  
Influenza Virus Neuraminidase

ABSTRACT We previously identified a novel inhibitor of influenza virus in mouse saliva that halts the progression of susceptible viruses from the upper to the lower respiratory tract of mice in vivo and neutralizes viral infectivity in MDCK cells. Here, we investigated the viral target of the salivary inhibitor by using reverse genetics to create hybrid viruses with some surface proteins derived from an inhibitor-sensitive strain and others from an inhibitor-resistant strain. These viruses demonstrated that the origin of the viral neuraminidase (NA), but not the hemagglutinin or matrix protein, was the determinant of susceptibility to the inhibitor. Comparison of the NA sequences of a panel of H3N2 viruses with differing sensitivities to the salivary inhibitor revealed that surface residues 368 to 370 (N2 numbering) outside the active site played a key role in resistance. Resistant viruses contained an EDS motif at this location, and mutation to either EES or KDS, found in highly susceptible strains, significantly increased in vitro susceptibility to the inhibitor and reduced the ability of the virus to progress to the lungs when the viral inoculum was initially confined to the upper respiratory tract. In the presence of saliva, viral strains with a susceptible NA could not be efficiently released from the surfaces of infected MDCK cells and had reduced enzymatic activity based on their ability to cleave substrate in vitro. This work indicates that the mouse has evolved an innate inhibitor similar in function, though not in mechanism, to what humans have created synthetically as an antiviral drug for influenza virus. IMPORTANCE Despite widespread use of experimental pulmonary infection of the laboratory mouse to study influenza virus infection and pathogenesis, to our knowledge, mice do not naturally succumb to influenza. Here, we show that mice produce their own natural form of neuraminidase inhibitor in saliva that stops the virus from reaching the lungs, providing a possible mechanism through which the species may not experience severe influenza virus infection in the wild. We show that the murine salivary inhibitor targets the outer surface of the influenza virus neuraminidase, possibly occluding entry to the enzymatic site rather than binding within the active site like commercially available neuraminidase inhibitors. This knowledge sheds light on how the natural inhibitors of particular species combat infection.

Influence of trifluoperazine on the late stage of influenza virus infection in MDCK cells

1991 ◽  
Vol 15 (2) ◽  
pp. 149-160 ◽  
Author(s):  
Hiroshi Ochiai ◽  
Masahiko Kurokawa ◽  
Seihachiro Niwayama
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Late Stage ◽  
Mdck Cells ◽  
Influenza Virus Infection

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

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.

Effect of anaferon for children on the life cycle of influenza virus A/H1N1

2018 ◽  
pp. 87-94
Author(s):  
А.Г. Емельянова ◽  
М.В. Никифорова ◽  
Е.С. Дон ◽  
Н.Р. Махмудова ◽  
И.Н. Фалынскова ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Life Cycle ◽  
Antiviral Activity ◽  
Influenza A ◽  
Mdck Cells ◽  
Antiviral Effect ◽  
H1n1 Influenza ◽  
Dose Dependence ◽  
Influenza Virus A

Цель исследования - изучение возможного прямого влияния препарата «Анаферон детский» на жизненный цикл вируса гриппа А в процессе развития инфекции, а также дозозависимости противовирусного эффекта in vitro . Методика. Исследование противовирусной активности препарата «Анаферон детский» in vitro было проведено с использованием культуры клеток MDCK (Madin Darby canine kidney) и эталонных штаммов вируса гриппа A (H1N1) pdm09: A/California/07/09 и А/California/04/09, полученных от ВОЗ. Использовались методы оценки подавления Анафероном детским вирусной репликации (по результатам иммуноферментного анализа по определению экспрессии внутренних белков NP и M1 вируса гриппа А) и его влияние на ультраструктурные особенности морфогенеза вируса гриппа методом электронной микроскопии. В качестве положительного контроля был использован Озельтамивир карбоксилат в концентрации 10 мкМ. Для мониторинга валидности экспериментальной модели в работе использовали клетки, зараженные вирусом без добавления экспериментальных образцов (контроль вируса), а также интактные клетки (клеточный контроль). Результаты. В ходе исследования показан дозозависимый противовирусный эффект препарата «Анаферон детский» для 3 тестируемых разведений - 1/8, 1/12, 1/16. Методом электронной микроскопии показано, что применение препарата «Анаферон детский» при сравнении с контрольным образцом влияло на процесс почкования вирионов. Заключение. Впервые показана дозозависимость противовирусного действия препарата «Анаферон детский», а также подтверждена его эффективность в отношении двух штаммов вируса пандемического гриппа А/H1N1. Документировано, что применение препарата «Анаферон детский» нарушает жизненный цикл вируса гриппа А. Механизмы развития такого эффекта требуют дополнительного изучения, однако можно предположить их связь с ИФН-индуцирующими свойствами препарата «Анаферон детский», так как было показано, что в начале лечения вирусной инфекции препарат вызывает индукцию синтеза белков системы интерферонов. The aim of this study was to evaluate a possible direct effect of Anaferon for Children on the life cycle of influenza A virus during infection development and a dose response of the antiviral effect in vitro. Methods. The in vitro antiviral activity of Anaferon for Children was studied on cultured MDCK cells and reference strains of influenza virus A (H1N1) pdm09: A/California/07/09 and A/California/04/09, both from the WHO. Inhibition of viral replication by Anaferon for Children and its effect on ultrastructural features of the influenza morphogenesis were evaluated using electron microscopy. Results. The study demonstrated a dose dependence of Anaferon for Children antiviral activity for three dilutions - 1/8, 1/12, and 1/16. Anaferon for Children affected the process of virion budding as compared to placebo. Conclusion. The study showed that the anti-influenza action of Anaferon for Children was dose-dependent and confirmed that this drug was effective against two strains of pandemic A/H1N1 influenza. Furthermore, Anaferon for children disrupted one or several stages of the virus life cycle.

scholarly journals In Vitro System for Modeling Influenza A Virus Resistance under Drug Pressure

2010 ◽  
Vol 54 (8) ◽  
pp. 3442-3450 ◽  
Author(s):  
Ashley N. Brown ◽  
James J. McSharry ◽  
Qingmei Weng ◽  
Elizabeth M. Driebe ◽  
David M. Engelthaler ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A Virus ◽  
Virus Replication ◽  
Influenza A ◽  
Mdck Cells ◽  
Influenza Virus Infection ◽  
Infection Model ◽  
Virus Infections ◽  
Drug Pressure

ABSTRACT One of the biggest challenges in the effort to treat and contain influenza A virus infections is the emergence of resistance during treatment. It is well documented that resistance to amantadine arises rapidly during the course of treatment due to mutations in the gene coding for the M2 protein. To address this problem, it is critical to develop experimental systems that can accurately model the selection of resistance under drug pressure as seen in humans. We used the hollow-fiber infection model (HFIM) system to examine the effect of amantadine on the replication of influenza virus, A/Albany/1/98 (H3N2), grown in MDCK cells. At 24 and 48 h postinfection, virus replication was inhibited in a dose-dependent fashion. At 72 and 96 h postinfection, virus replication was no longer inhibited, suggesting the emergence of amantadine-resistant virus. Sequencing of the M2 gene revealed that mutations appeared at between 48 and 72 h of drug treatment and that the mutations were identical to those identified in the clinic for amantadine-resistant viruses (e.g., V27A, A30T, and S31N). Interestingly, we found that the type of mutation was strongly affected by the dose of the drug. The data suggest that the HFIM is a good model for influenza virus infection and resistance generation in humans. The HFIM has the advantage of being a highly controlled system where multiplicity parameters can be directly and accurately controlled and measured.

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