In vitro virucidal activity of Echinaforce®, an Echinacea purpurea preparation, against coronaviruses, including common cold coronavirus 229E and SARS-CoV-2

Abstract Background Coronaviruses (CoVs) were long thought to only cause mild respiratory and gastrointestinal symptoms in humans but outbreaks of Middle East Respiratory Syndrome (MERS)-CoV, Severe Acute Respiratory Syndrome (SARS)-CoV-1, and the recently identified SARS-CoV-2 have cemented their zoonotic potential and their capacity to cause serious morbidity and mortality, with case fatality rates ranging from 4 to 35%. Currently, no specific prophylaxis or treatment is available for CoV infections. Therefore we investigated the virucidal and antiviral potential of Echinacea purpurea (Echinaforce®) against human coronavirus (HCoV) 229E, highly pathogenic MERS- and SARS-CoVs, as well as the newly identified SARS-CoV-2, in vitro. Methods To evaluate the antiviral potential of the extract, we pre-treated virus particles and cells and evaluated remaining infectivity by limited dilution. Furthermore, we exposed cells to the extract after infection to further evaluate its potential as a prophylaxis and treatment against coronaviruses. We also determined the protective effect of Echinaforce® in re-constituted nasal epithelium. Results In the current study, we found that HCoV-229E was irreversibly inactivated when exposed to Echinaforce® at 3.2 μg/ml IC50. Pre-treatment of cell lines, however, did not inhibit infection with HCoV-229E and post-infection treatment had only a marginal effect on virus propagation at 50 μg/ml. However, we did observe a protective effect in an organotypic respiratory cell culture system by exposing pre-treated respiratory epithelium to droplets of HCoV-229E, imitating a natural infection. The observed virucidal activity of Echinaforce® was not restricted to common cold coronaviruses, as both SARS-CoV-1 and MERS-CoVs were inactivated at comparable concentrations. Finally, the causative agent of COVID-19, SARS-CoV-2 was also inactivated upon treatment with 50μg/ml Echinaforce®. Conclusions These results show that Echinaforce® is virucidal against HCoV-229E, upon direct contact and in an organotypic cell culture model. Furthermore, MERS-CoV and both SARS-CoV-1 and SARS-CoV-2 were inactivated at similar concentrations of the extract. Therefore we hypothesize that Echinacea purpurea preparations, such as Echinaforce®, could be effective as prophylactic treatment for all CoVs due to their structural similarities.

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In vitro virucidal activity of Echinaforce®, an Echinacea purpurea preparation, against coronaviruses, including common cold coronavirus 229E and SARS-CoV-2

10.21203/rs.2.24724/v3 ◽

2020 ◽

Author(s):

Johanna Signer ◽

Hulda R. Jonsdottir ◽

Werner C. Albrich ◽

Marc Strasser ◽

Roland Züst ◽

...

Keyword(s):

Cell Culture ◽

Protective Effect ◽

Common Cold ◽

Natural Infection ◽

Gastrointestinal Symptoms ◽

Case Fatality ◽

Echinacea Purpurea ◽

Marginal Effect ◽

Virucidal Activity

Abstract Background: Coronaviruses (CoVs) were long thought to only cause mild respiratory and gastrointestinal symptoms in humans but outbreaks of Middle Eastern Respiratory Syndrome (MERS)-CoV, Severe Acute Respiratory Syndrome (SARS)-CoV, and the recently identified SARS-CoV-2 have cemented their zoonotic potential and their capacity to cause serious morbidity and mortality, with case fatality rates ranging from 4 to 35%. Currently, no specific prophylaxis or treatment is available for CoV infections.Therefore we investigated the virucidal and antiviral potential of Echinacea purpurea (Echinaforce®) against human coronavirus (HCoV) 229E, highly pathogenic MERS- and SARS-CoVs, as well as the newly identified SARS-CoV-2, in vitro.Methods: To evaluate the antiviral potential of the extract we pre-treated virus particles and cells and evaluated remaining infectivity by limited dilution. Furthermore, we exposed cells to the extract after infection to further evaluate its potential as a prophylaxis and treatment against coronaviruses. We also determined the protective effect of Echinaforce® in re-constituted nasal epithelium.Results: In the current study, we found that HCoV-229E was irreversibly inactivated when exposed to Echinaforce® at 3.2mg/ml IC50. Pre-treatment of cell lines, however, did not inhibit infection with HCoV-229E and post-infection treatment had only a marginal effect on virus propagation at 50 mg/ml. However, we did observe a protective effect in an organotypic respiratory cell culture system by exposing pre-treated respiratory epithelium to droplets of HCoV-229E, imitating a natural infection. The observed virucidal activity of Echinaforce® was not restricted to common cold coronaviruses, as both SARS-CoV-1 and MERS-CoVs were inactivated at comparable concentrations. Finally, the causative agent of COVID-19, SARS-CoV-2 was also inactivated upon treatment with 50ug/ml Echinaforce®.Conclusions: These results show that Echinaforce® is virucidal against HCoV-229E, upon direct contact and in an organotypic cell culture model. Furthermore, MERS-CoV and both SARS-CoV-1 and SARS-CoV-2 were inactivated at similar concentrations of the extract. Therefore we hypothesize that Echinacea purpurea preparations, such as Echinaforce®, could be effective as prophylactic treatment for all CoVs due to their structural similarities.

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In vitro antiviral activity of Echinaforce®, an Echinacea purpurea preparation, against common cold coronavirus 229E and highly pathogenic MERS-CoV and SARS-CoV

10.21203/rs.2.24724/v1 ◽

2020 ◽

Author(s):

Johanna Signer ◽

Hulda R. Jonsdottir ◽

Werner C. Albrich ◽

Marc Strasser ◽

Roland Züst ◽

...

Keyword(s):

Antiviral Activity ◽

Common Cold ◽

Natural Infection ◽

Gastrointestinal Symptoms ◽

Case Fatality ◽

Echinacea Purpurea ◽

Marginal Effect ◽

Virus Propagation ◽

Highly Pathogenic

Abstract Coronaviruses (CoVs) were long thought to only cause mild respiratory and gastrointestinal symptoms in humans but recent outbreaks of Middle Eastern Respiratory Syndrome (MERS)-CoV, Severe Acute Respiratory Syndrome (SARS)-CoV, and the newly identified SARS-CoV-2 have cemented their zoonotic potential and their capacity to cause serious morbidity and mortality, with case fatality rates ranging from 2 to 35%. Currently, no specific prophylaxis or treatment is available for CoV infections and therefore we investigated the antiviral potential of Echinacea purpurea (Echinaforce®) against human coronavirus (HCoV) 229E and the highly pathogenic MERS- and SARS-CoVs in vitro. We found that HCoV-229E was irreversibly inactivated when exposed to Echinaforce at 3.2µg/ml IC50. Pre-treatment of cell lines, however, did not inhibit infection with HCoV-229E and post-infection treatment had only a marginal effect on virus propagation at 50 µg/ml. However, we did observe a protective effect in an organotypic respiratory cell culture system by exposing pre-treated respiratory epithelium to droplets of HCoV-229E, imitating a natural infection. Finally, antiviral activity was not restricted to common cold coronaviruses, as the highly pathogenic SARS- and MERS-CoVs were inactivated at comparable concentrations. These results suggest that Echinacea purpurea preparations, such as Echinaforce, could be effective as prophylactic treatment for all CoVs, including newly occurring strains, such as SARS-CoV-2.

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In vitro antiviral activity of Echinaforce®, an Echinacea purpurea preparation, against common cold coronavirus 229E and highly pathogenic MERS-CoV and SARS-CoV

10.21203/rs.2.24724/v2 ◽

2020 ◽

Author(s):

Johanna Signer ◽

Hulda Run Jonsdottir ◽

Werner C. Albrich ◽

Marc Strasser ◽

Roland Züst ◽

...

Keyword(s):

Antiviral Activity ◽

Protective Effect ◽

Common Cold ◽

Post Infection ◽

Natural Infection ◽

Gastrointestinal Symptoms ◽

Echinacea Purpurea ◽

Marginal Effect ◽

Highly Pathogenic

Abstract Background: Coronaviruses (CoVs) were long thought to only cause mild respiratory and gastrointestinal symptoms in humans but recent outbreaks of Middle Eastern Respiratory Syndrome (MERS)-CoV, Severe Acute Respiratory Syndrome (SARS)-CoV, and the newly identified SARS-CoV-2 have cemented their zoonotic potential and their capacity to cause serious morbidity and mortality, with case fatality rates ranging from 2 to 35%. Currently, no specific prophylaxis or treatment is available for CoV infections and therefore we investigated the antiviral potential of Echinacea purpurea (Echinaforce®) against human coronavirus (HCoV) 229E and the highly pathogenic MERS- and SARS-CoVs in vitro.Methods:To evaluate the antiviral potential of Echinaforce we pre-treated virus particles and cells and evaluated remaining infectivity by limited dilution. Furthermore, we exposed cells to the extract post-infection to further estimate its potential as a prophylaxis and treatment against coronaviruses. We also determined the protective effect of Echinaforce in re-constituted nasal epithelium.Results:We found that HCoV-229E was irreversibly inactivated when exposed to Echinaforce at 3.2mg/ml IC50. Pre-treatment of cell lines, however, did not inhibit infection with HCoV-229E and post-infection treatment had only a marginal effect on virus propagation at 50 mg/ml. However, we did observe a protective effect in an organotypic respiratory cell culture system by exposing pre-treated respiratory epithelium to droplets of HCoV-229E, imitating a natural infection. Finally, antiviral activity was not restricted to common cold coronaviruses, as the highly pathogenic SARS- and MERS-CoVs were inactivated at comparable concentrations.Conclusions:These results suggest that Echinacea purpurea preparations, such as Echinaforce, could be effective as prophylactic treatment for all CoVs, including newly occurring strains, such as SARS-CoV-2.

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Author Correction: In vitro virucidal activity of Echinaforce®, an Echinacea purpurea preparation, against coronaviruses, including common cold coronavirus 229E and SARS-CoV-2

Virology Journal ◽

10.1186/s12985-020-01439-2 ◽

2020 ◽

Vol 17 (1) ◽

Author(s):

Johanna Signer ◽

Hulda R. Jonsdottir ◽

Werner C. Albrich ◽

Marc Strasser ◽

Roland Züst ◽

...

Keyword(s):

Common Cold ◽

Additional Data ◽

Echinacea Purpurea ◽

Virucidal Activity

An amendment to this paper has been published and can be accessed via the original article. The conclusions of this paper have been corroborated by additional data.

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Luxury at a Cost? Recombinant Mouse Hepatitis Viruses Expressing the Accessory Hemagglutinin Esterase Protein Display Reduced Fitness In Vitro

Journal of Virology ◽

10.1128/jvi.79.24.15054-15063.2005 ◽

2005 ◽

Vol 79 (24) ◽

pp. 15054-15063 ◽

Cited By ~ 38

Author(s):

A. Lissenberg ◽

M. M. Vrolijk ◽

A. L. W. van Vliet ◽

M. A. Langereis ◽

J. D. F. de Groot-Mijnes ◽

...

Keyword(s):

Cell Culture ◽

Hepatitis Virus ◽

Natural Infection ◽

Selective Advantage ◽

Rna Recombination ◽

Wild Type ◽

Growth Properties ◽

Group 2

ABSTRACT Group 2 coronaviruses encode an accessory envelope glycoprotein species, the hemagglutinin esterase (HE), which possesses sialate-O-acetylesterase activity and which, presumably, promotes virus spread and entry in vivo by facilitating reversible virion attachment to O-acetylated sialic acids. While HE may provide a strong selective advantage during natural infection, many laboratory strains of mouse hepatitis virus (MHV) fail to produce the protein. Apparently, their HE genes were inactivated during cell culture adaptation. For this report, we have studied the molecular basis of this phenomenon. By using targeted RNA recombination, we generated isogenic recombinant MHVs which differ exclusively in their expression of HE and produce either the wild-type protein (HE+), an enzymatically inactive HE protein (HE0), or no HE at all. HE expression or the lack thereof did not lead to gross differences in in vitro growth properties. Yet the expression of HE was rapidly lost during serial cell culture passaging. Competition experiments with mixed infections revealed that this was not due to the enzymatic activity: MHVs expressing HE+ or HE0 propagated with equal efficiencies. During the propagation of recombinant MHV-HE+, two types of spontaneous mutants accumulated. One produced an anchorless HE, while the other had a Gly-to-Trp substitution at the predicted C-terminal residue of the HE signal peptide. Neither mutant incorporated HE into virion particles, suggesting that wild-type HE reduces the in vitro propagation efficiency, either at the assembly stage or at a postassembly level. Our findings demonstrate that the expression of “luxury” proteins may come at a fitness penalty. Apparently, under natural conditions the costs of maintaining HE are outweighed by the benefits.

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Evaluation of the in-vitro protective effect of plant extract (astaxanthin) on chromosomal breakage in Fanconi anemia cell culture

Middle East Journal of Medical Genetics ◽

10.1097/01.mxe.0000430775.91633.7f ◽

2013 ◽

Vol 2 (2) ◽

pp. 45-49

Author(s):

Maha M. Eid ◽

Sami A. Temtamy ◽

Engy S. Soliman ◽

Marwa I. Shehab ◽

Sami H. Abd Alaziz ◽

...

Keyword(s):

Cell Culture ◽

Protective Effect ◽

Fanconi Anemia ◽

Plant Extract ◽

Chromosomal Breakage

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Two recombinant human monoclonal antibodies that protect against lethal Andes hantavirus infection in vivo

Science Translational Medicine ◽

10.1126/scitranslmed.aat6420 ◽

2018 ◽

Vol 10 (468) ◽

pp. eaat6420 ◽

Cited By ~ 13

Author(s):

Jose L. Garrido ◽

Joseph Prescott ◽

Mario Calvo ◽

Felipe Bravo ◽

Raymond Alvarez ◽

...

Keyword(s):

Severe Disease ◽

Gastrointestinal Symptoms ◽

Specific Treatment ◽

Case Fatality ◽

Hantavirus Infection ◽

Lethal Challenge ◽

Hamster Model ◽

Post Exposure ◽

Andes Hantavirus

Andes hantavirus (ANDV) is an etiologic agent of hantavirus cardiopulmonary syndrome (HCPS), a severe disease characterized by fever, headache, and gastrointestinal symptoms that may progress to hypotension, pulmonary failure, and cardiac shock that results in a 25 to 40% case-fatality rate. Currently, there is no specific treatment or vaccine; however, several studies have shown that the generation of neutralizing antibody (Ab) responses strongly correlates with survival from HCPS in humans. In this study, we screened 27 ANDV convalescent HCPS patient sera for their capacity to bind and neutralize ANDV in vitro. One patient who showed high neutralizing titer was selected to isolate ANDV–glycoprotein (GP) Abs. ANDV-GP–specific memory B cells were single cell sorted, and recombinant immunoglobulin G antibodies were cloned and produced. Two monoclonal Abs (mAbs), JL16 and MIB22, potently recognized ANDV-GPs and neutralized ANDV. We examined the post-exposure efficacy of these two mAbs as a monotherapy or in combination therapy in a Syrian hamster model of ANDV-induced HCPS, and both mAbs protected 100% of animals from a lethal challenge dose. These data suggest that monotherapy with mAb JL16 or MIB22, or a cocktail of both, could be an effective post-exposure treatment for patients infected with ANDV-induced HCPS.

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Carrageenan containing over-the-counter nasal and oral sprays inhibit SARS-CoV-2 infection of airway epithelial cultures

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00552.2020 ◽

2021 ◽

Author(s):

Desiree Schütz ◽

Carina Conzelmann ◽

Giorgio Fois ◽

Rüdiger Groß ◽

Tatjana Weil ◽

...

Keyword(s):

Cell Culture ◽

Virus Infection ◽

Antiviral Effect ◽

Airway Epithelial ◽

Virucidal Activity ◽

Over The Counter ◽

Viral Spread ◽

Epithelial Cultures ◽

Pharmaceutical Interventions

Pharmaceutical interventions are urgently needed to prevent SARS-CoV-2 infection and transmission. As SARS-CoV-2 infects and spreads via the nasopharyngeal airways, we analyzed the antiviral effect of selected nasal and oral sprays on virus infection in vitro. Two nose sprays showed virucidal activity but were cytotoxic precluding further analysis in cell culture. One nasal and one mouth spray suppressed SARS-CoV-2 infection of TMPRSS2-Vero E6 cells and primary differentiated human airway epithelial cultures. The antiviral activity in both sprays could be attributed to polyanionic ι- and κ-carrageenans. Thus, application of carrageenan containing nasal and mouth sprays may reduce the risk of acquiring SARS-CoV-2 infection and may limit viral spread, warranting further clinical evaluation.

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