Journal article
In vitro virucidal activity of Echinaforce®, an Echinacea purpurea preparation, against coronaviruses, including common cold coronavirus 229E and SARS-CoV-2.
- Signer J SPIEZ LABORATORY, Austrasse, 3700, Spiez, Switzerland.
- Jonsdottir HR SPIEZ LABORATORY, Austrasse, 3700, Spiez, Switzerland. hulda-run.jonsdottir@babs.admin.ch.
- Albrich WC Division of Infectious Diseases and Hospital Epidemiology, Kantonsspital St. Gallen, St. Gallen, Switzerland.
- Strasser M SPIEZ LABORATORY, Austrasse, 3700, Spiez, Switzerland.
- Züst R SPIEZ LABORATORY, Austrasse, 3700, Spiez, Switzerland.
- Ryter S SPIEZ LABORATORY, Austrasse, 3700, Spiez, Switzerland.
- Ackermann-Gäumann R SPIEZ LABORATORY, Austrasse, 3700, Spiez, Switzerland.
- Lenz N SPIEZ LABORATORY, Austrasse, 3700, Spiez, Switzerland.
- Siegrist D SPIEZ LABORATORY, Austrasse, 3700, Spiez, Switzerland.
- Suter A A.Vogel AG, Roggwil, Switzerland.
- Schoop R A.Vogel AG, Roggwil, Switzerland.
- Engler OB SPIEZ LABORATORY, Austrasse, 3700, Spiez, Switzerland. olivier.engler@babs.admin.ch.
- 2020-09-10
Published in:
- Virology journal. - 2020
Antivirals
Common cold
Coronavirus
Echinacea
HCoV-229E
MERS-CoV
Prevention
SARS-CoV-1
SARS-CoV-2
Animals
Antiviral Agents
Betacoronavirus
Cell Line
Chlorocebus aethiops
Common Cold
Coronavirus
Coronavirus 229E, Human
Coronavirus Infections
Humans
Middle East Respiratory Syndrome Coronavirus
Pandemics
Plant Extracts
Pneumonia, Viral
RNA Viruses
Randomized Controlled Trials as Topic
Severe Acute Respiratory Syndrome
Vero Cells
English
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.
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.
- Language
-
- English
- Open access status
- gold
- Identifiers
-
- DOI 10.1186/s12985-020-01401-2
- PMID 32907596
- Persistent URL
- https://folia.unifr.ch/global/documents/278365
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