In vitro antiviral activity against SARS-CoV-2 of common herbal medicinal extracts and their bioactive compounds
Leka et al.,
In vitro antiviral activity against SARS-CoV-2 of common herbal medicinal extracts and their bioactive..,
Phytotherapy Research, doi:10.1002/ptr.7463 (In Vitro)
Leka et al., 9 Apr 2022, peer-reviewed, 6 authors.
In Vitro studies are an important part of preclinical research, however results may be very different in vivo.
Abstract: Received: 14 February 2022
Revised: 21 March 2022
Accepted: 25 March 2022
DOI: 10.1002/ptr.7463
LETTER TO THE EDITOR
In vitro antiviral activity against SARS-CoV-2 of common
herbal medicinal extracts and their bioactive compounds
For raw herbal materials, ethanol crude extracts were prepared
To the Editor,
The coronavirus SARS-CoV-2 spread all around the world, leading to
by maceration of powdered plant with EtOH at room temperature. A
an unprecedented pandemic. Up to date, some effective treatments
10 g of dried powder was used for 100 ml of EtOH. The solvent of
have been highlighted to treat the symptoms, but not to cure the
the resulting filtrates was evaporated at low temperature (<40 C)
COVID-19 disease. At least, some well-known medicines have been
under reduced pressure and dissolved in DMSO. Commercially man-
proposed, but have rapidly become the subject of some controversy,
ufactured extracts were readily dissolved in DMSO for the assay.
such
azithromycin
Cells culture and virus preparation were performed as previously
(Maisonnasse et al., 2020; Okour, Al-Kofahi, & Austin, 2020) and iver-
described by our team (Ledoux et al., 2022). The antiviral and cyto-
mectin (Zaidi & Dehgani-Mobaraki, 2022). As no treatments were con-
toxic experiments were performed in triplicate in 96-well plates, as
sidered neither safe nor efficient enough, new coronavirus vaccines
previously reported (Ledoux et al., 2022). On day one, cells grown in
obtained conditional marketing authorisation. The public health crisis
10 cm standard tissue culture dishes (Falcon, Becton-Dickinson)
of COVID-19 led to countries around the world promoting massive
were trypsinized and counted using a Cedex XS cell analyser (Roche
vaccination programs. However, one can observe that the results are
Innovatis). A 100 μl of cell suspension containing 2,000 Vero E6 via-
not fulfilling the hopes and expectations concerning virus transmission
ble cells was seeded in a 96-well tissue culture plate (Falcon,
as
hydroxychloroquine
combined
or
not
(Franco-Paredes, 2022), while the data concerning pharmacovigilance
Becton-Dickinson) and grown overnight. On day two, 50 μl of
are still in process. In this context, research should focus on the hin-
extracts (or pure compound) were added to the wells of the 96-well
drances of implementing cost-effective and safe drugs, as well as pre-
plate containing confluent cells with a final range of concentration
ventive health products. Plants extracts and natural isolated
from 50 to 1.5 μg/ml in duplicate. A 50 μl of virus suspension or
compounds which are already used as medicines, dietary supplements
virus-free medium was added, respectively, to determine the ant-
or preventive health products, can offer a cost-effective way to fight
iviral activity or the cytotoxicity. The antiviral activity was
against COVID-19, especially since they have proven to be safe to use.
established regarding the minimal concentration, which was able to
In accordance with this strategy, we have then evaluated different
protect the cells from the viral cytopathic effects, observed through
plants and extracts for their antiviral activity against SARS-CoV-2
a microscope, compared to the untreated control on day five post-
strain. The selection of plant species included in this antiviral screening
infection.
was based on either their use in common winter ailments, on the previ-
Regarding the 17 plants..
Please send us corrections, updates, or comments. Vaccines and
treatments are complementary. All practical, effective, and safe means should
be used based on risk/benefit analysis. No treatment, vaccine, or intervention
is 100% available and effective for all current and future variants. We do not
provide medical advice. Before taking any medication, consult a qualified
physician who can provide personalized advice and details of risks and
benefits based on your medical history and situation.
FLCCC and
WCH
provide treatment protocols.
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