Covid-19 and thymoquinone: Connecting the dots
Ahmad et al.,
Covid-19 and thymoquinone: Connecting the dots,
Phytotherapy Research, doi:10.1002/ptr.6793 (Review) (Preprint)
Review of the potential benefits of thymoquinone (a component of nigella sativa) for COVID-19, recommending clinical trials.
Ahmad et al., 26 Jun 2020, preprint, 4 authors.
Abstract: Received: 30 May 2020
Revised: 15 June 2020
Accepted: 16 June 2020
DOI: 10.1002/ptr.6793
LETTER TO THE EDITOR
Covid-19 and thymoquinone: Connecting the dots
At present, the medical approaches to cope with Covid-19 infection
systemic inflammation of sepsis including vasodilatation, altered
caused by the respiratory syndrome coronavirus 2 (SARS-CoV-2) are
vascular permeability and extravasation, leukocyte migration, and
mainly supportive. In the absence of specific anti-viral therapies or
activation (Ince et al., 2016). Notably, inflammatory cytokines such as
vaccines, the medical care is complemented with different combina-
TNF-α, IL-1α, IL-2, IL-6, and IL-10 also enhance NO production
tions
via iNOS (Green et al., 1994). Thymoquinone has been shown to
of
broad-spectrum
antiviral
agents,
antibiotics,
hydro-
xychloroquine, and convalescent plasma transfusion (Jin et al., 2020).
downregulate inflammatory cytokines, reduce NO levels, and improve
Thymoquinone, the main constituent of Nigella sativa, has demon-
organ functions and survival of sepsis in an animal model (Alkharfy
strated anti-inflammatory, anti-oxidant, anti-tumor, and antimicrobial
et al., 2015). This perhaps through a redox mechanism, which
activities (Banerjee et al., 2009; Chaieb, Kouidhi, Jrah, Mahdouani, &
decreases the systemic oxidative stress and inflammatory response.
Bakhrouf, 2011). Thymoquinone was also effective and tolerable in
Consequently, thymoquinone decreases the levels of early-stage sep-
children with intractable epilepsy in a randomized controlled clinical
sis biomarkers (e.g., ESM-1, CRP, and VEGF) by 30–50% (Alkharfy
trial at a dose of 1 mg/kg/day orally (Akhondian et al., 2011). Interest-
et al., 2018). Interestingly, thymoquinone has also been found to have
ingly, thymoquinone and Nigella sativa extract were found to be effec-
a protective effect against lung fibrosis and collagen deposition by
tive against avian influenza virus (H9N2 AIV) and a murine
modulating the nuclear factor Kappa-B (NF-κB) and the antioxidant
cytomegalovirus infection model (Salem & Hossain, 2000; Umar
enzyme nuclear factor 2 heme oxygenase-1 (Nrf2/HO-1) signaling
et al., 2016). Ulasli and co-workers reported that the treatment of
pathway (Ahmad et al., 2020).
cells with Nigella sativa extract prior to infection with coronavirus
Virus-induced phagocyte activation is correlated with oxidative
decreases the replication of the virus (Ulasli et al., 2014). Moreover,
stress, not just because ROS is produced, but also because activated
gene expression analysis of the transient receptor potential proteins
phagocytes also produce inflammatory cytokines by the activation of
(TRPs) showed a reduction in virus loads upon extract treatments,
NF-κB (S. F. Liu & Malik, 2006; Schwarz, 1996). Actually, many genes
which can decrease coronavirus survival inside cells. It should be
that are regulated by NF-κB, including inflammatory cytokines,
noted, however, that these studies on the herbal extracts may not
COX-2, and iNOS, contribute to a rise in sepsis inflammatory
have been carried out according to the more recent scientific qualita-
responses (Ghosh, May, & Kopp, 1998; Schneider-Stock, Fakhoury,
tive standards for plant-derived products (Heinrich et al., 2020).
Zaki, El-Baba, & Gali-Muhtasib, 2014). Thus, NF-κB inhibition can sup-
Therefore, there is the possibility that high concentrations in vitro or
press inflammatory genes,..
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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