ABSTRACT
Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is a novel coronavirus identified at the end of 2019. It is recognized as the causative agent of coronavirus disease 2019 (COVID-19). Flavonoids have been shown to exhibit therapeutical effect on complications related to COVID-19. The present study reviews possible therapeutic benefits of flavonoids on SARS-CoV-2. The Web of Science, PubMed, Scopus, and Google Scholar were searched using keywords: 'COVID-19', 'SARS-CoV-2', 'Kaempferol' and 'Quercetin' in the Title/Abstract. Relevant published articles in the English language until August 2020 were considered. Kaempferol and quercetin showed antiviral properties such as inhibition of protein kinase B and phosphorylation of protein kinase and blocking effects on a selective channel (3a channel) expressed in SARS-CoV infected cells. They also reduced the level of reactive oxygen species, expression of inducible nitric oxide synthase, pro-inflammatory mediators including TNF-α, IL-1α, IL-1β, IL-6, IL-10, and IL-12 p70, and chemokines. Kaempferol and quercetin might exert beneficial effects in the control or treatment of COVID-19 because of their antiviral, antioxidant, anti-inflammatory, and immunomodulatory effects.
ABSTRACT
Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is a novel coronavirus identified at the end of 2019. It is recognized as the causative agent of coronavirus disease 2019 (COVID-19). Flavonoids have been shown to exhibit therapeutical effect on complications related to COVID-19. The present study reviews possible therapeutic benefits of flavonoids on SARS-CoV-2. The Web of Science, PubMed, Scopus, and Google Scholar were searched using keywords: 'COVID-19', 'SARS-CoV-2', 'Kaempferol' and 'Quercetin' in the Title/Abstract. Relevant published articles in the English language until August 2020 were considered. Kaempferol and quercetin showed antiviral properties such as inhibition of protein kinase B and phosphorylation of protein kinase and blocking effects on a selective channel (3a channel) expressed in SARS-CoV infected cells. They also reduced the level of reactive oxygen species, expression of inducible nitric oxide synthase, pro-inflammatory mediators including TNF-α, IL-1α, IL-1β, IL-6, IL-10, and IL-12 p70, and chemokines. Kaempferol and quercetin might exert beneficial effects in the control or treatment of COVID-19 because of their antiviral, antioxidant, anti-inflammatory, and immunomodulatory effects.
ABSTRACT
Background: The contribution of histamine (H1) receptors inhibitory and/or β-adrenoceptors stimulatory mechanisms in the relaxant property of Ferula assa-foetida. (F. asafoetida) was examined in the present study. Methods: We evaluated the effect of three concentrations of F. asafoetida extract (2.5, 5, and 10 mg/mL), a muscarinic receptors antagonist, and saline on methacholine concentration-response curve in tracheal smooth muscles incubated with β-adrenergic and histamine (H1) (group 1), and only β-adrenergic (group 2) receptors antagonists. Results: EC50 values in the presence of atropine, extract (5 and 10 mg/mL) and maximum responses to methacholine due to the 10 mg/mL extract in both groups and 5 mg/mL extract in group 1 were higher than saline (P < 0.0001, P = 0.0477, and P = 0.0008 in group 1 and P < 0.0001, P = 0.0438, and P = 0.0107 in group 2 for atropine, 5 and 10 mg/mL extract, respectively). Values of concentration ratio minus one (CR-1), in the presence of extracts were lower than atropine in both groups (P = 0.0339 for high extract concentration in group 1 and P < 0.0001 for other extract concentrations in both groups). Conclusion: Histamine (H1) receptor blockade affects muscarinic receptors inhibitory property of F. asafoetida in tracheal smooth muscle