Anti-viral and anti-inflammatory effects of kaempferol and quercetin and COVID-2019: A scoping review
Severe acute respiratory syndrome coronavirus type 2 (SARSCoV- 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 SARSCoV- 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, antiinflammatory, and immunomodulatory effects.