Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2024 Mar-Apr;14(2):189-201.
doi: 10.22038/AJP.2023.22920.

Quercetin may reduce the risk of developing the symptoms of COVID-19

Marjan Ajami  1 , Mohammadjavad Sotoudeheian  2 , Anahita Houshiar-Rad  3 , Mina Esmaili  3 , Fatemeh Naeini  4 , Fatemeh Mohammadi Nasrabadi  1 , Saied Doaei  5 , Ali Milani-Bonab  1
Affiliations
Review

Quercetin may reduce the risk of developing the symptoms of COVID-19

Marjan Ajami et al. Avicenna J Phytomed. 2024 Mar-Apr.

Abstract

Objective: Recent evidence reported that some dietary compounds like quercetin and apigenin as the most well-known flavonoids with anti-inflammatory effects may inhibit SARS-CoV-2 main protease. The hypothesis of the promising effects and possible mechanisms of action of quercetin against COVID-19 were assessed in this article.

Materials and methods: Related papers on the inhibitory effects of quercetin against COVID-19 were collected using the following search strategy: "corona or coronavirus or COVID or COVID-19 or viral or virus" AND "nutrient or flavonoid or Quercetin".

Results: The findings indicated that quercetin can be considered an effective agent against COVID-19 because of its SARS-CoV-2 main protease and RNA-dependent RNA polymerase inhibitory effects. In addition, quercetin may attenuate angiotensin-converting enzyme-2 (ACE-2) receptors leading to a reduction of SARS-CoV-2 ability to enter host cells. Moreover, the antiviral, anti-inflammatory, and immunomodulatory activities of quercetin have been frequently reported.

Conclusion: Quercetin may be an effective agent for managing the complications of COVID-19. Further longitudinal human studies are warranted.

Keywords: ACE-2 receptors; COVID-19; Quercetin; RNA-dependent RNA polymerase; SARS-CoV-2 main protease.

PubMed Disclaimer

Conflict of interest statement

The authors have declared that there is no conflict of interest.

Figures

Figure 1
Figure 1
Anti-inflammatory and antioxidant activities of quercetin: Quercetin binds transition metal ions and inhibits lipid peroxidation. Quercetin reduces irreversible damage to cell membranes by inhibiting inducible nitric oxide synthase activity. Quercetin decreases oxidative injury through inhibiting xanthine oxidase. As a calmodulin antagonist it stabilizes cell membrane action acting. Quercetin can suppress inflammatory response by scavenging free radicals. NF-κB triggers the expression of several pro-inflammatory cytokines including IL-6, CRP, and COX-2 and reduces TNF-α generation. Inhibition of inflammatory enzymes such as COX by Quercetin decreases prostaglandins and leukotrienes.
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Abd El-Aziz TM, Stockand JD. Recent progress and challenges in drug development against COVID-19 coronavirus (SARS-CoV-2)-an update on the status. Infect Genet Evol. 2020;83:104327. - PMC - PubMed
    1. Aliabadi F, Ajami M, Pazoki–Toroudi H. Why does COVID‐19 pathology have several clinical forms? Bioessays. 2020;42:e2000198. - PubMed
    1. Almeida AF, Borge GIA, Piskula M, Tudose A, Tudoreanu L, Valentová K, Williamson G, Santos CN. Bioavailability of quercetin in humans with a focus on interindividual variation. Compr Rev Food Sci Food Saf. 2018;17:714–731. - PubMed
    1. Álvarez P, Alvarado C, Puerto M, Schlumberger A, Jiménez L, De la Fuente M. Improvement of leukocyte functions in prematurely aging mice after five weeks of diet supplementation with polyphenol-rich cereals. Nutrition. 2006;22:913–921. - PubMed
    1. Bachmetov L, Gal‐Tanamy M, Shapira A, Vorobeychik M, Giterman‐Galam T, Sathiyamoorthy P, Golan‐Goldhirsh A, Benhar I, Tur‐Kaspa R, Zemel R. Suppression of hepatitis C virus by the flavonoid quercetin is mediated by inhibition of NS3 protease activity. J Viral Hepat. 2012;19:81–88. - PubMed

LinkOut - more resources