The anti-COVID-19 properties of Quercetin

Posted on by Jesse Santiano, M.D.

Quercetin is a flavonoid found in plants like apples, onions, capers, cilantro, berries, dill, and lovage.

Quercetin is a part of the I-MASK+ protocol for the Prevention and Early Treatment of COVID-19.

Studies have shown that Quercetin has antiviral and anti-inflammatory properties against the SRS-CoV-2. Looking at the course of COVID-19 below from the FLCCC website,

Source: FLCCC

We can see that viral replication is followed by Immune dysregulation. The SARS-CoV-2 multiplies, dies off, the viral debris stays behind, and the immune system acts on that viral debris and to the organ systems of the host, causing a cytokine storm which leads to severe illness.

Quercetin can stop both viral replications and prevent autoimmunity. Below is the scientific basis and supporting studies for Quercetin’s actions.

Antiviral Properties of Quercetin

  • Quercetin blocks the SARS-CoV-2 spike protein from attaching to the ACE2 receptor.
  • Quercetin blocks the RNA- dependent RNA polymerase and prevents viral replication.
  • Quercetin acts on  3-chymotrypsin-like protease (3CLpro), which controls coronavirus replication and is essential for its life cycle.
  • Quercetin inhibits papain-like protease (PLpro) of the SARS-CoV-2. In doing so
    • It prevents virus-induced cellular destruction.
    • Maintains the antiviral interferon pathway that is necessary for an effective immune response and
    • Reduces viral replication in infected cells. 

Quercetin’s anti-inflammatory functions

Quercetin decreases the mRNA and protein levels of the proinflammatory molecules;  Intracellular adhesion molecule-1 (ICAM-1), cell adhesion molecule-1 (CAM-1), Interleukin 1β, (IL-1β), IL-6 (IL-6), IL-8, IL-18, and  Monocyte chemoattractant protein-1 (MCP-1). Modulating inflammation is necessary to prevent the cytokine storm seen in severe COVID-19.

Quercetin also prevents abnormal blood clot formation thru its inhibition of thrombin which is a significant component of the clotting pathway. Abnormal blood clot formation is typically seen in severe COVID-19. The arterial blockage leads to pulmonary embolism, strokes, ischemic legs, hearts attacks, renal failure, and intestinal necrosis.

Quercetin also increases the expression of Sirtuin1 or SIRT-1. SIRT-1 downregulates neural factor kappa beta, thus decreasing inflammation.

Quercetin also has psychostimulant properties, can prevent platelet aggregation, decreases capillary permeability, lipid peroxidation, and enhances mitochondrial biogenesis.

Take Away Message

Quercetin has antiviral and anti-inflammatory actions, making it useful for all phases of COVID-19.

Where to get Quercetin

Quercetin is not water-soluble but fat-soluble. Take it with some extra-virgin olive oil or animal fat. Below are the Quercetins reviewed favorably by Consumerlab.com

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Read An update to the I-MASK+ Prevention & Early Outpatient Treatment Protocol for COVID-19 for the proper dosing of Quercetin.

Knowledge about Covid-19 is rapidly evolving. Information may update as new studies are made. Stay current by subscribing. Feel free to share and like.

Don’t Get Sick!

Related:

  1. The I-RECOVER Management Protocol for Long Haul COVID-19 Syndrome
  2. The MATH+ Protocol Results in Greater Survival in Hospitalized COVID-19 Patients
  3. Zinc Deficiency Impairs the Immune System
  4. Vitamin C and COVID-19
  5. Any Science behind Elderberry for Influenza and Covid-19?

References:

  1. Tahir et al.  Structural basis of SARS-CoV-2 3CLpro and anti-COVID-19 drug discovery from medicinal plants. J Pharm Anal. 2020 Aug;10(4):313-319. doi: 10.1016/j.jpha.2020.03.009. Epub 2020 Mar 26. PMID: 32296570; PMCID: PMC7156227.
  2. Shin et al. Papain-like protease regulates SARS-CoV-2 viral spread and innate immunity. Nature. 2020 Nov;587(7835):657-662. doi: 10.1038/s41586-020-2601-5. Epub 2020 Jul 29. PMID: 32726803; PMCID: PMC7116779.
  3. Anti-inflammatory potential of Quercetin in COVID-19 treatment
  4. Ali Saeedi-Boroujeni, Mohammad-Reza Mahmoudian-Sani
    J Inflamm (Lond) 2021; 18: 3. Published online 2021 Jan 28. doi: 10.1186/s12950-021-00268-6
  5. Derosa G, Maffioli P, D’Angelo A, Di Pierro F. A role for quercetin in coronavirus disease 2019 (COVID-19). Phytother Res. 2021 Mar;35(3):1230-1236. doi: 10.1002/ptr.6887. Epub 2020 Oct 9. PMID: 33034398; PMCID: PMC7675685.

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