Quercetin and Vitamin C: An Experimental, Synergistic Therapy for the Prevention and Treatment of SARS-CoV-2 Related Disease (COVID-19)

Front Immunol. 2020 Jun 19;11:1451. doi: 10.3389/fimmu.2020.01451. eCollection 2020.

Abstract

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) represents an emergent global threat which is straining worldwide healthcare capacity. As of May 27th, the disease caused by SARS-CoV-2 (COVID-19) has resulted in more than 340,000 deaths worldwide, with 100,000 deaths in the US alone. It is imperative to study and develop pharmacological treatments suitable for the prevention and treatment of COVID-19. Ascorbic acid is a crucial vitamin necessary for the correct functioning of the immune system. It plays a role in stress response and has shown promising results when administered to the critically ill. Quercetin is a well-known flavonoid whose antiviral properties have been investigated in numerous studies. There is evidence that vitamin C and quercetin co-administration exerts a synergistic antiviral action due to overlapping antiviral and immunomodulatory properties and the capacity of ascorbate to recycle quercetin, increasing its efficacy. Safe, cheap interventions which have a sound biological rationale should be prioritized for experimental use in the current context of a global health pandemic. We present the current evidence for the use of vitamin C and quercetin both for prophylaxis in high-risk populations and for the treatment of COVID-19 patients as an adjunct to promising pharmacological agents such as Remdesivir or convalescent plasma.

Keywords: COVID-19; Coronavirus; SARS-Cov-2; antiviral; flavonoids; immunonutrition; quercetin; vitamin C.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Antiviral Agents / adverse effects
  • Antiviral Agents / chemistry
  • Antiviral Agents / pharmacokinetics
  • Antiviral Agents / therapeutic use*
  • Ascorbic Acid / therapeutic use*
  • Betacoronavirus / drug effects
  • Betacoronavirus / physiology*
  • COVID-19
  • Coronavirus Infections / drug therapy
  • Coronavirus Infections / prevention & control*
  • Coronavirus Infections / virology
  • Drug Synergism
  • Drug Therapy, Combination
  • Humans
  • Immunologic Factors / therapeutic use*
  • Mice
  • Pandemics / prevention & control*
  • Pneumonia, Viral / prevention & control*
  • Pneumonia, Viral / virology
  • Pre-Exposure Prophylaxis / methods*
  • Quercetin / adverse effects
  • Quercetin / chemistry
  • Quercetin / pharmacokinetics
  • Quercetin / therapeutic use*
  • SARS-CoV-2
  • Virus Replication / drug effects

Substances

  • Antiviral Agents
  • Immunologic Factors
  • Quercetin
  • Ascorbic Acid

Supplementary concepts

  • COVID-19 drug treatment