Promising Antiviral Activities of Natural Flavonoids against SARS-CoV-2 Targets: Systematic Review

source extracted confidence: high 2026-04-09
#antiviral-agents #covid-19 #coronavirus-3c-proteases #coronavirus-nucleocapsid-proteins #flavonoids

Promising Antiviral Activities of Natural Flavonoids against SARS-CoV-2 Targets: Systematic Review

Kaul et al., 2021 | Int J Mol Sci | Systematic Review

Citation

Kaul Ridhima, Paul Pradipta, ... Chaari Ali. Promising Antiviral Activities of Natural Flavonoids against SARS-CoV-2 Targets: Systematic Review. Int J Mol Sci. 2021-Oct-14;22(20). doi:10.3390/ijms222011069

Abstract

The ongoing COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) became a globally leading public health concern over the past two years. Despite the development and administration of multiple vaccines, the mutation of newer strains and challenges to universal immunity has shifted the focus to the lack of efficacious drugs for therapeutic intervention for the disease. As with SARS-CoV, MERS-CoV, and other non-respiratory viruses, flavonoids present themselves as a promising therapeutic intervention given their success in silico, in vitro, in vivo, and more recently, in clinical studies. This review focuses on data from in vitro studies analyzing the effects of flavonoids on various key SARS-CoV-2 targets and presents an analysis of the structure-activity relationships for the same. From 27 primary papers, over 69 flavonoids were investigated for their activities against various SARS-CoV-2 targets, ranging from the promising 3C-like protease (3CLpro) to the less explored nucleocapsid (N) protein; the most promising were quercetin and myricetin derivatives, baicalein, baicalin, EGCG, and tannic acid. We further review promising in silico studies featuring activities of flavonoids against SARS-CoV-2 and list ongoing clinical studies involving the therapeutic potential of flavonoid-rich extracts in combination with synthetic drugs or other polyphenols and suggest prospects for the future of flavonoids against SARS-CoV-2.

Key Findings

We further review promising in silico studies featuring activities of flavonoids against SARS-CoV-2 and list ongoing clinical studies involving the therapeutic potential of flavonoid-rich extracts in combination with synthetic drugs or other polyphenols and suggest prospects for the future of flavonoids against SARS-CoV-2.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size See abstract
Age Range See abstract
Condition See abstract

MeSH Terms

  • Antiviral Agents
  • COVID-19
  • Coronavirus 3C Proteases
  • Coronavirus Nucleocapsid Proteins
  • Flavonoids
  • Humans
  • Middle East Respiratory Syndrome Coronavirus
  • Phosphoproteins
  • Rhinovirus
  • SARS-CoV-2
  • Virus Internalization
  • COVID-19 Drug Treatment

Evidence Classification

  • Level: Systematic Review
  • Publication Types: Journal Article, Systematic Review
  • Vertical: quercetin

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09