Roles of flavonoids against coronavirus infection

Chem Biol Interact. 2020 Sep 1:328:109211. doi: 10.1016/j.cbi.2020.109211. Epub 2020 Jul 28.


In terms of public health, the 21st century has been characterized by coronavirus pandemics: in 2002-03 the virus SARS-CoV caused SARS; in 2012 MERS-CoV emerged and in 2019 a new human betacoronavirus strain, called SARS-CoV-2, caused the unprecedented COVID-19 outbreak. During the course of the current epidemic, medical challenges to save lives and scientific research aimed to reveal the genetic evolution and the biochemistry of the vital cycle of the new pathogen could lead to new preventive and therapeutic strategies against SARS-CoV-2. Up to now, there is no cure for COVID-19 and waiting for an efficacious vaccine, the development of "savage" protocols, based on "old" anti-inflammatory and anti-viral drugs represents a valid and alternative therapeutic approach. As an alternative or additional therapeutic/preventive option, different in silico and in vitro studies demonstrated that small natural molecules, belonging to polyphenol family, can interfere with various stages of coronavirus entry and replication cycle. Here, we reviewed the capacity of well-known (e.g. quercetin, baicalin, luteolin, hesperetin, gallocatechin gallate, epigallocatechin gallate) and uncommon (e.g. scutellarein, amentoflavone, papyriflavonol A) flavonoids, secondary metabolites widely present in plant tissues with antioxidant and anti-microbial functions, to inhibit key proteins involved in coronavirus infective cycle, such as PLpro, 3CLpro, NTPase/helicase. Due to their pleiotropic activities and lack of systemic toxicity, flavonoids and their derivative may represent target compounds to be tested in future clinical trials to enrich the drug arsenal against coronavirus infections.

Keywords: Coronavirus; Flavonoids; MERS-CoV; SARS-CoV; SARS-CoV-2.

Publication types

  • Review

MeSH terms

  • Animals
  • Antiviral Agents / chemistry
  • Antiviral Agents / therapeutic use
  • Betacoronavirus* / drug effects
  • Betacoronavirus* / genetics
  • Betacoronavirus* / physiology
  • COVID-19
  • COVID-19 Drug Treatment
  • Computer Simulation
  • Coronaviridae / drug effects
  • Coronaviridae / physiology
  • Coronavirus Infections / drug therapy*
  • Coronavirus Infections / epidemiology
  • Coronavirus Infections / virology
  • Drug Evaluation, Preclinical
  • Flavonoids / chemistry
  • Flavonoids / therapeutic use*
  • Humans
  • Middle East Respiratory Syndrome Coronavirus / drug effects
  • Pandemics
  • Pneumonia, Viral / drug therapy*
  • Pneumonia, Viral / epidemiology
  • Pneumonia, Viral / virology
  • SARS-CoV-2
  • Severe acute respiratory syndrome-related coronavirus / drug effects
  • Viral Proteins / antagonists & inhibitors
  • Virus Replication / drug effects


  • Antiviral Agents
  • Flavonoids
  • Viral Proteins