The flavonoid quercetin in disease prevention and therapy: facts and fancies

Biochem Pharmacol. 2012 Jan 1;83(1):6-15. doi: 10.1016/j.bcp.2011.08.010. Epub 2011 Aug 16.

Abstract

Biochemical and genetic studies on cellular and animal models on the mechanism(s) of action of phytochemicals provide a functional explanation of how and why a diet rich in fruits and vegetables is considered healthy. It is not unusual to find molecules that protect against diseases, which greatly differ from a physiopathological point of view, such as cancer and cardiovascular disorders. Quercetin falls into this category and possesses a broad range of biological properties. Uptake, metabolism and circulating concentrations of quercetin and its metabolites suggest that a regular diet provides amounts of quercetin (<1 μM) not compatible with its chemopreventive and/or cardioprotective effects. However, it appears relatively easy to increase total quercetin concentrations in plasma (>10 μM) by supplementation with quercetin-enriched foods or supplements. Multiple lines of experimental evidence suggest a positive association between quercetin intake and improved outcomes of inflammatory cardiovascular risk. The ameliorating effect of quercetin administration can be extended to other chronic inflammatory disorders but only if supplementation occurs in patients. Quercetin can be considered the prototype of a naturally-occurring chemopreventive agent because of its key roles in triggering the "hallmarks of cancer". However, several critical points must be taken into account when considering the potential therapeutic use of this molecule: (1) pharmacological versus nutraceutical doses applied, (2) specificity of its mechanism of action compared to other phytochemicals, and (3) identification of "direct" cellular targets. The design of specific clinical trials is extremely warranted to depict possible applications of quercetin in adjuvant cancer therapy.

Publication types

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

MeSH terms

  • Animals
  • Antineoplastic Agents, Phytogenic / metabolism*
  • Antineoplastic Agents, Phytogenic / pharmacology
  • Antineoplastic Agents, Phytogenic / therapeutic use*
  • Cell Death / drug effects
  • Cell Death / physiology
  • Dietary Supplements
  • Flavonoids / metabolism*
  • Flavonoids / pharmacology
  • Flavonoids / therapeutic use*
  • Fruit
  • Growth Inhibitors / metabolism
  • Growth Inhibitors / pharmacology
  • Growth Inhibitors / therapeutic use
  • Humans
  • Neoplasms / pathology
  • Neoplasms / prevention & control*
  • Quercetin / metabolism*
  • Quercetin / pharmacology
  • Quercetin / therapeutic use*
  • Vegetables

Substances

  • Antineoplastic Agents, Phytogenic
  • Flavonoids
  • Growth Inhibitors
  • Quercetin