Cardiovascular Disease: A Target for the Pharmacological Effects of Quercetin

Quercetin, a prominent dietary antioxidant present in vegetables, especially onions, fruits, highlighting apples and berries, wine and tea, belongs to a group of plant derived heterocyclic polyphenols. These compounds could be important mediators of the biological actions attributed to healthy diets. Chemically, quercetin is a type of flavonoid that specifically belongs to the flavonols group. It naturally occurs either as glycoside or aglycone, both of which have biological activity. Many of the natural sources of quercetin are included in the Mediterranean diet, a dietary habit associated with a decrease of cardiovascular diseases. During the last years, several researches have reported effects consistent with pharmacological applications of quercetin in cardiovascular diseases, such as atherosclerosis, ischemia-reperfusion injury, cardiotoxicity, and hypertension, among others. In this review, the pathways and molecules involved in the beneficial effects of quercetin are summarized. In addition, a scope of the new insights concerning quercetin pharmacokinetics, pharmacodynamics and bioavailability are presented. The mechanisms whereby quercetin exerts its effects have not been fully elucidated. However, interesting results have been obtained from early clinical studies involving cardioprotection by quercetin, but much knowledge is still lacking in the field of its bioavailability to improve the clinical application of this flavonol. This study presents evidence supporting the point of view that quercetin should be considered a potential therapeutic agent against cardiovascular diseases, giving rise to novel applications in their prevention and treatment.