Antioxidant Activity of Quercetin: A Mechanistic Review

Abstract

Flavones and flavonoids are known to have potent antioxidant activity due to intracellular free radical scavenging capacities. Flavonoids are found ubiquitously in plants as a member of polyphenolic compounds which share diverse chemical structure and properties. Quercetin is among the most efficient antioxidants of the flavonoids. The antioxidant property of quercetin has been highlighted in this review. These compounds have pivotal role in treatment of diabetes, cancers and some cardiovascular diseases.

Histochemistry, phenolic content, antioxidant, and anti-diabetic activities ofVernonia amygdalinaleaf extract

“…Quercetin is one of the most studied flavonoids and has been reported for its potent antioxidant activities (Bentz, 2009;Ozgen, Kilinc, & Selamoğlu, 2016). Several studies have also reported the antioxidant activities of alkaloids Tiong et al, 2013), thereby indicating an influential role of the identified alkaloids on the mid rib of V. amygdalina leaf ( Figure 1G).…”

“…Identification of (‐)epi‐catechin in medicinal plants have also been correlated with their antioxidant activities (Chen, Chen, Xiao, & Fu, ; Grzesik, Naparło, Bartosz, & Sadowska‐Bartosz, ). Quercetin is one of the most studied flavonoids and has been reported for its potent antioxidant activities (Bentz, ; Ozgen, Kilinc, & Selamoğlu, ). Several studies have also reported the antioxidant activities of alkaloids (Erukainure, Oyebode et al, ; Tiong et al, ), thereby indicating an influential role of the identified alkaloids on the mid rib of V. amygdalina leaf (Figure G).…”

Dietary quercetin supplements: Assessment of online product informations and quantitation of quercetin in the products by high‐performance liquid chromatography

“…Like the parent compound, some quercetin metabolites can also interact with serum albumin, biotransformation enzymes, and drug transporters (Miron, Aprotosoaie, Trifan, & Xiao, 2017;Poór et al, 2017;Poór, Boda, Mohos, et al, 2018). Quercetin supplements received great attention by consumers and patients favoring Complementary and Alternative Medicine because of its potent antioxidant effect (Ozgen, Kilinc, & Selamoğlu, 2016). As quercetin and/or its metabolites appear in the circulation (and likely in some tissues), it is reasonable to hypothesize that quercetin intake at high doses may interfere with simultaneous medication therapy and/or causes adverse effects.…”

Polyphenolic Compounds in Human Health with Pharmacological Properties

“…The family members of flavonoids include flavones, flavonol, isoflavones, flavanones, flavanonol, flavanol and anthocyanidin. Flavonols are represented mainly by quercetin, kaempferol and myricetin, of these, quercetin is most ubiquitous [1,2]. Recently, the numbers of the studies conducted for the use of flavonoids in various areas of industry are increasing.…”

“…Both known cases of the antioxidant effect, preventive mechanism and chain-breaking mechanism, are implied to be responsible for the high action of flavonoids. There are most of studies demonstrated to the importance of flavonoid structure for their antiradical activity as chain-breaking antioxidants [1,2,6]. As a result, the use of ecological and natural products that inhibit oxidation of biomolecules in living organism became more preferable in human diet.…”