Quercetin: A Versatile Flavonoid

Abstract

Associative evidence from observational and intervention studies in human subjects shows that a diet including plant foods (particularly fruit and vegetables rich in antioxidants) conveys health benefits. There is no evidence that any particular nutrient or class of bioactive substances makes a special contribution to these benefits. Flavonoids occur naturally in fruits, vegetables and beverages such as tea and wine. Quercetin is the major flavonoid which belongs to the class called flavonols. Quercetin is found in many common foods including apples, tea, onions, nuts, berries, cauliflower, cabbage and many other foods. Quercetin provides many health promoting benefits, including improvement of cardiovascular health, eye diseases, allergic disorders, arthritis, reducing risk for cancers and many more. The main aim of this review is to obtain a further understanding of the reported beneficial health effects of Quercetin, its pharmacological effects, clinical application and also to evaluate its safety.

Quercetin attenuates, indomethacin-induced acute gastric ulcer in rats

“…In this study group, the treatment with indomethacin led to the loss of architecture and vacuolation of cells while the quercetin treatment resulted in a normal mucosa except for an increase in mucus granules in surface mucus cells. Quercetin exerts antioxidant influences by several mechanisms; these include scavenging oxygen radicals, protecting against lipid peroxidation, and chelating metal ions [37]. The high antioxidant activity of quercetin may be attributed to its capacity to diffuse through the cell membrane at a high rate [32].…”

Phytochemical Screening and Evaluation of in Vitro Antioxidant Potential of Immature Palmyra Palm (Borassus Flabellifer Linn.) Fruits

“…The toxicity of NO increases greatly when it reacts with the superoxide radical, forming the highly reactive peroxynitrite anion (ONOO−). Nitric oxide has been shown to be directly scavenged by flavonoids [59].…”

Quercetin – a flavonoid with a high health-promoting potential

“…Quercitrin (3-rhamnoside of quercitin), isoquercitrin (3-glucoside of quercetin), avicularin (3-arabinoside of quercetin), spiraeoside (4-glucoside of quercetin), hyperside (3-galactoside of quercetin) are listed among the derivatives of quercetin. Quercetin is also the basis of other flavonoids biosynthesis, such as hesperidin, naringenin, as well as tangeretin (Jowsa et al, 2008;Lakhanpal and Rai, 2007;Materska, 2008). The presence of hydroxyl groups in a molecule of quercetin makes it display its potent antioxidative properties (Jakubowicz-Gil, 2012).…”