Anti-Inflammatory Properties of Quercetin: A Review

Abstract

Quercetin, one of the most taken flavonoid with diet, belongs to the family of flavonols. Quercetin occurs as a glycoside or as an aglycone and is gotten from various dietary sources such as apples, berries, onions, kale. Quercetin is being reviewed based on its bioavailability, metabolism and anti-inflammatory properties. Inflammation is the body's immune response to an irritant; this could be a pathogen or foreign object. An inflammatory response is either acute or chronic depending on the duration of inflammation and prolonged inflammatory response can lead to various diseases that are harmful to the body. Studies have shown that quercetin exerts good anti-inflammatory, antioxidant and anti-allergic activity by acting on leukocytes, targeting signaling kinases as well as membrane proteins crucial for an inflammatory response and acts as a scavenger of free radicals. Quercetin also down regulates the expression of pro-inflammatory factor while up regulating the expression of anti-inflammatory factor and this aids in maintaining homeostasis. Although poorly bioavailable due to its rapid metabolism, quercetin is an effective modulator of inflammation. Keywords: Quercetin, inflammation, antioxidants, flavonols, free-radicals