Mechanism of Action of Flavonoids as Anti-inflammatory Agents: A Review

Flavonoids are polyphenolic compounds that occur ubiquitously in plants having a variety of biological effects both in vitro and in vivo. They have been found to have antimicrobial, antiviral, anti-ulcerogenic, cytotoxic, anti-neoplastic, mutagenic, antioxidant, antihepatotoxic, antihypertensive, hypolipidemic, antiplatelet and anti-inflammatory activities. Flavonoids also have biochemical effects, which inhibit a number of enzymes such as aldose reductase, xanthine oxidase, phosphodiesterase, Ca(+2)-ATPase, lipoxygenase, cycloxygenase, etc. They also have a regulatory role on different hormones like estrogens, androgens and thyroid hormone. They have been found to have anti-inflammatory activity in both proliferative and exudative phases of inflammation. Several mechanisms of action have been proposed to explain anti-inflammatory action of flavonoids. The aim of the present review is to give an overview of the mechanism of action of potential anti-inflammatory flavonoids.