Myricetin

Myricetin is a flavonoid, one of the large family of polyphenolic compounds that give many plants their color and contribute to their chemistry. More precisely it is a flavonol, the same structural subclass as quercetin, to which it is closely related and with which it shares many properties; chemically it is a hexahydroxyflavone, meaning it carries six hydroxyl groups on the flavonoid skeleton, a feature central to its antioxidant behavior ^[1].

Myricetin is widely distributed in the diet. It occurs in a range of fruits and vegetables, in berries, nuts, tea, red wine and various herbs, so that most people consume small amounts of it regularly, though typical daily intake is modest ^[1][2]. Because it is a normal constituent of foods, it is generally encountered as part of a mixed diet rather than in isolation, and it is also marketed on its own as a dietary supplement ^[1].

A large body of laboratory research has examined myricetin's biological activities. It is described as a strong antioxidant that scavenges reactive oxygen species and binds metal ions, and it has shown anti-inflammatory, antiviral, antithrombotic, neuroprotective, antidiabetic and anticancer effects in cell and animal studies ^[1][3][4]. Reviews highlight its potential relevance to conditions ranging from cardiovascular disease and diabetes to neurodegenerative disorders, and it has been studied for effects on inflammatory enzymes and cell-signaling pathways involved in cancer ^[3][4]. It is important to note, however, that much of this evidence comes from preclinical work; robust human clinical data are limited, and the compound's low absorption after ingestion is a recognized obstacle to translating laboratory findings into practical use ^[4].

Myricetin also has a more complicated side: under certain conditions it can behave as a prooxidant, undergoing autoxidation that generates free radicals, and it has produced mixed results in tests of mutagenicity, showing both anti-mutagenic and, in some assays, mutation-promoting behavior ^[1]. It is not an approved medicine but a dietary flavonoid, treated as a food component and supplement ingredient rather than a pharmaceutical ^[1].

Dietary myricetin is considered safe. Concentrated supplement doses are less studied; very high intakes could theoretically have pro-oxidant or enzyme-inhibiting effects. Interactions with drug-metabolizing enzymes are possible, so caution with medications.