Pharmacokinetics The bioavailability of<unk>  in humans is low and highly variable (0–50%), and it is rapidly cleared with an elimination half-life of 1–2 hours after ingesting<unk>  foods or supplements. Following dietary ingestion,<unk>  undergoes rapid and extensive metabolism that makes the biological effects presumed from in vitro studies unlikely to apply in vivo.<unk>  supplements in the aglycone form are far less bioavailable than the<unk>  glycoside often found in foods, especially red onions. Ingestion with high-fat foods may increase bioavailability compared to ingestion with low-fat foods, and carbohydrate-rich foods may increase absorption of<unk>  by stimulating gastrointestinal motility and colonic fermentation. Metabolism In rats,<unk>  did not undergo any significant phase I metabolism. In contrast,<unk>  did undergo extensive phase II (conjugation) to produce metabolites that are more polar than the parent substance and hence are more rapidly excreted from the body. In vitro, the meta-hydroxyl group of catechol is methylated by catechol-O-methyltransferase. Four of the five hydroxyl groups of<unk>  are glucuronidated by UDP-glucuronosyltransferase. The exception is the 5-hydroxyl group of the flavonoid ring which generally does not undergo glucuronidation. The major metabolites of orally absorbed<unk>  are<unk> -3-glucuronide, 3'-methylquercetin-3-glucuronide, and<unk> -3'-sulfate. A methyl metabolite of<unk>  has been shown in vitro to be more effective than<unk>  at inhibiting lipopolysaccharide-activated macrophages. Compared to other flavonoids<unk>  is one of the most effective inducers of the phase II detoxification enzymes.<unk>  is a strong inhibitor of the cytochrome P450 enzymes CYP3A4 and CYP2D6. Drugs that are metabolized by these pathways may have increased effect. Pharmacological research<unk>  has been reported to inhibit the oxidation of other molecules and hence is classified as an antioxidant in vitro. It contains a polyphenolic chemical substructure that stops oxidation in vitro by acting as a scavenger of free radicals.<unk>  has been shown to inhibit the PI3K/AKT pathway leading to downregulation of the anti-apoptotic protein Bcl-w.<unk>  activates or inhibits the activities of a number of proteins in vitro. For example, it is a nonspecific protein kinase enzyme inhibitor.
Quercetin
Ginkgo biloba
Retinol
Soybean oil
Gutter oil
Fish oil
Fish oil 
Psymberin