Pharmacokinetics of Quercetin
Muhammad Candragupta Jihwaprani, Wahyu Choirur Rizky, Mazhar Mushtaq
Abstract
Quercetin (QUE) is a primary polyphenol in the flavonoid family. It is categorized as one of the six subclasses of flavonoid compounds. As an abundant form of flavonoid molecules, quercetins are ubiquitously distributed in various dietary plants, including apples, berries, onions, bananas, tomatoes, and grapes. Furthermore, it is affordably marketed in the form of dietary supplement tablets. QUE is relatively lipophilic with low solubility in the water. Withal, QUE glucoside is more water soluble than the aglycone, and its absorption is limited to sodium-dependent glucose transporter-1 (SGLT-1); however, glucose transporter-2 (GLUT-2)-dependent absorption is also a significant contributor. Following absorption, QUE undergoes extensive metabolism in the liver, generating numerous metabolites. Data on the bioavailability of QUE differ substantially depending on the methods used for measuring QUE level. Pharmacokinetic interactions of QUE and its metabolites on cytochrome P450 enzymes have been studied extensively, but the results among the studies were inconsistent, such as weak inhibition toward CYP3A4 and no inhibition of CYP2D6 activity. Additionally, inhibition affects ATP- (adenosine triphosphate) binding cassette (ABC). Based on the pharmacokinetics profile, QUE has variable bioavailability based on the polymorphism of intestinal enzymes and transporters.