In vitro and in vivo conjugation of dietary hydroxycinnamic acids by UDP-glucuronosyltransferases and sulfotransferases in humans

摘要: Hydroxycinnamic acids are a class of phenolic antioxidants found widely in dietary plants. Their biotransformation the human organism primarily involves Phase II conjugation reactions. In this study, activities UDP-glucuronosyltransferases (UGTs) and sulfotransferases (SULTs) towards major hydroxycinnamic (caffeic, dihydrocaffeic, dihydroferulic, ferulic isoferulic acids) were investigated. Conjugate formation was evaluated using liver intestinal S9 homogenates, vitro characterization carried out recombinant UGTs SULTs. Analysis kinetics acid homogenates revealed that intrinsic clearance (V(max)/K(m)) is much greater for sulfation than glucuronidation. Assessment activity panel SULTs showed SULT1A1 most active caffeic, dihydrocaffeic acids, while SULT1E1 dihydroferulic acids. Only significantly glucuronidated by explained high liver-specific UGT1A9. Studies on demonstrated markedly lower K(m) To further corroborate our findings, we an intervention study healthy humans to determine conjugates urine after consumption hydroxycinnamate-rich coffee (200 ml). sulfates main urine, with exception acid, which mainly glucuronidated. These data suggest predominant humans, SULT mediated factor determining bioavailability vivo.