title: Novel resveratrol-based substrates for human hepatic, renal, and intestinal UDP-glucuronosyltransferases.
abstract: Trans-Resveratrol (tRes) has been shown to have powerful antioxidant, anti-inflammatory, anticarcinogenic, and antiaging properties; however, its use as a therapeutic agent is limited by its rapid metabolism into its conjugated forms by UDP-glucuronosyltransferases (UGTs). The aim of the current study was to test the hypothesis that the limited bioavailability of tRes can be improved by modifying its structure to create analogs which would be glucuronidated at a lower rate than tRes itself. In this work, three synthetic stilbenoids, (E)-3-(3-hydroxy-4-methoxyphenyl)-2-(3,4,5-trimethoxyphenyl)acrylic acid (NI-12a), (E)-2,4-dimethoxy-6-(4-methoxystyryl)benzaldehyde oxime (NI-ST-05), and (E)-4-(3,5-dimethoxystyryl)-2,6-dinitrophenol (DNR-1), have been designed based on the structure of tRes and synthesized in our laboratory. UGTs recognize and glucuronidate tRes at each of the 3 hydroxyl groups attached to its aromatic rings. Therefore, each of the above compounds was designed with the majority of the hydroxyl groups blocked by methylation and the addition of other novel functional groups as part of a drug optimization program. The activities of recombinant human UGTs from the 1A and 2B families were examined for their capacity to metabolize these compounds. Glucuronide formation was identified using HPLC and verified by β-glucuronidase hydrolysis and LC-MS/MS analysis. NI-12a was glucuronidated at both the -COOH and -OH functions, NI-ST-05 formed a novel N-O-glucuronide, and no product was observed for DNR-1. NI-12a is primarily metabolized by the hepatic and renal enzyme UGT1A9, whereas NI-ST-05 is primarily metabolized by an extrahepatic enzyme, UGT1A10, with apparent Km values of 240 and 6.2 μM, respectively. The involvement of hepatic and intestinal UGTs in the metabolism of both compounds was further confirmed using a panel of human liver and intestinal microsomes, and high individual variation in activity was demonstrated between donors. In summary, these studies clearly establish that modified, tRes-based stilbenoids may be preferable alternatives to tRes itself due to increased bioavailability via altered conjugation.
authors.affiliation: Departments of Biochemistry & Molecular Biology, College of Medicine, and ‡Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences , Little Rock, Arkansas 72205, United States.
authors.forename: Aleksandra K
authors.initials: AK
authors.lastname: Greer
authors.forename: Nikhil R
authors.initials: NR
authors.lastname: Madadi
authors.forename: Stacie M
authors.initials: SM
authors.lastname: Bratton
authors.forename: Sarah D
authors.initials: SD
authors.lastname: Eddy
authors.forename: Zofia
authors.initials: Z
authors.lastname: Mazerska
authors.forename: Howard P
authors.initials: HP
authors.lastname: Hendrickson
authors.forename: Peter A
authors.initials: PA
authors.lastname: Crooks
authors.forename: Anna
authors.initials: A
authors.lastname: Radominska-Pandya
mesh_terms: D002851:Chromatography, High Pressure Liquid; D014453:Glucuronosyltransferase / Q000378:metabolism*; D006801:Humans; D007422:Intestines / Q000201:enzymology*; D007668:Kidney / Q000201:enzymology*; D008099:Liver / Q000201:enzymology*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008861:Microsomes / Q000201:enzymology; D000077185:Resveratrol; D013267:Stilbenes / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D013267:Stilbenes; D014453:Glucuronosyltransferase; D000077185:Resveratrol