Glucuronidation of nonsteroidal anti-inflammatory drugs: identifying the enzymes responsible in human liver microsomes.

Article Details

Citation

Kuehl GE, Lampe JW, Potter JD, Bigler J

Glucuronidation of nonsteroidal anti-inflammatory drugs: identifying the enzymes responsible in human liver microsomes.

Drug Metab Dispos. 2005 Jul;33(7):1027-35. doi: 10.1124/dmd.104.002527. Epub 2005 Apr 20.

PubMed ID
15843492 [ View in PubMed
]
Abstract

Nonsteroidal anti-inflammatory drugs (NSAIDs), used for the treatment of pain and inflammation, are eliminated primarily through conjugation with polar sugar moieties to form glucuronides. Glucuronidation is catalyzed by the UDP-glucuronosyltransferases (UGT) superfamily. An inverse relationship may exist between glucuronidation activity and NSAID efficacy; however, specific UGTs catalyzing conjugation of the structurally diverse NSAIDs have yet to be identified systematically. Therefore, NSAID glucuronidation activity by 12 individually expressed UGTs was investigated by liquid chromatography-tandem mass spectrometry. The relative rates of NSAID glucuronidation varied among UGT enzymes examined, demonstrating specificity of the individual UGTs toward selected NSAIDs. Kinetic parameters were determined for expressed UGT Supersomes and compared with parameters determined in pooled human liver microsomes (HLMs). Comparison of K(m) values suggested roles for UGTs 1A3 and 2B7 in indene glucuronidation and UGTs 1A9, 2B4, and 2B7 in profen glucuronidation. Inhibitory studies in pooled HLMs support the role of UGTs 1A1, 1A3, 1A9, 2B4, and 2B7 in the glucuronidation of ibuprofen, flurbiprofen, and ketoprofen. Bilirubin did not inhibit indomethacin or diclofenac glucuronidation, suggesting that UGT1A1 was not involved in catalysis. Imipramine did not inhibit glucuronidation of sulindac, sulindac sulfone, indomethacin, or naproxen in pooled HLMs, suggesting that UGT1A3 was not a principal hepatic catalyst. Nevertheless, multiple UGT enzymes, most notably UGTs 1A1, 1A9, 2B4, and 2B7, seem to be involved in the hepatic catalysis of NSAID glucuronidation.

DrugBank Data that Cites this Article

Drugs
Drug Enzymes
DrugEnzymeKindOrganismPharmacological ActionActions
DiclofenacUDP-glucuronosyltransferase 1-3ProteinHumans
Unknown
Substrate
Details
DiclofenacUDP-glucuronosyltransferase 1-9ProteinHumans
Unknown
Substrate
Details
DiclofenacUDP-glucuronosyltransferase 2B4ProteinHumans
Unknown
Substrate
Details
DiclofenacUDP-glucuronosyltransferase 2B7ProteinHumans
Unknown
Substrate
Details
Drug Reactions
Reaction
Details