Praeruptorin A (PA) and B (PB) are two important compounds isolated from Bai-hua Qian-hu and have been reported to exert multiple biochemical and pharmacological activities. The present study aims to determine the inhibition of PA and PB on the activity of important phase II drug-metabolizing enzymes uridine 5'-diphospho-glucuronosyltransferase (UGTs) isoforms. In vitro UGT incubation system was used to determine the inhibition potential of PA and PB on the activity of various UGT isoforms. In silico docking was performed to explain the inhibition difference between PA and PB towards the activity of UGT1A6. Inhibition behaviour was determined, and in vitro-in vivo extrapolation was performed by using the combination of in vitro inhibition kinetic parameter (K ) and in vivo exposure level of PA. Praeruptorin A (100 μM) exhibited the strongest inhibition on the activity of UGT1A6 and UGT2B7, with 97.8% and 90.1% activity inhibited by 100 μM of PA, respectively. In silico docking study indicates the significant contribution of hydrogen bond interaction towards the stronger inhibition of PA than PB towards UGT1A6. Praeruptorin A noncompetitively inhibited the activity of UGT1A6 and competitively inhibited the activity of UGT2B7. The inhibition kinetic parameter (K ) of PA towards UGT1A6 and UGT2B7 was calculated to be 1.2 and 3.3 μM, respectively. The [I]/K value was calculated to be 15.8 and 5.8 for the inhibition of PA on UGT1A6 and UGT2B7, indicating high inhibition potential of PA towards these two UGT isoforms in vivo. Therefore, closely monitoring the interaction between PA and drugs mainly undergoing UGT1A6 or UGT2B7-catalyzed metabolism is very necessary. Copyright © 2016 John Wiley & Sons, Ltd.
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http://dx.doi.org/10.1002/ptr.5697 | DOI Listing |
Pharmacol Res Perspect
December 2024
Cansearch Research Platform for Pediatric Oncology and Hematology, Faculty of Medicine, Department of Pediatrics, Gynecology and Obstetrics, University of Geneva, Geneva, Switzerland.
UGT2B10 is a phase II drug metabolizing enzyme with limited information on its role in the metabolism of drugs, especially in the pediatric hematopoietic stem cell transplantation setting. Previously, we investigated UGT2B10's role through in silico analyses and prioritized acetaminophen (APAP), lorazepam (LOR), mycophenolic acid (MPA), and voriconazole N-oxide (VCZ N-oxide) for in vitro investigations. In this report, we present in vitro screening of these candidates and of voriconazole (VCZ) to assess their potential to be substrates and/or inhibitors of UGT2B10.
View Article and Find Full Text PDFDrug Metab Dispos
October 2024
Pharmacotherapy and Translational Research, University of Florida, United States
Many factors cause inter-person variability in the activity and expression of liver cytochrome P450 (CYP) drug-metabolizing enzymes, leading to variable drug exposure and treatment outcomes. Several liver-enriched transcription factors (TFs) are associated with CYP expression, with estrogen receptor alpha (ESR1) and constitutive androstane receptor (CAR or NR1I3) being the two top factors. ESR1 and NR1I3 undergo extensive alternative splicing that results in numerous splice isoforms, but how these splice isoforms associate with CYP expression is unknown.
View Article and Find Full Text PDFAAPS J
September 2024
Pharmacokinetics, Dynamics and Metabolism, Pfizer Research and Development, Pfizer Inc., 445 Eastern Point Rd, Groton, CT, 06340, USA.
Lamotrigine is a phenyltriazine anticonvulsant that is primarily metabolized by phase II UDP-glucuronosyltransferases (UGT) to a quaternary N2-glucuronide, which accounts for ~ 90% of the excreted dose in humans. While there is consensus that UGT1A4 plays a predominant role in the formation of the N2-glucuronide, there is compelling evidence in the literature to suggest that the metabolism of lamotrigine is catalyzed by another UGT isoform. However, the exact identity of the UGT isoform that contribute to the formation of this glucuronide remains uncertain.
View Article and Find Full Text PDFFront Pharmacol
August 2024
Department of Pharmacy, Huashan Hospital, Fudan University, Shanghai, China.
Objective: The metabolism- and transporter-based drug-drug interactions (DDIs) between mycophenolate mofetil (MMF) and co-administered medications may be key factors for the high individual variability in MMF exposure. This study systematically assessed the influence of co-medications on the mycophenolic acid (MPA) pharmacokinetic (PK) process , particularly to provide mechanistic evidence of the metabolic interaction among steroids, cyclosporine (CsA), and MMF.
Methods: Based on a previous study, we hypothesized that there are three main DDI pathways affecting MMF PK .
Cells
August 2024
Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, USA.
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