Metabolite profiling and enzyme reaction phenotyping of luseogliflozin, a sodium-glucose cotransporter 2 inhibitor, in humans.

1. To understand the clearance mechanism of luseogliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, we investigated its human metabolite profile and metabolic enzymes responsible for the primary metabolic pathways in human using reaction phenotyping. 2. Sixteen metabolites of luseogliflozin were found in human plasma and/or urine and their structural information indicated that the drug was metabolized via multiple metabolic pathways. The primary metabolic pathways involve (1) O-deethylation to form M2 and subsequent glucuronidation to form M12, (2) ω-hydroxylation at ethoxy group to form M3 followed by oxidation to form the corresponding carboxylic acid metabolite (M17) and (3) direct glucuronidation to form M8. 3. The reaction phenotyping studies indicated that the formation of M2 was mainly mediated by cytochrome P450 (CYP) 3A4/5, and subsequently M12 formation was catalyzed by UGT1A1, UGT1A8 and UGT1A9. The formation of M3 was mediated by CYP4A11, CYP4F2 and CYP4F3B, and the further oxidation of M3 to M17 was mediated by alcohol dehydrogenase and aldehyde dehydrogenase. The formation of M8 was catalyzed by UGT1A1. 4. These results demonstrate that luseogliflozin is metabolized through multiple pathways, including CYP-mediated oxidation and glucuronidation, in human.

Investigation of endogenous compounds for assessing the drug interactions in the urinary excretion involving multidrug and toxin extrusion proteins.

PURPOSE: Multidrug and toxin extrusion proteins (MATEs) are multispecific organic cation transporters mediating the efflux of various cationic drugs into the urine. The present study aimed at identifying endogenous compounds in human plasma and urine specimens as biomarkers to evaluate drug interactions involving MATEs in the kidney without administration of their exogenous probe drugs. METHODS: An untargeted metabolomic analysis was performed using urine and plasma samples from healthy volunteers and mice treated with or without the potent MATE inhibitor, pyrimethamine. Plasma and urinary concentrations of candidate markers were measured using liquid chromatography-mass spectrometry. Transport activities were determined in MATE- or OCT2-expressing HEK293 cells. The deuterium-labeled compounds of candidates were administered to mice for pharmacokinetics study. RESULTS: Urinary excretion of eleven compounds including thiamine and carnitine was significantly lower in the pyrimethamine-treatment group in humans and mice, whereas no endogenous compound was noticeably accumulated in the plasma. The renal clearance of thiamine and carnitine was decreased by 70%-84% and 90%-94% (p < 0.05), respectively, in human. The specific uptake of thiamine was observed in MATE1-, MATE2-K- or OCT2-expressing HEK293 cells with Km of 3.5 ± 1.0, 3.9 ± 0.8 and 59.9 ± 6.7 µM, respectively. The renal clearance of carnitine-d 3 was decreased by 62% in mice treated with pyrimethamine. CONCLUSIONS: Our findings indicate that MATEs account for the efflux of thiamine and perhaps carnitine as well as drugs into the urine. The urinary excretion of thiamine is useful to detect drug interaction involving MATEs in the kidney.

Association of multidrug resistance-associated protein 2 single nucleotide polymorphism rs12762549 with the basal plasma levels of phase II metabolites of isoflavonoids in healthy Japanese individuals.

OBJECTIVES: Multidrug resistance-associated protein 2 (MRP2; ABCC2) is an ATP-binding cassette transporter that mediates the efflux of anionic drugs and phase II metabolites. Our aim was to elucidate the impact of a single nucleotide polymorphism, rs12762549 (G>C), on the in-vivo activity of MRP2. METHODS: Plasma specimens collected from 18 healthy volunteers were subjected to an untargeted metabolomic analysis using liquid chromatography-mass spectrometry. The role of MRP2 in the disposition of substances of interest was then examined in vivo in Mrp2-deficient mutant rats (Eisai hyperbilirubinemic rats; EHBRs) and in vitro in human MRP2-expressing membrane vesicles. RESULTS: A multivariate analysis model using liquid chromatography-mass spectrometry data sets successfully differentiated the GG and the CC genotypes of rs12762549. The C allele is associated with the basal plasma levels of the five phase II metabolites of genistein and dihydrogenistein. Such phase II metabolites were also accumulated in EHBR, compared with normal rats, partly because of the reduced biliary excretion. Following oral administration of genistein and daidzein, the plasma concentrations of total genistein and total daidzein, which were mainly accounted for by sulfoglucuronide conjugates, were markedly higher in EHBR than in normal rats. ATP-dependent uptake of sulfoglucuronides and glucuronides of the isoflavonoids was observed only in MRP2-expressing membrane vesicles. CONCLUSION: MRP2 plays a significant role in preventing the accumulation of phase II metabolites of isoflavonoids. The rs12762549 is associated with an interindividual difference in the plasma levels of MRP2 substrates, phase II metabolites of isoflavonoids, suggesting that this single nucleotide polymorphism is associated with variations in in-vivo MRP2 activity.