Identification of an Alternative Glycyrrhizin Metabolite Causing Liquorice-Induced Pseudohyperaldosteronism and the Development of ELISA System to Detect the Predictive Biomarker

Liquorice is usually used as crude drug in traditional Japanese Kampo medicine and traditional Chinese medicine. Liquorice-containing glycyrrhizin (GL) can cause pseudohyperaldosteronism as a side effect. Previously, we identified 18β-glycyrrhetyl-3-O-sulfate (3) as a GL metabolite in Eisai hyperbilirubinuria rats (EHBRs) with the dysfunction of multidrug resistance-related protein (Mrp2). We speculated that 3 was associated with the onset of liquorice-induced pseudohyperaldosteronism, because it was mainly detected in serum of patients with suspected to have this condition. However, it is predicted that other metabolites might exist in the urine of EHBRs orally treated with glycyrrhetinic acid (GA). We explored other metabolites in the urine of EHBRs, and investigated the pharmacokinetic profiles of the new metabolite in EHBRs and normal Sprague-Dawley rats. We further analyzed the serum concentrations of the new metabolite in the patients of pseudohyperaldosteronism. Finally, we developed the analyzing method of these metabolites as a preventive biomarker for the onset of pseudohyperaldosteronism using an enzyme-linked immunosorbent assay (ELISA). We isolated a new GL metabolite, 18β-glycyrrhetyl-3-O-sulfate-30-O-glucuronide (4). Compound 4 significantly inhibited rat type-2 11β-hydroxysteroid dehydrogenase (11β-HSD2) and was a substrate of both organic anion transporter (OAT) 1 and OAT3. Compound 4 was also detected in the serum of patients with suspected pseudohyperaldosteronism at an approximately 10-fold lower concentrations than 3, and these concentrations were positively correlated. Compound 4 showed a lower serum concentration and weaker inhibitory titer on 11β-HSD2 than 3. We developed an enzyme-linked immunosorbent assay system using an anti-18β-glycyrrhetyl-3-O-glucuronide (3MGA) monoclonal antibody to measure the serum concentration of 3 to facilitate the measurement of biomarkers to predict the onset of pseudohyperaldosteronism. Although we found 4 as the secondary candidate causative agent, 3 could be the main potent preventive biomarker of liquorice-induced pseudohyperaldosteronism. Compound 3 was detected in serum at a higher concentration than GA and 4, implying that 3 may be a pharmacologically active ingredient mediating not only the development of pseudohyperaldosteronism but anti-inflammatory effects in humans administered GL or other liquorice-containing preparations.

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Limited Brain Distribution of [3R,4R,5S]-4-Acetamido-5-amino-3-(1-ethylpropoxy)-1-cyclohexene-1-carboxylate Phosphate (Ro 64-0802), a Pharmacologically Active Form of Oseltamivir, by Active Efflux across the Blood-Brain Barrier Mediated by Organic Anion Transporter 3 (Oat3/Slc22a8) and Multidrug Resistance-Associated Protein 4 (Mrp4/Abcc4)

Drug Metabolism and Disposition ◽

10.1124/dmd.108.024018 ◽

2008 ◽

Vol 37 (2) ◽

pp. 315-321 ◽

Cited By ~ 95

Author(s):

Atsushi Ose ◽

Mototsugu Ito ◽

Hiroyuki Kusuhara ◽

Kenzo Yamatsugu ◽

Motomu Kanai ◽

...

Keyword(s):

Multidrug Resistance ◽

Blood Brain Barrier ◽

Organic Anion ◽

Active Form ◽

Organic Anion Transporter ◽

Brain Distribution ◽

Active Efflux ◽

Anion Transporter ◽

Pharmacologically Active ◽

Organic Anion Transporter 3

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Reduced folate derivatives are endogenous substrates for cMOAT in rats

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1998.275.4.g789 ◽

1998 ◽

Vol 275 (4) ◽

pp. G789-G796 ◽

Cited By ~ 4

Author(s):

Hiroyuki Kusuhara ◽

Yong-Hae Han ◽

Minoru Shimoda ◽

Eiichi Kokue ◽

Hiroshi Suzuki ◽

...

Keyword(s):

Biliary Excretion ◽

Organic Anion ◽

Membrane Vesicles ◽

Organic Anion Transporter ◽

Sprague Dawley ◽

Anion Transporter ◽

Bile Drainage ◽

Endogenous Substrates

We examined the role of the canalicular multispecific organic anion transporter (cMOAT) in the biliary excretion of reduced folate derivatives in vivo and in vitro using normal [Sprague-Dawley rats (SDR)] and mutant [Eisai hyperbilirubinemic rats (EHBR)] rats whose cMOAT is hereditarily deficient. In vivo, the biliary excretion of endogenous tetrahydrofolate (H4PteGlu), 5-methyltetrahydrofolate (5-CH3-H4PteGlu), and 5,10-methylenetetrahydrofolate (5,10-CH2-H4PteGlu) in EHBR was reduced to 8.2%, 1.9%, and 5.5% of those in SDR, respectively, whereas that of 10-formyltetrahydrofolate (10-HCO-H4PteGlu) was detected only in SDR and not in EHBR. Bile drainage caused reduction of endogenous plasma folate concentrations in SDR but not in EHBR. In vitro, significant ATP-dependent uptake of3H-labeled 5-CH3-H4PteGlu into canalicular membrane vesicles was observed only in SDR. This ATP-dependent uptake was saturable with a Michaelis constant ( K m) value of 126 μM, which was comparable with its inhibitor constant ( K i) value of 121 μM for the ATP-dependent uptake of a typical cMOAT substrate, 2,4-dinitrophenyl- S-glutathione (DNP-SG). Vice versa, DNP-SG inhibited the uptake of 5-CH3-H4PteGlu with a K i of 35 μM, which was similar to its K m value. In addition, H4PteGlu and 5,10-CH2-H4PteGlu also inhibited the ATP-dependent uptake of DNP-SG. These results indicate that 5-CH3-H4PteGlu and other derivatives are transported via cMOAT. Therefore, reduced folate derivatives are the first endogenous substrates for cMOAT that do not contain glutathione, glucuronide, or sulfate moieties.

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Molecular cloning of canalicular multispecific organic anion transporter defective in EHBR

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1997.272.1.g16 ◽

1997 ◽

Vol 272 (1) ◽

pp. G16-G22 ◽

Cited By ~ 24

Author(s):

K. Ito ◽

H. Suzuki ◽

T. Hirohashi ◽

K. Kume ◽

T. Shimizu ◽

...

Keyword(s):

Amino Acid ◽

Stop Codon ◽

Organic Anion ◽

Amino Acid Level ◽

Premature Stop Codon ◽

Autosomal Recessive Inheritance ◽

Organic Anions ◽

Organic Anion Transporter ◽

Sprague Dawley ◽

Anion Transporter

Several organic anions are excreted into the bile via a canalicular multispecific organic anion transporter (cMOAT), which is hereditarily defective in mutant rats, such as the Eisai hyperbilirubinemic rat (EHBR) and TR- rat. In the present study, we cloned cMOAT from the Sprague-Dawley rat liver cDNA library based on the homology with human multidrug resistance-associated protein (hMRP). cMOAT was encoded by 4,623-base pair (bp) cDNA with a homology of 53.0 and 46.3% with hMRP at the cDNA and deduced amino acid level, respectively. The deduced amino acid sequence was the same as that cloned in Wistar rats (C. C. Paulusma, P. J. Bosma, G. J. Zaman, C. T. Bakker, M. Otter, G. L. Sceffer, P. Borst, and R. P. Oude Elferink. Science Wash. DC 271: 1126, 1996) except for four amino acid substitutions. By screening the library, three kinds of cDNA species for cMOAT with the same open reading frame and different 3'-untranslated region lengths (0.2, 1.5, and 3.5 kbp) were isolated. The Northern blot analysis of poly(A)+ RNA from the liver revealed that the expression of plural bands (approximately 5, 6, and 8 kb) was defective in EHBR, and this may be due to the presence of these cDNA species. Expression of cMOAT was observed almost exclusively in the liver and to a lesser extent in the duodenum, kidney, and jejunum. Reverse transcription-polymerase chain reaction (RT-PCR) and subsequent sequence analysis of EHBR liver, kidney, duodenum, and jejunum revealed that 1-bp replacement from G to A at nucleotide 2564 resulted in the introduction of the premature stop codon in all tissues examined. This mutation was different from that observed in TR (C. C. Paulusma, P. J. Bosma, G. J. Zaman, C. T. Bakker, M. Otter, G. L. Sceffer, P. Borst, and R. P. Oude Elferink. Science Wash. DC 271: 1126, 1996). Because EHBR and TR- are allelic mutants and both strains exhibit an autosomal recessive inheritance in the biliary excretion of organic anions it was concluded that the impaired expression of this particular protein is related to the pathogenesis of hyperbilirubinemia in the mutant animals.

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