3-Ketocholanoic Acid Is the Major in Vitro Human Hepatic Microsomal Metabolite of Lithocholic Acid

被引：33

作者：

Deo, Anand K. ^{[1
]}

Bandiera, Stelvio M. ^{[1
]}

机构：

[1] Univ British Columbia, Fac Pharmaceut Sci, Vancouver, BC V6T 1Z3, Canada

来源：

DRUG METABOLISM AND DISPOSITION | 2009年 / 37卷 / 09期

基金：

加拿大健康研究院;

关键词：

VITAMIN-D-RECEPTOR; BILE-ACID; INTRAHEPATIC CHOLESTASIS; CHENODEOXYCHOLIC ACID; NUCLEAR RECEPTORS; LIVER-MICROSOMES; KETOCONAZOLE; CYTOCHROME-P450; THERAPY; RAT;

D O I：

10.1124/dmd.109.027763

中图分类号：

R9 [药学];

学科分类号：

1007 ;

摘要：

3 alpha-Hydroxy-5 beta-cholan-24-oic (lithocholic) acid is a relatively minor component of hepatic bile acids in humans but is highly cytotoxic. Hepatic microsomal oxidation offers a potential mechanism for effective detoxification and elimination of bile acids. The aim of the present study was to investigate the biotransformation of lithocholic acid by human hepatic microsomes and to assess the contribution of cytochrome P450 (P450) enzymes in human hepatic microsomes using human recombinant P450 enzymes and chemical inhibitors. Metabolites were identified, and metabolite formation was quantified using a liquid chromatography/mass spectrometry-based assay. Incubation of lithocholic acid with human liver microsomes resulted in the formation of five metabolites, which are listed in order of their rates of formation: 3-oxo-5 beta-cholan-24-oic (3-ketocholanoic) acid, 3 alpha,6 alpha-dihydroxy-5 beta-cholan-24-oic (hyodeoxycholic) acid, 3 alpha,7 beta-dihydroxy-5 beta- cholan-24-oic ursodeoxycholic) acid, 3 alpha,6 beta-dihydroxy-5 beta-cholan-24-oic (murideoxycholic) acid, and 3 alpha-hydroxy-6-oxo-5 beta-cholan-24-oic (6-ketolithocholic) acid. 3-Ketocholanoic acid was the major metabolite, exhibiting apparent K-m and V-max values of 22 mu M and 336 pmol/min/mg protein, respectively. Incubation of lithocholic acid with a of human recombinant P450 enzymes revealed that all five metabolites were formed by recombinant CYP3A4. Chemical inhibition studies with human liver microsomes and recombinant P450 enzymes confirmed that CYP3A4 was the predominant enzyme involved in hepatic microsomal biotransformation of lithocholic acid. In summary, the results indicate that oxidation of the third carbon of the cholestane ring is the preferred position of oxidation by P450 enzymes for lithocholic acid biotransformation in humans and suggest that formation of lithocholic acid metabolites leads to enhanced hepatic detoxification and elimination.

引用

页码：1938 / 1947

页数：10

共 40 条

[1] 6α-hydroxylation of taurochenodeoxycholic acid and lithocholic acid by CYP3A4 in human liver microsomes [J].

Araya, Z ;

Wikvall, K .

BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR AND CELL BIOLOGY OF LIPIDS, 1999, 1438 (01) :47-54

[2]

AZER SA, 1995, J PHARMACOL EXP THER, V272, P1231

[3] Minimal role of hepatic transporters in the hepatoprotection against LCA-induced intrahepatic cholestasis [J].

Beilke, Lisa D. ;

Besselsen, David G. ;

Cheng, Quiqiong ;

Kulkarni, Supriya ;

Slitt, Angela L. ;

Cherrington, Nathan J. .

TOXICOLOGICAL SCIENCES, 2008, 102 (01) :196-204

[4]

BENSAUDE RJ, 1988, ANN GASTROENT HEPATO, V24, P55

[5] Novel pathways of bile acid metabolism involving CYP3A4 [J].

Bodin, K ;

Lindbom, U ;

Diczfalusy, U .

BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR AND CELL BIOLOGY OF LIPIDS, 2005, 1687 (1-3) :84-93

[6] CLINICAL PHARMACOKINETICS OF KETOCONAZOLE [J].

DANESHMEND, TK ;

WARNOCK, DW .

CLINICAL PHARMACOKINETICS, 1988, 14 (01) :13-34

[7] Identification of human hepatic cytochrome P450 enzymes involved in the biotransformation of cholic and chenodeoxycholic acid [J].

Deo, Anand K. ;

Bandiera, Stelvio M. .

DRUG METABOLISM AND DISPOSITION, 2008, 36 (10) :1983-1991

[8] Biotransformation of lithocholic acid by rat hepatic microsomes: Metabolite analysis by liquid chromatography/mass spectrometry [J].

Deo, Anand K. ;

Bandiera, Stelvio M. .

DRUG METABOLISM AND DISPOSITION, 2008, 36 (02) :442-451

[9] Lithocholic acid feeding induces segmental bile duct obstruction and destructive cholangitis in mice [J].

Fickert, P ;

Fuchsbichler, A ;

Marschall, HU ;

Wagner, M ;

Zollner, G ;

Krause, R ;

Zatloukal, K ;

Jaeschke, H ;

Denk, H ;

Trauner, M .

AMERICAN JOURNAL OF PATHOLOGY, 2006, 168 (02) :410-422

[10]

Findor JA, 1998, MEDICINA-BUENOS AIRE, V58, P277

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