title: Ritonavir, saquinavir, and efavirenz, but not nevirapine, inhibit bile acid transport in human and rat hepatocytes.
abstract: Human immunodeficiency virus-infected patients on antiretroviral drug therapy frequently experience hepatotoxicity, the underlying mechanism of which is poorly understood. Hepatotoxicity from other compounds such as bosentan and troglitazone has been attributed, in part, to inhibition of hepatocyte bile acid excretion. This work tested the hypothesis that antiretroviral drugs modulate hepatic bile acid transport. Ritonavir (28 microM), saquinavir (15 microM), and efavirenz (32 microM) inhibited [(3)H]taurocholate transport in bile salt export pump expressing Sf9-derived membrane vesicles by 90, 71, and 33%, respectively. In sandwich-cultured human hepatocytes, the biliary excretion index (BEI) of [(3)H]taurocholate was maximally decreased 59% by ritonavir, 39% by saquinavir, and 20% by efavirenz. Likewise, in sandwich-cultured rat hepatocytes, the BEI of [(3)H]taurocholate was decreased 100% by ritonavir and 94% by saquinavir. Sodium-dependent and -independent initial uptake rates of [(3)H]taurocholate in suspended rat hepatocytes were significantly decreased by ritonavir, saquinavir, and efavirenz. [(3)H]Taurocholate transport by recombinant NTCP and Ntcp was inhibited by ritonavir (IC(50) = 2.1 and 6.4 microM in human and rat, respectively), saquinavir (IC(50) = 6.7 and 20 microM, respectively), and efavirenz (IC(50) = 43 and 97 microM, respectively). Nevirapine (75 microM) had no effect on bile acid transport in any model system. In conclusion, ritonavir, saquinavir, and efavirenz, but not nevirapine, inhibited both the hepatic uptake and biliary excretion of taurocholate.
authors.affiliation: School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599-7360, USA.
authors.forename: Mary Peace
authors.initials: MP
authors.lastname: McRae
authors.forename: Carolina M
authors.initials: CM
authors.lastname: Lowe
authors.forename: Xianbin
authors.initials: X
authors.lastname: Tian
authors.forename: David L
authors.initials: DL
authors.lastname: Bourdet
authors.forename: Richard H
authors.initials: RH
authors.lastname: Ho
authors.forename: Brenda F
authors.initials: BF
authors.lastname: Leake
authors.forename: Richard B
authors.initials: RB
authors.lastname: Kim
authors.forename: Kim L R
authors.initials: KL
authors.lastname: Brouwer
authors.forename: Angela D M
authors.initials: AD
authors.lastname: Kashuba
mesh_terms: D000074020:ATP Binding Cassette Transporter, Subfamily B, Member 11; D018528:ATP-Binding Cassette Transporters / Q000037:antagonists & inhibitors / Q000502:physiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000480:Alkynes; D000818:Animals; D019380:Anti-HIV Agents / Q000494:pharmacology*; D048588:Benzoxazines; D001692:Biological Transport / Q000187:drug effects; D002478:Cells, Cultured; D002648:Child; D003521:Cyclopropanes; D022781:Hepatocytes / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019829:Nevirapine / Q000494:pharmacology; D027361:Organic Anion Transporters / Q000037:antagonists & inhibitors / Q000502:physiology; D029363:Organic Anion Transporters, Sodium-Dependent / Q000037:antagonists & inhibitors / Q000502:physiology; D010078:Oxazines / Q000494:pharmacology; D051381:Rats; D019438:Ritonavir / Q000494:pharmacology; D019258:Saquinavir / Q000494:pharmacology; D027981:Symporters / Q000037:antagonists & inhibitors / Q000502:physiology; D013656:Taurocholic Acid / Q000378:metabolism*
chemical_list: C093491:ABCB11 protein, human; D000074020:ATP Binding Cassette Transporter, Subfamily B, Member 11; D018528:ATP-Binding Cassette Transporters; D000480:Alkynes; D019380:Anti-HIV Agents; D048588:Benzoxazines; D003521:Cyclopropanes; D027361:Organic Anion Transporters; D029363:Organic Anion Transporters, Sodium-Dependent; D010078:Oxazines; D027981:Symporters; C071908:sodium-bile acid cotransporter; D013656:Taurocholic Acid; D019829:Nevirapine; C098320:efavirenz; D019258:Saquinavir; D019438:Ritonavir