Assessment of the roles of P-glycoprotein and cytochrome P450 in triptolide-induced liver toxicity in sandwich-cultured rat hepatocyte model.
Triptolide (TP), a main bioactive component of Tripterygium wilfordii Hook F., is a promising agent for treatment of autoimmune diseases. However, a high incidence of dose-limiting hepatotoxicity was observed in the clinic. Sandwich-cultured rat hepatocyte model was used in this study to identify the involvement of P-glycoprotein (P-gp) in TP disposition and to evaluate TP-induced hepatotoxicity after modulation of P-gp by the known inhibitors, ritonavir and tariquidar, and known inducers, phenobarbital, quercetin, and H(2)O(2). Our data showed that biliary clearance of TP reduced 73.7% and 84.2% upon treatment of ritonavir (25 µM) and tariquidar (5 µM), respectively. In contrast, increases of 346%, 280%, and 273% in biliary clearance of TP were observed with treatment of phenobarbital (1.0 mM), quercetin (20 µM), and H(2)O(2) (0.5 mM), respectively. The TP-induced hepatotoxicity increased by twofold when CYP activity was blocked by 1-aminobenzotriazole, suggesting that CYP and P-gp may both contribute to the detoxification of TP in the SCRH model. In addition, hepatotoxicity and the expression of apoptosis proteins Bax and Bcl-2 were correlated qualitatively with the TP exposure duration and its intracellular concentration, which, in turn, can be modulated by P-gp inhibitors or inducers. Our results for the first time demonstrated that in addition to CYP-mediated metabolism, P-gp also plays an important role in the disposition of TP and TP-induced hepatotoxicity. Thus, the modulation of canalicular P-gp has a potential to cause drug-drug interaction between TP and the coadministered P-gp inhibitors or inducers in the clinic.
The Key Laboratory of Drug Metabolism and Pharmacokinetics, Beijing Institute of Pharmacology and Toxicology, Beijing, China (X.-M.Z., G.-L.S., W.-B.X., Y.T., H.L.); and Millennium, The Takeda Oncology Company, Cambridge, Massachusetts (C.L.).
Xiao-Mei
XM
Zhuang
Guo-Lin
GL
Shen
Wei-Bin
WB
Xiao
Yan
Y
Tan
Chuang
C
Lu
Hua
H
Li
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D051544:Cytochrome P-450 CYP3A / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004224:Diterpenes / Q000494:pharmacology*; D004852:Epoxy Compounds / Q000494:pharmacology; D022781:Hepatocytes / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008099:Liver / Q000201:enzymology / Q000378:metabolism; D008297:Male; D010616:Phenanthrenes / Q000494:pharmacology*; D010634:Phenobarbital / Q000494:pharmacology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011794:Quercetin / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D019438:Ritonavir / Q000494:pharmacology; D051028:bcl-2-Associated X Protein / Q000378:metabolism
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; C489249:Abcg2 protein, rat; D004224:Diterpenes; D004852:Epoxy Compounds; D010616:Phenanthrenes; D019253:Proto-Oncogene Proteins c-bcl-2; D011804:Quinolines; D051028:bcl-2-Associated X Protein; C001899:triptolide; D003577:Cytochrome P-450 Enzyme System; D011794:Quercetin; D006861:Hydrogen Peroxide; D051544:Cytochrome P-450 CYP3A; D000251:Adenosine Triphosphatases; C402343:tariquidar; D019438:Ritonavir; D010634:Phenobarbital