title: Quercetin significantly decreased cyclosporin oral bioavailability in pigs and rats.
abstract: Cyclosporin, an immunosuppressant with a narrow therapeutic window, is a substrate for both CYP3A4 and P-glycoprotein (Pgp). Quercetin is an inhibitor of CYP3A4 and a modulator of Pgp. This study aimed to measure the effect of quercetin on the absorption and disposition of cyclosporin in pigs and rats. Cyclosporin (Sandimmune, 10 mg/kg) was orally administered with and without a concomitant dose of quercetin (50 mg/kg) to pigs and rats. Cyclosporin concentrations in blood samples were determined by a specific monoclonal fluorescence polarization immunoassay. The pharmacokinetic parameters were calculated by noncompartmental analysis using WINNONLIN. A paired Student's t-test was conducted for statistical comparison. A study using the everted intestinal sac was carried out to evaluate the effect of quercetin on the function of intestinal Pgp. The coadministration of quercetin significantly decreased cyclosporin AUC(0-3) (area under the concentration-time curve from time zero to 3 h) by 56% and AUC(0-t) (area under the concentration-time curve from time zero to the last point) by 43% in pigs and rats, respectively, indicating that the coadministration of quercetin significantly decreased cyclosporin oral bioavailability. However, the inverted sac study showed that quercetin significantly inhibited the function of intestinal Pgp. It is suggested that concurrent use of quercetin or quercetin-containing dietary supplement or herbs with cyclosporin or other medications whose absorption and metabolism are mediated by Pgp and/or CYP3A4 should require close monitoring.
authors.affiliation: Department of Pharmacy, China Medical College, Taichung, 404 Taiwan, ROC.
authors.forename: Su-Lan
authors.initials: SL
authors.lastname: Hsiu
authors.forename: Yu-Chi
authors.initials: YC
authors.lastname: Hou
authors.forename: Yao-Horng
authors.initials: YH
authors.lastname: Wang
authors.forename: Chih-Wan
authors.initials: CW
authors.lastname: Tsao
authors.forename: Sheng-Fang
authors.initials: SF
authors.lastname: Su
authors.forename: Pei-Dawn L
authors.initials: PD
authors.lastname: Chao
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors; D000284:Administration, Oral; D000818:Animals; D019540:Area Under Curve; D001682:Biological Availability; D001692:Biological Transport / Q000187:drug effects; D016572:Cyclosporine / Q000097:blood*; D051544:Cytochrome P-450 CYP3A; D065607:Cytochrome P-450 Enzyme Inhibitors; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D007166:Immunosuppressive Agents / Q000097:blood*; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000187:drug effects; D007700:Kinetics; D008297:Male; D011794:Quercetin / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013552:Swine
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D065607:Cytochrome P-450 Enzyme Inhibitors; D004791:Enzyme Inhibitors; D007166:Immunosuppressive Agents; D016572:Cyclosporine; D011794:Quercetin; C104464:CYP3A protein, human; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human