Cranberry Ingestion Modulated Drug Transporters and Metabolizing Enzymes: Gefitinib Used as a Probe Substrate in Rats

Abstract

Cranberry, a polyphenol-rich functional food, is commonly used for the prophylaxis of urinary tract infections. Gefitinib, an anticancer agent clinically prescribed to treat non-small-cell lung cancer, is a substrate of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP), and metabolized mainly by cytochrome P450 (CYP) 3A4 and CYP2D6. This study used gefitinib as a probe substrate to investigate the modulation of cranberry on P-gp, BCRP, CYP3A4 and CYP2D6. Rats were administered gefitinib with and without 5.0 g/kg of cranberry as juice (CJ). The concentration of gefitinib in serum was determined by LC-MS/MS. The results showed that CJ significantly increased the C_max and AUC_0-t of gefitinib by 28% and 55%, respectively. Mechanism studies indicated that CJ activated P-gp, and cranberry metabolites (CM) inhibited CYP2D6. Moreover, the protein level of P-gp in rat enterocytes was decreased, whereas that in hepatocytes was increased. In addition, the protein levels of BCRP, CYP3A4 and CYP2D6 in enterocytes and hepatocytes were decreased. In conclusion, CJ ingestion affected the activities and protein levels of P-gp, BCRP, CYP3A4 and CYP2D6.

Keywords: cranberry; cytochrome P450s; drug transporter; gefitinib; pharmacokinetics.

Figure 1

LC-MS/MS chromatograms: (A) blank serum spiked with erlotinib (1, internal standard), O-desmethyl gefitinib (2) and gefitinib (3); (B) a serum sample obtained at 240 min after a dose of gefitinib.

Figure 2

Mean (±S.E.) serum concentration–time profiles of gefitinib after oral administration of gefitinib alone (○, 50 mg/kg) and coadministration with CJ (●, 5.0 g/kg of cranberry) in rats.

Figure 3

Effect of CJ (mg/mL) on the intracellular accumulation of R123 in LS 180 cells. V: verapamil (100 μM, positive control of P-gp inhibitor). ** p < 0.01 and *** p < 0.001.

Figure 4

Effects of CM (1-, 0.5- and 0.25-fold serum concentration) on the activity of CYP2D6. Q: quinidine (10 μM in blank serum, positive control of CYP2D6 inhibitor). * p < 0.05, ** p < 0.01 and *** p < 0.001.

Figure 5

Protein levels (mean ±S.D.) of P-gp, BCRP, CYP3A4 and CYP2D6 in enterocytes (A) and hepatocytes (B) after ingestion of water (N, n = 3) and CJ (5.0 g/kg) (n = 3). * p < 0.05, ** p < 0.01 and *** p < 0.001.