Aim: To investigate the choleretic effects of inchinkoto (ICKT) on livers of patients with biliary obstruction due to bile duct carcinoma.
Methods: Twenty-seven patients with bile duct carcinoma who were due to undergo biliary drainage and subsequent major hepatectomy were randomly assigned to preoperative ICKT (n = 13) or untreated (n = 14) groups. ICKT was administered from the day of admission until one day before surgery. Changes in bile constituents, expression of multidrug resistance-associated protein (MRP) 2, MRP3 and MRP4 in the liver, and the incidence of postoperative complications were included as end-points.
Results: The biliary concentration of total bilirubin was significantly increased after administration of ICKT (23.7 +/- 2.8 mg/dL before ICKT; 34.0 +/- 4.0 mg/dL after ICKT, P < 0.05). The biliary concentration of total bile acids was also significantly increased. Protein levels of MRP2 and MRP3 in the crude plasma membrane fraction of livers of treated patients were significantly higher than those without treatment. MRP2 staining in the livers of patients without ICKT treatment was weak and diffuse around the bile canaliculi, whereas staining in patients with ICKT treatment was strong and restricted to the bile canaliculi.
Conclusion: ICKT exerts a choleretic effect on the livers of patients with biliary obstruction. This beneficial effect was associated with increased expression of MRP2. ICKT thus has therapeutic potential for treatment for obstructive cholestasis due to bile duct carcinoma.