Chemopreventative Effect of Hochu-ekki-to (TJ-41) on Chemically Induced Biliary Carcinogenesis in Hamsters

BackgroundBilioenterostomy is a common surgical technique that is widely used. Recently, clinical studies have revealed that biliary carcinomas can occur after bilioenterostomy. The present study was designed to evaluate whether hochu-ekki-to (TJ-41), a Japanese herbal drug, could prevent chemically induced biliary carcinomas in bilioenterostomized hamsters.Materials and methodsSyrian golden hamsters were subjected to choledochojejunostomy and then received subcutaneous injections of N-nitrosobis(2-oxopropyl) amine every 2 weeks at a dose of 10 mg/kg. N-nitrosobis(2-oxopropyl) amine administration was started 4 weeks after surgery. The animals were simultaneously p.o. administered TJ-41 in water every day at a dose of 1000 mg/kg (TJ-41 group). The control hamsters were administered water alone. The hamsters were sacrificed 22 weeks after surgery, and the development of biliary carcinomas, the presence and degree of cholangitis, and the cell kinetic status of the biliary epithelium were evaluated histologically.ResultsIntrahepatic bile duct carcinomas developed in 15/17 (88%) hamsters in the control group and in only 8/17 (47%) hamsters in the TJ-41 group (P < 0.05). The degree of cholangitis was not different between the two groups. However, the proliferating cell nuclear antigen labeling index of the biliary epithelium in the TJ-41 group (6.46%) was significantly lower than the controls (9.67%) (P < 0.05). These findings indicated that TJ-41 reduced accelerated biliary epithelial cell kinetics after bilioenterostomy, resulting in the prevention of carcinogenesis.ConclusionTJ-41 has a preventive effect on chemically induced carcinoma of the biliary tract after bilioenterostomy.