Chemoprevention of hamster pancreatic carcinogenesis

研究了α-胡萝卜素、β-胡萝卜素、棕榈胡萝卜素和绿茶多酚(GTP)对快速形成导管病变后胰腺癌进展阶段的影响。25ppm的β-胡萝卜素和40ppm的棕榈胡萝卜素具有剂量阈值抑制效应，其中包括25ppm的β-胡萝卜素，可减少导管上皮增生、不典型增生以及原位癌和浸润性癌的癌前病变的数量。500ppm和5000ppm的GTP，而不是100ppm的GTP，也显著减少了增生和总胆管病变的数量。联合使用40ppm的棕榈胡萝卜素和50ppm的GTP同样可以抑制病变的发展。然而，α-胡萝卜素并不影响胰腺癌的发生。这些结果表明，超过临界剂量的β-胡萝卜素和GTP具有化学预防作用，联合应用棕榈胡萝卜素和GTP可能是一种候选的胰腺癌化学预防策略。

The effect of alpha-carotene, beta-carotene, palm carotene and green tea polyphenols (GTP) on the progression stage of pancreatic carcinogenesis after rapid production of ductal lesions were studied in Syrian hamsters. Dose threshold inhibitory effects were noted for beta-carotene, 25 ppm and palm caratene, 40 ppm which includes 25 ppm beta-carotene reducing the numbers of putative preneoplastic lesions of duct epithelial hyperplasia, atypical hyperplasia, as well as carcinoma in situ and invasive carcinomas. GTP at deses of 500 and 5000 ppm, but not 100 ppm, also significantly decreased the numbers of hyperplasia and total duct lesions. Combined administration of 40 ppm palm carotene and 50 ppm GTP similarly inhibited the lesion development. alpha-Carotene, however, did not affect pancreatic carcinogenesis. These results suggest that chemopreventive effects are exerted by beta-carotene and GTP above critical doses and that combined administration of palm carotene and GTP might be a candidate chemoprevention strategy for pancreatic cancer in man.