The effect of d-limonene on pancreatic carcinogenesis induced by N-nitrosobis(2-oxopropyl)amine (BOP) was investigated in Syrian golden hamsters. During and after 5 weekly injections of BOP, each hamster was fed diet containing d-limonene. In week 26, quantitative histological analysis showed that prolonged treatment with d-limonene significantly reduced the number of pancreatic carcinomas. Administration of d-limonene did not cause a significant increase in the apoptotic index, but caused a significant decrease in the BrdU labeling index of carcinoma. These findings indicate that d-limonene inhibits the development of pancreatic carcinoma not by enhancing tumor cell loss through apoptosis, but rather by inhibiting cell proliferation.
Nakaizumi A, Baba M, Uehara H, Iishi H, Tatsuta M. d-Limonene inhibits N-nitrosobis(2-oxopropyl)amine induced hamster pancreatic carcinogenesis. Cancer Lett. 1997 July Department of Gastrointestinal Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Higashinari-ku, Japan.