d-Limonene inhibits N-nitrosobis(2-oxopropyl)amine induced hamster pancreatic carcinogenesis

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.