CHEMOPREVENTIVE EFFECTS OF PHENETHYL ISOTHIOCYANATE ON LUNG AND PANCREATIC TUMORIGENESIS IN N-NITROSOBIS(2-OXOPROPYL)AMINE-TREATED HAMSTERS

The chemopreventive effects of phenethyl isothiocyanate (PEITC) were i nvestigated in N-nitrosobis(2-oxopropyl) amine (BOP)-treated hamsters. Female 5-week-old Syrian golden hamsters were divided into six groups . Animals in groups 1-3, each consisting of 30 hamsters, were given BO P by two subcutaneous injections 7 days apart at a dose of 20 mg/kg bo dy weight, plus either 100, 10 or 0 mu mol of PEITC in corn oil by gav age 2 h prior to each BOP treatment, respectively per group. Animals i n groups 4 and 5, each consisting of 10 hamsters, were given 100 and 1 0 mu mol of PEITC alone in corn oil, and 10 animals in group 6 served as a vehicle control. Animals were sacrificed 52 weeks after the first BOP injection. Both the incidences and multiplicities of lung adenoma s and/or adenocarcinomas were significantly decreased in a dose-depend ent manner by PEITC treatments (P < 0.01 or 0.05). The lung tumor inci dences were inhibited by 100% with 100 mu mol PEITC and by 82% with th e 10 mu mol dosage. In addition, the high dose of PEITC also significa ntly inhibited pancreatic carcinogenesis (P < 0.05) and showed a tende ncy to lower the incidences of liver and renal tumors, although these effects were not statistically significant. Under the present experime ntal conditions, PEITC itself did not cause any apparent toxicity. Our results thus indicate that PEITC is a remarkably effective chemopreve ntive agent for the BOP-induced lung and pancreatic tumors in hamsters .