Effect of Cyclopropenoid Compounds on the Carcinogenic Activity of Diethylnitrosamine and Aflatoxin B in Rats 2 3

Abstract

The cocarcinogenic activity of cyclopropenoid fat ty acids (CPFA) was investigated in Wistar and Fischer rat s fed food-grade cottonseed oil (0.35% CPFA) or Sterculia fo etida oil (50% CPFA) with aflatoxin B₁ or diethylnitrosamine (DEN). Wistar rats fed 0.2 and 1.0 mg DEN/kg body weight daily had hepatoma incidences of 40 and 70%, respectively, and developed no other tumors, Wistar rats fed 20 and 100 parts per billion (ppb) aflatoxin B₁ had hepatoma incidences of 0 and 43% and total tumor incidences of 10 and 51%, respectively. The hepatoma incidence increased from 41 to 61% in male Wistar rats when CPFA was added to the 100 ppb aflatoxin B₁ diets. Wistar rats fed DEN alone did not develop lung tumors, but incidences were 4 and 14% when CPFA was added to the low and high level DEN diets, respectively. Fischer rats fed 0.1 mg DEN/kg body weight were free of tumors but developed a 7% hepatoma incidence and a 10% total tumor incidence when also fed CPFA. Fischer rats were more sensitive to 20 ppb aflatoxin B₁ than Wistar rats (21 vs, 0% hepatoma incidence). Incidence of kidney tumors was 1 or DEN.