Enhancing effects of mustard oil on preneoplastic hepatic foci development in Wistar rats.

Dietary habits are known to be the major contributory factor in the development of cancer. Mustard oil, which is extensively used in India and elsewhere as a flying and cooking medium, is reported to induce an inflammatory response. The development of altered hepatic foci is an early carcinogenic change in rat liver in diethylnitrosamine (DEN)-induced hepatocarcinogenesis. In the present study, the development of preneoplastic lesions was observed following administration of mustard oil (0.5 mL/day for 8 weeks) in DEN-initiated and partially hepatomized Wistar rats. A significant decrease in the relative and absolute liver weight of mustard oil-exposed rats was recorded. The results revealed a significant increase in the number and area of placental glutathione-S-transferase (GST-P) and gamma-glutamyl transpeptidase (GGT)-positive foci in mustard oil-administered animals. The GST-P- and GGT-positive foci were more prominent in the animals given boiled (up to 300 degrees C for 3 hours) mustard oil in comparison to the animals given fresh mustard oil. These results indicate the possible tumourigenic risk associated with mustard oil consumption.