EFFECT OF DIETARY-FAT ON DIETHYLNITROSAMINE-INDUCED HEPATOCARCINOGENESIS IN WISTAR RATS

In a diethylnitrosamine (DEN) induced hepatoma model, the effect of fi sh oil, a rich source of eicosapentaenoic acid (EPA) and docosahexaeno ic acid (DHA), and ground nut oil, a rich source of oleic acid (OA) an d linoleic acid (LA), was studied. Both 20% fish oil and ground nut oi l inhibited DEN-induced hepatocarcinogenesis in rats. Contrary to gene ral belief, an inverse correlation was observed between the developmen t of neoplastic nodules and the amount of lipid peroxides formed in th e high fat (20% fish oil and ground nut oil) diet groups, indicating t hat the higher the lipid peroxides formed, the lower the incidence of liver tumours in DEN-treated animals. Results of the analysis of liver fatty acid composition of the phospholipid fraction suggested that DE N and fish oil treatment can inhibit the activity of the delta-6- and 5-desaturases. It is concluded from the results of the present study t hat a 'high fat' diet and lipid peroxidation can modulate DEN-induced hepatocarcinogenesis in rats.