REDUCTION IN FORMATION AND GROWTH OF 1,2-DIMETHYLHYDRAZINE-INDUCED ABERRANT CRYPT FOCI IN RAT COLON BY DOCOSAHEXANOIC ACID

The effect of intragastric gavage administration of docosahexaenoic ac id (DHA) on the formation of 1,2-dimethylhydrazine (DMH)-induced aberr ant crypt foci in rat colon was investigated. Male F344 rats were trea ted three times s.c. with 20 mg/kg of DMH and were given either 0.7 ml of DHA or water intragastrically 5 times a week for 4. 8, or 12 weeks from the day before the first carcinogen treatment. The numbers of DM H-induced aberrant crypt foci per colon after 4, 8, and 12 weeks of DH A treatment were approximately 40% of those in the respective control groups, and the differences were statistically significant. The number s of foci reached plateau levels at 8 weeks in both the DHA-treated an d control groups. The mean number of aberrant crypts per focus was als o significantly smaller in the group given DHA than that in the contro l group at each time. These results suggest that DHA suppresses the fo rmation and growth of aberrant crypt foci and has a preventive effect on colon carcinogenesis.