DIETARY QUERCETIN, IMMUNE FUNCTIONS AND COLONIC CARCINOGENESIS IN RATS

Rats fed 100 mg/kg quercetin (QUE) daily for 7 weeks had significantly enhanced natural killer cell activity compared to their vehicle (VEH) -fed control. In contrast, rats fed 100 mg/kg QUE and treated with the colon carcinogen, azoxymethane had significantly reduced natural kill er cell activity compared to their VEH-fed azoxymethane-treated contro l. There was no significant difference in natural killer cell activity between the two control groups. Antibody production and delayed-type hypersensitivity were not altered by QUE feeding in any treatment grou p. In vitro exposure of splenic natural killer cells to 1mM QUE signif icantly decreased natural killer cell cytotoxicity. Lower QUE concentr ations produced a non-significant reduction in natural killer cell act ivity that was restored to control values at 1x10(-13)M QUE. The distr ibution, multiplicity and total number of colonic preneoplastic lesion s, aberrant crypt foci, was not significantly different in the QUE-fed azoxymethane-treated rats when compared to azoxymethane-treated vehic le-fed rats at the conclusion of the 7 week feeding period. We found n o correlation between immune function and development of preneoplastic colon lesions in this study.