TY - JOUR
T1 - Cruciferous vegetables reduce morphological markers of colon cancer risk in dimethylhydrazine-treated rats
AU - Arikawa, Andrea Y.
AU - Gallaher, Daniel D.
PY - 2008/3
Y1 - 2008/3
N2 - Consumption of cruciferous vegetables has been associated with reduced colon cancer risk in human populations. However, little experimental evidence exists to support this association. Here, we report the effects of diets containing cruciferous vegetables on colon cancer risk. In Expt. 1, rats were fed a vegetable-free (basal) diet or diets containing different lyophilized cruciferous vegetables in concentrations between 4 and 10%. In Expt. 2, rats were fed the basal diet or diets containing 10-22.6% fresh cruciferous vegetables. Diets were fed for 2 wk (Expt. 1) or 3 wk (Expt. 2) before and 7 wk (Expt. 1) or 12 wk (Expt. 2) after administration of the colon carcinogen 1,2-dimethylhydrazine. Rats fed fresh vegetables were also injected with a low dose of carcinogen 18-24 h prior to termination. Groups fed lyophilized vegetables did not differ in aberrant crypt foci (ACF), sialomucin-producing foci, or mucin-depleted foci (MDF) numbers. However, all fresh vegetable diets significantly decreased ACF (∼40%) and MDF numbers. Activities of the hepatic phase I enzyme CYP2E1 did not differ among groups in either experiment. Hepatic glutathione S-transferase (GST) and quinone reductase activities did not differ among groups fed fresh vegetables, whereas the lyophilized cabbage diets decreased GST activity compared with the basal diet. Groups did not differ in apoptosis and cell proliferation labeling indices in colonic mucosa. This study indicates that fresh but not lyophilized cruciferous vegetables reduce colon cancer risk in rats. These results do not support changes in hepatic carcinogen metabolism or colonic crypt cytokinetics as a mechanism.
AB - Consumption of cruciferous vegetables has been associated with reduced colon cancer risk in human populations. However, little experimental evidence exists to support this association. Here, we report the effects of diets containing cruciferous vegetables on colon cancer risk. In Expt. 1, rats were fed a vegetable-free (basal) diet or diets containing different lyophilized cruciferous vegetables in concentrations between 4 and 10%. In Expt. 2, rats were fed the basal diet or diets containing 10-22.6% fresh cruciferous vegetables. Diets were fed for 2 wk (Expt. 1) or 3 wk (Expt. 2) before and 7 wk (Expt. 1) or 12 wk (Expt. 2) after administration of the colon carcinogen 1,2-dimethylhydrazine. Rats fed fresh vegetables were also injected with a low dose of carcinogen 18-24 h prior to termination. Groups fed lyophilized vegetables did not differ in aberrant crypt foci (ACF), sialomucin-producing foci, or mucin-depleted foci (MDF) numbers. However, all fresh vegetable diets significantly decreased ACF (∼40%) and MDF numbers. Activities of the hepatic phase I enzyme CYP2E1 did not differ among groups in either experiment. Hepatic glutathione S-transferase (GST) and quinone reductase activities did not differ among groups fed fresh vegetables, whereas the lyophilized cabbage diets decreased GST activity compared with the basal diet. Groups did not differ in apoptosis and cell proliferation labeling indices in colonic mucosa. This study indicates that fresh but not lyophilized cruciferous vegetables reduce colon cancer risk in rats. These results do not support changes in hepatic carcinogen metabolism or colonic crypt cytokinetics as a mechanism.
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U2 - 10.1093/jn/138.3.526
DO - 10.1093/jn/138.3.526
M3 - Article
C2 - 18287361
AN - SCOPUS:40449084279
SN - 0022-3166
VL - 138
SP - 526
EP - 532
JO - Journal of Nutrition
JF - Journal of Nutrition
IS - 3
ER -