Novel application of Shochu distillery by-products to prophylaxis against mammary carcinogenesis induced by 7,12-dimethylbenz[a]anthracene in rats

The effect of the heat-dried product of Shochu distillery by-products (HSDB) derived from sweet potato on mammary carcinogenesis in rats was investigated. HSDB was fed at 2.5% or 5% of the total feed weight. Dietary HSDB at the 5% level suppressed the incidence and number of tumors, and delayed the latency of mammary tumor development relative to the control diet. Experiments were conducted to determine the relative polarity, of the anticarcinogenic constituent(s). The number of tumors per tumor-bearing rat was lower in the diet group fed with an ethyl acetate extract of HSDB than in the control group. The tumor incidence evaluated at both palpation and autopsy was slightly lower in the group fed with a methanol extract than in the control group. These results suggest that HSDB contained at least two constituents of differing polarity that counteracted mammary carcinogenesis.