Protection against dimethylhydrazine-induced adenomatous tumors of the mouse colon by the dietary addition of an extract of soybeans containing the Bowman-Birk protease inhibitor.

Dimethylhydrazine (DMH) induces adenocarcinomas of the colon and rectum in rodents; this animal cancer model system is thought to closely resemble human colorectal cancer. An extract of soybeans containing the Bowman-Birk protease inhibitor added to the diet of DMH-treated mice resulted in a significant suppression of adenomatous tumors of the colonic mucosa. Non-treated mice maintained on the same diet for most of their natural life-span (1.5 years) showed no observable health problems.