title: Prevention of precancerous colonic lesions in rats by soy flakes, soy flour, genistein, and calcium.
abstract: The main purpose of this research was to determine whether diets containing soy products would inhibit the early stages of azoxymethane-induced colon cancer in F344 rats. Additional objectives were to determine whether feeding starch instead of sucrose, feeding additional calcium (0.5% compared with 0.1%), or feeding a low-fiber powdered enteral formula would influence early colon carcinogenesis. Colon cancer was initiated with 2 injections of azoxymethane (15 mg/kg body wt) and a 12-wk dietary treatment period was started 1 wk after the second injection. Precancerous colon lesions were assessed as foci with aberrant crypts (FAC). The mean numbers of FAC were 133 [soy concentrate (low concentration of phytochemicals)], 111 (starch substituted for sucrose), 98 [full-fat soy flakes (whole soybeans)], 87 (defatted soy flour), 77 (0.015% genistein), and 70 (0.5% Ca). The soy flour and full-fat soy flake diets contained 0.049% genistein derivatives (primarily glycosides), but were less effective in inhibiting the formation of FAC than the diet containing 0.015% genistein (as the aglycone). Eating soybeans and soy flour may reduce the early stages of colon cancer.
authors.affiliation: Department of Food Science and Human Nutrition, Michigan State University, East Lansing 48824-1224, USA.
authors.forename: D G
authors.initials: DG
authors.lastname: Thiagarajan
authors.forename: M R
authors.initials: MR
authors.lastname: Bennink
authors.forename: L D
authors.initials: LD
authors.lastname: Bourquin
authors.forename: F A
authors.initials: FA
authors.lastname: Kavas
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents / Q000627:therapeutic use*; D001397:Azoxymethane / Q000633:toxicity; D002118:Calcium / Q000627:therapeutic use*; D002273:Carcinogens / Q000633:toxicity; D003110:Colonic Neoplasms / Q000473:pathology / Q000517:prevention & control*; D004032:Diet; D019833:Genistein / Q000627:therapeutic use*; D006965:Hyperplasia / Q000139:chemically induced; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D030262:Soybean Proteins / Q000627:therapeutic use*
chemical_list: D016588:Anticarcinogenic Agents; D002273:Carcinogens; D030262:Soybean Proteins; D019833:Genistein; D001397:Azoxymethane; D002118:Calcium