Chemopreventive potential of soy flour, flaxseed meal and a probiotic in a rat model

Abstract

Soy flour, flaxseed meal and probiotics have been widely researched individually for their beneficial effects against various diseases, including colon cancer. Research determining possible chemopreventive synergies among the three ingredients is limited. Objective of the study was to determine the effects of feeding various combinations of Soybean Flour (SF), Flaxseed Meal (FM) and Bifidobacterium longum (Bl.) on azoxymethane (AOM) induced Aberrant Crypt Foci (ACF) in male Fisher 344 rats. After 1 week acclimatization period, rats were divided into Control (C) and 9 treatment groups and fed AIN-93G diets containing Bl singly, SF and FM in various combinations (5 and 10%) and combinations of Bl.+SF+FM (0.25, 5 and 10%). Rats were subcutaneously injected with AOM at 16 mg kg-1 body weight at 7 and 8 weeks to induce ACF. At 17 weeks of age, the rats were killed using CO2 asphyxiation. Colons were removed and prepared for enumeration of ACF. Selected hepatic detoxification and antioxidant enzymes were also determined. Total ACF ranged from 37 in the group fed Bl.+SF+FM (0.25, 10 and 5%) to 144 in the group fed C. Enzyme activities in rats fed treatment diets were increased by 2-3 fold compared to rats fed C. Some synergies may exist among treatment ingredients. Incorporation of moderate levels of soybean flour, flaxseed meal and Bifidobacterium longum in diets may have implications in the incidence of colorectal cancer.