Abstract A98: Prevention of gastrointestinal adenomas in the ApcMin mouse by high-fiber rice bran

Abstract

Abstract Consumption of dietary bran has been considered to be beneficial to health. It has also been linked to a lower risk of developing malignancies, most notably, colorectal cancer. Rice bran (containing 23-35% dietary fiber) at 30% in the diet interfered with adenoma development in the ApcMin mouse, a preclinical model of colorectal cancer (Verschoyle et al., Br J Cancer 2007). Here we used a high fiber rice bran extract (Nutracea, USA), with a fiber content of 40-50% to explore whether an increase in fiber imparts higher efficacy in the ApcMin mouse. The bran was mixed in with the diet at three concentrations: 5, 15 and 30% (n=19-22 per group) and administered to ApcMin mice from 4 weeks of age until termination of study at 16 weeks. Adenoma numbers were reduced by 12, 26, 74 % and adenoma burden by 30, 26 and 84 %, respectively, in the treatment groups in comparison to control mice, with reduction being significant only at the highest dose (p<0.05). The high fiber rice bran seems to be more efficacious than the rice bran used in the previous study in which 30% rice bran reduced adenoma numbers by 51% (Verschoyle et al., Br J Cancer 2007). Plasma samples from each experimental group were collected and undergo proteomic analysis using liquid chromatography-mass spectrometry to identify potential biomarkers of efficacy. This study highlights the potential health benefit of high-fiber rice bran, but further investigations are warranted to better understand the role of fiber in colorectal cancer prevention. Citation Information: Cancer Prev Res 2010;3(12 Suppl):A98.