Effects of Dietary Flaxseed on Intestinal Tumorigenesis in Apc^Min  Mouse

Ajay Bommareddy¹, Xiaoying Zhang¹, Dustin Schrader¹, Radhey Kaushik^{2, 3}, David Zeman², Duane P. Mathees² and Chandradhar Dwivedi¹

Department of Pharmaceutical Sciences¹, Department of Veterinary Sciences², and Department of Biology and Microbiology³, South Dakota State University, Brookings, SD 57007

ABSTRACT

            Dietary flaxseed containing a-linolenic acid and lignans has been shown to prevent azoxymethane-induced colorectal cancer in male Fisher rats. The present study was designed to investigate the chemopreventive effects of dietary flaxseed on the development of intestinal polyps in Apc^Min mice. Apc^Min mice, 6 weeks old were divided into five different groups (8 mice per group), fed with Control (AIN 93M alone), Corn meal (15% in AIN 93M), Flaxseed meal (15% in AIN 93M), Corn oil (15% in AIN 93M), and Flaxseed oil (15% in AIN 93M) supplement diets, respectively. All groups were fed their respective diets until the termination of experiment at 12 weeks. Mice were sacrificed under ether anesthesia, and small intestine and colon were isolated and washed with cold normal saline. Number, site and size of tumors were recorded. A 100% tumor incidence was observed in all the groups. However, tumor multiplicity and size were significantly (p<0.05) lower in dietary flaxseed meal and flaxseed oil groups compared to corn meal and corn oil groups. Intestine, colon and serum samples of corn meal and corn oil groups showed higher levels of ω-6 fatty acids, whereas the flaxseed meal and flaxseed oil groups exhibited higher levels of ω-3 fatty acids. Lignans were detected in the serum, intestine and colon samples for flaxseed meal group. Dietary flaxseed meal containing ω-3 fatty acids and lignans, and dietary flaxseed oil containing ω-3 fatty acids and no lignans were effective in preventing intestinal tumor development possibly by increasing ω-3 fatty acid levels and lignans. Dietary flaxseed might be chemopreventive for colon caner developed in genetically predisposed individuals.