Abstract 4617: Bioactive phytochemicals in wheat bran for colon cancer prevention

Abstract

Abstract Colorectal cancer is a leading cause of cancer deaths in the United States. Many studies have found that dietary cereal fibers protect against colon cancer, however, not all cereal fibers are equally effective. Wheat bran is the only cereal bran that shows consistent protection against colon cancer in laboratory animal models, and corn and oat bran may enhance colon tumorigenesis. We and others have reported that phytochemicals in wheat bran instead of fiber are the major active components for colon cancer prevention. However, the active components are still unknown. Using human colon cancer cells (HCT-116 and HT-29) as the guiding assay, we further purified the active components from wheat bran using column chromatography. In this study, we identified fraction containing 5-n-alkylresorcinols (ARs) had the strongest inhibitory effect on the proliferation of human HCT-116 and HT-29 colon cancer cells. Further purification led to the identification of 5-n-heptadecylresorcinol (C17:0) and 5-n-nonadecylresorcinol (C19:0) as the major active components, whereas 5-n-heneicosenylresorcinol (C21:0) and 5-n-tricosylresorcinol (C23:0) had no inhibitory effects, indicating that the length of the side chain of ARs significantly affects their activities. The effects of other components in wheat bran, such as sphingolipids, will also be discussed. In summary, we identified all the major components in wheat bran and our study indicates that 5-n-alkylresorcinols are the major active colon cancer preventive agents in wheat bran and the length of the alkyl chain significantly affects 5-n-alkylresorcinols’ cancer preventive activities. 5-n-Alkylresorcinols are phenolic lipids present in high amounts in wheat bran and are not found in oat and corn bran. Our finding will help us to further understand why wheat bran inhibits and oat and corn bran (which do not contain ARs) have no effect or enhance colon carcinogenesis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4617. doi:10.1158/1538-7445.AM2011-4617