#B182 Anthocyanin-Rich Extracts Inhibit Growth of Human Colon Cancer Cells and Azoxymethane-Induced Colon Aberrant Crypts in Rats: Implications for Colon Cancer Chemoprevention. Bernadene A. Magnuson, Cuiwei Zhao, Geeta Lala, YoungJoo Kwon, Tao Yu, Jonathan Friedman, Chika Obele, Minnie Malik, Univ. of Maryland, College Park, MD. Anthocyanins are naturally occurring colored flavonoids known for their antioxidant activity. The purpose of this study was to compare the effect of commercially available Anthocyanin Rich Extracts (AREs) from chokeberry, bilberry and grape on growth of human colon cancer cells (in vitro) and on azoxymethane (AOM) induced colon aberrant crypt foci (ACF) in rats (in vivo). Significant growth inhibition of colon adenocarcinoma derived HT-29 cells with exposure to chokeberry, bilberry and grape AREs was observed. The growth inhibitory effect was dose- and time-dependent. After 24 h, chokeberry ARE inhibited HT-29 cell growth to the greatest extent. After 72 h exposure, both bilberry and chokeberry ARE inhibited the cell growth by about 69%, demonstrating similar inhibitory activity. To determine whether AREs would similarly inhibit ACF development, F344 rats were fed either AIN diet (control) or AIN diets containing 4g/kg monomeric anthocyanin from chokeberry, bilberry or grape ARE for one week before AOM (20 mg/kg body wt) injection. After 14 weeks, animals were killed and the colons were collected and scored for number and multiplicity of ACF. Total ACF was significantly reduced (P<0.05) in the ARE-fed rats compared to the control group. The number of large ACFs (>5 multiplicity) was significantly reduced in rats fed chokeberry ARE and bilberry ARE. As a measure of in vivo oxidative stress, levels of 8-OHdG were measured in the urine of all groups using competitive ELISA. No significant difference was observed in rats fed different diets. To understand the molecular mechanisms involved, RNA was isolated from colon mucosa and changes in expression of various genes including cytokeratin and COX-2 were studied. Semi-quantitative RT-PCR demonstrated a significant inhibition of COX-2 gene expression in colons of rats on ARE diets compared to the controls. Further analysis of the effect of the AREs on cell proliferation and COX-2 protein expression are underway. In conclusion, diets rich in anthocyanin may play a significant role in chemoprevention of colorectal cancer. In this study, in vitro data suggests that with increased time of exposure ARE from chokeberry and bilberry were the most potent inhibitors of colon cancer cell growth. Similarly, in vivo data indicates that these two extracts are effective chemopreventive agents for colon carcinogenesis. Frontiers in Cancer Prevention Research, 2003 AACR Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.