Both Wheat (Triticum aestivum) Bran Arabinoxylans and Gut Flora-Mediated Fermentation Products Protect Human Colon Cells from Genotoxic Activities of 4-Hydroxynonenal and Hydrogen Peroxide

• Published in: Journal of agricultural and food chemistry 2006-03, Vol.54 (6), p.2088-2095
• Main Authors: Glei, Michael, Hofmann, Thomas, Küster, Katrin, Hollmann, Jürgen, Lindhauer, Meinolf G, Pool-Zobel, Beatrice L
• Format: Article
• Language: English
• Subjects: 4-hydroxynonenal; Aldehydes - toxicity; alkali extractable arabinoxylan; anticarcinogenic activity; antimutagenic activity; antiproliferative effect; arabinoxylan; Biological and medical sciences; Cell Death - drug effects; Cell Division - drug effects; cell lines; cell proliferation; Cereal and baking product industries; Colon - drug effects; Colon - enzymology; Colon - metabolism; colorectal neoplasms; cytotoxicity; dietary fiber; Dietary Fiber - analysis; enzyme activity; Fermentation; fermentation supernatants; Food industries; Fundamental and applied biological sciences. Psychology; genotoxicity; glutathione transferase; HT29 Cells; Humans; hydrogen peroxide; Hydrogen Peroxide - toxicity; intestinal microorganisms; Intestines - microbiology; metabolic detoxification; Mutagens - toxicity; short chain fatty acids; Triticum aestivum; water extractable arabinoxylan; wheat bran; Xylans - pharmacology
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf052768e

Dietary fibers are fermented by the gut flora to yield short chain fatty acids (SCFAs), which inhibit the growth of tumor cells, induce glutathione S-transferases (GSTs), and protect cells from the genotoxic activity of 4-hydroxynonenal (HNE). Here, we investigated effects of wheat bran-derived arabinoxylans and fermentation products on these parameters of chemoprevention. Newly isolated water extractable (WeAx) and alkali extractable arabinoxylans (AeAx) were fermented under anaerobic conditions with human feces. Resulting fermentation supernatants (FSs) were analyzed for SCFAs and used to treat HT29 colon cancer cells. Cell growth, cytotoxicity, antigenotoxicity against hydrogen peroxide (H2O2) or HNE, and GST activity were determined. Nonfermented WeAx decreased H2O2-induced DNA damage by 64%, thus demonstrating chemoprotective properties by this nonfermented wheat bran fiber. The fermentation of WeAx and AeAx resulted in 3-fold increases of SCFA, but all FSs (including the control without arabinoxylans) inhibited the growth of the HT29 cells, reduced the genotoxicity of HNE, and enhanced the activity of GSTs (FS WeAx, 2-fold; FS AeAx, 1.7-fold; and control FS, 1.4-fold), which detoxify HNE. Thus, increases in SCFAs were not reflected by enhanced functional effects. The conclusion is that fermentation mixtures contain modulatory compounds that arise from the feces and might add to the effectiveness of SCFAs. Keywords: Chemoprevention; GST; HT29; single cell microgelelectrophoresis (comet assay); triticum aestivum; wheat bran arabinoxylan