Fermented wheat aleurone induces enzymes involved in detoxification of carcinogens and in antioxidative defence in human colon cells

Abstract

Dietary fibre is fermented by the human gut flora resulting mainly in the formation of SCFA, for example, acetate, propionate and butyrate. SCFA, in particular butyrate, may be important for secondary cancer prevention by inducing apoptosis and inhibiting cell growth of cancer cells, thereby inhibiting the promotion and/or progression of cancer. Furthermore, SCFA could also act on primary cancer prevention by activation of detoxifying and antioxidative enzymes. We investigated the effects of fermented wheat aleurone on the expression of genes involved in stress response and toxicity, activity of drug-metabolising enzymes and anti-genotoxic potential. Aleurone was digested and fermented in vitro to obtain samples that reflect the content of the colon. HT29 cells and colon epithelial stripes were incubated with the resulting fermentation supernatant fractions (fs) and effects on mRNA expression of CAT, GSTP1 and SULT2B1 and enzyme activity of glutathione S-transferase (GST) and catalase (CAT) were measured. Fermented aleurone was also used to study the protection against H2O2-induced DNA damage in HT29 cells. The fs of aleurone significantly induced the mRNA expression of CAT, GSTP1 and SULT2B1 (HT29) and GSTP1 (epithelial stripes), respectively. The enzyme activities of GST (HT29) and CAT (HT29, epithelial stripes) were also unambiguously increased (1.4- to 3.7-fold) by the fs of aleurone. DNA damage induced by H2O2 was significantly reduced by the fs of aleurone after 48 h, whereupon no difference was observed compared with the faeces control. In conclusion, fermented aleurone is able to act on primary prevention by inducing mRNA expression and the activity of enzymes involved in detoxification of carcinogens and antioxidative defence.