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 H 2 O 2 -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 H 2 O 2 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.

Polymorphisms in Metabolism/Antioxidant Genes May Mediate the Effect of Dietary Intake on Pancreatic Cancer Risk

“…Our results provide evidence that those with ≥ 1 minor allele for the missense polymorphism rs1138272 in GSTP 1 and higher intakes for the categories: total grains and non-whole grains have an increased risk of pancreatic cancer (Table 5). This result is consistent with evidence that dietary fiber intake induces antioxidant/detoxification enzymes including GSTP 1 94 . We observed that those with ≥ 1 minor allele for the gene UGT2 B4 (rs17671289) and intake of dry beans and peas had reduced pancreatic cancer risk (Table 5).…”

Butyrate modulates antioxidant enzyme expression in malignant and non‐malignant human colon tissues

“…Due to the limited number of samples and large variation range, the incubation of colon adenoma and adenocarcinoma samples with butyrate yielded no significant outcome. Nevertheless, as partly shown by our study and that from Stein et al [43], transformed colon cells respond to butyrate by upregulating CAT expression and/or activity. An increase in CAT activity seems to be desirable since the H 2 O 2 -mediated process of metastasis might be stopped or at least slowed down [44].…”

Wheat Aleurone: Separation, Composition, Health Aspects, and Potential Food Use

“…In these studies the material was digested in vitro, subsequently followed by in vitro fermentation, after which the fermentation supernatants were exposed to HT29 cells. The results showed that wheat aleurone and aleurone containing whole grain fractions contribute to decreasing colon cancer risk by the reduction of secondary bile acids production, induction of apoptosis, cell differentiation, and detoxification as a result of colon fermentation (Borowicki, 2010;2010a;2010b;Stein et al, 2010;. A very recent work of Ross et al (2011) points to the fact that favorable changes observed in the colonic metabolism of humans after whole grain consumption compared to the consumption of "refined" white flour products are the result of the importance of both fiber and phytochemical components.…”