Composition and Chemopreventive Effect of Polysaccharides from Common Beans (Phaseolus vulgaris L.) on Azoxymethane-Induced Colon Cancer

Abstract

Common beans ( Phaseolus vulgaris L.) contain a high proportion of undigested carbohydrates (NDC) that can be fermented in the large intestine to produce short-chain fatty acids (SCFA) such as acetate, propionate, and butyrate. The objective of the present study was to evaluate the composition and chemopreventive effect of a polysaccharide extract (PE) from cooked common beans ( P. vulgaris L) cv. Negro 8025 on azoxymethane (AOM) induced colon cancer in rats. The PE induced SCFA production with the highest butyrate concentrated in the cecum zone: 6.7 +/- 0.06 mmol/g of sample for PE treatment and 5.29 +/- 0.24 mmol/g of sample for PE + AOM treatment. The number of aberrant crypt foci (ACF) and the transcriptional expression of bax and caspase-3 were increased, and rb expression was decreased. The data suggest that PE decreased ACF and had an influence on the expression of genes involved in colon cancer for the action of butyrate concentration.

A Non-digestible Fraction of the Common Bean (Phaseolus vulgaris L.) Induces Cell Cycle Arrest and Apoptosis During Early Carcinogenesis

“…The results are consistent with our previous study where similar chemoprotective effect of polysaccharide extract (PE) from Negro 8025 bean was observed in AOM-induced rats [4]. This result could be related with the SCFAs production, since NDF+AOM treatment induces higher levels of butyrate (5.49 mmol/g) in the feces of the treated animals, when compared to those receiving AOM alone (3.66 mmol/g of sample) [4]. Several authors have shown that diets rich in non-digestible compounds, including NDF from flaxseeds [15], decreased the formation of ACF [16] and increase the total SCFAs concentration [14] and microbiota biodiversity [17] in the distal region.…”

“…These data suggest that NDF can function as preventive treatment at an early or initiation stage of colon cancer. The results are consistent with our previous study where similar chemoprotective effect of polysaccharide extract (PE) from Negro 8025 bean was observed in AOM-induced rats [4]. This result could be related with the SCFAs production, since NDF+AOM treatment induces higher levels of butyrate (5.49 mmol/g) in the feces of the treated animals, when compared to those receiving AOM alone (3.66 mmol/g of sample) [4].…”

“…The NDF group displayed a lower number of ACF in both histological analyses (methylene blue and H&E stain) ( Figs. 1a and b), which has been previously reported [4]. Control group (normal tissue) displayed crypt foci with normal morphology (Fig.…”

“…Our previous results have shown that the non-digestible fraction (NDF) of common beans (P. vulgaris L., cv Negro 8025) is fermented in the large intestine, produces SCFAs, and induces butyrate production. This process results in decreased formation of ACF, likely via the activation of genes involved in proliferation, cell cycle arrest, and apoptosis [4]. The objective of this study was to partially characterize the NDF of common cooked beans (Phaseolus vulgaris L., cv Negro 8025), and determine its effects on cell cycle and the induction of apoptosis on colon cancer cells after the induction of colonic ACF by AOM.…”

The fermented non-digestible fraction of common bean (Phaseolus vulgaris L.) triggers cell cycle arrest and apoptosis in human colon adenocarcinoma cells

“…We previously demonstrated that compounds of common bean can inhibit proliferation and induce apoptosis in both in vivo and in vitro models by modulating the expression of genes involved in cell cycle arrest, cell proliferation and apoptosis (Feregrino-Pérez et al 2008;Campos-Vega et al 2010). Our previous study showed that common bean (Phaseolus vulgaris L.) Negro 8025 has fermentable substrates, such as the NDF (total dietary fiber, oligosaccharides, resistant starch and phenolic compounds), and the NDF was submitted to gut in vitro fermentation producing compounds that showed chemoprotective effect by inducing DNA fragmentation (apoptosis) and inhibiting the HT-29 cell survival (CruzBravo et al 2011).…”