We have previously demonstrated that the non-digestible fraction (NDF) from 
common cooked beans (P. vulgaris L., cv Negro 8025) inhibits azoxymethane 
(AOM)-induced colon cancer and influences the expression of genes involved in 
the induction of apoptosis and cell cycle arrest through the action of butyrate. 
The objective of this study was to identify cell cycle alterations and 
morphological changes induced by treatment with AOM and to examine the formation 
of colonic aberrant crypt foci (ACF) in male Sprague Dawley rats fed with these 
beans. Rats were fed control diets upon arrival and were randomly placed into 
four groups after one week of acclimatization: control, NDF (intragastric 
administration), NDF + AOM and AOM. Rats treated with NDF + AOM exhibited a 
significantly lower number of total colonic ACF with a notable increase in the 
number of cells present in the G1 phase (83.14%); a decreased proliferation 
index was observed in the NDF + AOM group when compared to AOM group. NDF + AOM 
also displayed a higher number of apoptotic cells compared to AOM group. NDF of 
cooked common beans inhibited colon carcinogenesis at an early stage by inducing 
cell cycle arrest of colon cells and morphological changes linked to apoptosis, 
thus confirming previous results obtained with gene expression studies.