Article

Protective effects of yacon (Smallanthus sonchifolius) intake on experimental colon carcinogenesis

UNESP Sao Paulo State University, Institute of Biosciences, Program of Post-Graduation in General and Applied Biology Program, Botucatu 18618-970, SP, Brazil.
Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association (Impact Factor: 2.61). 05/2012; 50(8):2902-10. DOI: 10.1016/j.fct.2012.05.006
Source: PubMed

ABSTRACT Yacon (Smallanthus sonchifolius), a tuberous root native to the Andean region of South America, contains high concentration of fructans with potential for colon cancer prevention. This study investigated the potential beneficial of yacon intake on colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in male Wistar rats. After 4 weeks of DMH-initiation, groups were fed basal diet (G1 and G6) or basal diet containing dried extract of yacon root at 0.5% (G2), 1.0% (G3 and G5) or a synbiotic formulation (G4) (1.0% yacon plus Lactobacillus casei at 2.5 × 10(10)CFU per g diet) for 13 weeks. At week 20, a significant reduction in number and multiplicity of aberrant crypt foci (ACF) and in number of invasive adenocarcinomas was observed in the groups orally treated with 1.0% yacon (G3) or the synbiotic formulation (G4) (0.05<p<0.001). Tumor multiplicity (noninvasive plus invasive) was significantly lower in the group fed synbiotic formulation (p<0.02). A significant reduction in cell proliferation in colonic crypts and tumors and short chain fatty acids (SCFA) caecal contents was observed in the groups orally treated with 1.0% yacon (G3) or the synbiotic formulation (G4). Therefore, the findings this study indicate that yacon and yacon plus L. casei intake may reduce the development of chemically-induced colon cancer.

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    • "In the initial phase of tumor progression, groups that ingested AYE (G4) and its association with L. acidophilus CRL 1014 (G5) showed better suppressor response when compared to DMH group (G2) and probiotic (G3), once only 50 and 66.67% of macroscopic tumors in G4 (prebiotic) and G5 (synbiotic) were adenocarcinomas (Fig. 3A). Likewise, de Moura et al. (2012) reported lower proportion of adenocarcinomas induced by DMH in groups receiving a synbiotic formulation (1% yacon root and L. casei at 2.5 × 10 −10 CFU per gram). However, no additional or synergic effects were observed using our synbiotic formulation. "
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