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: 2.9). 05/2012; 50(8):2902-10. DOI: 10.1016/j.fct.2012.05.006
Source: PubMed


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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Available from: Kátia Sivieri, Jan 18, 2016
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    • "A number of these proteins are described as oxidoreductases and are primarily found in bacterial lineages that exhibit toxic, mutagenic or carcinogenic activities [14] [15]. Colon cancer has been postulated as a complex and multistage process that includes a series of pathological alterations ranging from discrete microscopic mucosal lesions , such as aberrant crypt foci (ACF), to malignant tumors [16]. ACF are generally considered the earliest identifiable macroscopic lesion within the colonic mucosa that may be associated with risk of future neoplastic development [17]. "
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    ABSTRACT: Colon cancer remains as a serious health problem around the world despite advances in diagnosis and treatment. Dietary fibers are considered to reduce the risk of colon cancer as they are converted to short chain fatty acids by the presence of anaerobic bacteria in the intestine, but imbalanced diet and high fat consumption may promote tumor formation at different sites, including the large bowel via increased bacterial enzymes activity. The present study was conducted to characterize the inhibitory action of myrtenal on bacterial enzymes and aberrant crypt foci (ACF). Experimental colon carcinogenesis induced by 1,2-dimethylhydrazine is histologically, morphologically, and anatomically similar to human colonic epithelial neoplasm. Discrete microscopic mucosal lesions such as ACF and malignant tumors function as important biomarkers in the diagnosis of colon cancer. Methylene blue staining was carried out to visualize the impact of 1,2-dimethylhydrazine and myrtenal. Myrtenal-treated animals showed decreased levels of bacterial enzymes such as β-glucuronidase, β-glucosidase, and mucinase. Characteristic changes in the colon were noticed by inhibiting ACF formation in the colon. In conclusion, treatment with myrtenal provided altered pathophysiological condition in colon cancer-bearing animals with evidence of decreased crypt multiplicity and tumor progression.
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    • "Studies have reported that yacon also presents antioxidant activity related to compounds such as flavonoids (Arnao et al. 2011), phenolic acids (Castro et al. 2012), and tryptophan (Yan et al. 1999), beyond anti-inflammatory (Honoré et al. 2012), anti-obesity (Hasani-Ranjbar et al. 2013), antibacterial (Joung et al. 2010), antifungal (Yun et al. 2012), and anticancer (Moura et al. 2012) activities. Yacon has a high moisture content (around 83–90 % of the fresh weight) and a structure composed by weak internal tissues, which increase the incidence of deterioration during harvesting, packaging, and transportation. "
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    ABSTRACT: Yacon juice and concentrated yacon juice were added with an ovalbumin or emulsifier in order to form foams which were subjected to different whipping times according to a 22 factorial design. After formation of the foams, their density, overrun, physical stability, yield stress, and structural microscopy were assessed. The data analysis obtained by response surface methodology was able to identify that the concentration of the foaming agent together with the time of air incorporation led to reduced density, increased expansion and air volume fraction, and physical stability of the product. Foams formed with the addition of an ovalbumin showed higher yield stress values than those added with an emulsifier. During the resting period, the yield stress was reduced for both foaming agents. By analyzing the images of the foams, it was found that the greater the number of air bubbles present, the smaller their diameter, a behavior affected by the resting time. Foams formed with higher concentrations of foaming agent and longer whipping times showed the most desirable characteristics for the purpose of foam mat drying.
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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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    ABSTRACT: The modifying effects of aqueous yacon extract (AYE) and L. acidophilus CRL 1014 against colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in male Wistar rats were investigated. Animals were allocated into five groups: G1: untreated group; G2: DMH-treated group; G3: DMH + L. acidophilus- treated group; G4: DMH + AYE-treated group; G5: DMH + L. acidophilus and AYE-treated group. A significant reduction (p<0.05) in leukocyte DNA damage and in colonic cell proliferation were observed after the first DMH administration in G3 (probiotic), G4 (prebiotic) and G5 (synbiotic) groups. In this moment, a significant increase (p<0.05) in colonic apoptosis was also observed in G3 (probiotic) and G5 (synbiotic) groups. In special, at five months after DMH administrations, a significant reduction (p < 0.05) in ACF development was observed in G3 (probiotic), G4 (prebiotic) and G5 (synbiotic) groups. Incidence of colon tumors was lower at five months in G4 (prebiotic) and G5 (synbiotic) groups but not in eight months after DMH administrations. In conclusion, the findings suggest that the oral treatments have potential effects as a chemopreventive agent against colon carcinogenesis on early stage of tumor development.
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