The present study aims to evaluate the preventive effect of administration of synbiotic (prebiotic inulin associated with the probiotic Bifidobacterium bifidus) and indole-3-carbinol on the chemical process of colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in rats Wistar rats fed a diet containing heme. The animals will be allocated into seven groups with 10 to 22 animals each, animals in groups 1 to 6 and 7 the group will receive four subcutaneous injections of DMH (40 mg / kg) and EDTA solution (DMH vehicle) in the initial two weeks the experiment, respectively. Groups 1 and 7 will receive basal diet until the end of the experiment, groups 2-6 respectively receive basal diet with added heme (0.32 g / kg diet), basal diet with added heme (0.32 g / kg diet) + symbiotic (inulin + Bifidobacterium bifidum 2.5 x 1010 CFU per kg diet), basal diet with added heme (0.32 g / kg diet) + indole-3-carbinol (2g/kg diet), basal diet + symbiotic (inulin + Bifidobacterium bifidum 2.5 x 1010 CFU of feed) and basal diet + Indo-3-carbinol (2g/kg feed). The animals will be euthanized on the 12th and 22nd weeks of the experiment. The colon (medial and distal) will be removed and immersed in fixative (24 h) and stored in 70% alcohol. The colon is stained with methylene blue 2% for the detection of stereoscopic ACF (incidence and multiplicity) and after analysis of ACF to the colon will be processed to obtain the histological classification of dysplasia of the FCA and immunohistochemical detection of the expression of ²-catenin (²-catenin positive ACF), Ki-67 and cleaved caspase 3. Tumor samples collected at the end of the 22nd week of the trial will be frozen in liquid nitrogen and stored at -80 ° C Biofreeze. The gene expression pathways that regulate cell proliferation and apoptosis in the tumor samples will be analyzed by the technique Taqman ® Low Density Array (TLDA). Tumor samples are immersed in fixative (24 h) and stored in 70% alcohol and subsequently processed to obtain histological and immunohistochemical expression for ²-catenin (²-catenin positive ACF), Ki-67 and cleaved caspase 3 and other markers selected after analysis of gene expression.
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