Efeito da fibra como alimento funcional na prevenção da incidência de focos de criptas aberrantes (FCA) no cólon de camundongos induzida por 1,2- dimetilhidrazina

• Ano de defesa: 2010
• Autor(a) principal: Gomides, Antônio Frederico de Freitas
• Orientador(a): Paula, Sérgio Oliveira de
• Banca de defesa: Leite, Jacqueline Isaura Alvarez , Fietto, Luciano Gomes
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Biologia Celular e Estrutural
• Departamento: Análises quantitativas e moleculares do Genoma; Biologia das células e dos tecidos
• País: BR
• Palavras-chave em Português: Prebióticos; Linhaça; Focos de criptas aberrantes; Bifidobacterium spp.; Clostridium spp.; Ciclinas
• Palavras-chave em Inglês: Prebiotics; Flaxseed; Aberrant crypt foci; Bifidobacterium spp.; Clostridium spp.; Cyclins
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL
• Link de acesso: http://locus.ufv.br/handle/123456789/241

The use of healthy diets has been a great ally in the prevention and treatment of various diseases, including colorectal cancer (CRC), a disease that affects much of the world population, configuring it as a public health problem. Genetic and environmental factors are cited as the main causes of the CRC. Among the diet can highlight the environmental. The use of probiotics as an alternative in the prevention of CRC is gaining more support from the scientific community. Prebiotics are soluble fibers that reduce the risk of CRC by the production of protective metabolites, such as the shortchain fatty acids such as acetate, propionate and butyrate. Prebiotics also influence the growth of lactic acid bacteria and bifidobacteria providing inhibitory effect in many bacteria that produce carcinogenic enzymes. Flaxseed is also a food beneficial in preventing the CRC being a food source rich in essential fatty acids that can function as an anti-inflammatory, to the decrease in cell proliferation and induce apoptosis in cancer cells. Another component of flaxseed is associated with the fibers and compounds that can be converted into biologically active phytochemicals, facultative aerobic bacteria present in the colon of mammals and may decrease the activity of pro-carcinogenic and increase the activity of enzymes that act in the process of cellular detoxification and protection against cancer. Flaxseed is available in the market as whole grains, bran and the like. The aim of this study was to investigate the effects of fiber (inulin and fructooligosaccharides) and defatted flaxseed meal in the colon of Balb/C and defatted flaxseed meal compared C57BL 6 male and female induced the appearance of aberrant crypt foci (ACF) with 1,2-dimethylhydrazine (DMH) was performed histological techniques, biochemical and molecular biological evaluation of results. In Balb/C results of this study showed that inulin has a greater efficacy in preventing the onset of ACF with fewer or equal to three crypts in the proximal colon, middle and distal. In the middle and distal colon inulin also was effective in preventing the incidence of ACF with number greater than three crypts. The low expression of p53, p21 and p16 in the distal colon in the treatment with inulin did not affect its preventive effect of prebiotics, suggesting that other mechanisms for the prevention of ACF may be involved. For the appearance of ACF in three equal number memor or crypts in the proximal colon, the middle and distal fructooligosaccharides was effective. This efficiency can be attributed to increased gene expression of p16 protein in the distal colon of mice. For the middle and distal colon the defatted flaxseed meal was effective in preventing the onset of ACF with fewer or equal to three crypts. For the incidence of ACF in number greater than three crypts in the middle and distal colon the defatted flaxseed meal also has preventive effects. This efficiency in the distal colon can be attributed to increased gene expression of p53 protein. When comparing the different sexes of C57BL/6 using only the defatted flaxseed meal, that food had preventive effects in the proximal colon, middle and distal male mice decreases the incidence of ACF with fewer or equal to three crypts. For distal colon this effectiveness can be attributed to increased gene expression of p53 protein. In females the defatted flaxseed meal did not protect the distal colon in the incidence of ACF with fewer or equal to three crypts. ACF for a number higher than three crypts in both sexes the defatted flaxseed meal not prevented the emergence of ACF. Faced with such evidence found in this study, the prebiotics inulin and fructooligosaccharides or defatted flaxseed bran dietary fibers are effective in preventing the development of CRC, but further studies should be undertaken to elucidate other mechanisms that may be involved in this process both in the line of Balb/C mice receiving prebiotics and defatted flaxseed meal in the diet, as well as in C57BL/6 mice that were fed the defatted flaxseed meal.