Efeito prebiótico de produto à base de Yacon (Smallanthus sonchifolius) na modulação de indicadores da saúde óssea em ratas wistar

• Ano de defesa: 2013
• Autor(a) principal: Paula, Hudsara Aparecida de Almeida
• Orientador(a): Ferreira, Célia Lúcia de Luces Fortes
• Banca de defesa: Louzada, Mario Jefferson Quirino , Ribeiro, Sônia Machado Rocha , Ribeiro, Rita de Cássia Lanes
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Ciência e Tecnologia de Alimentos
• Departamento: Ciência de Alimentos; Tecnologia de Alimentos; Engenharia de Alimentos
• País: BR
• Palavras-chave em Português: Prebiótico; Yacon; Saúde óssea; Modelo animal; Microbiota intestinal
• Palavras-chave em Inglês: Prebiotic; Yacon; Bone health; Animal model; Intestinal microbiota
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS
• Link de acesso: http://locus.ufv.br/handle/123456789/480

Fructooligosaccharides (FOS) and inulin are food compounds able to optimize calcium absorption. Among natural sources of fructans of inulin type, one has attracted increasing attention from the scientific community, the yacon (Smallanthus sonchifolius) which is a tuberous root of Andean origin considered, nowadays, the major vegetable source, mainly FOS. Regarding this, a yacon-based product (YBP) (INPI: 014 110 002 964) was developed in the Department of Food Technology at Federal University of Viçosa. This study constitutes the first, so far, reported in literature about prebiotic effect of PBY in modulation of biomarkers of bone health in intact adult rats, ovariectomized and non-ovariectomized. This study aimed to evaluate the effect of PBY in modulation of cecal variables (cecal weight, pH, organic acids); intestinal absorption of calcium, mineral retention in bones, serum biochemical markers of bone metabolism, bone mineral density and biomechanical properties in head and shaft of the femur. Through a pre-experiment different doses were tested and 6% FOS / inulin dose of YBP was set to be used. The study consisted of three distinct phases. In the first phase (90 days) by Completely Randomized Design (CRD) the growth diet AIN-93G was administered to the animals with and without YPB; in the second phase, the animals undergone surgery for removal of ovaries (ovariectomy - OVX) or undergone to simulated organ removal (celiotomy - SHAM), following suspention of "Wash out" treatments over four weeks for recovering. In the third phase of the study (60 days) the diet AIN-93M was administered with and without YPB. The animals were divided into 4 groups (n = 16), by CRD in 22 factorial design for the two factors surgery and diet, in two levels: Surgery (with and without ovarian), diet (with and without yacon-based product) . Statistical analyzes were performed by SAS®. A significance level of 5% was considered. The study protocol was previously approved by the Ethics Committee for Animal Research of Federal University of Viçosa, opinion nº. 55/2011.The results obtained in the first phase of the study indicated promising clinical effects in relation to the higher production of acetate and lactate; the lower fecal calcium excretion, and higher fractional apparent absorption, higher percentage apparent absorption, higher mineral balance and higher percentage of calcium retention. These results assume positive impact, in long-term, in the bone metabolism. It is noteworthy that rats in phase 1 were "intact" no being exposed to any invasive procedure, which explains the slight biological variations observed in the variables measured, in contrast to the observed in phase 2. In the second phase, higher concentrations of acetate and lactate were observed in the group that received YPB diet in both ovariectomized rats (without ovary) and celiotomized-SHAM rats (with ovary) (P <0.05). In a consistent manner, a higher percentage of mineral retention and mineral balance of calcium was observed in the OVX group receiving YPB, compared to the OVX group that did not receive the diet. Serum marker of bone resorption (amino-terminal telopeptide of type I collagen - NTx) were lower in animals receiving YPB in the diet (P <0.05) and serum marker of bone formation (alkaline phosphatase) were higher in animals of YPB group (P <005), significantly in OVX animals. Biomechanical properties (in OVX rats and SHAM) both head and shaft of the femur showed higher percentage values in YPB group, presupposing favorable effect on bone strength. YPB presented a more pronounced effect when the animals were in a regenerative process due to the decline of estrogen, which is an interesting and innovative result, allowing good expectations about the investigated issue. It is concluded that YPB favorably modulated bone metabolism in ovariectomized rats and can be considered a promising alternative to attenuate the deleterious effects on bone metabolism arising from osteopenia in animal models.