Association of prebiotic ingestion (β-glucan of Saccaromyces Cerevisaie) and a resistance training on the bone tissue ofovariectomized female mice

Abstract

Osteoporosis is a systemic skeletal disease characterized by decreased mass and deterioration of bone tissue micro-architecture caused mainly by ovarian failure in menopause. This process leads bone fragility and the consequent increased risk of fractures. This is a serious public health problem. Due to its high prevalence and morbidity and mortality, the study of antiosteoporotic therapies is essential. The treatments currently available also have adverse effects that justify further studies investigating alternative strategies for both treatment and prevention of osteoporosis. In this sense, β-Glucans, soluble fibers derived from the cell wall of yeasts, cereals and many medicinal mushrooms, have been studied, due to their anti-inflammatory potential. Physical exercise, especially resistance training (RT), has also been researched due to its ability to induce osteogenesis. Studies evaluating the interaction of these two therapeutic modalities have not yet been carried out. Thus, this project aimed to evaluate the effect in bone health of ingestion of the prebiotic (β-glucan extracted from the cell wall of the yeast Saccaromyces cerevisiae) associated with the load-climbing RT, in a model of osteoporosis induced by ovariectomy (OVX) in mice. 48 animals (N = 6 per group) were randomly assigned to 6 groups: SHAM group and 5 groups of OVX animals treated with: SAL group, alendronate (ALE - 0.1 mg / kg), BG (62.5 mg / kg), RT (climbing) and the association BG and RT. Treatments were performed three times a week for eight weeks. The consumption of BG by OVX females helped to maintain body mass similar to animals in the SHAM group. The isolated RT produced the best results on the bone, with values of mass and strength needed for fractures of the femurs similar to the ALE group. Bone densitometry of the femur (DMODEXA) in the RT group was similar to the SHAM group. However, computed microtomographs (microCTs) demonstrated intermediate effects, inferior to the ALE group and similar to the BG + RT group for Bone Mineral Density (BMDMCT), bone volume (BV), bone volume / total volume ratio (BV /TV) and trabeculae separation (Tb.Sp). The BG + RT association increased the calcium concentration by X-Ray Fluorescence Spectrometry. The amount of osteocytes in the RT group was similar to the SHAM group. It was concluded with the present study, therefore, that RT was effective in minimizing the effects of osteoporosis induced by OVX, and the association with BG intake brought benefits only for the concentration of calcium in the bone mineral content. The use of BG reduced body mass, which can be a cardiovascular benefit but a limiting factor for bone strengthening, since the reduction in body mass decreases the mechanical load and disadvantages osteogenesis.