Antiosteoporotic effect of prebiotics ingestion (Saccaromyces cerevisae β-glucan) and resistance training in female ovariectomized mice
Osteoporosis denotes reduction in bone mass, often caused by decreased synthesis and
secretion of female sex hormones due to menopause. We evaluate the effects of
prebiotic β-glucan (BG) ingestion (isolated from Sacharomyces cereviseae) in
association with Resistance Training (RT) in ovariectomized (OVX) female mice.
Forty-eight female C57BL/6J mice were divided into 6 treatments: SHAM surgery and
five OVX groups treated with: saline solution (SAL), Alendronate (ALE) (0.1 mg/kg),
BG (62.5 mg/kg), RT (climbing a ladder with load) and the association BG and RT. All
treatments were performed three times a week, for 8 weeks. There was a significant
reduction in uterine mass and an increase in body mass after OVX (p <0.05). The
consumption of BG by OVX females maintained body mass similar to animals in the
SHAM group (p> 0.05). However, it caused a reduction in training performance in
relation to the group that did not consume BG (p <0.05). The isolated RT produced the
best results on the bone, with values bone mass and strength necessary for fracture the
femurs similar to the ALE group (p> 0.05). Bone mineral density of the femur
(BMD DEXA ) in the RT group was also similar to the SHAM group (p> 0.05). However,
bone microarchitecture (microCTs) demonstrated intermediate effects, inferior to ALE
and similar to the BG + RT group for Bone Mineral Density (BMD MCT ), trabecular bone
volume (BV) and bone volume/total volume ratio (BV/TV) and trabecular separation
(Tb.Sp). The association BG + RT increased the concentration of Calcium (Ca 2+ ) by X-
Ray Fluorescence Spectrometry (XRF). The number of osteocytes/mm 2 in the RT group
in femurs was similar to the SHAM group (p> 0.05). There was no difference among
groups in terms of the number of muscle fibers/mm 2 or cross-section area in
gastrocnemius muscle. In conclusion, RT was effective in minimizing the effects of
osteoporosis induced by OVX, with benefits of BG intake only for the concentration of
calcium in bone. The use of BG reduced body mass, which in menopause is a benefit
for general health. However, for bone tissues, body mass decrease reduces mechanical
overload and favors bone loss.