Effect of resistance training combined with ß-glucan ingestion on bone of ovariectomized mice.

OBJECTIVE: This study aimed to evaluate the effects of resistance training (RT) combined with prebiotic ß-glucan (BG) ingestion (Saccharomyces cerevisiae) in ovariectomized (OVX) mice. METHODS: Forty-eight mice were divided into six treatments: SHAM group and five OVX groups treated with saline (SAL), alendronate (ALE) (0.1 mg/kg), BG (62.5 mg/kg), RT (climbing a ladder with load) and the combination of BG + RT. All treatments were performed three times per week for 8 weeks starting 38 days after ovariectomy. RESULTS: OVX effectiveness was confirmed by a reduction in uterus mass (p < 0.05). Femur weight was higher in the SHAM group, followed by the ALE and RT groups with intermediate values and the BG + RT, BG and SAL groups with the lowest values (p < 0.05). The bone mineral density (BMDDEXA) results were higher for the SHAM and RT groups compared to the other groups (p < 0.05). RT provided similar bone mass and resistance to fracture to ALE and SHAM. We found a similar number of osteocytes in the RT and SHAM groups, which was significantly higher than that found in animals receiving BG (p < 0.05). The BG + RT combination increased calcium bone concentration. CONCLUSION: RT promoted benefits on bone health in the OVX model, which were not complemented by the consumption of BG.

Memory impairment induced by brain iron overload is accompanied by reduced H3K9 acetylation and ameliorated by sodium butyrate.

Iron accumulation in the brain has been associated to the pathogenesis of neurodegenerative disorders. We have previously demonstrated that iron overload in the neonatal period results in severe and persistent memory deficits in adult rats. Alterations in histone acetylation have been associated with memory deficits in models of neurological disorders. Here we examine histone acetylation in the brain and the effects of the histone deacetylase inhibitor (HDACi) sodium butyrate (NaB) on memory in the neonatal iron overload model in rats. Rats received vehicle or 30.0-mg/kg Fe⁺² orally at postnatal days 12-14. When animals reached adulthood, they were given training in either novel object recognition or inhibitory avoidance. Histone acetylation in the dorsal hippocampus and the effects of NaB were examined in separate sets of rats. Iron overload led to a reduction in H3 lysine 9 acetylation in the hippocampus, without affecting the acetylation of other H3 and H4 lysine residues. A single systemic injection of NaB (1.2 g/kg) immediately after training ameliorated iron-induced memory impairments. The results suggest that a reduction in H3K9 acetylation might play a role in iron-induced memory impairment and support the view that HDACis can rescue memory dysfunction in models of brain disorders.