Inhibitory effect of Astragalus polysaccharide on osteoporosis in ovariectomized rats by regulating FoxO3a/Wnt signaling pathway

Purpose: To investigate inhibitory effect of Astragalus polysaccharide (APS) on osteoporosis in ovariectomized rats by regulating FoxO3a/Wnt2 signaling pathway. Methods: Postmenopausal osteoporosis (PMOP) animal model was developed by excising the bilateral ovaries of rats. The model rats were administered with APS (200 mg/kg, 400 mg/kg, 800 mg/kg) by intragastric administration once daily for 12 weeks. Bone density, bone metabolism index and oxidative stress index were measured in all groups. Furthermore, the regulation of APS of FoxO3a / Wnt2 signaling pathway was observed. Results: APS has an estrogen-like effect, which can increase bone mass, lower serum ALP and BGP values, increase blood calcium content, and increase bone density of the femur and vertebrae in rats. At the same time, APS can increase the bone mineral content of the femur, increase the maximum stress, maximum load and elastic modulus of the ovariectomized rats, improve oxidative stress in rats by increasing the gene expression of β-catenin and Wnt2 mRNA and inhibiting the gene expression of FoxO3a mRNA. Conclusion: Astragalus polysaccharide can effectively alleviate oxidative stress-mediated osteoporosis in ovariectomized rats, which may be related to its regulation of FoxO3a/Wnt2/β-catenin pathway.(AU)

Efeitos do pamidronato e zoledronato no incremento da densitometria óssea e histomorfometria em ratos / Pamidronate and zoledronate effects in the increment of bone mineral density and histomorphometry in rats

PURPOSE: To compare increment of bone mineral density (BMD) with pamidronate, zoledronate and the isolated effect of proteinous diet in undernourished oophorectomized and non-oophorectomized female rats, besides validating BMD's indexes. METHODS: 60 young female Lewis rats were divided into five experimental groups and a control group, oophorectomized and non-oophorectomized. The administration of drugs were submitted to proteinous and aproteinous diets. The variables analyzed were weight, bone densitometry, histomorphometry and biochemical evolution. RESULTS: In weight evaluation, the first interval showed a statistically meaningful increase in oophorectomized sample. In densitometry evaluation, the first interval showed statistically meaningful decrease in four medicated groups and third showed a statistically meaningful increase in 2 non-oophorectomized groups. In laboratory evaluation, there were an increase of total proteins and globulin, decrease of alkaline phosphatase, phosphorus and calcium (except for the oophorectomized) in four medicated groups and increase of phosphorus and calcium in 2 not medicated groups. In histomorphometric evaluation, the oophorectomized groups had smaller increment of BMD. CONCLUSIONS: The pamidronate and zoledronate have shown effectives in the increment of BMD. The proteinous diet itself possesses therapeutic effect in BMD though not significant compared with medicated animals. The results of histomorphometry allow validating BMD's indexes in this experimental model.(AU)

OBJETIVO: Comparar o incremento de densidade mineral óssea (DMA) com pamidronato, zoledronato e o efeito isolado de dieta protéica em ratas desnutridas ooforectomizadas e não ooforectomizadas, além de validar índices de DMA. MÉTODOS: 60 ratas jovens Lewis foram divididas em cinco grupos experimentais e um grupo controle, com e sem ooforectomia. A administração das drogas foi submetida às dietas protéica e aprotéica. As variáveis analisadas foram peso, densitometria óssea, histomorfometria e evolução bioquímica. RESULTADOS: Na avaliação ponderal, o primeiro intervalo mostrou aumento estatisticamente significante nos grupos ooforectomizados. Na avaliação densitométrica, o primeiro intervalo mostrou diminuição estatisticamente significante nos quatro grupos medicados e o terceiro mostrou aumento estatisticamente significante nos dois não ooforectomizados. Na avaliação laboratorial, houve aumento de proteínas totais e globulina, diminuição de fosfatase alcalina, fósforo e cálcio (exceto nos ooforectomizados) nos quatro grupos medicados e aumento de fósforo e cálcio nos dois não medicados. Na avaliação histomorfométrica, os grupos ooforectomizados tiveram incremento menor de DMA. CONCLUSÕES: O pamidronato e o zoledronato se mostraram efetivos no incremento de DMA. A dieta protéica em si possui efeito terapêutico na DMA, porém menos significativa, comparada aos animais medicados. Os resultados da histomorfometria permitem validar os índices de DMA neste modelo experimental.(AU)