| Objective To explore the effects of astragalus polysaccharide on bone mass and bone metabolism and BMP-2/Smads signaling pathway in ovariectomized rats. Methods Thirty female Sprague-Dawley rats underwent ovariectomy or sham surgery. After 12 weeks of normal feeding, the rats were divided into astragalus polysaccharide group (ASNT group), control group (CON group), and ovarian removal group (OVX group). Rats in the astragalus polysaccharide group received 400 mg/kg astragalus polysaccharide every day. The effect of ASNT on bone mass, bone metabolism, and BMP-2/Smads signaling pathway in osteoporotic rats were evaluated with bone mineral density, bone metabolism indicators, micro-CT, and WB tests. Results After 12 weeks of treatment, bone mineral density in ASNT group increased significantly compared to that in OVX group (P<0.05). ASNT treatment for 12 weeks reduced serum ALP and OC levels, increased blood calcium content, and increased femoral bone density. After 12 weeks of treatment, bone volume fraction (BV/TV), surface area volume fraction (BS/TV), trabecular thickness (Tb.Th), and number of trabecular bone (Tb.N) in ASNT group were significantly higher than those in OVX group. Trabecular space (Tb.Sp) was significantly lower than that in OVX group, and there was a significant difference (P<0.05). WB results showed that the BMP-2/Smsds signaling pathway in OVX rats was inhibited. ASNT significantly activated BMP-2/Smsds signaling pathway by up-regulating the expression of BMP-2, p-Smad1 and p-Smad5. Conclusion Studies have shown that ASNT has a protective effect on bone mineral density and bone mass in ovariectomized rats, which may be related to activating the BMP-2/Smads signaling pathway. |