Aim:To investigate the protective effect of steroidal saponins from Anemarrhenaasphodeloides(ATS)on ovariectomy(OVX)-induced bone loss.Methods:Sprague-Dawley rats were divided into sham and OVX groups.The OVX ratswere treated with vehicle,nylestriol or steroidal saponins extract for 12 weeks.Serum calcium,phosphorus,estradiol(E_2),osteocalcin concentration and serumalkaline phosphatase activity were measured.Bone density was assayed by dual-energy X-ray absorptiometry.The undecalcified longitudinal proximal tibial meta-physical(PTM)sections were cut and stained for histomorphometric analysis ofthe bone.Results:In OVX rats,alkaline phosphatase activities in serum weremarkedly increased and concentrations of osteocalcin were decreased by ATStreatment,which had no influence on the body weight.Meanwhile,atrophy of theuterus and descent of bone mineral density(BMD)was suppressed by treatmentwith ATS.In addition,ATS completely corrected the decreased the concentrationof calcium and E_2 in serum observed in OVX rats.Histological results showedATS prevented decreases in trabecular thickness and increases in trabecular sepa-ration of proximal tibia metaphysis(PTM)in OVX rats.However,it did not alterosteoclast number in OVX rats.Moreover,ATS(300 mg/kg)had a remarkableeffect on promoting bone formation action in OVX rats.Nylestriol treatmentdecreased the bone formation rate and mineral apposition rate.Conclusion:Anadequate supply of steroidal saponins of Anemarrhena asphodeloides preventedOVX-induced bone loss in rats through the promotion of bone formation but notthe inhibition of bone resorption. Aim:To investigate the protective effect of steroidal saponins from Anemarrhenaasphodeloides(ATS)on ovariectomy(OVX)-induced bone loss.Methods:Sprague-Dawley rats were divided into sham and OVX groups.The OVX ratswere treated with vehicle,nylestriol or steroidal saponins Extract for 12 weeks.Serum calcium,phosphorus,estradiol(E_2),osteocalcin concentration and serumalkaline phosphatase activity were measured.Bone density was assayed by dual-energy X-ray absorptiometry.The undecalcified longitudinal melt tibial meta-physical(PTM)sections were Cut and stained for histomorphometric analysis of the bone.Results:In OVX rats,alkaline phosphatase activities in serum weremarkedly increased and concentrations of osteocalcin were decreased by ATStreatment, which had no influence on the body weight.Meanwhile,atrophy of theuterus and descent of bone mineral Density(BMD)was suppressed by treatmentwith ATS.In addition, ATS completely corrected the decreased the concentration of calcium and E_2 in se Rum observed in OVX rats.Histological results showed ATS prevented in trabecular thickness and increased in trabecular sepa-ration of proximal tibia metaphysis(PTM) in OVX rats.However,it did not alterostoclast number in OVX rats.Moreover,ATS(300 mg/ Kg)had a significant effect on promoting bone formation action in OVX rats.Nylestriol treatmentdecreased the bone formation rate and mineral apposition rate.Conclusion:Anadequate supply of steroidal saponins of Anemarrhena asphodeloides preventedOVX-induced bone loss in rats through the promotion of bone formation but notthe Inhibition of bone resorption.