Prevention of bone loss by aqueous extract of Epimedii sagittatum in an ovariectomized rat model of osteoporosis

Abstract

To investigate the prevention effect of aqueous extract of Epimedii sagittatum (ESE) on ovariectomy-induced (OVX) bone loss in rats. Rats were divided into sham-operated and OVX groups. The OVX rats were divided into four groups treated with distilled water, 17beta-estradiol (1 mg/kg, ig) and ESE (0.5 and 1 g/kg, ig) for 11 weeks. Serum calcium, phosphorus, estradiol, bone gla protein concentrations and serum alkaline phosphatase activity were measured. Bone density was assayed by dual-energy X-ray absorptiometry. The undecalcified longitudinal proximal tibial metaphysical sections were cut and stained for the bone histomorphometric analysis. In OVX rats, alkaline phosphatase activity in serum was markedly increased by ESE treatment, which had no obvious influence on the body weight. Meanwhile, atrophy of uterus and descent of bone mineral density were suppressed by ESE treatment. In addition, ESE completely corrected the decreased concentrations of calcium and E2 in serum observed in OVX rats. Histological results also showed ESE prevented the increases in trabecular separation (Tb.Sp) in OVX rats whereas it did not alter trabecular thickness (Tb.Th) and trabecular number (Tb.N) in OVX rats. Moreover, ESE had remarkable effect on bone formation rate with bone volume as referent (BFR/BV) and bone formation rate with bone surface as referent (BFR/BS). The findings assessed on the basis of biochemical test, bone mineral density and histomorphometric parameters show that aqueous extract of Epimedii sagittatum has a definite antiosteoporotic effect and can prevent the OVX-induced bone loss in rats.