[Determination of ecdysterone in Achyranthes bidentata Bl. and its activity promoting proliferation of osteoblast-like cells].

To study the activity of ecdysterone from Achyranthes bidentata Bl. (AB) promoting proliferation of osteoblast-like (OB-like) UMR106 cells and to determine its content in AB by HPLC method.Ecdysterone isolated from AB was cultured with OB-like cells UMR106 together in vitro and the proliferation of OB-like cells was determined by MTT assay. The chromatographic conditions for determining ecdysterone included an ODS column (250 mm x 4.6 mm, 5 microns), a mobile phase consisting of a mixture of water-acetontrile-tetrahydrofuran (86:11:3), detection wavelength of 243 nm, and column temperature of 27 degrees C. Phenacetin was used as the internal standard.The ecdysterone from AB had significant activity promoting proliferation of OB-like cells, the proliferation was promoted by 41% (n = 3). The average recovery of ecdysterone was 96.2% (RSD = 2.1%), the calibration was linear in the range of 30-300 micrograms.mL-1 (gamma = 0.9998).Ecdysterone was screened quickly by cultivating with OB-like cells together in vitro. The HPLC method is accurate, fast and reproducible for the determination of ecdysterone in AB.