Regulation of Cbfa1 expression by total flavonoids of Herba epimedii.

Core binding factor alpha1 (Cbfa1) is a member of the runt family of transcription factors, which appears to play a pivotal role in regulating the differentiation of osteoblastic precursors and the activity of mature osteoblasts. Total flavonoids of Herba epimedii (HEF) is a recognized bone anabolic agent, but there is lack of reports on the modulation of Cbfa1 expression by HEF. Here we investigated the effect of HEF on Cbfa1 expression in the bone of ovariectomized (OVX) rats. HEF could increase the expression of Cbfa1 mRNA in the bone of ovariectomized rats in a dose-dependent manner. Furthermore, the high dose HEF (160 mg/kg) administered for 12 weeks in vivo stimulated osteocalcin expression. These findings suggest that Cbfa1 is required for mediating the anabolic effects of HEF.