Effects of Angelica sinensis Root on Longitudinal Bone Growth Rate in Adolescent Female Rats

Abstract

Objectives : This study aimed to investigate the effects of Angelicae sinensis Radix on longitudinal bone growth rate in rats. We have screened traditional medicinal herbs to develop the longitudinal bone growth stimulator by wellestablished rat model. A. sinensis was identified as one of the effective herbs in the screening process. Methods : Adolescent female rats were administered A. sinensis at doses of 30 ㎎/㎏ and 300 ㎎/㎏ for 10 consecutive days. To observe the rate of longitudinal bone growth, tetracycline was injected intraperitoneally on day 8 to stain a fluorescent band on the anew formed bone. To elucidate the mode of action, we observed insulin-like growth factor-1 (IGF-1) and bone morphogenetic protein-2 (BMP-2) expression after A. sinensis administration in growth plate. Results : In the 300 ㎎/㎏ A. sinensis group, the length between the proximal endpoint of the tetracycline label and the division line between growth plate and bone was significantly increased compared with vehicle-treated control group. Height of the proximal tibial growth plate was higher in the A. sinensis group compared with control group. A. sinensis also upregulated the expressions of IGF-1 and BMP-2 in the proliferative zone and hypertrophic zone of the proximal tibial growth plate. Conclusions : A. sinensis increases longitudinal bone growth rate in rats. According to immunohistochemistry, A. sinensis increases local IGF-1 and BMP-2 expressions in the growth plate which can be considered as direct stimulation of GH on the local growth plate.