Effect of Angelica sinensis on the proliferation of human bone cells

Background: Angelica sinensis, an herbal medicine known for its effect to purify blood quality and improve circulation, frequently appears as the main ingredient in prescriptions for bone injuries. Currently, how pharmacologically it contributes to the reformation of bone is unclear. Methods: The effect of the aqueous extract of Angelica sinensis on bone cells was investigated in vitro for the first time. The human osteoprecursor cells (OPC-1) were incubated in the medium with different concentrations of the aqueous extract of Angelica sinensis and the cell proliferation was studied. Results: When the concentration of Angelica sinensis aqueous extract was <125 μg/ml, the proliferation of OPC-1 was enhanced. However, the proliferation of OPC-1 was inhibited by Angelica sinensis extract with the concentrations >250 μg/ml. Under most treatments, the cells presented very pale expression for cyclooxygenase-2 (Cox 2) protein; slightly intensified band showed at the highest Angelica sinensis concentration, 1.0 mg/ml during the course of culture. Conclusion: The aqueous extract of Angelica sinensis was found to directly stimulate the proliferation, alkaline phosphatase (ALP) activity, protein secretion and particularly type I collagen synthesis of OPC-1 at dose-dependent manner.