Key Lab of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China.

Salvia miltiorrhiza Bge. (SMB), a traditional Chinese medicinal herb, has been alleged to support bone healing. However, the effects of the isolated major components of SMB on osseous cells and their corresponding effective doses are still unclear. In the present study, the effects of three components of SMB, including tanshinone IIA (Ts), salvianolic acid B (salB) and protocatechuic aldehyde (Pca), on mesenchymal bone marrow cells with the potential for osteoblastic differentiation were investigated. Various concentrations of Ts, salB and Pca were added to a rat bone marrow cell culture. The total metabolic activity and differentiation of bone marrow cells were evaluated by a metabolic assay and alkaline phosphatase (ALP) activity, respectively. The morphology and number of cells was observed by phase contrast microscopy and fluorescent microscopy after propidium iodide staining, respectively. Ts suppressed the growth and differentiation of bone precursor cells. SalB exhibited a biphasic effect: the high concentration of 160 microg/mL significantly depressed the population of bone marrow cells, however, lower concentrations (3-80 microg/mL) enhanced the total metabolic activity and their ALP expression. Pca suppressed the bone marrow cell population in a dose-dependent manner. Therefore, SalB has the potential to ameliorate bone healing by stimulating both the total metabolic activity and ALP activity of osteoblastic cells. Aqueous extracts, which preferably contain salB over Pca and are free of Ts therefore are recommended for bone formation.