Figure 1

SWT extract increases bone mineralization in cultured osteoblasts. (A) Osteoblasts were seeded in 24-well plates and cultured for 2 wks in medium containing vitamin C (50 μg/mL) and β-glycerophosphate (10 mM). The cells were concomitantly treated with SWT extract. At the end of the experiment, cultures were fixed in 75% ethanol, and mineralized nodule formation was assessed by alizarin red-S staining. The bound stain was eluted with a solution of 10% cetylpyridinium chloride and quantified using a microtiter plate reader. (B) Cells were incubated with SWT extract for 72 h, and ALP was measured with an ALP activity assay kit. (C) Cells were incubated with SWT extract for 24 h, and ALP, BMP-2, and OPN mRNA expression was measured by qPCR. (D) Cells were incubated with SWT extract (150 μg/mL) plus BMP-2, OPN, or IgG (negative control) neutralizing antibodies. Mineralized nodule formation was assessed by alizarin red-S staining. (E) Cells were incubated with SWT extract (150 μg/mL) plus BMP-2, OPN, or IgG (negative control) neutralizing antibodies for 72 h, and ALP was measured with an ALP activity assay kit. (F) Cells were incubated with SWT extract, the cell viability was examined by MTT assay. Results are expressed as mean ± SEM *, p < 0.05 compared to the control group; #, p < 0.05 compared to the SWT extract-treated group.