Earthworm induces the differentiation of osteoblasts. MG-63 cells were cultured with PBS as a control or different concentrations of earthworm extract. After culturing for 2 days, osteoblast differentiation was assessed by ALP activity assay. Results are expressed as percentage of control (*p < 0.05, **p < 0.01 and ***p < 0.001 vs. control; ###
p < 0.001 vs. 3 mg/ml).