Pleurotus cornucopiae (PC) mushrooms is found in the field and commonly known in Japan as Tamogidake mushrooms. Recently it has been reported that PC also alleviating the toxicity of heavy metals. However little is known about mechanism of the action of PC on osteoblast differentiation, especially in transcription factor. Inhibitor of DNA binding-1 (Id-1) function has been linked to the proliferation, migration, and senescence of cells, and studies about relationship between Id-1 and biological function. Therefore, this study was aimed to investigate the effect of PC on osteoblast differentiation and expression of Id-1 and Id-2. PC treatment increased ALP, Col 1 and OCN. PC treatment up-regulated the mRNA levels of Id-1 and Id-2 genes. This PC–induced osteoblast differentiation is more effective in lower doses rather than high doses. This study shows that expression of Id-1 and Id-2 was increased in a dose-dependent manner during PC-induced osteoblast differentiation.

Ursolic acid, triterpenoid compound has been shown to stimulate osteoblast differentiation and enhance bone formation. In the present study, we examined the effects of similar triterpenoid compounds, oleanolic acid (OA) and its derivatives, such as oleanolic acid acetate (OAA) and oleanolic acetate methyl ester (OAM) on the bone formation in MC3T3-E1 osteoblast cells. We determined cellular proliferation, alkaline phosphatase (ALP) activity, mineralization, and expression of osteoblast specific genes and mitogen activated protein kinase phosphorylation. Treatment of 0.1-10μm OA, OAA, and OAM increased cellular proliferation, but not significantly increased as compared with dimethyl sulfoxide (DMSO). OA, OAA, and OAM at 5uM concentration enhanced ALP expression, mineralization, and osteocalcin (OCN) mRNA level. In conclusion, OA and its derivatives stimulated the osteoblast differentiation by increasing ALP, mineralization, and OCN mRNA expression. However, there were no significantly difference on osteoblast differentiation among treatment of OA, OAA, and OAM.