As prediction of rapidly
aging society,
bone health is considered increasingly important and received more
attention than ever.
Bone health is regulated by balancing between
bone resorptive
osteoclasts and
bone formative
osteoblasts. Disruption of balance between
bone-resorbing
osteoclasts and
bone-forming
osteoblasts results in
bone disease.
Natural products have recently received much
attention as an alternative tool for the development of novel
therapeutic strategy. Baicalein is reported it has anti-
cancer, anti-inflammatory and
antioxidant effects. Baicalein also has been known that it has both promotive effect on MC3T3-E1
cell line and inhibitory effect on
RAW 264.7 cell line. However, the inhibitory mechanism of baicalein using
bone marrow derived macrophages (BMMs) on
osteoclast differentiation remains not clear. In this study, the suppressive mechanism by baicalein on
osteoblast differentiation was evaluated. Bicalein inhibited
receptor activator of nuclear factor-kappaB ligand (RANKL)-induced
osteoclast differentiation in BMMs in a
dose dependent manner without any
toxicity. Baicalein suppressed
phosphorylation of
protein kinaseB (Akt), c-Jun N-terminal
kinases (JNK) and
phosphoinositide-specific phospholipaseCgamma2 (
PLCgamma2). Furthermore, Baicalein suppressed the induction of RANKL-induced c-Fos and Nuclear factor of activated
T cell c1 (NFATc1),
essential genes on
osteoclastogenesis. In BMMs, Bicalein inhibited the
mRNA expression of
tartrate-resistant acid phosphatase (TRAP),
osteoclast-associated receptor (OSCAR), cathepsinK,
dendritic cell-specific transmembrane
protein (DC-STAMP). Moreover, baicalein promoted differentiation of
osteoblast on
bone marrow stromal cells (BMSCs). Taken together, these results suggest that baicalein has a potential for treating
bone lytic
diseases, such as
osteoporosis,
periodontitis, and
rheumatoid arthritis.