Erxian Decoction (EXD) is an anti-menopausal Chinese medicinal formula with anti-osteoporotic effect. It has been clinically used for more than 60 years without adverse effects reported. In this study, the anti-osteoporotic mechanism of EXD and the drug compatibility according to Chinese medicine theory were investigated. Our results revealed that EXD inhibited the proliferation of RAW 264.7 osteoclast precursor cells mainly mediated by the Monarch herb (Herba Epimedii). The Monarch herb (Herba Epimedii) and Minister herb (Radix Morindae officinalis) also contribute to the inhibition of differentiation of RAW 264.7 into mature osteoclast cells. EXD also stimulates the proliferation of hFOB 1.19 osteoblast cells and the osteoprotegerin secretion. Immunoblotting analysis reveals that EXD down-regulates NFATc1, a key protein involved in osteoclastogenesis, through the action of the Assistant herb Cortex Phellodendri Chinensis. This study provides a scientific ground for EXD as an alternative approach coping with menopausal osteoporosis. The drug compatibility of EXD according to Chinese medicine theory has also been demonstrated.
