Compatibility of multiple herbal components in Erxian Decoction, a Chinese medicinal formula, for treating osteoporosis

Introduction: Estrogen deficiency during menopause would increase the risk of osteoporosis. Erxian Decoction (EXD), an anti-menopausal Chinese medicinal formula with anti-osteoporotic effect, appears to be an attractive alternative for treating menopausal osteoporosis. However, the drug compatibility of component herbs in EXD according to traditional Chinese medicine theory has not been explored. In this study, the drug compatibility of EXD according to the organizing principle of Chinese medicinal formula was investigated, using anti-osteoporotic properties as a study model. Methodology: Proliferation of RAW 264.7 osteoclast precursor cells and hFOB 1.19 human fetal osteoblasts was determined by MTT assay. Osteoclastogenesis of RAW 264.7 cells was assessed by tartrate-resistant acid phosphatase (TRAP) staining. Osteoprotegerin secretion from hFOB 1.19 cells was determined by ELISA. The protein levels of NF-kappa B, I kappa B, c-Fos and NFATc1 involved in osteoclastogenesis were studied by immunoblotting analysis. Results: EXD inhibited the proliferation of RAW 264.7 cells while it stimulated the proliferation of hFOB 1.19 cells, which was mainly mediated by the Monarch herb (Herba Epimedii) and the Minister herbs (Radix Morindae officinalis) respectively. EXD also stimulated secretion of osteoprotegerin from hFOB 1.19 cells. EXD exerted an inhibitory effect on the differentiation of RAW 264.7 cells into mature osteoclast, as revealed in TRAP staining, which was probably mediated by the Assistant herb (Cortex Phellodendri) through down-regulation of NFATc1 protein. Conclusions: EXD inhibited proliferation and differentiation of osteoclast precursor cells, while it stimulated proliferation of osteoblasts and osteoprotegerin secretion. The drug compatibility of EXD according to Chinese medicine theory was also demonstrated. (C) 2012 Elsevier GmbH. All rights reserved.