Effects of a traditional Chinese herbal preparation on osteoblasts and osteoclasts

Background: Bone formation and resorption is a balanced and continuous process. When osteoclastic bone resorption exceeds osteoblastic bone formation, bone density decreases, which can lead to osteoporosis. Er-Zhi-Wan (EZW), a famous traditional Chinese formulation, has been developed as a restorative formula for hundreds of years, which contains two herbs viz. Herba Ecliptae and Fructus Ligustri Lucidi. EZW is widely used to prevent and treat various kidney diseases for its actions of nourishing the kidney yin and strengthening tendon and bone. The objective of current study was to investigate the effects of EZW on proliferation and differentiation of osteoblasts and osteoclasts in vitro using a serum pharmacological method. Methods: The rats were orally administered EZW (0.45. 1.8 and 7.2 gkg(-1)) for total seven doses and twice a day, and then the different concentrations of EZW-containing serum were prepared. The proliferation of primary cultural osteoblasts, UMR706 and RAW264.7 cells and differentiation of osteoclasts were determined after these cells were treated with different concentrations of EZW-containing serum for a period of time. Results: The serum from rats treated with EZW for 4 days did not facilitate proliferation of primary cultural osteoblasts and UMR 106 cells, but evidently inhibited both proliferation of RAW264.7 cells and differentiation of osteoclasts from RAW264.7 cells induced by receptor activator of nuclear factor kappa B ligand (RANK-L) and macrophage-colony stimulating factor (M-CSF). Conclusion: Antiosteoporotic activity of EZW is carried out mainly via restraint of osteoclastic bone resorption, which is in accordance with the traditional Chinese medicine theory on nourishing the kidney yin. Therefore EZW has favorable potency to develop a new anti-osteoporotic agent in clinic. (C) 2008 Elsevier Ireland Ltd. All rights reserved.