Effect of Trifolium pratense L. extracts on the bone resorption and osteogenic differentiation of osteoclasts and the underlying mechanisms / 中国组织工程研究

ABSTRACT

BACKGROUND: Isoflavone isolated from Trifolium pratense L. has been found to be able to effectively inhibit bone resorption, reduce bone turnover rate, improve osteocyte activity and bone mineral density by enhancing the effect of estrogen, which is helpful for the prevention and treatment of osteoporosis. OBJECTIVE: To investigate the effect of Trifolium pratense L. extracts on the bone resorption and differentiation of osteoclasts.METHODS: Rat bone marrow cells were extracted, isolated by lymphocyte separation and cultured for 5 hours; then, the non-adherent cells were selected followed by induced by 30 μg/L macrophage colony stimulating factor and 75 μg/L RANKL (control groups), or different concentrations of Trifolium pratense L. extracts (0.3, 0.6 and 1.2 g/L) to observe their effect on the osteoclast differentiation and bone resorption. The levels of osteoclast differentiation-associated proteins c-fos and NFATcl were determined by western blot assay. RESULTS AND CONCLUSION: Compared with the control group, different concentrations of Trifolium pratense L. extracts could suppress osteoclast differentiation and bone resorption to different degrees. Tartrate-resistant acid phosphatase staining showed that Trifolium pratense L. extracts could significantly reduce the number of osteoclasts. Western blot assay results suggest that Trifolium pratense L. extracts significantly inhibited the expression levels of c-fos and NFATcl. These results reveal that Trifolium pratense L. extracts can inhibit osteoclast differentiation and bone resorption.