The Effects Of 8-prenylnaringenin (8-pn) On Differentiation Of Osteoblasts Mc3t3-e1

Objective: 8-Prenylnaringenin (8-PN) is the most powerful phytoestrogen by far. It was reported that 8-PN can improve the experimental postmenopausal osteoporosis in rats. However, it is still unknown whether its function due to the effect on the bone formation or bone resorption. The present study was to observe the effects of 8-PN on the proliferation, differentiation and mineralization of mice osteoblast cell line (MC3T3-E1) and make it clear whether caveolin-1 is involved in the regulation of 8-PN on the MC3T3-E1 differentiation. We try to explain the mechanism for the treatment of postmenopausal osteoporosis from the pathway of bone formation.Methods:Different concentrations of 8-PN(10-5, 10-6, 10-7M)were used to treat different growth phases of MC3T3-E1.The effects of 8-PN in proliferation phase MC3T3-E1 (at day 2) treated for 48h were observed by methyl thiazolyl tetrazolium (MTT); The roles of 8-PN in differentiation phase MC3T3-E1 (at day 10, 11) treated for 48-72 h were evaluated by detection the cell lysate ALP activity and the supernate osteocalcin concentration by PNPP and ELISA respectively; For the effects of 8-PN on mineralization, MC3T3-E1 were treated with 8-PN in whole culture process and mineralized nodules were observed with alizarin red at day 28. In addition, we detected the expression of caveolin-1 protein in differentiation phase MC3T3-E1 by Western Blotting. Estrogen(10-8, 10-10 M)was used as positive control in all the experimental groups.Results:8-PN had no effect on osteoblast in proliferation phase MC3T3-E1; but 8-PN can dose-dependently increase ALP activity and the supernate osteocalcin concentration in differentiation phase MC3T3-E1, 8-PN can promote the formation of mineralized nodules at day 28. Estrogen plays a similar role. The effects of promote osteoblast are similar between 10-5M 8-PN and 10-8M estrogen. 8-PN can down-regulated the expression of caveolin-1 protein in differentiation phase MC3T3-E1.Conclusion:8-PN can promote osteoblast MC3T3-E1 differentiation, its mechanism involves the Caveolin-1 pathway.