In vitro and in vivo effects of puerarin on promotion of osteoblast bone formation

Objective:To assess the effect of puerarin,a natural flavonoid found in Chinese Pueraria Lobata (Wild.) Ohwi,on promotion of new bone formation.Methods:Osteoblasts isolated from calvarial of newborn rats were cultured in vitro in the presence of puerarin at various concentrations.The viability of osteoblasts and alkaline phosphotase activity and mineral node formation were determined.In addition,osteoblasts seeded in theβ-tricaclium phosphate scalfolds as bone substitute were implanted in rat dorsal muscles.Half of the recipient rats received intramuscular injection of puerarin at 10 mg/(kg·d) for 7 days.Osteogenesis was analyzed by examining the histology after 4 weeks of implantation.Results:The viability of osteoblasts treated with puerarin at either 40 or 80μmol/L was significantly higher than that of the control(P<0.05 and P<0.01, respectively).Alkaline phosphatase and mineral modules were significantly increased in osteoblasts cultured with puerarin at 40 or 80 mol/L when compared with that of the untreated cells.The puerarin-treated rats had a higher rate of bone formation in the osteoblast implants than the control rats(6.35%vs.1.32%,respectively, P<0.05).Conclusion:Puerarin was able to affect osteoblast proliferation and differentiation,and promote the new bone formation in osteoblast implants.