Study On The Osteogenic Activity Of Flavonoids

This thesis is composed of four chapters.The first chapter is a review about the fuctions and action mechanisms of epimedium flavonoids in regulating bone remoding.The second studied the effects of flavonoids on osteoblasts in vitro,the first study is the effects of Isoquercitrin on the osteogenic differentiation of MC3T3-E1 cells;the second is the effects and mechanism of Luteolin on the osteogenic differentiation of rBMSCs cells.The third chapter studied the enhanced bone defect repair of icariin/calcinated antler cancellous bone in osteoporotic rat.The last Chapter was a summary of the thesis.Epimedium Herb is one of the most frequently used for osteoporosis in traditional Chinese Medicinefor more than 1000 years.Icariin,a prenylated flavonol glycoside,has been isolated from the herb and found to be one of the main effective constituents.Studies demonstrated that icariin enhances osteogenic differentiation of rat bone marrow stromal cells,MC3T3-E1 cells,improves maturation and mineralization,protect from bone loss.The aim of this present study was to investigate the performance of icariin/calcinated antler cancellous(CACB)bone into osteoporotic critical-sized femur defects in ovariectomised rats following treatment periods of 2 and 4 weeks.The results showed that CACB pefromed good biocompatibility and osteoconduction,ICA/CACB from the present study demonstrate their potent ability to recruit mesenchymal progenitor cells through sustained release of ICA which may be beneficial for patients suffering from osteoporotic-related fractures.Natural products especially flavonoids are being explored for their therapeutic potentials in reducing bone loss and maintaining bone health.The first study is to investigate the osteoblastic activity of isoquercitrin on MC3T3-E1 cells.The results showed isoquercitrin had a dose-dependent effect on the proliferation,osteogenic differentiation,mineralization and gene expression of MC3T3-E1.All these results implied that isoquercitrin performed well osteoblastic activity.This study demonstrates for the first time that Luteolin has potential to induce osteogenic differentiation and promote maturation in rBMSCs cells.We found that Luteolin at low concentration performed best osteoblast activity,the underlying molecular mechanism shows that ERK1/2 is responsible for the inductive effects of Luteolin.Our data further confirmed that ER might involved in luteolin-induced osteogenesis,but ER is not necessary for luteolin induced ERK1/2 activation.