Effects Of Icariin In The Prevention And Treatment Of Aseptic Loosening Of Prothesis And Its Molecular Mechanism

Objective: To explore the effect of Icariin in the preventing and treatment of aseptic loosening of prosthesis at three levers:the cellular,the moleculer and the animal ones.Methods:(1) the enzymes digesting method was used to isolate the osteoblasts of rats.the osteoblasts was cultured with various concentrations of Ti particles or Icariin injection mixed Ti particles with for 24 hours respectively.by flow cytom etric analysis and electronscope observation were detected to determine the conditions of cellular apoptosis.(2)OB was isolated from calvaria of new-born fetal SD rats by means of modified sequential collagenase digestion and incubated in MEM medium and the cell morphology was observed under inverted phase contrast microscope,OB was identified ALP staining.Different concentration(0.1mg/ml,1.0mg/ml,10mg/ml) of Icariin was added to the OB and incubated.The effect of Icariin on the proliferation and osteogenesis of OB was monitored by MTT analysis The expression of type I collagen was estimated with immunohistochmistry techniques.The expression levels of mRNA of OPN in the cells in every group were examined by reverse-transcriptase ploymerase chain reaction (RT-PCR).(3) 30 rabbits were randomly divided into 3 groups: positive contrasting group(Ⅰ),negative contrasting group(Ⅱ),medicine treatment group(Ⅲ).they accepted operation of knee arthroplasty.six weeks later, groupⅠand groupⅢwere injected Ti debris but groupⅡwas injected normal saline,16 weeks later, all rabbits were sacrificed and the content of IL-1βand TNF in the joint capsule tissue were examined .In addition, the density of tibia were examined with special computer system. Results:(1) Ti particles can induce osteoblasts apoptosis and also in dose and time dependent manner. osteoblasts incubated with Icariin injection for 3 days can resist the cell injury induced by Ti particles.(2) The expression of OPN mRNA andⅠtype collagen was strengthened gradually with the increase of Icariin concentration and peaked with 10mg/ml Icariin on the 5th day. Icariin could significantly promote the expression of OPN mRNA andⅠtype collagen in rat osteoblasts in vitro. The levels of expression of OPN mRNA andⅠtype collagen were changed with different concentration(3) compared with groupⅡand groupⅢ, IL-1βand TNF of groupⅠwere significantly high.Conclusion: particles can induce the apoptosis of the cultured osteoblasts and Icariin injection might partly protect osteoblasts to resist apoptosis. Icariin injection can promote the growth of OB and Icariin injection can lower inflammatory factors related to prosthesis loosening and prevent the disease.