The Protective Effect Of Simvastatin On Hydrogen Peroxide Induced Apoptosis Of MG63 Cells

[AIM]To investigate the protective effect of simvastatin against H2O2-induced apoptosis of osteosarcoma MG63 cells and the possible molecular mechanisms involved.[METHODS]H2O2(500μmol/L) and different concentration of simvastatin(10-7-10-9mol/L) was used to treat the MG63 cells. According to different treatment cells were divided into five groups:Cells without simvastatin or H2O2 (Normal); Cells with only 500μmol/L H2O2 treatment; Cells pretreated with10-7 mol/L,10-8 mol/L and 10-9 mol/L simvastatin followed by the treatment of 500μmol/L H2O2. Cells'morphological change was observed with light microscope. MTS assay was used to evaluate cell viability. the expression of caspase-9 and bcl-2 were assayed by Western blot to investigate the possible molecular mechanisms involved.[RESULTS]1. Morphological change of MG63 cellsMorphologic change of MG63 cells with different concentration of simvastatin was performed with microscopy to study the effect of simvastatin on MG63 cells. In normal group almost no abnormal cells were observed; In only H2O2 treated group, a large proportion of cells demonstrated apoptosis signs such as detachment, chromosome condensation and cell body shrink; In another three groups (pretreated with 10-9 mol/L, 10-8 mol/L and 10-7 mol/L simvastatin followed by the addition of 500μmol/L H2O2), the proportion of cells with abnormal morphology suggestive of apoptosis decreased with the increasing simvastatin concentration, indicating a concentration-dependent protection effect by simvastatin.2. MTS assayCompared with normal group, the value of OD in only H2O2 treatment group decreased significant. In different concentration of simvastatin groups (MG63 cells pretreated with 10-9,10-8and 10-7 simvastatin followed by the addition of 500μmol/L H2O2), the value of OD increased with the increasion of simvastatin concentration.. The concentrations of simvastatin used in our experiment show protective effect to MG63 cells, and this protection was related with the simvastatin concentration.3. Western Blot analysisSimvastatin significantly decreased the protein expression of Caspase-9 and increased the protein expression of bcl-2, and the effect was positively correlated with the concentrations of simvastatin. These show that the protective effect of simvastatin against H2O2-induced apoptosis may have relation with Caspase-9 and bcl-2.[CONCLUSION]Simvastatin displays a protective effect against H2O2-induced apoptosis of MG63 cells, and this protection shows a dose-dependent manner. This effect may be related to the down-regulation of the expression of Caspase-9 and up-regulation of the expression of bcl-2.