Protective Effect Of Polysaccharides From Boschniakia Rossica On TBHP Inducded Apoptosis Of Vascular Endothelial Cells

Objective:To study the protective effect and mechanism of polysaccharides from Boschniakia rossica(BRPS)on apoptosis induced by tert-butyl hydroperoxide(TBHP)in human umbilical vein endothelial cells(HUVECs).Methods:The cellular apoptotic model was established by treating human umbilical vein endothelial cells with TBHP.Cell toxicity was tested by MTT method,and the levels of reduced glutathione(GSH),malondialdehyde(MDA),and superoxide dismutase(SOD)activity were measured by colorimetric method.The reactive oxygen species(ROS)was observed by DCFH-DA fluorescent staining,the apoptotic and morphological changes were detected by Hoechst and TUNEL fluorescent staining,and the mitochondrial membrane potentials were observed by JC-1 fluorescent staining.The protein expressions of tBid,Bax,Bcl-2,cleaved caspase3,cleaved caspase8,cleaved caspase9,procaspase3,procaspase8,procasepase9 and cytochrome(Cyto)c were determined with western blotting method.Result:The results revealed that TBHP decreased the cell viabilities,promoted cell apoptosis,increased ROS formation,decreased the mitochondrial membrane potentials,up-regulated the protein expressions of cleaved caspase3,cleaved caspase8,cleaved caspase9,Bax,cytoplasmic Cyto c and mitochondrial tBid,and down-regulated the protein expressions of procaspase3,procaspase8,procasepase9 and Bcl-2.Compared to the model group,BRPS significantly increased the cell viabilities,reduced the MDA formation,increased the SOD and GSH levels,reduced cell apoptosis,decreased ROS formation,and elevated the mitochondrial membrane potentials.In addition,BRPS down-regulated the protein expressions of cleaved caspase3,cleaved caspase8,cleaved caspase9,Bax,cytoplasmic Cyto c and mitochondrial tBid,while up-regulated the protein expressions of procaspase3,procaspase8,procasepase9 and Bcl-2.Conclusion:BRPS have the protective effect on apoptosis of HUVECs induced by TBHP,maybe via inhibition of mitochondrial pathway and death receptor pathway.