Résumé
OBJECTIVE To investigate the protective effect of velvet antler polypeptides(VAP)on hydrogen peroxide( H2 O2 )-induced injury in vascular endothelial cells and the possible mechanism.METHODS The EVC-304 cells cultured invitrowere incubated with H2 O2 for another 12 h after pretreat-ment with VAP 20,40 and 80 mg·L-1 for 24 h. Cell viability was determined by MTT assay, Hoechst333258 staining was used to observe cell morphology,the activity of superoxide dismutase (SOD)and the level of malondialdehyde( MDA)were detected with kits and the expression of heat shock protein(HSP70)and caspase 3 was detected by Western blotting. RESULTS Compared with the normal control group,the cell survival rate was decreased significantly in H2 O2 injury group( P ﹤0.01),cell shrinkage,chromatin condensation,and nuclear fragmentation were seen,the intracellular SOD activity decreased while MDA content increased(P﹤0.01),and caspase 3 and HSP70 expression increased(P﹤0.01). Compared with H2 O2 group,the cell survival rate in VAP 20,40 and 80 mg·L-1 pre-treatment groups increased significantly(P﹤0.01),the apoptosis ratio declined from(25.3±1.0)% to (15.2±1.2)%,(10.3±0.9)% and(7.9±1.4)%(P﹤0.01),the SOD activity increased to 19.2±0.5,22.3± 1.7 and(24.9±0.6)kU·g-1 protein(P﹤0.01),MDA concentration decreased to 1.51±0.2,1.48±0.3 and (1.02±0.1)μmol·g-1 protein(P﹤0.01),and the expression of caspase 3 and HSP70 declined significant-ly(P﹤0.01). CONCLUSION VAP has exert protective effect on H2 O2-induced injury in vascular endothe-lial cells. The possible mechanism might be related to improvement of intracellular oxidative stress level.