Abstract: AIM: To observe the effect and mechanisms of curcumin to hydrogen peroxide induced oxidative vascularendothelial cells ECV304 damage.METHODS: Estimate cell survival rates of curcumin to H₂O₂ induced oxidative ECV304 damage by trypan blue staining.The observed the change of cell cycle and cell apoptosis rates by FACS.Detect the expression of NO,MDA contents and SOD,Gractivity by test kits.RESULTS: When added simultaneously with 500μmol·L^-1 curcumin (0-100μmol·L^-1) for5 h effectively protected cells form ox-idative damage.However,when the cells were pretreated with curcumin (25-100μmol·L^-1) for1h before H₂O₂ exposure for4 h,curcumin was unable to inhibit H₂O₂-induced cell damage.Instead;when pretreated with H₂O₂ for4h and then added curcumin (25-100μmol·L^-1),cell survival rate also increased.It was no obviously change of cell apoptosis rates by curcumin to H₂O₂-induced cell damage,but curcumin was found to induce Sphase cell cycle arrest in curcumin togetherwith H₂O₂ grouPand post-treatment with curcumin group,and adversely in pretreatment with curcumin group.CONCLUSION: The curcumin has dual action to hydrogen peroxide induced oxidative vascularendothelial cells ECV304 damage,cytoprotective and cytotoxic effects,which is correlated different chronologicaol ordertreated with curcumin.

Key words: curcumin, ECV304, hydrogen peroxide, cytoprotective effects, cytotoxic effects