Abstract: ObjectiveTo study the effects of soybean isoflavone(SI)on the apoptosis of vascular endothelial cells following oxidative injury in vitro.MethodsThe vascular endothelial cells were cultured in vitro and divided into 6 groups, vascular control,oxidized low density lipoprotein(ox-LDL),VE+ox-LDL,SI-Low(SI-L)ox-LDL,SI-Middle(SI-M)ox-LDL,SI-High(SI-H)ox-LDL grops.The vein endothelial cells were incubated with ox-LDL for 24 hours after incubated with VE on different doses of SI for 24 hours.The levels of MTT(A),LDHreleasing and AI of cells were measured and their morphologic characters were observed.ResultsThe MTT(A)levels of control,VE+ox-LDL and(SI-L,M,H)+ox-LDL groups were significantly higher than those of ox-LDLgroup(P<0.01).The levels of releasing percentage of LDH and apoptosis index in control,VE+ox-LDL and(SI-L,M,H)+ox-LDL groups were significantly lower than those in ox-LDL group(P<0.01).ConclusionSIcan inhibit apoptosis of vascular endothelia cells following oxidative injury in vitro.