effect of safflor yellow b on vascular endothelial cells injury induced by angiotensinii this study is to investigate protective effect of safflor yellow b syb against vascular endothelial cells vecs injury induced by angiotensinii angii vecs were cultured and divided into six groups control group angii group angii syb 1 micromoll1 group angii syb 10 micromoll1 group angii syb 100 micromoll1 group and ang ii verapamil 10 micromoll1 group except control group all of vecs in other groups were treated with ang ii at the final concentration of 01 micromoll1 mitochondria membrane potential mmp and free calcium concentration ca2i were measured by laser scanning confocal microscopy and mitochondria complex iv activity was detected by bca method the levels of reactive oxygen species ros in vecs were analyzed by fluorescence detector and apoptosis of vecs was observed by flow cytometer caspase 3 was determined by western blotting method comparing with control group angii was able to increase ca2i and ros level decrease mmp level inhibit complex iv activity and enhance caspase 3 activity in vecs as a result enhance apoptosis of vecs but syb could significantly reduce the result induced by ang ii relying on different dosages p 005 or p 001 syb was able to eliminate the effect of angii on vecs via regulating ca2i mitochondrial structure and function and inhibiting apoptosis