Effect of safflor yellow B on vascular endothelial cells injury induced by angiotensin-II

This study is to investigate protective effect of safflor yellow B (SYB) against vascular endothelial cells (VECs) injury induced by angiotensin-II (Ang-II).  VECs were cultured and divided into six groups: control group, Ang-Ⅱ group, Ang-Ⅱ + SYB (1 µmol·L⁻¹) group, Ang-Ⅱ + SYB (10 µmol·L⁻¹) group, Ang-Ⅱ + SYB (100 µmol·L⁻¹) group and Ang-Ⅱ + verapamil (10 µmol·L⁻¹) group.  Except control group, all of VECs in other groups were treated with Ang-Ⅱ at the final concentration of 0.1 µmol·L⁻¹.  Mitochondria membrane potential (MMP) and free calcium concentration (Ca²⁺_i) 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, Ang-Ⅱ was able to increase Ca²⁺_i 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-Ⅱrelying on different dosages (P < 0.05 or P < 0.01).  SYB was able to eliminate the effect of Ang-Ⅱ on VECs via regulating Ca²⁺_i , mitochondrial structure and function and inhibiting apoptosis.