Effects Of Salvianolic Acid B On NO Production In Vascular Endothelial Cells

Nitric oxide (NO) plays an important role in the regulation of endothelial cell function. Antioxidants may exert their pharmacological effects on biological systems through scavenging reactive oxygen (nitrogen) species (RONS). To understand the effect of antioxidants on regulating NO and ROS, we took the potent water-soluble antioxidant of Salvia Miltiorrhiza-Salvianolic acid B (Sal B) as an example to investigate its effect on NO production of human umbilical vein endothelial cell line (EA.hy926), the relation with ROS. The relationship between antioxidant capacity and chemical structure of Sal B was also studied.The extracellular NO production was increased while human EA.hy926 endothelial cells treated with Sal B for12 h by Griess assay and the intracellular NO production was also enhanced using fluorescent probe DAF-FM DA detection. Western blotting analysis demonstrated that Sal B increased the level of eNOS, and meanwhile activized iNOS expression for a long term treatment.When endothelial cell was treated with exogenous H2O2, the expression level of eNOS and iNOS were increased, NO and ROS were simultaneously generated. And these phenomena were inhibited by Sal B. Sal B also showed positive effect of NO production of LPS-damaged endothelial cells.The results of VCEAC assay using ABTS and DPPH radical scavenging activities showed that the antioxidant capacity of Sal B was 1.87-fold of VC. The analysis of structural relationship of antioxidant capacity for Sal B confirmed the result.The study suggested that the effective antioxidant Sal B could increase endothelial NO production, scavenge intracellular ROS and modulate the reaction of NO and ROS. It is helpful to explain the efficacy of Sal B and provide molecular pharmacological evidences for secondary exploitation of Salvia Miltiorrhiza.