Danggui Buxue Decoction Protects Retinal Vascular Endothelial Cells from High Glucose-Induced Apoptotic and Oxidative Injury by Decreasing Forkhead Box O4

To explore the effect and mechanism of Danggui Buxue decoction on high glucose-induced apoptotic and oxidative injury in human retinal vascular endothelial cells. Human retinal vascular endothelial cells were treated with high glucose to mimic the diabetic retinopathy condition in vitro. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay and flow cytometry were used to investigate cell viability and apoptosis. Western blot was applied to detect the proteins of apoptosis-related markers and forkhead box O4. The oxidative injury was assessed using enzyme-linked immunosorbent assay analysis. Human retinal vascular endothelial cells in high glucose group showed the decrease of cell viability and superoxide dismutase activity, as well as the increase of cell apoptosis rate, reactive oxygen species level and malondialdehyde content, which were reversed by Danggui Buxue decoction treatment in a dose-dependent manner. Subsequently, we found that forkhead box O4 level was elevated in high glucose-induced human retinal vascular endothelial cells, while Danggui Buxue decoction dose-dependently down-regulated forkhead box O4 level in human retinal vascular endothelial cells. Deficiency of forkhead box O4 could reverse high glucose-induced apoptotic and oxidative injury in human retinal vascular endothelial cells. Moreover, the inhibitory effects of Danggui Buxue decoction on high glucose-induced human retinal vascular endothelial cells were attenuated by forkhead box O4 overexpression. Danggui Buxue decoction may inhibit the apoptosis and oxidative damage of human retinal vascular endothelial cells induced by high glucose by down-regulating forkhead box O4.