Protective effects of total flavonoids in Caragana against hypoxia/reoxygenation-induced injury in human brain microvascular endothelial cells

This study aimed to explore the protective effect of total flavonoids in Caragana against hypoxia/reoxygenation (H/R)-induced injury in human brain microvascular endothelial cells (BMECs). Human BMECs were selected and assigned into control, H/R, H/R + NMP, H/R + Low dose, H/R + Moderate dose, H/R + High dose groups. MTT and Transwell assays were used to detect cell viability and migration, respectively. Cell adhesion rate and tube formation were also detected. Real-time polymerase chain reaction (RT-PCR) and Western blotting were performed to test HIF-1α, VEGF and Notch1 mRNA and protein expressions. Compared with the H/R group, the cell viability rates in the H/R + NMP, H/R + Moderate dose and H/R + High dose groups were increased. The cell adhesion rates in the H/R + NMP, H/R + Moderate dose and H/R + High dose groups were significantly different from those in the H/R group. As compared to the H/R group, the cell migration abilities in the H/R + NMP, H/R + Moderate dose and H/R + High dose groups were enhanced. Compared with the H/R group, the number and length of tubes of BMECs in the H/R + NMP, H/R + High dose and H/R + Moderate dose groups were increased. HIF-1α, VEGF and Notch1 mRNA and protein expressions were higher in the H/R + Low dose, H/R + Moderate dose and H/R + High dose groups than in the H/R group. These findings revealed that total flavonoids in Caragana can protect BMECs from H/R-induced injury in a dose-dependent manner and it also may promote angiogenesis in BMECs by activating HIF- 1α-VEGF-Notch 1 signaling pathway.