Effect of AL on VEGF-induced endothelial migration, invasion and tube formation in vitro . HUVECs were plated to full confluence on six-well plates. A single scratch was made and cells were treated with VEGF in the presence or absence of AL. A, VEGF stimulation led to an increase in cell migration after 7 h. AL remarkably reduced numbers of migrated endothelial cells induced by VEGF. The migrated cells were quantified by direct counting. B, AL inhibited VEGF-induce invasion of HUVECs. Cells were seeded in the upper chamber of Transwell and treated with different concentrations of AL. Representative images were shown as described in “Materials and methods.” C, tube formation assay on Matrigel. HUVECs were exposed to different concentration of AL with or without VEGF(50 ng/mL) for 9–10 h. Significant inhibition of endothelial tubular structures formation was observed in a dose dependent manner. Indexing was performed by counting micro tubes or cell in randomly selected four different fields. The results shown are representative of four independent experiments.*, P < 0.05; **, P < 0.01; ***, P < 0.001 vs. control.