Brazilian Propolis Suppresses Angiogenesis by Inducing Apoptosis in Tube-Forming Endothelial Cells through Inactivation of Survival Signal ERK1/2
Figure 1
EEBP inhibits tube formation, induces apoptosis and inactivates ERK1/2 in tube-forming HUVECs. (a) HUVECs were sandwiched between two layers of collagen gel and induced to form blood vessel-like tubes. The tube-forming cells were treated with indicated concentrations of EEBP or EGCg for 24 h, fixed and stained with DAPI. Representative photographs are shown. Bar indicates 100 μm. (b) Areas of the formed tubes (area ratios of the tubes per pictured field) and (c) rates of apoptosis (percentage of condensed and fragmented cell nuclei against total cell nuclei) were quantified as described in Materials and methods section. *P < .05, **P < .01, as compared to the control. (d) After 12 h treatment with indicated concentrations of EEBP, cellular proteins were collected from tube-forming HUVECs. Changes in phosphorylation state of ERK1/2 at Thr202/Tyr204 and Akt at Ser473 were analyzed by western blotting. Each experiment was repeated at least three times and representative data are shown.
