Ursolic acid (UA) and oleanolic acid (OA) were examined for anti-angio
genic activities by using the chick embryo chorioallantoic membrane (C
AM) assay. The presence of UA or OA inhibited angiogenesis in a dose-d
ependent manner; the doses required for half-maximal inhibition (ID50)
Were 5 mu g and 40 mu g per CAM, respectively. UA was a more potent a
ngiogenic inhibitor than OA. We also tested for inhibitory effect on t
he proliferation of bovine aortic endothelial cell. They effectively i
nhibited the proliferation of bovine aortic endothelial cell in a conc
entration-dependent manner. The IC50 values of anti-proliferative effe
cts were determined to be 5 mu M for UA and 20 mu M for OA. Based on t
hese results, we speculated that the inhibitory effects on bovine aort
ic endothelial cell proliferation of UA and OA might be important for
anti-angiogenesis.