Oroxylin A inhibits angiogenesis through blocking vascular endothelial growth factor-induced KDR/Flk-1 phosphorylation.
OBJECTIVE
In this study, we examined the antiangiogenic effect of oroxylin A in vitro and in vivo and explored the potential mechanisms for this effect.


METHODS
Transwell assay and tube formation assay were used to evaluate the effects of oroxylin A on vascular endothelial growth factor (VEGF)-induced migration and tube formation of human umbilical vein endothelial cells (HUVECs). Rat aortic ring assay was also employed to assess the effect of oroxylin A on microvessel outgrowth from rat aorta. Human tumor xenografts model in nude mice was further used to investigate the antiangiogenic activity of oroxylin A in vivo. Western blot analysis was used to investigate the related mechanism.


RESULTS
Oroxylin A remarkably suppressed the VEGF-stimulated migration and tube formation of HUVECs. It also inhibited microvessel sprouting from rat aortic ring in vitro. In addition, it suppressed the angiogenesis of xenograft tumor in nude mice, which concurred with the inhibition of tumor growth. Moreover, oroxylin A blocked VEGF-induced phosphorylation of KDR/Flk-1 and related downstream signaling molecules, including p38 mitogen-activated protein kinase, extracellular signal-regulated kinase and Akt.


CONCLUSIONS
Oroxylin A possessed antiangiogenic activities in vitro and in vivo, which could be an underlying mechanism of its anticancer effect.
Gao
Ying
Y
China Pharmaceutical University, Nanjing, Jiangsu, China.
Lu
Na
N
Ling
Yun
Y
Chen
Yan
Y
Wang
Ling
L
Zhao
Qing
Q
Qi
Qi
Q
Liu
Wei
W
Zhang
Haiwei
H
You
Qidong
Q
Guo
Qinglong
Q
D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D000818:Animals; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D042783:Endothelial Cells; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005419:Flavonoids / Q000494:pharmacology*; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D051058:Oncogene Protein v-akt / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism*; D023041:Xenograft Model Antitumor Assays; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D020533:Angiogenesis Inhibitors; D005419:Flavonoids; D042461:Vascular Endothelial Growth Factor A; C080669:5,7-dihydroxy-6-methoxy-2-phenylchromen-4-one; D040301:Vascular Endothelial Growth Factor Receptor-2; D051058:Oncogene Protein v-akt; D048049:Extracellular Signal-Regulated MAP Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases