Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are the most important angiogenic molecules associated with tumor-induced neovascularization. This study was carried out to investigate inhibitory effect of extracts from root of Rehmannia glutinosa LIBOSCHITZ (Rehmannia Radix and Rehmannia Radix Preparata) on endothelial cell proliferation. The methanol extracts from the medicinal herb were fractionated into n-hexane, ethyl acetate, n-butanol and aqueous fractions. Among the four fractions, the n-butanol fraction from R. Radix on exhibited highly effective inhibition (≈79% inhibition) on the binding of KDR/Flk-1-Fc to immobilized VEGF165 and then ethyl acetate fraction from R. Radix (≈45% inhibition) at the concentration of 100 μg/ml. The n-butanol fraction efficiently blocked the VEGF- and bFGF-induced HUVEC proliferation in a dose-dependent manner, but did not affect the growth of HT1080 human fibrosarcoma cells. The n-butanol fraction more efficiently blocked the binding of KDR/Flk-1-Fc to immobilized VEGF165 and VEGF- and bFGF-induced human umbilical vein endothelial cell proliferation than the fraction from R. Radix Preparata. Our results suggest that Rehmannia Radix may be used as a candidate for developing anti-angiogenic agent.

• Sung-Jin Lee
• Hak-Kyo Lee