Ethyl Acetate Fraction of Teucriumpolium Extract Abolishes Human Umbilical Vein Endothelial Cells (HUVEC) Tubulogenesis in Collagen Bed through Suppression of Cell Proliferation/VEGF Secretion

摘要

Angiogenesis has essential role in growth and metastasis of tumors. Development of therapies aimed to suppress angiogenesis using medicinal plants is one of the effective approaches for prevention/treatment of cancer. The current study was performed to investigate in vitro anti-angiogenic effect of Teucrium Polium (TP) extract and its fractions.?The aerial part of Teucrium Polium was powdered and extracted with 50% ethanol. The extract was fractionated in to aqueous (AQ), n-butanol (BU), ethyl acetate (EA) and n-hexane (HE) fractions. Anti-angiogenic effect of TP was examined on human umbilical vein endothelial cells (HUVECs) in three-dimensional collagen matrix. The endothelial cells form capillary-like branches that can be visualized using phase contrast microscope and the number of tube-like structures can be quantified as a measure of in vitro angiogenesis. Furthermore, anti-proliferative and vascular endothelial growth factor(VEGF )suppressive effect of TP as important factors in the process of angiogenesis were assessed using3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT)and quantitative ELISA, respectively.?Based on our findings, among the TP fractions, EA fraction showed the highest inhibitory activity on angiogenesis. This fraction with IC50: 68 μg/mL, inhibited angiogenesis at 60 μg/mL. The crude extract and other fractions of TP inhibited angiogenesis in a dose-dependent manner at doses higher concentrations than EA fraction, significantly.TP extract and EA fraction were able to inhibit proliferation of HUVEC and inhibited VEGF secretion in a dose dependent manner. The ethyl acetate fraction at 60 μg/ml inhibited VEGF secretion perfectly. Our data indicated that ethyl acetate fraction of Teucrium Polium could be a potential candidate for the prevention of angiogenesis in cancer and other related disorders. However, this suggestion needs more quantitative and in vivo investigations for confirmation.