Abstract

Scutellaria barbata D. Don is a medicinal herb that has long been clinically used in China to treat various types of cancer. Extracts of S. barbata D. Don have been shown to inhibit the growth of many cancer cells. Previously, we reported that S. barbata D. Don promotes cancer cell apoptosis via activation of the mitochondrion-dependent pathway. To further elucidate the precise mechanism of its tumorcidal activity, we investigated the effects of ethanol extract of S. barbata D. Don (EESB) on tumor angiogenesis. We found that EESB inhibited angiogenesis in vivo in chick embryo chorioallantoic membrane (CAM). In addition, we observed that EESB dose and time-dependently inhibited the proliferation of human umbilical vein endothelial cells (HUVEC) via blocking the cell cycle G1 to S progression. Moreover, EESB inhibited the migration and tube formation of HUVECs. Furthermore, EESB treatment down-regulated the mRNA and protein expression levels of VEGF-A in both HT-29 human colon carcinoma cells and HUVECs. Our findings suggest that inhibiting tumor angiogenesis is one of the mechanisms by which S. barbata D. Don treats cancer.

Key words: Tumor angiogenesis, traditional Chinese medicine, multi-target agents,Scutellaria barbata D. Don.

Abbreviation

EESB, Ethanol extract of Scutellaria barbata D. Don; TCM, traditional Chinese medicine; CAM, chorioallantoic membrane; HUVEC, human umbilical vein endothelial cell; DMSO, dimethyl sulfoxide; MTT, 3-(4, 5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide.