Rabdosia rubescens inhibits breast cancer growth and angiogenesis.

Investigators have shown that PC-SPES is a potent herbal mixture which has often been used by prostate cancer patients. In this study, we examined the inhibitory effects of certain individual components of PC-SPES on the in vitro proliferation of the human breast cancer cells MDA-MB231 and the human umbilical vein endothelial cells (HUVEC). Our data showed that individual components of PC-SPES had varying suppressive effects on cellular proliferation, and that Rabdosia rubescens appeared to be the most potent agent in these assays. Apoptosis was up-regulated by Rabdosia rubescens, as seen in the caspase-9 and TUNEL assays. These effects may be mediated via both the MAPK (mitogen-activated protein kinase) and the Akt kinase pathways. In mouse experiments, the extract from Rabdosia rubescens suppressed breast cancer xenograft size and decreased the tumor vessel density. We conclude that Rabdosia rubescens may potentially be used to treat or prevent breast cancer, and that the extract from this herbal source deserves further studies.