Terrestrosin D, a steroidal saponin from Tribulus terrestris L., inhibits growth and angiogenesis of human prostate cancer in vitro and in vivo

Pathobiology. 2014;81(3):123-32. doi: 10.1159/000357622. Epub 2014 Mar 8.

Abstract

Objective: The aim of this study was to investigate whether terrestrosin D (TED) inhibits the progression of castration-resistant prostate cancer and consider its mechanism.

Methods: Cell cycle, mitochondrial membrane potential (ΔΨm) and apoptosis were determined by flow cytometry. Caspase-3 activity and vascular endothelial growth factor secretion were detected by a caspase-3 assay and human vascular endothelial growth factor kit, respectively. A PC-3 xenograft mouse model was used to evaluate the anticancer effect of TED in vivo.

Results: In vitro, TED strongly suppressed the growth of prostate cancer cells and endothelial cells in a dose-dependent manner. TED induced cell cycle arrest and apoptosis in PC-3 cells and human umbilical vascular endothelial cells (HUVECs). TED-induced apoptosis did not involve the caspase pathway. TED also decreased ΔΨm in PC-3 cells and HUVECs. In vivo, TED significantly suppressed tumor growth in nude mice bearing PC-3 cells, without any overt toxicity. Immunohistochemical analysis showed TED induced apoptotic cell death and inhibited angiogenesis in xenograft tumor cells.

Conclusion: Cell cycle arrest and induction of apoptosis in cancer cells and endothelial cells might be plausible mechanisms of actions for the observed antitumor and antiangiogenic activities of TED.

MeSH terms

  • Adenocarcinoma / blood supply
  • Adenocarcinoma / metabolism
  • Adenocarcinoma / pathology*
  • Animals
  • Apoptosis / drug effects
  • Caspase 3 / metabolism
  • Cell Cycle / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects*
  • Disease Models, Animal
  • Endothelium, Vascular / drug effects
  • Endothelium, Vascular / metabolism
  • Endothelium, Vascular / pathology
  • Heterografts
  • Humans
  • In Vitro Techniques
  • Male
  • Mice
  • Mice, Nude
  • Neovascularization, Pathologic / drug therapy*
  • Plant Extracts / pharmacology*
  • Plant Extracts / therapeutic use
  • Prostatic Neoplasms / blood supply
  • Prostatic Neoplasms / metabolism
  • Prostatic Neoplasms / pathology*
  • Saponins / pharmacology*
  • Saponins / therapeutic use
  • Tribulus*
  • Vascular Endothelial Growth Factor A / metabolism
  • Xenograft Model Antitumor Assays

Substances

  • Plant Extracts
  • Saponins
  • Vascular Endothelial Growth Factor A
  • Caspase 3