New Natural Pigment Fraction Isolated from Saw Palmetto: Potential for Adjuvant Therapy of Hepatocellular Carcinoma

Int J Mol Sci. 2016 Aug 5;17(8):1277. doi: 10.3390/ijms17081277.

Abstract

For the first time, we discovered a small proportion of aqueous fraction from Saw Palmetto apart from the fatty acid-rich fraction exhibited pharmacological activity. Therefore, this study aims to explore the anti-tumor potential of red pigmented aqueous fraction of Saw Palmetto, NYG on human hepatocellular carcinoma and its possible targets. Subcutaneous xenograft and orthotopic implantation models of HCC were used to evaluate the tumor inhibitory effect of NYG. Human hepatocellular carcinoma (HCC) cell lines and human umbilical vein endothelial cells (HUVEC) were used as in vitro model. The mRNA expression was conducted by qPCR. Protein expression was monitored by immunoblotting and immunohistochemistry. Cell migration and blood vessel formation were determined by chamber assay and tube formation assay, respectively. Significant tumor inhibition of NYG in dose-dependent manner was observed on subcutaneous xenograft and orthotopic HCC model. NYG has no direct action on cell viability or VEGF secretion of HCC cells. However, NYG reduced in vitro migration and vessel formation activities of HUVEC cells, as well as in vivo intratumoral neovascularization. NYG attenuated extracellular signal-regulated kinases (ERK) activation in endothelial cells, which may be associated with the suppression of migration and tube formation of HUVEC. NYG suppressed tumor expansion of HCC via inhibiting neovascularization, and may be potential adjuvant treatment for HCC.

Keywords: HUVEC; NYG; angiogenesis; hepatocellular carcinoma; saw palmetto.

MeSH terms

  • Animals
  • Carcinoma, Hepatocellular / drug therapy*
  • Carcinoma, Hepatocellular / pathology
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Chemotherapy, Adjuvant
  • Enzyme Activation / drug effects
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Hep G2 Cells
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Liver Neoplasms / drug therapy*
  • Liver Neoplasms / pathology
  • Mice
  • Models, Biological
  • Neovascularization, Pathologic / drug therapy
  • Pigments, Biological / pharmacology
  • Pigments, Biological / therapeutic use*
  • Plant Extracts / pharmacology
  • Plant Extracts / therapeutic use*
  • Xenograft Model Antitumor Assays

Substances

  • Pigments, Biological
  • Plant Extracts
  • Extracellular Signal-Regulated MAP Kinases
  • saw palmetto extract