Antiproliferative Activity and Induction of Apoptosis in Human Melanoma Cells by Houttuynia cordata Thunb Extract

Anticancer Res. 2017 Dec;37(12):6619-6628. doi: 10.21873/anticanres.12119.

Abstract

Background/aim: To analyze the apoptotic effect of Houttuynia cordata Thunb (HCT) extract on human melanoma A375 cells and its underlying mechanisms.

Materials and methods: The effects of HCT on cell death were determined using the MTT assay. Hoechst 33342 staining was conducted to confirm the detection of cell apoptosis. Caspase-3 and caspase-8 mRNA and cleaved protein levels were investigated by RT-PCR and western blotting, respectively. The release of high mobility group box 1 (HMGB1) and phosphorylation of mitogen-activated protein kinase (MAPK) were determined by ELISA.

Results: Caspase-3 and caspase-8 specific inhibitors suppressed HCT-induced cell death. HCT increased caspase-3 and caspase-8 mRNA, protein levels, and caspase activities in a concentration- and time-dependent manner. HCT induced MAPK phosphorylation in a time-dependent fashion. Pretreatment of cells with a selective inhibitor of p38 MAPK reduced apoptosis and reversed the levels of HMGB1 release in response to HCT treatment.

Conclusion: HCT induces A375 programmed cell death by activating the caspase-dependent pathway and by p38 phosphorylation associated with HMGB1 reduction.

Keywords: Houttuynia cordata Thunb; apoptosis; caspase; high mobility group box 1; melanoma; mitogen-activated protein kinase.

MeSH terms

  • Apoptosis / drug effects*
  • Blotting, Western
  • Caspase 3 / genetics
  • Caspase 3 / metabolism
  • Caspase 8 / genetics
  • Caspase 8 / metabolism
  • Cell Line, Tumor
  • Cell Proliferation / drug effects*
  • Dose-Response Relationship, Drug
  • Gene Expression Regulation, Neoplastic / drug effects
  • Houttuynia / chemistry*
  • Humans
  • Melanoma / genetics
  • Melanoma / metabolism
  • Melanoma / pathology
  • Mitogen-Activated Protein Kinases / metabolism
  • Phosphorylation / drug effects
  • Plant Extracts / pharmacology*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Time Factors

Substances

  • Plant Extracts
  • Mitogen-Activated Protein Kinases
  • CASP3 protein, human
  • Caspase 3
  • Caspase 8