Bioassay for the identification of natural product-based activators of peroxisome proliferator-activated receptor-gamma (PPARgamma): the marine sponge metabolite psammaplin A activates PPARgamma and induces apoptosis in human breast tumor cells

J Nat Prod. 2006 Apr;69(4):547-52. doi: 10.1021/np050397q.


Peroxisome proliferator-activated receptors (PPARs), members of the nuclear hormone receptor (NHR) family, are ligand-activated transcription factors. Ligands (agonists) of PPARgamma have been shown to inhibit growth, promote terminal differentiation, and induce apoptosis in human breast tumor cells. A cell-based reporter assay was developed to examine extracts of terrestrial and marine organisms for the ability to activate PPARgamma. Bioassay-guided fractionation and isolation of an active extract from Pseudoceratina rhax yielded the known histone deacetylase (HDAC) inhibitor psammaplin A (1). Compound 1 activates PPARgamma in a MCF-7 cell-based reporter assay and induces apoptosis in human breast tumor cells in vitro. Molecular modeling studies suggest that 1 may interact with binding sites within the PPARgamma ligand-binding pocket. Therefore, in addition to its known effects on HDAC-mediated processes, activation of PPARgamma-regulated gene expression may play a role in the ability of 1 to induce apoptosis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Breast Neoplasms
  • Disulfides / chemistry
  • Disulfides / isolation & purification
  • Disulfides / pharmacology*
  • Dose-Response Relationship, Drug
  • Female
  • Histone Deacetylase Inhibitors
  • Humans
  • Micronesia
  • PPAR gamma / agonists*
  • Porifera / chemistry*
  • Tyrosine / analogs & derivatives*
  • Tyrosine / chemistry
  • Tyrosine / isolation & purification
  • Tyrosine / pharmacology


  • Disulfides
  • Histone Deacetylase Inhibitors
  • PPAR gamma
  • psammaplin A
  • Tyrosine