Dipyrithione induces cell-cycle arrest and apoptosis in four cancer cell lines in vitro and inhibits tumor growth in a mouse model

BMC Pharmacol Toxicol. 2013 Oct 21;14:54. doi: 10.1186/2050-6511-14-54.


Background: Dipyrithione (PTS2) is widely used as a bactericide and fungicide. Here, we investigated whether PTS2 has broad-spectrum antitumor activity by studying its cytotoxicity and proapoptotic effects in four cancer cell lines.

Methods: We used MTT assays and trypan blue staining to test the viability of cancer cell lines. Hoechst 33258 and DAPI staining were used to observe cell apoptosis. Cell-cycle percentages were analyzed by flow cytometry. Apoptosis was assayed using caspase-3 and poly (ADP-ribose) polymerase (PARP) combined with Western blotting. Student's t-test was used for statistical analysis.

Results: PTS2 inhibited proliferation in four cancer cell lines in a dose-dependent manner. Treated cells showed shrinkage, irregular fragments, condensed and dispersed blue fluorescent particles compared with control cells. PTS2 induced cycle-arrest and death. Cleavage of caspase-9, caspase-3, and PARP were detected in PTS2-treated cells. Antitumor activity of PTS2 was more effective against widely used cancer drugs and its precursor.

Conclusions: PTS2 appears to have novel cytotoxicity and potent broad-spectrum antitumor activity, which suggests its potential as the basis of an anticancer drug.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects*
  • Cell Cycle Checkpoints / drug effects*
  • Cell Proliferation / drug effects
  • Flow Cytometry
  • Humans
  • K562 Cells
  • Male
  • Mice
  • Mice, Inbred ICR
  • Molecular Structure
  • Pyridines / pharmacology*
  • U937 Cells
  • Xenograft Model Antitumor Assays


  • Antineoplastic Agents
  • Pyridines
  • dipyrithione