The roles of endogenous reactive oxygen species and nitric oxide in triptolide-induced apoptotic cell death in macrophages

J Mol Med (Berl). 2007 Jan;85(1):85-98. doi: 10.1007/s00109-006-0113-x. Epub 2006 Nov 16.


Triptolide, a major active component extracted from the root of Tripterygium wilfordii Hook f, has been shown to possess potent immunosuppressive and anti-inflammatory properties. In the present report, we reported that triptolide increased the generation of reactive oxygen species (ROS) and nitric oxide (NO) and induced apoptosis of RAW 264.7 cells in a dose-dependent manner (5-25 ng/ml). The antioxidant, reduced glutathione (GSH), significantly inhibited triptolide-induced apoptosis and inhibited the degradation of Bcl-2 protein, disruption of mitochondrial membrane potential, release of cytochrome c from mitochondria into the cytosol, activation of caspase-3, and cleavage of poly-(ADP-ribose)-polymerase. The inducible nitric oxide synthase-specific inhibitor 1400w blocked triptolide-induced apoptosis, but did not alter mitochondria disruption and caspase-3 activation. These results, for the first time, implicated that the increased endogenous ROS and NO co-mediated triptolide-induced apoptosis in macrophages. ROS initiated triptolide-induced apoptosis by the mitochondria signal pathway, while the apoptotic cell death mediated by NO was not via mitochondria collapse and caspase-3 activation. In addition, combining mathematical calculation and computer simulation based on our conventional experimental results, we set and validated the apoptotic model and provided more dynamic processes of triptolide-induced apoptotic cascade in macrophages.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology
  • Antineoplastic Agents, Alkylating / pharmacology*
  • Apoptosis / drug effects*
  • Caspases / metabolism
  • Cytochromes c / metabolism
  • Diterpenes / pharmacology*
  • Enzyme Activation / drug effects
  • Epoxy Compounds / pharmacology
  • Humans
  • Macrophages / drug effects*
  • Macrophages / metabolism
  • Macrophages / pathology
  • Membrane Potential, Mitochondrial / drug effects
  • Mice
  • Nitric Oxide / metabolism*
  • Nitric Oxide Synthase Type II / metabolism
  • Nitrites / metabolism
  • Phenanthrenes / pharmacology*
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Reactive Oxygen Species / metabolism*
  • U937 Cells


  • Anti-Inflammatory Agents, Non-Steroidal
  • Antineoplastic Agents, Alkylating
  • Diterpenes
  • Epoxy Compounds
  • Nitrites
  • Phenanthrenes
  • Proto-Oncogene Proteins c-bcl-2
  • Reactive Oxygen Species
  • triptolide
  • Nitric Oxide
  • Cytochromes c
  • Nitric Oxide Synthase Type II
  • Caspases