The relationship between diphenylamine structure and NSAIDs-induced hepatocytes injury

Toxicol Lett. 2009 Apr 25;186(2):111-4. doi: 10.1016/j.toxlet.2009.01.005. Epub 2009 Jan 16.


Objective: Many nonsteroidal anti-inflammatory drugs (NSAIDs) with diphenylamine structure induce severe hepatotoxicities. We evaluated the role of diphenylamine structure in liver injuries induced by these NSAIDs.

Methods: Effects of diphenylamine, diclofenac and tolfenamic acid on mitochondrial permeability transition (MPT) and efflux of calcium in isolated liver mitochondria as well as on cellular ATP content and mitochondrial membrane depolarization in rat primary hepatocyte cultures were examined.

Results: Diclofenac and tolfenamic acid induced cyclosporine A (CsA)-sensitive mitochondrial swelling and membrane depolarization in isolated liver mitochondria. Only diclofenac caused the release of calcium in isolated liver mitochondria. Diphenylamine had no effects on isolated liver mitochondria. All three compounds decreased ATP content and induced mitochondrial membrane depolarization. CsA attenuated these effects, suggesting MPT might be involved in the hepatotoxicities caused by diphenylamine, diclofenac and tolfenamic acid. SKF-525A, a general inhibitor of CYP450, markedly inhibited the injury induced by diphenylamine, but not diclofenac or tolfenamic acid.

Conclusion: The hepatotoxicities caused by diclofenac and tolfenamic acid may be attributed to the mitochondrial dysfunction induced by these drugs instead of the diphenylamine structure per se.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / chemistry*
  • Anti-Inflammatory Agents, Non-Steroidal / toxicity*
  • Cell Survival / drug effects
  • Cells, Cultured
  • Chemical and Drug Induced Liver Injury / pathology*
  • Diclofenac / toxicity
  • Diphenylamine / analogs & derivatives*
  • Diphenylamine / chemistry
  • Diphenylamine / toxicity*
  • Enzyme Inhibitors / pharmacology
  • Hepatocytes / drug effects*
  • Hepatocytes / pathology*
  • Male
  • Membrane Potentials / drug effects
  • Mitochondria, Liver / drug effects
  • Mitochondrial Swelling / drug effects
  • Proadifen / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Structure-Activity Relationship
  • ortho-Aminobenzoates / toxicity


  • Anti-Inflammatory Agents, Non-Steroidal
  • Enzyme Inhibitors
  • ortho-Aminobenzoates
  • Diclofenac
  • tolfenamic acid
  • Adenosine Triphosphate
  • Diphenylamine
  • Proadifen