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Published on: November 15, 2013

Oleandrin suppresses activation of nuclear transcription factor-kappaB, activator protein-1, and c-Jun NH2-terminal

S K Manna1, N K Sah, R A Newman

  • 1Department of Bioimmunotherapy, The University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.

Cancer Research
|August 5, 2000
PubMed

Insights

Oleandrin, a compound from Nerium oleander, effectively suppresses key inflammatory pathways like nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1) activation. This inhibition may offer a molecular basis for its potential anti-inflammatory and anti-tumorigenic effects.

Area of Science:

  • Molecular Biology
  • Pharmacology
  • Cancer Research

Background:

  • Nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1) are critical transcription factors involved in inflammation and tumorigenesis.
  • Agents that modulate NF-kappaB and AP-1 activation hold potential for therapeutic intervention in inflammatory diseases and cancer.
  • Oleandrin, a cardiac glycoside from Nerium oleander, is investigated for its potential role as an NF-kappaB and AP-1 modulator.

Purpose of the Study:

  • To investigate the effect of oleandrin on the activation of NF-kappaB induced by inflammatory stimuli.
  • To elucidate the molecular mechanisms by which oleandrin modulates NF-kappaB and AP-1 signaling pathways.
  • To assess the potential of oleandrin as a therapeutic agent for inflammation and tumorigenesis.

Main Methods:

  • Treatment of various cell types with oleandrin and inflammatory agents (e.g., TNF, phorbol ester, lipopolysaccharide).
  • Assessment of NF-kappaB and AP-1 activation using reporter gene assays and Western blotting to analyze IkappaBalpha phosphorylation and degradation.
  • Investigation of the upstream signaling cascade, including TNF receptor-associated factor 2 and NF-kappaB-inducing kinase.

Main Results:

  • Oleandrin demonstrated a concentration- and time-dependent inhibition of tumor necrosis factor (TNF)-induced NF-kappaB activation.
  • This inhibition was mediated by suppressing the phosphorylation and degradation of IkappaBalpha, a key inhibitor of NF-kappaB.
  • Oleandrin also suppressed AP-1 activation and TNF-induced c-Jun NH2-terminal kinase activation, and its effects were observed across multiple cell types.

Conclusions:

  • Oleandrin effectively inhibits the activation of NF-kappaB and AP-1 signaling pathways.
  • The compound interferes with critical components of the NF-kappaB cascade, including TNF receptor-associated factor 2 and NF-kappaB-inducing kinase.
  • These findings provide a molecular basis for oleandrin's potential to suppress inflammation and possibly tumorigenesis.

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