Protective effects of tryptophan on neuro-inflammation in rats after administering lipopolysaccharide

Biomed Pharmacother. 2011 Jun;65(3):215-9. doi: 10.1016/j.biopha.2011.02.008. Epub 2011 May 5.

Abstract

Tryptophan (TRP), which plays an important role in immune system regulation, protein synthesis, serotonin (5-HT) and melatonin production, is a potent endogenous free radical scavenger and antioxidant. The aim of this work was to determine the efficacy of TRP in neuro-inflammation induced by systemic administration of lipopolysacharide (LPS, 20mg/kg) which promotes the synthesis of free radical (LPO: MDA and 4-HDA), and pro-inflammatory cytokine Interferon-γ (IFN-γ) in different brain regions (cerebral cortex and hippocampus) of rats. Experiments were performed on adult female, pregnant and lactating rats fed with a diet of TRP content (0.5mg/100g protein), cerebral cortex and hippocampus were evaluated for lipid peroxidation (LPO) products, nitrites, nitrates and plasmatic concentration of IFN-γ. LPO levels in LPS+TRP groups were significantly decreased than that obtained in the LPS group. However, there were no observed differences in plasmatic levels of nitrites and nitrates as well as IFN-γ, neither in the cerebral cortex or hippocampus. The TRP has protective effect in the oxidative damage in a model of endotoxic shock in the breading nurslings induced by the systemic administration of LPS, acting as a scavenger of free radicals. So, it can be proposed as an innocuous protector agent in the endotoxic shock process.

MeSH terms

  • Animals
  • Antioxidants / pharmacology
  • Cerebral Cortex / drug effects*
  • Cerebral Cortex / metabolism
  • Drug Interactions
  • Female
  • Free Radical Scavengers / metabolism
  • Free Radical Scavengers / pharmacology
  • Hippocampus / drug effects
  • Hippocampus / metabolism
  • Inflammation / blood
  • Inflammation / drug therapy*
  • Inflammation / metabolism
  • Interferon-gamma / blood
  • Lactation
  • Lipid Peroxidation / drug effects
  • Lipopolysaccharides / pharmacology*
  • Neuroprotective Agents / pharmacology*
  • Nitrates / blood
  • Nitrites / blood
  • Pregnancy
  • Rats
  • Rats, Sprague-Dawley
  • Shock, Septic / blood
  • Shock, Septic / drug therapy
  • Shock, Septic / metabolism
  • Tryptophan / pharmacology*

Substances

  • Antioxidants
  • Free Radical Scavengers
  • Lipopolysaccharides
  • Neuroprotective Agents
  • Nitrates
  • Nitrites
  • Interferon-gamma
  • Tryptophan