Triptolide protects dopaminergic neurons from inflammation-mediated damage induced by lipopolysaccharide intranigral injection

Hui Fang Zhou, Xian Yu Liu, Dong Bin Niu, Feng Qiao Li, Qi Hua He, Xiao Min Wang

Research output: Contribution to journalArticlepeer-review

107 Scopus citations

Abstract

Converging lines of evidence suggest that neuroinflammatory processes may account for the progressive death of dopaminergic neurons in Parkinson's disease (PD). Therefore, anti-inflammatory strategies have attracted much interest for their potential to prevent further deterioration of PD. Our previous study showed that triptolide, a traditional Chinese herbal compound with anti-inflammatory and immunosuppressive properties, protected dopaminergic neurons from lipopolysaccharide (LPS)-induced damage in primary embryonic midbrain cell cultures. To examine further if triptolide can protect dopaminergic neurons from inflammation-mediated damage in vivo, microglial activation and injury of dopaminergic neurons were induced by LPS intranigral injection, and the effects of triptolide treatment on microglial activation and survival ratio and function of dopaminergic neurons were investigated. Our results demonstrated that microglial activation induced by a single intranigral dose of 10 μg of LPS reduced the survival ratio of tyrosine hydroxylase-immunoreactive (TH-ir) neurons in the substantia nigra pars compacta (SNpc) to 29% and the content of dopamine (DA) in striatum to 37% of the non-injected side. Intriguingly, treatment with triptolide of 5 μg/kg for 24 days once per day dramatically improved the survival rate of TH-ir neurons in the SNpc to 79% of the non-injected side. Meanwhile, treatment with triptolide of 1 or 5 μg/kg for 24 days once per day significantly improved DA level in striatum to 70% and 68% of the non-injected side, respectively. Complement receptor 3 (CR3) immunohistochemical staining revealed that triptolide treatment potently inhibited LPS-elicited deleterious activation of microglia in SNpc. The excessive production of cytokines, such as tumor necrosis factor (TNF)-α and interleukin (IL)-1β, was significantly abolished by triptolide administration. These results, together with our previous data in vitro, highly suggest the effectiveness of triptolide in protecting dopaminergic neurons against inflammatory challenge.

Original languageEnglish
Pages (from-to)441-449
Number of pages9
JournalNeurobiology of Disease
Volume18
Issue number3
DOIs
StatePublished - Apr 2005

Keywords

  • Inflammation
  • Microglia
  • Neurodegeneration
  • Neuroinflammation
  • Parkinson's disease
  • Proinflammatory cytokines
  • Tripterygium wilfordii Hook F
  • Triptolide

Fingerprint

Dive into the research topics of 'Triptolide protects dopaminergic neurons from inflammation-mediated damage induced by lipopolysaccharide intranigral injection'. Together they form a unique fingerprint.

Cite this