Effects of Danggui Sini decoction on neuropathic pain: experimental studies and clinical pharmacological significance of inhibiting glial activation and proinflammatory cytokines in the spinal cord

Int J Clin Pharmacol Ther. 2017 May;55(5):453-464. doi: 10.5414/CP202613.

Abstract

Aim: Neuropathic pain responds poorly to drug treatments. Partial relief is achieved in only about half of the patients. Danggui Sini decoction (DSD), an aqueous extract of Angelica sinensis, Ramulus Cinnamomi, and Radix Puerariae, has been used extensively in China to treat inflammatory and ischemic diseases. The current study examined the putative effects of DSD on neuropathic pain.

Method: We used two commonly-used animal models: chronic constriction injury (CCI) and diabetic neuropathy for the study. And we examined effects of DSD on pain response, activation of microglia and astroglia in spinal dorsal horn, and expression of proinflammatory cytokines in the spinal cord.

Results: Consecutive intragastric administration of DSD (25 - 100 mg/kg) for 10 days inhibited the mechanical and thermal nociceptive response induced by CCI and diabetes without interfering with the normal pain response. Meanwhile, in both models, DSD inhibited the over-expression of specific markers for microglia (Iba-1) and astroglia (GFAP) activation in the spinal dorsal horn. DSD also reduced the elevated nuclear NF-κB level and inhibited the up-regulation of proinflammatory cytokines, such as IL-6, IL-1β, and TNF-α, in the spinal cord.

Conclusion: DSD can alleviate CCI and diabetes-induced neuropathic pain, and its effectiveness might be due to the inhibition of neuroinflammation in the spinal dorsal horn. The anti-inflammation effect of DSD may be related to the suppression of spinal NF-κB activation and/or cytokines expression. .

MeSH terms

  • Analgesics / pharmacology*
  • Animals
  • Cytokines / metabolism*
  • Diabetic Neuropathies / complications
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Drugs, Chinese Herbal / pharmacology*
  • Inflammation Mediators / metabolism*
  • Ligation
  • Male
  • NF-kappa B / metabolism
  • Neuralgia / etiology
  • Neuralgia / metabolism
  • Neuralgia / physiopathology
  • Neuralgia / prevention & control*
  • Neuroglia / drug effects*
  • Neuroglia / metabolism
  • Pain Threshold / drug effects*
  • Rats, Sprague-Dawley
  • Sciatic Nerve / surgery
  • Signal Transduction / drug effects
  • Spinal Cord / drug effects*
  • Spinal Cord / metabolism
  • Spinal Cord / physiopathology
  • Time Factors

Substances

  • Analgesics
  • Cytokines
  • Drugs, Chinese Herbal
  • Inflammation Mediators
  • NF-kappa B
  • danggui sini