Pain relieving and protective effects of Astragalus hydroalcoholic extract in rat arthritis models

J Pharm Pharmacol. 2017 Dec;69(12):1858-1870. doi: 10.1111/jphp.12828. Epub 2017 Sep 29.


Objectives: The evaluation of the pharmacological profile of the dried 50% hydroalcoholic extract (50%HA) of Astragali radix in two different animal models of articular damage resembling osteoarthritis and rheumatoid arthritis.

Methods: Sodium monoiodoacetate (MIA) or complete Freund's adjuvant (CFA) was intra-articular injected (day 0) in the rat tibiotarsal joint to induce damages mimicking osteoarthritis or rheumatoid arthritis. Pain measurements (responses to non-noxious and noxious stimuli, spontaneous pain, articular pain) were assessed on days 7 and 14. On day 14, the tibiotarsal joints were explanted in order to measure the diameter and to assess histological evaluations. Furthermore, the plasmatic concentrations of inflammatory and anti-inflammatory cytokines were measured.

Key findings: A single administration of 50%HA (300 mg/kg per os) significantly reduced both MIA-induced pain and CFA-induced pain (78% and 96% pain relief, respectively). The repeated administration prevented the development of hypersensitivity on day 14. The haematoxylin/eosin staining revealed that 50% HA attenuated joint alterations in MIA-injected rats, and furthermore, the joint inflammatory infiltrate was reduced in both models (by about 50%). In CFA-treated rats, 50%HA lowered the plasmatic levels of the pro-inflammatory cytokines interleukin-1β and tumour necrosis factor-α as well as the joint diameter.

Conclusions: The 50% hydroalcoholic extract of Astragali radix is a valuable candidate for the adjuvant treatment of articular diseases.

Keywords: Astragalus hydroalcoholic extract; anti-inflammatory; arthritis; articular pain; pain reliever.

MeSH terms

  • Analgesics / isolation & purification
  • Analgesics / pharmacology
  • Animals
  • Anti-Inflammatory Agents / isolation & purification
  • Anti-Inflammatory Agents / pharmacology
  • Arthritis, Experimental / drug therapy*
  • Arthritis, Rheumatoid / drug therapy*
  • Astragalus Plant / chemistry*
  • Freund's Adjuvant
  • Interleukin-1beta / blood
  • Male
  • Osteoarthritis / drug therapy*
  • Pain / drug therapy
  • Pain / etiology
  • Plant Extracts / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Tumor Necrosis Factor-alpha / blood


  • Analgesics
  • Anti-Inflammatory Agents
  • Interleukin-1beta
  • Plant Extracts
  • Tumor Necrosis Factor-alpha
  • Freund's Adjuvant