[Mongolian medicine Naru-3 reduces neuroinflammation in maintenance stage of neuropathic pain by inhibiting astrocyte activation].

ABSTRACT

Neuropathic pain(NP) is difficult to be treated since it has similar phenotypes but different pathogenesis in different pathological stages. Targeted intervention of the core regulatory elements at different pathological stages of NP has become a new direction of drug research and development in recent years and provides the possibility for the treatment of NP. The Mongolian medicine Naru-3(NR-3) is effective in the treatment of sciatica and trigeminal neuralgia, the mechanisms of which remain unknown. On the basis of the previous study of the priming stage, this study established the mouse model of spinal nerve ligation(SNL) and measured the changes of pain thresholds by behavioral tests. The network analysis, Western blot, immunofluorescence assay, ELISA, and agonist/antagonist were employed to decipher the mechanism of NR-3 in the treatment of NP in the maintenance stage. The results showed that NR-3 increased the mechanical and thermal pain thresholds of SNL mice, while it had no significant effect on the basal pain threshold of normal mice. NR-3 may relieve the pain in the maintenance stage of NP by blocking the matrix metalloproteinase 2(MMP2)/interleukin-1ß(IL-1ß) pathway in the astrocytes of the dorsal root ganglion(DRG) and spinal cord. The findings have enriched the biological connotation of NR-3 in the treatment of the maintenance stage of NP and provide reference for the rational use of this medicine in clinical practice.