Excitatory toxicity(ET) is an important factor of neuropathic pain(NPP) induced by central sensitization(CS), and the association of pannexin-1(Panx1)-Src-N-methyl-D-aspartate receptor subunit 2 B(NMDAR-2 B) is an important new pathway for ET to initiate CS. The present study confirmed whether the central analgesic effect of Chuanxiong Rhizoma extract(CRE) was achieved through the synchronous regulation of the brain and spinal pathways of Panx1-Src-NMDAR-2 B. In this study, dynamic and simulta-neo-us microdialysis of the brain and spinal cord in vivo combined with behavioristics, high performance liquid chromatography(HPLC)-fluorescence detection, microdialysis analysis(ISCUS~(flex)), ultrasensitive multifactorial electrochemiluminescence immunoassay, ELISA, and Western blot was employed to investigate the protein expression of NMDAR-2 B, Src, and Panx1, extracellular excitatory amino acids, cytokines, energy metabolites, and substance P in spinal dorsal horn(SDH) and anterior cingulate cortex(ACC) after CRE intervention with the rat model of spared sciatic nerve injury(SNI) as the experimental tool. Compared with the sham group, the SNI group exhibited diminished mechanical withdrawal threshold(MWT)(P<0.01), increased cold spray scores(P<0.01), glutamate(Glu), D-serine(D-Ser), and glycine(Gly) in extracellular fluids of ACC, and Glu, D-Ser, interleukin-1β(IL-1β), and lactic acid(Lac) in extracellular fluids of SDH(P<0.05), dwindled tumor necrosis factor(TNF-α)(P<0.05), and elevated protein levels of NMDAR-2 B, Src, and Panx1 in ACC(P<0.05). Compared with the SNI model rats, high-and medium-dose CRE(CRE-H/M) could potentiate the analgesic activity as revealed by the MWT test(P<0.05) and CRE-M enabled the decrease in cold spray scores(P<0.05). CRE-H/M could inhibit the levels of Glu, D-Ser and Gly in the extracellular fluids of ACC(P<0.05), and the levels of Glu in the extracellular fluids of SDH(P<0.05) in SNI rats. CRE-M significantly increased the levels of glucose(Gluc), Lac, interferon-gamma(IFN-γ), keratinocyte chemoattractant/human growth-regulated oncogenes(KC/GRO), and IL-4 in extracellular fluids of SDH in SNI rats(P<0.05). CRE-H/M/L could also inhibit the levels of NMDAR-2 B, Src and Panx1 in ACC and SDH in SNI rats(P<0.05). The central analgesic effect of CRE is presumedly related to the inhibited release of excitatory amino acid transmitters(Glu, D-Ser and Gly) in ACC and SDH of SNI rats, decreased protein expression of NMDAR-2 B, Src and Panx1 in the two regions, and the regulation of the Panx1-Src-NMDAR-2 B pathway in the spinal cord and brain. The above findings partially clarified the scientific basis of clinical analgesic effect of Chuanxiong Rhizoma.
Keywords: Chuanxiong Rhizoma extract(CRE); Panx1-Src-NMDAR-2B; amino acid neurotransmitters; anterior cingulate cortex; neuropathic pain(NPP); spinal dorsal horn.