[Analgesic mechanism of Entadae Semen based on its in vivo material basis and regulation of SRC-mediated microglial polarization in a rat model of chronic compression of dorsal root ganglion].

The ethnic medicine Entadae Semen shows good therapeutic effects on neuropathic pain(NP) such as chronic low back pain caused by lumbar disc herniation(LDH), yet its in vivo metabolites under pathological conditions and analgesic mechanisms remain unclear. In this study, a chronic compression of the dorsal root ganglion(CCD) model was established to simulate clinical LDH, and behavioral testing, safety evaluation, in vivo material-basis analysis, network pharmacology, and molecular biology were employed to investigate the analgesic mechanisms of the 70% ethanol extract of Entadae Semen(KB). Pharmacodynamic studies showed that KB dose-dependently increased mechanical pain thresholds and thermal radiation pain thresholds in CCD rats, alleviated spontaneous pain, and improved paw print parameters, while exerting no significant effects on basal pain thresholds or motor coordination in normal animals, and showing no obvious toxic or side effects. RESULTS:: from hot plate, tail-flick, and formalin tests suggested that the analgesic effects of KB occurred at the spinal and supraspinal levels and were associated with inhibition of central neuroinflammation. UHPLC-Q-Orbitrap-HRMS identified nine KB-derived components entering the spinal cord, including cuchiloside, curdione, eclalbasaponin V, muscone, 3-O-β-D-galactopyranosyl-(1→2)-β-D-glucuronopyranosyl-gypsogenin-28-O-β-D-xylopyranosyl(1→4)-[β-D-6-O-acetylglucopyranosyl(1→3)]-α-L-rhamnopyranosyl(1→2)-β-D-fucopyranoside, isoalantolactone, N-oxynarcotine, sweroside, and violutoside. Network analysis showed that six core pharmacological targets, i.e., non-receptor tyrosine kinase(SRC), phosphatidylinositol 3-kinase(PI3K), protein kinase B(AKT)1, Kirsten rat sarcoma viral oncogene homolog(KRAS), RAF proto-oncogene serine/threonine-protein kinase 1(RAF1), and extracellular signal-regulated kinase(ERK), were densely enriched in the chemokine signaling pathway and exhibited stable binding to the spinal cord-distributed components. Further experiments using ELISA, Western blot, immunofluorescence, pharmacological inhibitors, and behavioral testing revealed that the analgesic mechanisms of KB may be associated with inhibition of SRC-regulated MAPK and PI3K/AKT signaling axes, thereby suppressing spinal microglial polarization and neuroinflammation. These findings provide a scientific basis for the clinical application and rational use of KB in the treatment of chronic low back pain.