Bee venom acupuncture reduces neuroinflammation modulating microglia/macrophage phenotype polarization in spinal cord injury compression model

Abstract

Aim: The present study aimed to examine whether apipuncture (stimulation of acupuncture points with bee venom) at ST36 and GV3 acupoints promotes neuroprotection and reduces neuroinflammation by modulating M1 and M2 phenotype polarization. Methods: Wistar rats were treated with bee venom (BV) (0.08 mg/kg) injection at acupoints ST36 and GV3 [BV (ST36 + GV3)-spinal cord injury (SCI)] or BV injection at non-acupoints [BV (NP)-SCI] or no treatment (CTL-SCI) after SCI by compression. The spinal cord mRNA expression of iNOS, Arg-1 and TGF-β was measured by real time PCR and the levels of IBA-1; BCL-2; NeuN e CNPase was measured by western blotting. Locomotor performance was measured by Basso, Beattie, and Bresnahan (BBB) and grid-walking tests. Results: Apipuncture treatment was able to (1) ameliorate locomotor performance; (2) reduce inflammatory markers (Cox-2 levels) and activation of microglia and macrophages; (3) reduce the polarization of the M1 phenotype marker (iNOS) and increase M2 (Arg-1 and TGF-β) phenotypic markers; (4) promote neuroprotection by reducing the death of neurons and oligodendrocytes; and (5) increase the expression of the anti-apoptotic factor BCL-2. Conclusion: Apipuncture treatment induces locomotor recovery and neuroprotection after the compression model of spinal cord injury. Further, it reduces neuroinflammation by decreasing M1 polarization and increasing M2 phenotype.