Electroacupuncture Suppresses Mechanical Allodynia and Nuclear Factor Kappa B Signaling in Streptozotocin-Induced Diabetic Rats

Aims To investigate whether electroacupuncture (EA) produced analgesic effect and whether nuclear factor kappa beta (NF-kappa B) and cystathionine beta synthase (CBS) involved in EA-mediated analgesia in painful diabetic neuropathy in rats. Methods Diabetes was induced by an intraperitoneal injection of streptozotocin (STZ) in adult female rats. Mechanical pain threshold was measured by von Frey filaments. EA was applied at acupoint Zu-San-Li (ST-36) in both hindlimbs. Western blot analysis was employed to detect changes in protein levels of NF-kappa B and CBS in spinal dorsal root ganglion (DRGs). Results Mechanical allodynia was developed 2weeks after STZ injection and lasted for another 4weeks. STZ injection significantly enhanced expression of p65 and CBS in lumbar L4-6 DRGs when compared with age-matched controls. EA markedly attenuated mechanical allodynia. Importantly, EA treatment remarkably inhibited p65 and CBS expression in DRGs. Additionally, intrathecal injection of the p65 antagonist pyrrolidine dithiocarbamate attenuated mechanical allodynia and markedly inhibited CBS expression in DRGs in STZ rats. Conclusions These data indicate that EA produced an analgesic effect, which might be mediated at least in a part by inhibition of NF-kappa B signaling pathway in primary sensory neurons in rats with diabetes.