Analgesic mechanism of Goshajinkigan for neuropathic pain

Abstract

In recent years, numerous studies have reported the clinical utility of Japanese herbal medicines for pain diseases, and their demand is increasing. However, it is difficult to conduct basic research on these medicines because Japanese herbal treatments are multi­component systems, composed of herbal medicines with multiple actions. Hence, scientif­ic elucidation of their pharmaceutical mechanisms is complicated.

Here, we have outlined studies indicating the use of on Goshajinkigan (GJG) in relieving neuropathic pain. Furthermore, efforts have been made to elucidate the underly­ing analgesic mechanisms. Basic research on GJG has primarily explored strepto­zotocin–induced diabetic neuropathy models and chemotherapy–induced neuro­pathy models. We have demonstrated that GJG is also valuable in the choronic constrictive injury (CCI) models and that its analgesic mechanism is the inhibition of activated microglia–derived tumor necrosis factor–alpha in the spinal dorsal horn. Scientific elucida­tion of the analgesic mechanisms of Japanese herbal medicines may lead to the establishment of new uses and indications for these treatments fused with modern medicine and may be a great help in the treatment of refractory neuropathic pain that is prone to becoming chronic pain.