Objectives: We examined the effects of Toki-shigyaku-ka-goshuyu-shokyo-to on chronic constriction injury of the sciatic nerve as a neuropathic pain model in rats.
Methods: Sprague-Dawley rats were randomly divided into 3 groups: group 1, no constriction and no medication (n=8); group 2, constriction without medication (n=8); group 3, constriction with medication (n=8). On each group we performed thermal stimulation tests for pain measurement before the operation and 7 and 14 days after the operation. We also measured body temperature at the tympanum and the planta.
Results and conclusions: A significant increase of pain was observed at 7 and 14 days after constriction in group 2. Toki-shigyaku-ka-goshuyu-shokyo-to relieved their pain 14 days after constriction. Furthermore,
Toki-shigyaku-ka-goshuyu-shokyo-to warmed their feet significantly, while chronic constriction injury induced coldness in the constricted feet. We conclude that Toki-shigyaku-ka-goshuyu-shokyo-to relieves both pain and coldness in a neuropathic pain model.