Backgrounds: Botulinum toxin type A (BoNT-A) has been used to treat pain related to muscle contraction or other pain state. Recently, some reported that BoNT-A reduced neuropathic pain in clinical trial and partial nerve transected state. So, we designed this study to evaluate antiallodynic properties of BoNT-A against mechanical and cold allodynia in neuropathic pain model of rats. Methods: BoNT-A or saline was administered to the plantar surface of the affected left hindpaw in neuropathic rats. To evaluate the systemic effect, BoNT-A was injected into the unaffected right paw. Mechanical and cold allodynia was measured on the affected left hindpaw before and after drug administration. Motor coordination was also measured using rotarod test. Results: In the BoNT-A treated rats, withdrawal frequencies to mechanical and cold stimuli were significantly reduced as compared with pre-administration values and with saline treated rats. The effects were maintained for 7 days. Only the highest dose (40 U/kg) of the BoNT-A reduced Rotarod performance time. Conclusion: So, we concluded that BoNT-A can be used effectively to reduce mechanical and cold allodynia in neuropathic rats.

KeywordsAllodynia; neuropathic pain; BotuHnum Toxin type A; rats.