The present study evaluated the effects of systemic
pregabalin (PG) and
diclofenac (
Dic) on neuropathic
orofacial pain induced by chronic constriction injury (CCI) of the infraorbital nerve (ION) and on the pro-inflammatory
cytokines levels in the affected nerve. Fifty-four rats underwent left infra orbital nerve CCI, and 7 days after the procedure as the
pain developed, the rats were randomly assigned to one of the treatment groups: PG 300, 30 or 10 mg/kg,
Dic 10, 5 or 1 mg/kg or saline group (Sal) (n/group = 8). Addiitonal 8 rats served as naïve control group.
Tactile-allodynia and Mechano-
hyperalgesia were tested before the
surgical procedure and at days 7, 8, and 9 postoperatively. On the 9th day, the rats were euthanized and the affected and contralateral sciatic nerves were harvested to assess
IL-6 and IL-1β nerve levels employing
enzyme linked
immunosorbent assay (ELISA). Daily injection of PG (all doses) significantly reduced
tactile-allodynia and mechano-
hyperalgesia (p < .05) while
Dic did not. On the 9th day, the ipsilateral nerve
IL-6 levels were significantly decreased (p < .05) in the PG and
DIC groups compared to the Sal group. IL-1β levels demonstrated a significant reduction (p < .05) in the PG group when compared to saline. These results suggest that PG but not
Dic may be effective in reducing neuropathic
orofacial pain. The mechanisms of action may be associated to some extent with reduction in IL-1β levels in the affected nerve.