Comparison of the Effects of Curcumin, Tramadol and Surgical Treatments on Neuropathic Pain Induced by Chronic Constriction Injury in Rats.

AIM Nerve entrapment syndromes are the most common causes of neuropathic pain. Surgical decompression is the preferred method of treatment. The aim of this study was to compare the efficacy of curcumin, tramadol and chronic constriction release treatment (CCR), individually or together, in a rat model of sciatic nerve injury. MATERIAL AND METHODS Eighty male rats were divided into eight study groups. Group 1 was the sham group. Group 2 was the control group with established chronic constriction injury (CCI). CCI was also established in Groups 3?8. Group 3 underwent chronic constriction release (CCR). Groups 4 and 5 received curcumin and tramadol. Groups 6 and 7 also received curcumin (100 mg/kg daily, oral) and tramadol (10 mg/kg daily, intraperitoneal, 14 days) after CCR, respectively. Combined curcumin-tramadol treatment was applied to Group 8. Behavioral tests (thermal hyperalgesia, dynamic plantar, cold plate test) were performed on days 0,3,7,13,17, and 21. Tissue tumor necrosis factor-? (TNF-?) and interleukin-10 (IL-10) levels were analyzed in the nerve and dorsal root ganglion (DRG) samples on day 21. Histopathological examination was performed on the nervous tissue and DRG. RESULTS Tramadol-CCR and tramadol-curcumin significantly attenuated mechanical allodynia and thermal hyperalgesia. In the CCI-CCR-tramadol treatment group, TNF-? levels were significantly lower in the sciatic nerve tissue, and DRG and IL-10 levels were significantly higher in the sciatic nerve tissue. CONCLUSION CCI-CCR-tramadol treatment is highly effective in the symptomatic treatment of neuropathic pain. CCR-curcumin is associated with less degeneration and high levels of regeneration in the nerve tissue.