The effect of turmeric and curcumin on neuropathic pain behavioral response of CCI model in rats

Background: Neuritis is one of the causes of neuropathic pains. It is proved that turmeric and curcumin have anti-neuritis effect that may be reduce of neuropathic pain. Objective: In this study, effects of turmeric and curcumin have been evaluated on behavioral response resulted from chronic constriction injury (CCI) in rat. Methods: In this experimental study Wistar male rat (200-250 gr) were used. For create of CCI, Bennet and Xie (1988) method has been used. 2 weeks after neuritis occurrence, turmeric 60 mg/kg and curcumin 30 and 60 mg/kg injection have been begun and continued until 26th day as daily and Intraperitonealy. Animal behavioral responses have been measured by using of mechanical allodynia (Von Frey) test and thermal hyperalgesia test during 14, 17, 20, 23, 26 and 40 days after neuritis occurrence. Results: Results indicated that creation of CCI increases behavioral responses as significant. Curcumin injection with dosage of 30 mg/Kg leads to decrease of mechanical allodynia from 20th and thermal hyperalgesia from 23th day. This effect has been observed until 40th day. Curcumin injection with dosage of 60 mg/Kg leads to decrease of mechanical allodynia and thermal hyperalgesia in 26th day. Turmeric injection with dosage of 60 mg/kg had no effect on mechanical allodynia and thermal hyperalgesia. Conclusion: Finding shown that curcumin has positive effect on decrease of neuropathic pain that induced by CCI. Previous study suggested that the effect of curcumin is partly attributed to attenuation of lipid peroxidation in the periphery that finally reduced of inflammation.