Background: Since use of synthetic drugs for relief of pain has many side effects, today medical plants are becoming more prominent as substitute therapeutic agents. Previous findings indicate that Coriandrum sativum (CS) modulates pain in both animal and human. Objective: The present work investigated the effects of CS seed on acute pain using hot plate and tail flick models. Method: Albino mice (25-30 g) were used for this study. Aqueous extract of CS seed was injected in doses of 100 and 200 mg/kg 30 min before test. The analgesic effect of the drug on acute pain was evaluated using Hot plate and Tail flick models. Results: Results indicated that CS has analgesic effect in both doses in both models and higher dose of the drug was more effective (p<0.01). Conclusion: The findings above showed that CS could modulate acute pain. Further research is required to determine the mechanisms by which CS has an inhibitory effect on pain sensation.

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 26^th 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 20^th and thermal hyperalgesia from 23^th day. This effect has been observed until 40^th day. Curcumin injection with dosage of 60 mg/Kg leads to decrease of mechanical allodynia and thermal hyperalgesia in 26^th 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.