بررسی اثر ضددردی گیاه خردل سیاه (Brassica nigra) در موش سوری

Background and purpose: Brassica nigra is used traditionally to relieve neurotic and rheumatic pains. The aim of this study was to evaluate the analgesic effect of this plant. Materials and methods: Percolated extract of Brassica nigra with different doeses were injected intraperitonealy to mice and the analgesic effect was determined by tail flick and formalin test. Results: Ïn formalin test, the percolated formalin with doeses of 100, 200 and 300 mg/kg. Çould have significant analgesic property compare to control group, and 300 mg/kg of the extract had the highest analgesic property.  comparison of analgesic property of 300 mg/kg percolated extract with 2.5 mg/kg of morphine and 300 mg/kg of ÂS in formalin test indicated that there was no significant difference between the analgesic property of extract, Â.S. and morphine in first phase of pain. Ïn chronic phase, the analgesic property of extract with significant difference (P<0.05), was better than Â.S.Â, but in this phase, compare to morphine, no significant difference was observed. The analgesic property of 300 mg/kg of extract did not show any significant difference with 2.5 mg/kg of morphine at 15, 30 and 90 minutes of tail-flick test. No significant difference was observed between analgesic property of extract and Â.S. at 15, 30 and 45 minutes after injection. By tail-flick method, there was significant reduction in analgesic property of extract in combination with naloxane at 15 and 30 minutes (P<0.05). Çonclusion: Ïn this study, it was shown that the extract of Brussica nigra, has satisfactory analgesic property, hence, more investigation should be done.