Journal of Ethnopharmacology 109 (2007) 226–228 The analgesic effect of Carum copticum extract and morphine on phasic pain in mice Mohammad Hossein Dashti-Rahmatabadi ∗ , Seyed Hassan Hejazian, Abbas Morshedi, Ali Rafati Department of Physiology Sahid Sadughi Medical University, Postal Code 8944157963, Yazd, Iran Received 30 May 2005; received in revised form 19 June 2006; accepted 20 July 2006 Available online 1 August 2006 Abstract Pain is a universal complaint, which needs further investigations for new pain relieving agents. Carum copticum (L.) Sprague ex Turrill is a plant in Umbelliferae family, which is mentioned to have some therapeutic effects on headache and joint pains in Iranian traditional literature, but there are not enough scientific reports to prove its effects on pain. So, we conducted to design an experimental clinical trial study to assess and compare the analgesic effect of ethanolic extract of Carum copticum fruit with morphine by using a tail-flick analgesiometer device. Our results indicate that the test drug produced significant increase in tail-flick latency (TFL) during 2 h post-drug administration (p < 0.05). The peak of the effect was observed at 45 min after drug injection, which was comparable to that of 1 mg/kg morphine (i.p.). Positive results in this type of analgesiometric test indicate that the antinociceptive action may be of the opoid type. The present study supports the claims of Iranian traditional medicine showing that Carum copticum extract possesses a clear-cut analgesic effect. However, further investigations are required to evaluate the efficacy and safety of this herbal medication in man. © 2006 Elsevier Ireland Ltd. All rights reserved. Keywords: Pain; Carum copticum; Tail-flick; Mice 1. Introduction Carum copticum (L.) Sprague ex Turrill is a plant in the Umbelliferae family and constituents of it’s seed are: an aromatic volatile essential oil, and a crystalline substance stearoptene. The stearoptene is known as ajowan-ka-phul (crude thymol) (Asghari and Lockwood, 1996; Farooq, 1953; Lockwood, 2002; Nadkarni, 1976). A phenolic glucoside has been isolated from the seeds and identified as 2-methyl-3- glucosyloxy-5- isopropylphenol (Garg, 1980). Thymol crystallizes easily from the oil extracted from seeds of Carum copticum and the remain- der consists of p-cymene, b-pinene, dipentene -terpinene and carvacrol (Chopra, 1982). This plant has been mentioned in Ira- nian traditional literature to have therapeutic effect on flatulence, indigestion, colic, dyspepsia and diarrhea (Astarabadi, 1966; Nadkarni, 1976; Avesina, 1985). It is also applied to eradicate worms and to relieve urticaria, rheumatic and neuralgic pain ∗ Corresponding author. Tel.: +983518226127; fax: +983517249331. E-mail address: Dashti mh@yahoo.com (M.H. Dashti-Rahmatabadi). such as joint pains and headache (Garg, 1980). Although there are a few scientific reports about antibacterial, antihelmentic, antiflatulent and antidiarrheal effects of this plant (Ashebir and Ashenafi, 1999; Fisseha et al., 1999; Rani and Khullar, 2004; Singh et al., 2002). We did not find any scientific reports to prove its effects on pain. So, we conducted an experimental clin- ical trial to assess and compare the analgesic effect of ethanolic extract of Carum copticum fruit with different doses of morphine sulphate in a model of phasic pain in mice. 2. Materials and methods In this study, the stimulus for pain induction was a heat stim- ulus produced by a light beam, applied to the tail of the animals by using an Analgesiometer, type 812 (Hugo Sachs Electronik, Germany). For behavioral testing permission of the animal ethics committee of Shahid Sadughi Medical University (Yazd, Iran), in accordance with the internationally accepted principles for laboratory animal use and care mentioned by the European Com- munity guidelines, were obtained. The animals used in this study were Syrian mice, housed in five groups of seven in a controlled 0378-8741/$ – see front matter © 2006 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.jep.2006.07.035