Original Article Inhibition of leucocyte migration: A mechanism of anti-inflammatory effect of the ethanol extract of the stem bark of Alstonia boonei in Wistar rats Osmund C. Enechi, Christian E. Odo*, Onyedika N. Onyekwelu Pharmacology Research Unit, Department of Biochemistry, University of Nigeria, Nsukka, Nigeria article info Article history: Received 16 August 2013 Accepted 16 September 2013 Available online 3 October 2013 Keywords: Alstonia boonei Indomethacin Inflammation Leucocyte migration abstract Background and aim: The stem bark of Alstonia boonei is used in traditional medicine to treat or reduce inflammation and pain in Nigeria. In view of these, the effect of the ethanol extract of its stem bark on agar-induced leucocyte migration in rats as a mechanism of anti-inflammation was investigated. Methods: The effect of the ethanol extract of the stem bark of A. boonei on agar-induced leucocyte migration in rats was evaluated using standard analytical method. Results: The results showed significant (p < 0.05) inhibitions of leucocyte migrations in the rats administered 400, 800 and 1200 mg/kg body weight (b. w) compared to the leucocyte migration of the rats in the control group (5 ml/kg b. w of normal saline). The inhibitory effect of the extract was dose-dependent and comparable to that of the reference anti- inflammatory drug, indomethacin (0.3 mg/kg b. w). Conclusion: The data indicate that the ethanol extract of the stem bark of A. boonei possesses remarkable inhibitory effect on leucocyte migration and therefore, justifies the traditional use of the stem bark of A. boonei as an anti-inflammatory agent. Copyright ª 2013, JPR Solutions; Published by Reed Elsevier India Pvt. Ltd. All rights reserved. 1. Introduction Plants form the main ingredients of medicine in traditional medical practice and have been the major source of several pharmaceutical drugs. Their uses are increasing world wide due to the persistent and sometimes expansion of traditional medicine and a growing interest in herbal treatments. 1 Inflammation is part of the complex biological response of vascular tissues to harmful stimuli including pathogens, irri- tants or damaged cells. 2 It is also a pathophysiological response of living tissues to injuries that leads to the local accumulation of plasmatic fluids and body cells. It is a pro- tective attempt by an organism to remove injurious stimuli as well as initiate a healing process for tissues. The process of inflammation is necessary for healing of wounds, however, if not controlled, may lead to the onset of diseases as vasomotor rhinorrhoea, rheumatoid arthritis, atherosclerosis and cancer inter alia. 3 Alstonia boonei de Wild (Fig. 1) (Apocynaceae) is a medicinal plant used extensively in west and central Africa. It has been found to elicit several pharmacological and therapeutic ac- tions. It is a large deciduous tree that is up to 45 m tall and * Corresponding author. Tel.: þ234 7067470739. E-mail addresses: christiano12@yahoo.com, christian.odo@unn.edu.ng (C.E. Odo). Available online at www.sciencedirect.com journal homepage: www.elsevier.com/locate/jopr journal of pharmacy research 6 (2013) 925 e927 0974-6943/$ e see front matter Copyright ª 2013, JPR Solutions; Published by Reed Elsevier India Pvt. Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jopr.2013.09.005