SHORT COMMUNICATION Biological Effects of Myristica fragrans (Nutmeg) Extract Olumayokun A. Olajide, 1 * Franklin F. Ajayi, 2 Ambrose I. Ekhelar, 2 S. Olubusayo Awe, 1 J. Modupe Makinde 1 and A. R. Akinola Alada 2 1 Department of Pharmacology and Therapeutics, College of Medicine, University of Ibadan, Ibadan, Nigeria 2 Department of Physiology, College of Medicine, University of Ibadan, Ibadan, Nigeria The chloroform extract of nutmeg has been evaluated for antiinflammatory, analgesic and antithrombo- tic activities in rodents. The extract inhibited the carrageenan-induced rat paw oedema, produced a re- duction in writhings induced by acetic acid in mice and offered protection against thrombosis induced by ADP/adrenaline mixture in mice. Copyright # 1999 John Wiley & Sons, Ltd. Keywords: Myristica fragrans; antiinflammatory activity; analgesic activity; antithrombotic activity. INTRODUCTION Myristica fragrans also known as ‘nutmeg’ is popular in most parts of West Africa as a spice. However, the essential oil of nutmeg is used externally for rheumatism and internally as a carminative (Oliver-Bever, 1986). It is also used in soups as a postpartum medication (Iwu, 1993). Compounds isolated from the seeds of this plant have been reported to possess strong platelet antiaggregatory activity (Venton et al., 1991). Being a popular spice in foods, this study aims to establish the biological effects of nutmeg in experimen- tally induced inflammation, pain and thrombosis, with the possibility of identifying its therapeutic potentials. MATERIALS AND METHODS Plant material and extraction. Dried seeds of nutmeg were purchased from the nearby market and identified at the Herbarium of the Botany Department, University of Ibadan. The seeds were powdered, soxhlet - extracted with chloroform and then concentrated to a solid residue under reduced pressure at 40 °C. The extract was suspended in 2.5% Tween 80 then dissolved in saline for biological studies. Animals. Male Swiss albino mice (weighing 20–28 g) and male Wistar rats (weighing 170–270 g) bred and housed in the Pre-Clinical Animal House, College of Medicine, University of Ibadan were used. The animal house was well-ventilated and the animals had free access to water and normal diet (Ladokun Feeds Ltd, Ibadan). Drugs and chemicals. The following were used: carrageenan sodium, acetylsalicylic acid, adrenaline and ADP were from Sigma, St Louis, Mo., USA. Acetic acid (BDH Chemicals, UK). Antiinflammatory study. This was carried out using the method described by Winter et al. (1962). 0.1 mL of 1% carrageenan suspension was injected into the subplantar tissue of the right hind paw of rats in different groups 1 h, after oral administration of 50–200 mg/kg extract, acetylsalicylic acid (150 mg/kg) or Tween 80 (10 mL/ kg). Oedema was measured by the cotton thread method (Bamgbose and Noamesi, 1981) and inhibitory values at 3 h after carrageenan were taken as measures of activity. Analgesic study. 0.2 mL of 3% (v/v) acetic acid was injected i.p. to mice in different groups 1 h, after oral administration of extract (50–200 mg/kg), acetylsalicylic acid (150 mg/kg) or Tween 80 (10 mL/kg). The number of writhings occurring between 5 and 15 min after acetic acid were recorded for each animal (Koster et al., 1959). Antithrombotic study. Saline solutions (0.1 mL) of adrenaline and ADP at a dose of 1.8 mg/mouse and 260 mM respectively were injected into the tail vein of mice at a rate of 20 mL/s 1 h after oral administration of extract (50–200 mg/kg), acetylsalicylic acid (20 mg/kg) or Tween 80 (10 mL/kg). The ability to protect animals from death or paralysis for 15 min was taken as a measure of antithrombotic activity (DiMinno and Silver, 1983). Statistical analysis. Student’s t-test was used to determine significant differences between treated and control groups. RESULTS AND DISCUSSION The chloroform extract of the seeds of Myristica fragrans demonstrated antiinflammatory activity by inhibiting the PHYTOTHERAPY RESEARCH Phytother. Res. 13, 344–345 (1999) CCC 0951–418X/99/040344–02 $17.50 Copyright # 1999 John Wiley & Sons, Ltd. * Correspondence to: Mr. O. A. Olajide, Department of Pharmacology, Faculty of Pharmacy, Obatemi Anolono University, IIE-IFE, Nigeria. Accepted 7 September 1998