have been formulated for treating the common cold infection. These include Black Cherry (Prunus serotina), Echinacea (Echinacea angustifolia and E purpurea), Elderberry (Sam- bucus nigra), Ephedra (Ephedra sinica), Garlic (Allium sativum) and Ginger (Zingiber officinale) (2). Similarly, several plant species have been used in Jamaica for treating the common cold eg Aaron’s Rod (Gliricidia sepium (Jacq) Kunth ex Griseb), Barsley (Ocimum micranthum L), Con- sumption weed (Wedelia gracilis LC Rich), Doctor Johnson (Boehmeria jamaicensis Urb), Fresh cut (Justica pectoralis Jacq Enum), Jackie’s Saddle (Peperomia amplexicaulis (Sw) A Dietr), John Charles (Hyptis verticillata Jacq), Leaf-of- Life (Bryophyllum pinnatum (LAM) Oken), Susumber (Solanum torvum Sw) and White Sage (Lantana camara L) (3, 4). Based on the time taken to recover from the common West Indian Med J 2007; 56 (6): 487 Immunological Evidence Supporting the Use of Extracts From Boehmeria jamaicensis Urb for Treating the Common Cold and Sinus Infections LAD Williams 1 , JU Igietseme 2 , JA Whittaker 3 , MF Smikle 4 , YA Bailey-Shaw 1 , EN Barton 5 ABSTRACT Mixed lymphocyte responses assays were conducted at 25.0 and 250.0 μg/mL of the crude ethanolic extract of Boehmeria jamaicensis Urb (coded as BJE) using peripheral lymphocytes obtained from individuals suffering from the common cold after four days of infection and from healthy individuals (without the common cold infection). At a concentration of 25 ug/mL, gamma interferon (IFN-γ) was increased by 24.03 fold and interleukin 4 (IL-4) by 1.71 fold for the cells obtained from individuals with the common cold (Group A). The extract suppressed IFN-γ by 8.3% while IL-4 was stimulated by 9.90 fold from peripheral lymphocytes obtained from healthy individuals (Group B). Gamma interferon was suppressed at 250 μg/mL while IL-4 was elevated by 1.86 fold for cells obtained from individuals suffering from the common cold (Group A). In conclusion, BJE could have implications for the treatment of the common cold. Evidencia Inmunológica que Fundamenta el uso de Extractos de Boehmeria Jamaicensis Urb Para el Tratamiento del Catarro Común y la Sinusitis LAD Williams 1 , JU Igietseme 2 , JA Whittaker 3 , MF Smikle 4 , YA Bailey-Shaw 1 , EN Barton 5 RESUMEN Ensayos de reacción linfocitaria mixta fueron realizados a 25.0 y 250.0 μg/mL de extracto etanólico crudo de Boehmeria jamaicensis Urb (codificado como BJE), usando linfocitos periféricos obtenidos de individuos con catarro común luego de cuatro días de infección, y de individuos sanos (sin la infección del catarro común). Se halló que el interferón-gamma (IFN-γ) aumentó en 24.03 veces, y la interleucina 4 (IL-4) en 1.71 veces para las células obtenidas de individuos con catarro común, a 25 μg/mL. El extracto inhibió IFN-γ en un 8.3 % en tanto que el IL-4 fue estimulado en 9.90 veces a partir de los linfocitos periféricos obtenidos de individuos sanos. El gamma-interferón fue inhibido a 250 μg/mL, mientras que la IL-4 se elevó en 1.86 veces para las células obtenidas de individuos que sufren de catarro común. West Indian Med J 2007; 56 (6): 487 From: 1 The Natural Products Unit of the Scientific Research Council of Jamaica, PO Box 350, Kingston 6, Jamaica, West Indies; 2 Department of Microbiology and Immunology, Morehouse School of Medicine, Atlanta, Georgia, 30310-1494 USA; 3 School of Computer, Mathematical and Natural Sciences, Morgan State University, 1700 E. Cold Spring Lane, USA; Richard N Dixon Science Research Center, Suite 200, Baltimore, MD 21251, USA; 4 Departments of Microbiology and 5 Medicine, the University of the West Indies, Kingston 7, Jamaica. Correspondence: Dr LAD Williams, The Natural Products Unit of the Scientific Research Council of Jamaica, PO Box 350, Kingston 6, Jamaica, West Indies, email: lawrencew@src-jamaica.org. INTRODUCTION The common cold infection and sinusitis are two of the most frequent human illnesses and are responsible for substantial morbidity and economic losses (1). Several plant extracts