Table of Contents
International Journal of Carbohydrate Chemistry
Volume 2012 (2012), Article ID 458456, 7 pages
http://dx.doi.org/10.1155/2012/458456
Research Article

Partial Chemical Characterization of Immunomodulatory Polysaccharides from Plantago palmata Hook. f. s. Leaves

1Laboratoire de Pharmacognosie, de Bromatologie, et de Nutrition Humaine, Faculté de Pharmacie, Université Libre de Bruxelles (ULB), Campus Plaine CP 205/9, Boulevard du Triomphe, 1050 Bruxelles, Belgium
2Laboratoire de Pharmacologie et de Toxicologie, Unité de Formation et de Recherche en Sciences de la Santé, Université de Ouagadougou, Ouagadougou 03, Burkina Faso
3Laboratoire d’Immunologie Expérimentale, Faculté de Médecine, Université Libre de Bruxelles (ULB), Campus Erasme, Route de Lennik, 1070 Bruxelles, Belgium
4Department of Pharmaceutical Chemistry-Pharmacognosy, School of Pharmacy, University of Oslo, P.O. Box 1068, Blindern, 0316 Oslo, Norway

Received 30 May 2012; Accepted 25 June 2012

Academic Editor: Jianjun Li

Copyright © 2012 Gabriel Biringanine et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A previous work on Plantago palmata polysaccharides (PS) attributed immunomodulatory properties of leaves to a polysaccharide fraction (PS50) that stimulated NO and TNF-α production by interferon gamma- (IFN-γ-) activated macrophages. The present work aims to elucidate the chemical structure of these immunomodulatory polysaccharides. Size exclusion chromatography showed that the active polymers present an active fraction with a very high molecular weight (about 1200 kDa). These polysaccharides are pectic in nature, with a predominantly unbranched galacturonan domain and with a domain bearing side chains that consist of highly branched arabinan, galactan, and/or arabinogalactan. Comparatively to the well-known Plantago major biologically active PS, Plantago palmata PS50 contained less arabinogalactan-proteins (AGPs) and had a different composition in glucose, galactose, and galacturonic acid. DNA contamination of the polysaccharide was estimated at about 0.04%, a concentration much lower than those reported immunomodulatory in hyaluronic acid preparations (3 to 15%). Therefore, the eventuality of a contaminating DNA-mediated biological activity could be ruled out.