Plant polysaccharides with immunostimulatory activities

Polysaccharides from plants have been the subject of study for a very long time, but mainly for their physical properties and industrial use based on these properties. Over the last 20 years there has been an ever increasing interest in the biological activity of biomolecules. These studies became p ossible as a result of the scientific development of isolation, purificatio n and characterisation methods concomitant with the development of fairly s imple in vitro tests, especially for effects on the immune system. The grow ing acceptance of the knowledge to be gained by people still using so-calle d traditional medicine in finding sources worthy of investigation has led t o new sources for interesting bioactive plant polysaccharides. This review covers only a small part of the field; it focuses primarily on the pectic t ype polymers and their activity; some important neutral polysaccharides lik e lentinan and acemannan are mentioned as well as methods used for these st udies.