Natural polysaccharides with immunomodulatory activities.

Abstract

Natural polysaccharides can be extracted from plants, fungi, algae, animals, and bacteria. The monosaccharide compositions and glucosidic bonds of polysaccharides from different origins vary substantially. Natural polysaccharides have been shown to possess a variety of biological activities including antitumor, anticoagulant, antioxidative, antiviral, immunomodulatory, antihyperlipidemic and antihepatotoxic activities. Their properties are mainly due to their structure characteristics. The present paper will review the mechanisms of the immunomodulatory activities of natural polysaccharides. In particular, it will provide an overview on representative natural polysaccharide immunomodulators. Additionally, the structure-activity relationship of these activities will be discussed.