Table 1 Examples of dietary polysaccharides that have been studied in relation to their biological activities
Dietary polysaccharides | Features/examples | Biological functions |
|---|---|---|
Sulfated polysaccharides; glycosaminoglycans | Heparin-like fucoidans— obtained from edible seaweed. | Potent antioxidant and anticoagulant properties, as well as immunopharmacological properties such as anti-inflammatory activity (Cumashi et al., 2007; Kim and Joo, 2008; Mizuno et al., 2009). |
Glucomannan polysaccharides | Acemannan—obtained from Aloe vera. | Potent immunostimmulants (Leung et al., 2006) that also exhibit anti-tumor and wound-healing properties via induction of fibroblast proliferation and increased type I collagen expression (Leung et al., 2006; Jettanacheawchankit et al., 2009). |
β-glucans; wide-spread homo-polysaccharides (D-glucose monomers linked by glycosidic bonds) with different molecular weights and degree of branching. | They occur most commonly as the cell wall of yeast, certain fungi and mushrooms (e.g. lentinan). | These exhibit marked anti-tumor (Chan et al., 2009; Liu et al., 2009) and immunostimulatory (Mizuno et al., 2009) activity, affecting both the innate, as well as the adaptive arm (Th1 and Th2) of the immune response (Dalmo and Bogwald, 2008), and may be effective in controlling blood lipids (Chen and Huang, 2009). Generally insoluble (1,3/1,6) β-glucan, has greater biological activity than the soluble (1,3/1,4) β-glucans. |
Inulin polysaccharides; fructans | Fructose polymers±terminal glucose. Found in many types of plants. Foods naturally high in inulin include garlic, onion and chicory. | These are associated with immunomodulatory anti-inflammatory effects as well as selective mineral absorption. They have also been implicated in controlling blood lipids (Bruzzese et al., 2009; Courtois, 2009; van den Heuvel et al., 2009). |
Arabinogalactan polysaccharides | Consisting of arabinose and galactose. Major constituents of many gums, including gum gutti and gum tragacanth. | A number of these exhibit immunomodulatory effects via induction of both pro- and anti-inflammatory cytokines (Schepetkin and Quinn, 2006), and have been shown to exhibit potent complement-fixing activity and beneficial prebiotic properties, particularly in gastrointestinal functional disorders such as Irritable bowel syndrome, by increasing the colonic contents of short-chain fatty acids. Guar gum has also been implicated in improving blood lipids (Rideout et al., 2008). |
