Bioactive polysaccharides from natural sources: A review on the antitumor and immunomodulating activities

Polysaccharides are a structurally diverse group of biological macromolecules of well-known occurrence in nature. The mushroom, plant and other polysaccharides draw a lot of attention due to their several difficult biological properties, such as, anticancer, antiviral, immunomodulating, antimicrobial, anticoagulant, antidiabetic, antioxidant, and antitumor activities. Several bioactive glucans and heteroglycans were isolated from different mushroom, plant and bacterial cell wall. Polysaccharides have highest ability for carrying biological information comparison with other biopolymers such as proteins and nucleic acids due to the structural variability. It is the focus of this review to bring together the available knowledge of the structure, and function of the different polysaccharides of the mushroom, plant and bacterial cell wall.