Holistic Review of Polysaccharides Isolated from Pumpkin: Preparation Methods, Structures and Bioactivities

Pumpkin polysaccharides have arrested researchers' attention in fields of food supplements for healthy product and traditional Chinese medicine due to their multiple bioactivities with non-toxic and highly biocompatible. This review emphatically summarized recent progresses in the primary and spatial structural features, various bioactivities, structure-to-function associations, different preparation techniques, and absorption characteristics across intestinal epithelial and in vivo bio-distribution of pumpkin polysaccharides. Additionally, current challenges and future trends in development of pumpkin polysaccharides were pointed out. We found that pumpkin polysaccharides were primary structure (e.g. glucan, galactoglucan, galactomannan, galactan, homogalacturonan (HG), and rhamnogalacturonan-Ι (RG-Ι)) and special structure diverse (e.g. hollow helix, linear, and sphere-like) and significant functional foods or therapeutic agents (e.g. oral hypoglycemic agents). Moreover, we found that the molecular weight (Mw), uronic acid, linkage types, and modifications all could affect their bioactivities (e.g. anti-oxidant, anti-coagulant, and anti-diabetic activities), and pumpkin polysaccharides may across intestinal epithelial into the blood reaching to target organs. Collectively, the structures diversity and pharmacological values of pumpkin polysaccharides support their therapeutic potentials and sanitarian functions.