Polysaccharides from echinoderms: unlocking health benefits and food applications – a review

Echinoderms (phylum Echinodermata), including sea cucumbers, sea urchins, and starfish, are found in the marine environment. They have no freshwater or terrestrial representatives and inhabit the entire depth of the ocean. The phylum contains more than 7000 living species. Their bodies contain nutrients like proteins (peptides, collagen, and protein hydrolysates), lipids (polyunsaturated fatty acids), saponins (frondoside A), carotenoids (canthaxanthin and astaxanthin), phenolics (flavonoids and phenolic acids), vitamins, and minerals. Besides, these are the leading sources of unique polysaccharides, such as fucosylated chondroitin sulfate, sulfated fucans, and glycosaminoglycans, which possess a wide range of bioactivities. This review intends to explore the health-promoting properties of these polysaccharides, highlighting their anti-inflammatory, anticoagulant, antioxidant, antitumor, anticancer, and other effects along with their mechanisms of action. Their heterogeneous structural composition and remarkable biological activity make them promising candidates for many applications in the functional foods and nutraceuticals area. Furthermore, this review discusses the major challenges and future prospects of polysaccharides from marine echinoderms, focusing on their extraction, purification, characterization, and structural diversity. In addition, the potential of echinoderm polysaccharides as novel nutrients that can contribute to human health is described and it also highlights the growing desire for natural food products in health promotion and disease risk reduction.