Beneficial Activities of Fucoidan Polysaccharides Derived from Brown Seaweeds in Aquatic Organisms. A Review with Special Reference to the Egyptian Situation

The aquaculture industry faces increasing challenges arising from the emergence of fish and shrimp diseases, making immunomodulators (beneficial substances that modify the immune response) an urgent necessity. For a long time, researchers have focused on identifying suitable, cost-effective, and environmentally safe immunostimulants. These products aim to enhance the immune systems and antioxidant capacity of fish and shrimp, improving their ability to resist pathogens. Fucoidan, a sulfated polysaccharide primarily derived from brown seaweed, has emerged as a promising candidate due to its wide range of biological functions. Fucoidan has garnered significant attention in aquaculture due to its diverse beneficial properties. It is increasingly being incorporated into aquafeed as a natural additive to improve the health and productivity of farmed fish and shellfish. Alongside other major seaweed polysaccharides like laminarin and alginic acid, fucoidan exhibits anti-inflammatory, immunomodulatory, antioxidant, antiviral, antibacterial, antitumor, anticoagulant, and growth-enhancing effects. This review focuses on the beneficial impacts of fucoidan in aquatic animals, emphasizing its structural features, extraction techniques, and therapeutic potential, with special attention to findings from Egyptian research.