Chapter 33 - Antioxidant potentials of polysaccharides derived from marine brown algae

Abstract

The utility of seaweeds has been known for many years and is being explored further day by day. The biological activity of seaweeds is caused by their bioactive compounds. Many bioactive compounds with pharmacological as well as nutraceutical aspects have been discovered. Most of the therapeutic effects of seaweeds are connected to their antioxidant property. The polysaccharides isolated from seaweed, especially brown algae, are known to have rich antioxidant potential. Brown algae produces polysaccharide compounds at a higher rate than red and green seaweeds do. Antioxidant compounds are rich sources to alleviate the oxidative stress caused by certain molecules present inside or outside the body through several pathways. Polysaccharides from brown algae are found to have a potential role in inhibiting oxidative stress by activating the oxidative defense pathways. The antioxidant potential of polysaccharides has not been completely studied. The polysaccharides with high antioxidant potential are phlorotannins, polyphenols, fucoidan, sulfated polysaccharides, heterofucan, and diterpenes. A wide spectrum of biological properties are related to antioxidant potency, which include antidiabetic, anticoagulant, antiproliferative, antimicrobial, antiinflammatory, and anticancer properties. The antioxidant properties of polysaccharide have a wide range of utility in suppressing oxidative stress, in preventing melanogenesis, in inhibiting photodamage, as an effective therapy for postprandial hyperglycemia, as a functional dietary supplement, in cosmeceutical applications, for neuroprotective effects, in preventing urolithiasis, in treatment of bone fragility, in inhibiting calcium oxalate crystallization and treatment of urinary stones, as a food preservative, and as a wound-healing agent. These functional properties of polysaccharides have been well studied through in vivo and in vitro models. This chapter focuses on the recent advancements in the area of antioxidants derived from marine brown algae, which will be useful in extending the knowledge related to the pharmacological and nutraceutical aspects of bioactive compounds.