Sulfated polysaccharide from Phyllophorella kohkutiensis: Extraction, purification, and bioactivity assessment

Sulfated polysaccharides from marine sources exhibit diverse biological activities influenced by species and extraction methods. Herein, a sulfated polysaccharide (Pk-P1) was isolated and purified from the edible sea cucumber Phyllophorella kohkutiensis Heding & Panning, 1954. Structural characterization revealed that Pk-P1 is primarily composed of chondroitin sulfate. Thermogravimetric analysis demonstrated its thermal stability up to 231 °C, supporting its suitability for food processing applications. Both crude and purified polysaccharides significantly inhibited nitric oxide production in LPS-induced RAW264.7 macrophages, with IC₅₀ values of 128.90 ± 12.03 and 105.12 ± 16.57 μg/mL, respectively, without cytotoxicity at tested concentrations. Antioxidant assays also confirmed their free radical scavenging activity and ferric-reducing power. These results highlight the dual anti-inflammatory and antioxidant properties of Pk-P1, supporting its potential as a functional food ingredient or nutraceutical. This work underscores the value of marine-derived sulfated polysaccharides for promoting health and reducing oxidative stress.