Comparative study on the extraction methods, characterization, and bioactivity of crude fucoidan, a polysaccharide derived from Sargassum ilicifolium

Fucoidan, a sulfated polysaccharide known for its anticancer, immunomodulant, antioxidant and antimicrobial activity is abundant in brown seaweeds. Sargassum ilicifolium, a brown alga, was not extensively explored for fucoidan extraction using different methods and assessments of their impact on its structural and therapeutic characteristics. This study aimed to compare the structural features, biological activity, solubility, and emulsification characteristics of fucoidan extracted from Sargassum ilicifolium using conventional and ultrasonic bath extraction. The ultrasonic bath extraction method was 2.5 times higher than the conventional method to extract fucoidan. The structural integrity of fucoidan obtained by both methods was compared using FTIR, 1HNMR, XRD, FESEM, EDX, and DSC. The monosaccharide composition of fucoidan was determined by TLC. The IC50 values for antioxidant, anti-inflammatory and antitumor effects on oral cancer cells were found to be significantly lesser for crude fucoidan of S. ilicifolium obtained by ultrasonic bath method than for conventional extraction. Furthermore, fucoidan from the alga has emulsifying and water-holding characteristics which supports its potential use in the food processing industries.