Comparative antioxidant capacity of fucoidan batches extracted from Sargassum species

Abstract

Fucoidans are sulfated heteropolysaccharides which is majorly found in brown marine algae and certain marine invertebrates. The fucoidan heteropolysaccharide is predominantly made of L-fucose, galactose and sulfate groups. In addition, it also comprises other monosaccharides and proteins. Recent studies have reported about the various biological activities including anticancer, antioxidant, antithrombotic, immunoregulatory anti-inflammatory and antimicrobial activities of fucoidans among different species of brown algae. In this study, polysaccharide fraction was extracted from the brown algae of Sargassum species using two different extraction procedures. Followed by this, the extracts of Batch-I and II were fractionated using anion exchange chromatography. The FTIR spectroscopy was used for the characterization and identification of fucoidans of both the batches. The FTIR spectra obtained for fucoidan from both the batches are almost similar, but they showed varied elution fraction range in anion exchange chromatography. Free radical and Hydroxyl radical scavenging activity were performed to analyze the activity of fucoidans extracted and compared with natural antioxidant ascorbic acid. Both Batches showed comparable antioxidant capacity to natural antioxidant ascorbic acid and difference in antioxidant activity is insignificant (p>0.05). Also, the free radical scavenging activity of fucoidan of Batch-I was observed to be around 4.03 % higher than Batch-II fucoidan but showed insignificant difference with p>0.05 between Batch I and Batch II. Similarly, the hydroxyl radical scavenging activity of Batch-I was observed to be around 2.98 % slightly higher than Batch-II and showed insignificant difference with p>0.05 between Batch I and Batch II. Hence fucoidan isolated from Sargassum can be utilized as a natural antioxidant in food and cosmetic space in place of synthetic antioxidants.