Potential antibacterial and antioxidant properties of a sulfated polysaccharide from the brown marine algae Sargassum swartzii

AIMS: Sulfated polysaccharide extracted from the brown algae Sargassum swartzii was studied for antioxidant potential. METHODS: The extracted sulfated polysaccharide was analyzed for physico-chemical characteristics, TAC, reducing power, free radical scavenging potentials (DPPH, ABTS, H2O2 radical) and antibacterial properties. RESULTS: The extract showed a high percentage of carbohydrate (7.40 0.63)%, followed by sulfate (5.3 1.54)%. The highest antioxidant activity was observed in ABTS (55 3.61)%, followed by H2O2 (47.23 2.81)% and DPPH (25.33 2.52)%; significant differences were observed at (P 0.05). Among the ten human pathogenic strains tested, E. coli was the more sensitive. The characterization and mobility of the sulfated polysaccharide was examined by the FT-IR spectrum and assayed by agarose gel electrophoresis which showed highest mobility at higher pH buffer in carbonate-bicarbonate (pH 10) buffer. The molecular weight of the sulfated polysaccharide was determined by gradient PAGE and was found to be 50 KDa. Finally, GC-MS analysis revealed the presence of peaks corresponding to dimethyl-4-nitroaniline (26.34%). CONCLUSIONS: It is suggested that the sulfated polysaccharide from Sargassum swartzii could be a better source of natural antioxidant, as well as an antibacterial agent.