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

AimsSulfated polysaccharide extracted from the brown algae Sargassum swartzii was studied for antioxidant potential.MethodsThe extracted sulfated polysaccharide was analyzed for physico-chemical characteristics, TAC, reducing power, free radical scavenging potentials (DPPH, ABTS, H2O2 radical) and antibacterial properties.ResultsThe 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%).ConclusionIt is suggested that the sulfated polysaccharide from Sargassum swartzii could be a better source of natural antioxidant, as well as an antibacterial agent.