Abstract

In the present study, Laminaria japonica polysaccharides was investigated for its free radical scavenging activity using three different in vitro assays and antibacterial activity. Laminaria japonica polysaccharides effectively scavenged the following free radicals: superoxide radical (O₂^-), hydroxyl radicals (OH^-) and 1,1-diphenyl-picrylhydrazyl radical (DPPH^-). The radical scavenging effect was found to be concentration-dependent. Also, L. japonica polysaccharides exhibited an inhibitory effect on several bacterial in vitro. Of several bacteria, Escherichia coli and Staphylococcus aureus are most sensitive to the polysaccharides. In conclusion, findings of the present study strongly suggest a free radical scavenging and antibacterial role for L. japonica polysaccharides.

Key words: Laminaria japonica polysaccharides, antioxidant, hydroxyl radicals.