해조류 추출물의 항산화 활성

Antioxidant Activity of Seaweed Extracts

The brown seaweed Scytosiphon lomentaria was enzymatically hydrolyzed to prepare water- soluble extracts by five carbohydrases (AMG, Celluclast, Termamyl, Ultraflo and Viscozyme) and five proteases (Alcalase, Flavourzyme, Koj izyme, Neutrase, Protamex). The enzymatic extracts exhibited strong scavenging activity on hydroxyl, alkyl and DPPH radical, and the activity increased with increment of concentration of the enzymatic extracts. These results were similar to the scavenging values on hydroxyl and alkyl radical, and lower to the scavenging value on DPPH radical compared with vitamin C used as a reference, respectively. Therefore, the enzymatic extracts of S. lomentaria are a potent antioxidant. The methanolic extract (2 mg/mL) of Grateloupia filicina scavenged 82% of DPPH radicals which is almost three times higher than that of BHT. The same methanolic extract scavenged 65% of superoxide anion which is almost two times higher than that of BHT and α-tocopherol. In contrast, the extracts in chloroform and carbon tetrachloride inhibited lipid peroxidation more effectively than all commercial antioxidants tested in a linoleic acid model system. The activities of lipophilic extracts from 16 species of seaweeds were compared with those of commercial antioxidants such as BHA, BHT and α-tocopherol. The highest antioxidant capacities among the tested samples were observed for Rhodomela confervoides and Symphyocladia latiuscula and were comparable with that of the well-known antioxidant BHT and greater than that of PG. The lipophilic content of all 16 samples and the chemical composition of 4 selected seaweeds, R. confervoides and S. latiuscula, which had higher AA, Laminaria japonica, which had intermediate AA, and Plocamium telfairiae, which had lower AA, were analyzed by gas chromatography and gas chromatography-mass spectrometry, respectively. Fatty acids and alkanes were found. The present data indicated an increase in antioxidative property with increasing content of unsaturated fatty acid.