Radical Scavenging and Hyaluronidase Inhibitory Activities of Phlorotannins from the Edible Brown Alga Eisenia arborea

Abstract

Six anti-allergic phlorotannins from the brown alga Eisenia arborea were examined for their inhibitory effects on oxidation and hyaluronidase activities. To investigate the radical scavenging activities of the phlorotannins, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was evaluated. Although the radical scavenging activity of a typical scavenger, epigallocatechin gallate (EGCg), was the strongest, the six tested phlorotannins exhibited activities of various degrees. When the hyaluronidase inhibitory activity was examined, eckol inhibited the hyaluronidase activity similar to the typical inhibitors, EGCg and disodium cromoglycate. The other five phlorotannins inhibited the enzymatic activity stronger than the above inhibitors. Since the six phlorotannins from E. arborea expressed radical scavenging and hyaluronidase inhibitory activities, E. arborea could be used as an anti-inflammatory and anti-allergic food ingredient.