Suppressive effects of the diethyl ether fraction from a brown alga Sargassum fusiforme on allergic and inflammatory reactions

This study investigated the anti-allergic effect of a diethyl etherfraction from dried Sargassumfusiforme. In vivo experiments showed that percutaneous administration of this fraction suppressed mouse ear swelling induced by three types of sensitizers (arachidonic acid, 12-O-tetradecanoylphorbol-13-acetateand oxazolone). At a dose of 0.1 mg/mouse, the suppression ratios were from 47 to 61 %. Oral administration of the fraction also suppressed mouse ear swelling. At a dose of 1 mg/mouse, the suppression ratios were from 69 to 92 % which were comparable to those obtained by the typical natural inhibitor, epigallocatechin gallate(EGCG). In vitro experiments were performed to elucidate the inhibitory effects of the fraction on the enzymatic activities ( phospholipase A2, cyclooxygenase-2, lipoxygenase and hyaluronidase) involved in inflammation and degranulationin rat basophilic leukemia (RBL)-2H3 cells to understand the mechanism that underlies the suppression of mouse ear swelling. Similar to EGCG, the fraction inhibited the enzymatic activities tested and suppressed degranulationin RBL cells in a dose-dependent manner. Therefore, the active components present in this S. fusiforme fraction achieve the anti-inflammatory effects by inhibiting the enzymatic activities and degranulationin the ear of mice. Thus, S. fusiforme and its diethyl etherfraction could be useful ingredients in functional foods.