Studies on anti-allergic activity of Sargassum horneri extract

Chlorophyll c2 in a Sargassum horneri extract suppressed the degranulation of rat basophilic leukaemia RBL-2H3 cells. In this contribution, the mode of action of S. horneri extract was revealed. The extract inhibited the elevation of intracellular Ca2+ concentration induced by the antigen. Immunoblot analysis showed that S. horneri extract down-regulated the phosphorylation of both Syk and PI3K in the signalling pathways involved in degranulation triggered by antigen-antibody interaction. In addition, oral administration of S. horneri extract inhibited mice nasal rubbing behaviour sensitized with anti-DNP IgE. These findings suggest that S. horneri extract has anti-allergic activity via the suppression of degranulation of mast cells and basophils.