Edible seaweeds' phlorotannins in allergy: A natural multi-target approach

The anti-allergenicity of phlorotannin-targeted extracts from four edible seaweed species of Fucus genus was evaluated herein for the first time. Extracts were able to act upon cellular events triggered by immunological reaction (IgE/antigen), and on cellular events downstream the Ca²⁺ influx caused by a chemical stimulus (calcium ionophore A23187), preventing degranulation of RBL-2H3 cells. Furthermore, a dose-dependent behaviour towards allergy-related enzymatic systems was observed for all the phlorotannin extracts. Linear correlations were found between reduction of the allergic mediators released and the total phlorotannin content, as well as between the enzyme inhibition and the amount of phlorotannins in the extracts. These results point to a multi-target anti-allergic capacity of phlorotannin-targeted extracts, which displayed effects on different critical steps of the allergic response, contributing to the valorisation of Fucus spp. both as food and for nutraceutical applications.