The anti-allergic and anti-inflammatory effects of phlorotannins and their use in functional foods

Abstract

The number of patients exhibiting allergies in developed countries like Japan is increasing; allergies have become a societal issue. While diverse remedies and strategies are employed in the medical and pharmaceutical fields, anti-allergic compounds have also been investigated for the prevention and alleviation of allergies. Phenolic compounds from terrestrial food materials are well-known as typical anti-allergic components including flavonoids and tea catechins. Phenolic compounds are also present in seaweeds, such as species in the brown alga genera Ecklonia and Eisenia, and these are collectively known as phlorotannins. The anti-allergic effects of phlorotannins were have been repeatedly demonstrated. Here, we have reviewed the general properties and bioactivities of phlorotannins and provided a detailed description of the anti-allergic effects of the brown alga Eisenia nipponica and phlorotannins isolated from it. We have also reviewed the anti-allergic effects of the brown alga Ecklonia cava subsp. stolonifera as well as its phlorotannins and discussed the potential use of these algae in functional foods.