Anti-Allergic Activity of Fucoidan Can Be Enhanced by Coexistence with Quercetin

Abstract

In recent years, the incidence of type I hypersensitivity including hay fever has been increasing year by year in Japan. Our previous study using mice showed that only oral, but not intraperitoneal, administration of fucoidan extracted from seaweed (Saccharina japonica) suppressed type I hypersensitivity by secretion of galectin-9, which has a high affinity for IgE in the blood. However, the amount of seaweed required to achieve this activity is quite high (12 g dry weight per person per day). Therefore, the purpose of this study was to search for food ingredients in vegetables that enhance type I hypersensitivity suppression effect when consumed together with fucoidan. As a result, the enhanced effect was observed in extracts from Welsh onions and onions among vegetables. When we compared the polyphenols in the vegetables that showed activity with those that did not, flavonols such as quercetin and kaempferol were found as candidates. When quercetin or kaempferol (100 μg each) were orally administered at the same time, even at amounts where fucoidan alone showed no anti-allergic activity, anti-allergic effects were observed. More interestingly, when both flavonols were combined and administered simultaneously at half the amount of each of the above flavonols (50 μg), while the fucoidan amount remained the same, a similar effect was observed as when each flavonol (100 μg) was administered alone. The simultaneous intake of fucoidan and vegetables containing high contents of quercetin or kaempferol may reduce fucoidan intake while maintaining the allergy suppression effect, suggesting the importance of food combination.

Recent Mechanistic Studies in Allergic Diseases

“…However, 12 g of seaweed would need to be consumed daily for fucoidan to significantly reduce the development of allergies, which is difficult to achieve. Therefore, in an article entitled “Anti-Allergic Activity of Fucoidan Can Be Enhanced by Coexistence with Quercetin” [ 5 ], Mizuno et al delve into introducing other food factors in order to enhance the anti-allergenic functionality of fucoidan, so that it can be consumed in smaller amounts while its positive effects continue to be implemented. The authors find that the consumption of foods containing quercetin and kaempferol induces an anti-allergic response, enabling a reduction in the amount of fucoidan needed to almost half of that initially deemed necessary in an allergic mouse model.…”