External Application of Apo-9'-fucoxanthinone, Isolated from Sargassum muticum, Suppresses Inflammatory Responses in a Mouse Model of Atopic Dermatitis.

Allergic skin inflammation such as atopic dermatitis is characterized by skin barrier dysfunction, edema, and infiltration with various inflammatory cells. The anti-inflammatory effects of Apo-9'-fucoxanthinone, isolated from Sargassum muticum, have been described in many diseases, but the mechanism by which it modulates the immune system is poorly understood. In this study, the ability of Apo-9'-fucoxanthinone to suppress allergic reactions was investigated using a mouse model of atopic dermatitis. The Apo-9'-fucoxanthinone-treated group showed significantly decreased immunoglobulin E in serum. Also, Apo-9'-fucoxanthinone treatment resulted in a smaller lymph node size with reduced the thickness and length compared to the induction group. In addition, Apo-9'-fucoxanthinone inhibited the expression of interleukin-4, interferon-gamma and tumor necrosis factor-alpha by phorbol 12-myristate 13-acetate and ionomycin-stimulated lymphocytes. These results suggest that Apo-9'-fucoxanthinone may be a useful therapeutic strategy for treating chronic inflammatory diseases.