Effect of administrating polysaccharide from black currant (Ribes nigrum L.) on atopic dermatitis in NC/Nga mice

Atopic dermatitis (AD) is a chronic inflammatory skin disease that causes dry skin and functional disruption of the skin barrier. AD is often accompanied by allergic inflammation. AD patient suffer from heavy itching, and their quality of life is severely affected. Some pharmaceuticals for AD have some side effects such as skin atrophy. So it is necessary to develop mild solutions such as food ingredients without side effects. There are various causes of AD. It is especially induced by immunological imbalances such as IFN-γ reduction. IFN-γ has an important role in regulating IgE, which can cause an allergy reaction. NC/Nga mice develop AD and IgE hyperproduction. In a previous study, we revealed that administration of polysaccharide from black currant (R. nigrum) has an effect on immunomodulation. It induces IFN-γ production from myeloid dendritic cells. We named this polysaccharide cassis polysaccharide (CAPS). In this report, we studied the effect of administering CAPS on atopic dermatitis in NC/Nga mice. Thirty NC/Nga mice that developed symptoms of atopic dermatitis were used. We divided them into three groups (control, CAPS administration 12 mg/kg/day, CAPS administration 60 mg/kg/day). For 4 weeks, we evaluated clinical score, serum IgE levels, gene expression of spleen, and skin pathology. We revealed that CAPS administration improves atopic dermatitis symptoms. We also found that CAPS administration suppresses IgE hyperproduction and induces IFN-γ gene transcription in the spleen. Finally, we confirmed that CAPS administration suppresses mast cell migration to epidermal skin. These results indicated that CAPS has an effect on AD.