Abstract
Atopic dermatitis is a representative intractable chronic eczematous skin disease. The symptoms of atopic dermatitis are eczema and an itching sensation, and this disease is caused by skin dysfunction and immune imbalance. Because the symptoms vary between individuals, several therapies are required for atopic dermatitis. Kampo medicines, traditional Japanese medicines, are used as an alternative medical option for the treatment of chronic allergic diseases such as rhinitis, asthma, and atopic dermatitis. Since Kampo medicines should be used according to the particular physical and mental conditions, the use of distinctive animal models is necessary for the experimental assessment of the efficacy of Kampo medicines. In this study, Kampo medicines were assessed for their anti-itching effect and with respect to the cure and prophylaxis of pruritus by single or serial oral administration to 2 types of atopic dermatitis-like pruritus models. We assessed 7 kinds of Kampo medicines that have been used for atopic dermatitis patients. In 7 Kampo medicines, only shofusan (SFS) had an instant effect —even on using a single dose —on scratching behavior induced by multiple treatments with 2,4,6-trinitrochlorobenzene (TNCB) for 4 weeks in NC mice; it ameliorated chronic itching on oral administration for 11 d, by preventing mast cell differentiation and degranulation. In the other model using BALB/c mice painted with TNCB repeatedly, another Kampo medicine, hochuekkito (HET) inhibited the induction of scratching behavior. The results indicate that certain Kampo medicines such as SFS and HET may improve chronic itching sensation in atopic dermatitis to the same extent as or better than existing antiallergic medicines.
