Inhibition of 2,4-dinitrofluorobenzene-induced atopic dermatitis by topical application of the butanol extract of Cordyceps bassiana in NC/Nga mice

Ethnopharmacological significance: The Cordyceps species are insect-borne mushrooms that have been ethnopharmacologically used for skin diseases such as eczema and dermatitis. Aim of the study: In this study, we investigated the curative effects of the butanol fraction (CBBF) of Cordyceps bassiana on atopic dermatitis. Materials and methods: Dermatitis was induced by repeated application of 2,4-dinitrofluorobenzene (DNFB) in NC/Nga mice. After a topical application of CBBF on the skin lesions, the dermatitis score, epidermal thickness, mast cell number, and interleukin (IL)-4 and interferon (IFN)-γ, as well as the levels of histamine and immunoglobulin E (IgE) in the serum, were measured. Moreover, effect of CBBF on histamine release was examined using RBL-2H3 under stimulation with 2,4-dinitrophenylated bovine serum albumin (DNP-BSA). Results: CBBF inhibited atopic dermatitis symptoms and signs in the DNFB-treated NC/Nga mice. The suppressive activity of topically applied CBBF may be due to the dose-dependent blockade of a series of immunopathological events, including the release of histamine, the production of IgE, and the secretion of IL-4 and IFN-γ. However, this extract did not directly suppress the degranulation process, assessed by measuring β-hexosaminidase release. Conclusions: Our results suggest that CBBF can be applied as an effective herbal remedy to treat atopic dermatitis.