Oral Administration of the Extract from Hatakeshimeji (Lyophyllum decastes Sing.) Mushroom Inhibits the Development of Atopic Dermatitis-Like Skin Lesions in NC/Nga Mice

We examined whether the extract from Hatakeshimeji (Lyophyllum decastes, LD) mushrooms suppresses the development of atopic dermatitis (AD)-like skin lesions induced by repeated application of picryl chloride (PiCl) in NC/Nga mice. Oral administration of LD extract to NC/Nga mice inhibited the development of AD-like skin lesions based on lower total skin severity scores and serum immunoglobulin E (IgE) levels. Splenic lymphocytes were stimulated with the T cell mitogen concanavalin A, and secretion of a Th1 cytokine (IFN-γ) and a Th2 cytokine (IL-4) was determined by ELISA. IFN-γ production was not inhibited by treatment with LD extract. On the other hand, IL-4 production was significantly decreased by treatment with LD extract. These results suggest that LD extract exerts anti-allergic actions by suppressing the serum IgE and Th2-type immune responses.