In vivo and in vitro inhibitory activity of an ethanolic extract of Sargassum fulvellum and its component grasshopper ketone on atopic dermatitis

The present study investigated the effect of Sargassum fulvellum ethanol extract (SFEE) on 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD)-like skin lesions in BALB/c mice. The severity of skin dermatitis, production of cytokines, and total IgE content were measured, and the histopathological features were analyzed. SFEE decreased the severity of DNCB-induced dermatitis and suppressed the serum levels of total immunoglobulin E (IgE), tumor necrosis factor (TNF)-α, and interleukin (IL)-4. In addition, SFEE reduced the production of IL-4, IL-5, and IL-13 in mice splenocytes. However, the levels of IL-10 and interferon (IFN)-γ significantly increased in mice sera and splenocytes. Histological examination revealed decreased dermal thickness and infiltration by mast cells after treatment with SFEE. Furthermore, grasshopper ketone, a compound isolated from SFEE, was found to significantly decrease cytokine production in concanavalin A-stimulated splenocytes from BALB/c mice with no cytotoxicity. Taken together, these results indicate that SFEE and the isolated grasshopper ketone have an inhibitory effect on AD by regulating immune mediators and cells and may be a potential effective alternative therapy for AD. •We examine the inhibitory effect of SFEE and its compound, GK on atopic dermatitis.•SFEE decreased the symptom severity of DNCB-induced atopic dermatitis.•SFEE decreased the dermal thickness and mast cell numbers in histological analysis.•SFEE suppressed the levels of total IgE and Th2 cytokines.•GK isolated from SFEE decreased cytokine levels in ConA-stimulated splenocytes.