Immunomodulatory effects of balneotherapy with hae-un-dae thermal water on imiquimod-induced psoriasis-like murine model

Background: Balneotherapy, although not a well-established dermatological treatment, is thought to have therapeutic properties for psoriasis and is used as an alternative treatment modality throughout the world. Objective: To evaluate the mechanism underlying the therapeutic immunologic effects of thermomineral water. Methods: A murine model of imiquimod-induced psoriasis-like skin inflammation was used for evaluating the therapeutic effects of balneotherapy with Hae-Un-Dae hot spring mineral water. The clinical improvements were evaluated by a dermatologist. Lesional cytokines, including interleukin (IL)-17A, IL-23, and IL-22, were quantitatively measured by real-time reverse transcriptase polymerase chain reaction. Serum levels of interferon- γ, IL-4, IL-5, and IL-17A were measured by enzyme- linked immunosorbent assay. T cell proportions in the spleen were evaluated by flow cytometry, and histopathological evaluation of the skin was also performed. Results: The mineral water balneotherapy group showed faster improvement in skin erythema and scales than the distilled water bathing group. A substantial reduction was observed in the lesional mRNA levels of IL-17A and IL-23 in the mineral water group. Serum levels of IL-4 and IL-5 were significantly decreased in the mineral water group but not in the distilled water group. Normalized T cell proportions were observed after bathing. Conclusion: Balneotherapy showed immunomodulatory effects in a psoriasis-like murine model. Balneotherapy suppressed lesional IL-23 and IL-17A, which are important cytokines in the pathogenesis of psoriasis. These results suggest that balneotherapy can be used as an effective and safe treatment for psoriasis. (Ann Dermatol 26(2) 221∼230, 2014).