Immunomodulatory Effects of Deokgu Thermomineral Water Balneotherapy on Oxazolone-Induced Atopic Dermatitis Murine Model

Background: Although the therapeutic mechanism of balneotherapy for atopic dermatitis has not been clarified, many atopic patients who visit thermomineral springs have shown clinical improvements. Objective: This study was aimed to evaluate the immunomodulatory effect of thermomineral water balneotherapy on the atopic dermatitis murine model. Methods: The oxazolone-induced atopic dermatitis murine model was used to evaluate the therapeutic effect of balneotherapy with Deokgu thermomineral water compared with distilled water. Histologic evaluation and confocal microscopic imaging were performed to analyze the lesional expression of cluster-of-differentiation (CD)4 and forkhead box p3 (Foxp3). Lesional mRNA expression of interleukin (IL) 33, thymic stromal lymphopoietin (TSLP), and Foxp3 was evaluated by real-time reverse transcription polymerase chain reaction. Results: Compared with the distilled water bath group, confocal microscopic evaluation of CD4 and Foxp3 merged images showed increased expression of regulatory T cells in the thermomineral balneotherapy group. The lesional mRNA level of IL-33 showed a reduced trend in the thermomineral balneotherapy group, whereas the level of mRNA of Foxp3 was increased. TSLP showed a decreased trend in both distilled water and thermomineral water bath groups. There was a trend of reduced expression in lesional IL-33 mRNA but increased cell count of CD4(+) Foxp3(+) regulatory T cells in thermomineral balneotherapy compared with distilled water bath. Conclusion: Therefore, thermomineral balneotherapy can be an effective and safe adjuvant therapeutic option for atopic dermatitis.