Beneficial Effect of a Thermal Spring Water on the Skin Barrier Recovery after Injury: Evidence for Claudin-6 Expression in Human Skin

Abstract

Aim: To evaluate the possible advantages of dermo-cosmetic products formulated with thermal spring water instead of deionized water. We studied the effect of a dermo-cosmetic product on skin barrier recovery after injury. In one test the product was formulated with de-ionized water and again using the identical product formulated with thermal spring water. Study Design/Methods: Stratum corneum of human skin explants was removed (and not removed for the control) with an ether/acetone mixture. A cosmetic product, either formulated with de-ionized or thermal spring water, was then topically applied on the explants. After a 5 - day incubation period, epidermal expression of aquaporine-3, filaggrin, claudin-4 and claudin-6 was studied by using immunohistochemical techniques. Results: The formulation containing de-ionized water seemed to act on the epidermal expression of filaggrin and claudin-4. When thermal spring water was used to make the formulation, we noted that this expression was greatly enhanced. The formulation containing thermal spring water also acted to increase aquaporin-3 and claudin-6 expression. Conclusion: The use of thermal spring water in cosmetic formulations would appear to contribute to the cosmetic product’s efficacy. It was also interesting to note that this study revealed claudin-6 expression in human skin for the first time.