Polettini AJ, Eberlin S, Costa A, Pereira AFC, Dolis E, Torloni LBO.
Atopic dermatitis (AD) is a chronic inflammatory skin disease in which hereditary, environmental and immunological factors play a major role. Characterized by xerosis, eczematous lesions and pruritus, AD changes between two phases, acute Th2 predominant state with its cytokine pattern up-regulating IgE to chronic AD with Th1 cytokines, predominantly interferon-? (IFN-?) and interleukin-12 (IL-12) that down regulates Ig-E. It is important to notice that pruritus usually leads to an “itch-scratch” cycle that may compromise the epidermal barrier, dermis architecture and function, resulting in transepidermal water loss and defective wound healing. The wound signature of AD is proliferation of progenitor cells leading to epidermal hyperplasia, and tissue remodeling resulting in the development of spongiosis. In this study, we evaluated the anti-inflammatory and regenerative properties of a cosmetic product through quantification of INF?, interleukins 12 and IFN-? using an ex vivo model of human skin. We also assessed wound healing ability by measurement of transforming growth factor beta (TGF?) and cell migration using an in vitro model of human fibroblast culture. The synthesis of IL-12, INF? and TGF-? were measured using human skin explants, obtained from plastic surgery. This study was carried out with approval of Ethics Committee. Incubation of skin explants with IL-1? promoted increases of 42.2% in the production of IFN-?. Concurrent treatment of skin explants with test product prevented the increase of inflammatory cytokine reaching up to 48.5% reduction in relation to IL-1-stressed group. IL-1? stimulation did not produce increases in the amount of IL-12; however, test product reduced the synthesis of this cytokine to undetectable levels compared to the basal control group. The synthesis of TGF-? was significantly decrease by the addition of IL-1? in cultured skin ex vivo. Conversely, test product was able to promote 1.9-fold increase in the synthesis of TGF-? when compared to IL-1?-stressed group. The increase in the production of this growth factor corroborates the results obtained in the cell migration assay, where test product was able to increase cell migration when compared to the control group. After 48 hours the scratch was completely filled, similarly to the group stimulated with TGF-?. AD is associated with hyper responsiveness of lymphocytes to allergens. In acute AD only Th2-type lymphocytes are activated, whereas in more chronic forms of AD, the activity of both Th1- and Th2-type lymphocytes increases. Th1 cytokines IL-12 and IFN-? are present in chronic phase of AD and are responsible for the perpetuation of inflammatory state culminating in connective tissue damage. A third group of cytokines, which include TGF-?1 and IL-10, have general immunosuppressive activity, blocking both Th1-and Th2-type cytokine activity. In this work, it was demonstrated that test product exerts a protective effect against inflammatory and immunological imbalance induced by IL-1? in human skin explants. The results also showed the ability of test product in the stimulation of TGF-?1 and fibroblast migration, both involved in wound healing process. Taken together, these data suggest that test product might be considered as an effective skin care formulation for atopic skin.