Psoriasis is an inflammatory and auto-immune
skin-disease characterized by uncontrolled keratinocyte proliferation. Its pathogenesis is not still fully understood; however, an aberrant and excessive inflammatory and immune response can contribute to its progression. Recently, more attention has been given to the anti-inflammatory and
immunomodulators effects of
melatonin in inflammatory diseases. The aim of this paper was to investigate the effect of
melatonin on psoriatic phenotype and also in S. aureus
infection-associated
psoriasis, with an in vitro model using Skinethic Reconstructed Human Epidermis (RHE). An in vitro model was constructed using the RHE, a three-dimensional-model obtained from human primary-keratinocytes. RHE-cells were exposed to a mix of pro-inflammatory
cytokines, to induce a psoriatic phenotype; cells were also infected with S. aureus to aggravate
psoriasis disease, and then were treated with
melatonin at the concentrations of 1 nM, 10 nM, and 50 nM. Our results demonstrated that
melatonin at higher concentrations significantly reduced histological damage, compared to the
cytokine and S. aureus groups. Additionally, the treatment with
melatonin restored tight-junction expression and reduced pro-inflammatory
cytokine levels, such as interleukin-1β and
interleukin-12. Our results suggest that
melatonin could be considered a promising strategy for
psoriasis-like skin
inflammation, as well as complications of
psoriasis, such as S. aureus
infection.