O-Coumaric acid attenuates atopic dermatitis-like skin inflammation

Abstract

Abstract Background Hydroxycinnamic acids (coumaric acid; CA) and their derivatives display anti-oxidant and anti-inflammatory effects. CA has three isomers including o-CA, m-CA, and p-CA. Among them, recent report showed the effectiveness of p-CA on skin inflammation. Objective In this study, we investigated the role of o-CA on atopic dermatitis (AD) comparing with p-CA. Methods For the induction of atopic dermatitis (AD)-like skin inflammation, 1,4-dinitrochlorobenzene (DNCB) and house dust mite extract (Dermatophagoides farinae extract, DFE) were applicated repeatedly, and o-CA were orally administered. For mechanism study, tumor necrosis factor (TNF)-α and interferon (IFN)-γ stimulated human keratinocyte cell line (HaCaT) was used. Results In AD-like skin inflammation, the clinical symptoms including the redness, dermal/epidermal thickness, and infiltration of mast cells were significantly reduced by the oral treatment of o-CA. Local inflammatory cytokines expression and systemic production of IgE and IgG2a were also suppressed by the o-CA. In addition, o-CA inhibited the expression of interleukin (IL)-1β, IL-6 and CC-chemokine ligand 17 in TNF-α/IFN-γ stimulated HaCaT cells by the reduction of nuclear translocation of nuclear factor-κB. In all cases, o-CA showed more effectiveness than p-CA. Conclusions These results showed that o-CA could be a potential candidate for AD treatment.