3,4,5-Trihydroxycinnamic acid exerts anti-inflammatory effects on TNF-α/IFN-γ-stimulated HaCaT cells

3,4,5-Trihydroxycinnamic acid (THCA) exhibits anti-inflammatory activity in acute or chronic inflammatory disorders, such as acute lung injury and asthma. The present study investigated the anti-inflammatory activity of THCA in a tumor necrosis factor-α/interferon-γ (TI) mixture-stimulated human keratinocyte cell line. The results of ELISA and reverse transcription-quantitative PCR revealed that THCA reduced the secretion and mRNA expression levels of interleukin (IL)-6; IL-8; thymus and activation-regulated chemokine; macrophage-derived chemokine; regulated upon activation, normal T cell expressed and secreted; and monocyte chemoattractant protein-1 in TI mixture-stimulated HaCaT cells. In addition, the results of western blot analysis demonstrated that THCA exerted inhibitory activity on the activation of AKT, ERK and nuclear factor-κB in TI mixture-stimulated HaCaT cells. Furthermore, THCA upregulated the expression levels of heme oxygenase-1 and NAD(P)H:quinone oxidoreductase 1, and the activation of nuclear factor erythroid 2-related factor 2 in HaCaT cells. These results demonstrated that THCA may exhibit anti-inflammatory activity in activated HaCaT cells.