3,4,5­Trihydroxycinnamic acid exerts anti­inflammatory effects on TNF­α/IFN­Î³­stimulated HaCaT cells.

3,4,5­Trihydroxycinnamic acid (THCA) exhibits anti­inflammatory activity in acute or chronic inflammatory disorders, such as acute lung injury and asthma. The present study investigated the anti­inflammatory activity of THCA in a tumor necrosis factor­α/interferon­Î³ (TI) mixture­stimulated human keratinocyte cell line. The results of ELISA and reverse transcription­quantitative PCR revealed that THCA reduced the secretion and mRNA expression levels of interleukin (IL)­6; IL­8; thymus and activation­regulated chemokine; macrophage­derived chemokine; regulated upon activation, normal T cell expressed and secreted; and monocyte chemoattractant protein­1 in TI mixture­stimulated HaCaT cells. In addition, the results of western blot analysis demonstrated that THCA exerted inhibitory activity on the activation of AKT, ERK and nuclear factor­κB in TI mixture­stimulated HaCaT cells. Furthermore, THCA upregulated the expression levels of heme oxygenase­1 and NAD(P)H:quinone oxidoreductase 1, and the activation of nuclear factor erythroid 2­related factor 2 in HaCaT cells. These results demonstrated that THCA may exhibit anti­inflammatory activity in activated HaCaT cells.