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.