Curcumin attenuates the expression of IL-1ß, IL-6, and TNF-α as well as cyclin E in TNF-α-treated HaCaT cells; NF-κB and MAPKs as potential upstream targets

Abstract

. TNF-· induces some proinflammatory cytokines including IL-1ß, IL-6, IL-8, and itself by activation of NF-κB or MAPKs (p38, JNK, ERK). These cytokines play important roles in various inflammatory skin diseases, such as psoriasis. Recently it was also reported that expression of cyclin E is upregulated by ERK pathway after TNF-· treatment. However, it was unknown whether curcumin, showing inhibitory effects on NF-κB and MAPKs, attenuates the expression of TNF-·- induced IL-1ß, IL-6, IL-8, and TNF-· as well as cyclin E expression in HaCaT cells. In this study, we investigated the inhibitory effect of curcumin on expression of proinflammatory cytokines and cyclin E in TNF-·-treated HaCaT cells. We found that curcumin inhibited the expression of TNF-·-induced IL-1ß, IL-6, and TNF-·, but not IL-8, in TNF-·-treated HaCaT cells as well as the TNF-·-induced cyclin E expression. In addition, curcumin inhibited the activation of MAPKs (JNK, p38 MAPK, and ERK) and NF-κB in TNF-·-treated HaCaT cells. Taken together, curcumin exerts anti-inflammatory and growth inhibitory effects in TNF-·-treated HaCaT cells through inhibition of NF-κB and MAPK pathways.