Curcumin attenuates the expression of IL-1β, 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.

Modulation of inflammatory signaling pathways by phytochemicals in ovarian cancer

“…EF24, a synthetic analog of curcumin, blocked the nuclear translocation of NF-jB and inhibited TNF-a-induced I-jB degradation through direct inhibition of IKK activity [30]. Since NF-jB is also a transcription factor for inflammatory cytokines, curcumin has been demonstrated to attenuate the expression of IL-1, IL-6, and TNF-a [11]. Curcumin increased the sensitivity of SKOV3 and CAOV3 cells to cisplatin, and one of the suggested mechanisms was reducing the production of IL-6 [9].…”

Curcumin as “Curecumin”: From kitchen to clinic

“…In experiments with ex vivo cultured BALB/c mouse peritoneal macrophages, curcumin reduced the production of iNOS mRNA in a concentration-dependent manner. Finally, curcumin appears to be able to exert anti-inflammatory and growth-inhibitory effects on cancer cells by inhibiting the expression of interleukin 1b (IL-1b), interleukin 6 (IL-6), and tumor necrosis factor-a (TNF-a) on the one hand and cyclin E on the other [80,81].…”

Curcumin: an orally bioavailable blocker of TNF and other pro‐inflammatory biomarkers

“…Secondly, when curcumin was tested as an anti-psoriatic drug in the modified mouse tail test, an animal model of psoriasis, it exhibited some activity (Bosman, 1994). Thirdly, curcumin has been shown to inhibit the proliferation of human keratinocytes through suppression of pro-inflammatory pathways (Pol et al, 2003;Cho et al, 2007). Curcumin inhibited the expression of TNF-a-induced IL-1b, IL-6, TNF-a, cyclin E, MAPKs (JNK, p38 MAPK and ERK) and NF-kB in HaCaT cells.…”