Anti-inflammatory Effect of Curcumin on UVB-induced Inflammatory Cytokines in HaCaT Cells

Cho, Jae We; Lee, Kyu Suk

Abstract

BACKGROUND
UVB irradiation induces acute inflammation through expressions of IL-6, IL-8, and TNF-alpha, in keratinocytes. Curcumin, extracted from the rhizomes of Curcuma longa, has been described as having anti-inflammatory properties; however, it still unknown as to whether curcumin inhibits the UVB-induced expressions of IL-6, IL-8, and TNF-alpha in HaCaT cell lines.
OBJECTIVE
In this study we investigated the effects of curcumin on the expression of IL-6, IL-8, and TNF-alpha in HaCaT cells, as well as the photoprotective effect of curcumin ointment in UVB-irradiated hair less mice.
METHODS
HaCaT cells were irradiated with various doses of UVB (0, 100, 200, 300 mJ/cm2). Total RNA was extracted from the cells and gene expression was confirmed by RT-PCR, EMSA, and Western blot analysis. In addition we examined whether the ointment containing curcumin prevents the photo damaging events in hairless mice.
RESULTS
UVB-irradiated HaCaT cells clearly showed an increased expression of IL-6, IL-8, and TNF-alpha in a UVB dose-dependent manner (0, 100, 200, 300 mJ/cm2). Interestingly, pretreatment of curcumin (40 uM) dramatically reduced the expressions of UVB-induced IL-6, IL-8, and TNF-alpha. In addition, activation of NF-kappaB and MAPKs (p38, JNK, ERK) by UVB were partially attenuated by pretreatment of curcumin in HaCaT cells. Furthermore, the application of ointment containing curcumin partially protected the erythema and skin atrophy in UVB-irradiated hairless nude mice.
CONCLUSION
Collectively, these results indicate that curcumin may be applied as a promising anti-inflammatory natural agent through modulation of inflammatory cytokines such as IL-6, IL-8, and TNF-alpha.