UVB‐induced interleukin‐18 production is downregulated by tannic acids in human HaCaT keratinocytes

Abstract

Tannic acids (TAs) are believed to be the key active components in plants, and are believed to be responsible for their anti-inflammatory, anti-viral effects and chemoprevention of cancer. However, the molecular mechanisms for the action of TA are unclear. This study examined the effects of TA on cutaneous inflammation with a human keratinocyte cell line (HaCaT). Interleukin-18 (IL-18) has multiple effects upon various cells involved in inflammatory response. In this study, the IL-18 mRNA expression and protein levels were reduced by a TA pretreatment. UV radiation can trigger the induction of the p38 mitogen-activated protein kinase (MAPK)-dependent signalling cascade. Immunoprecipitation and Western blot analysis was performed to determine if TA regulate the MAPK signalling pathway. TA significantly inhibited the activation of p38 MAPK and extracellular signal-regulated protein kinases. Moreover, TA-inhibited UVB enhanced the expression of the inflammatory mediators, IL-1, IL-6, tumor necrotic factor-alpha, cyclooxygenase-2 and prostaglandin E(2) in UVB-irradiated HaCaT cells. The topical application of TA on mouse skin treated with UVB irradiation has shown that TA inhibited the formation of erythema. These findings suggest that TA has significant anti-inflammatory effects on the UVB-induced response on the skin and may be a candidate natural compound for the regulation of cutaneous inflammation.

Sargassum fulvellumProtects HaCaT Cells and BALB/c Mice from UVB-Induced Proinflammatory Responses

“…Water extract of Zingiber officinale , gingerol, and shogaol inhibited production of cytokines such as TNF- α , IL-1 β , IL-6, and IL-8 in UVB-irradiated HaCaT cells and hyperplasia, infiltration of leukocytes, and dilation of blood vessels in UVB-exposed C57BL/6 mice [3]. Tannic acids attenuated UVB-induced cutaneous inflammation in HaCaT cells by inhibiting UVB-enhanced expression of cytokines including TNF- α , IL-1 β , IL-6, and IL-18 [21]. …”

Candida albicans phospholipomannan triggers inflammatory responses of human keratinocytes through Toll‐like receptor 2

“…Our results are consistent with the results of the previous study that PLM trigger the activation of NF‐κB in J774 mouse macrophage‐like cells (21). It has been reported that p38MAPK and its downstream signal mediators including MAPK signal‐integrating kinase 1 and eukaryotic initiation factor 4E play important roles in the expression of pro‐inflammatory cytokines in human keratinocytes (42,43). PLM also triggered the p38MAPK phosphorylation.…”

Hydrocaffeic andp-coumaric acids, natural phenolic compounds, inhibit UV-B damage in WKD human conjunctival cellsin vitroand rabbit eyein vivo

“…Accordingly, Andley et al [46] found a 121-fold increase in PGE 2 in the aqueous humour after irradiating rabbit eyes with 2800 J/m 2 . In cell culture studies 5 mM tannic acids decrease PGE 2 concentration in keratinocytes exposed to 100 J/m 2 UV-B [47]. Eye drops containing HCAF, even at the lowest dose used, decreased PGE 2 production in the aqueous humour.…”