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Quercetin and its derivatives have anti-inflammatory and anti-oxidant effects. However, the effect of quercetin-3-O-(2″-galloyl)-α-l-rhamnopyranoside (QGR), a new quercetin derivative, on the tumor necrosis factor (TNF)-α-stimulated production of inflammatory mediators in keratinocytes is unclear. In addition, the effect of QGR on the ERK and NF-κB-mediated inflammatory process has not been studied. In human keratinocyte HaCat cells, we investigated the effect of QGR on the TNF-α-stimulated production of inflammatory mediators in relation to the nuclear factor (NF)-κB, which regulates the transcription genes involved in immune and inflammatory responses. QGR inhibited the TNF-α-stimulated production of cytokines and chemokines in HaCaT cells. QGR, dexamethasone, cyclosporine A, Bay 11-7085 (an inhibitor of NF-κB activation) and cell signaling ERK inhibitor attenuated the TNF-α-induced formation of inflammatory mediators and activation of the NF-κB and ERK. Unlike other compounds, dexamethasone and cyclosporine A did not reduce formation of reactive oxygen species. The results show that QGR may attenuate TNF-α-stimulated inflammatory mediator production in HaCaT cells by suppressing the activation of the ERK-mediated NF-κB pathway that is mediated by reactive oxygen species. Additionally, QGR may exhibit a preventive effect against the proinflammatory mediator-induced skin diseases by inhibiting the activation of the ERK and NF-κB pathways., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Particulate matter (PM) is known to have harmful effects on human health. Epidemiological studies have suggested that PM exposure is related to skin diseases and extrinsic skin ageing. However, the mechanisms by which PM affects skin are unclear. The aim of this study was to investigate the mechanism of action of PMs on epidermal inflammation and skin ageing using a co‐culture of human keratinocytes (HaCaT) and fibroblasts (HDF). SRM 1648a (pmA) and 1649b (pmB), which mainly comprise heavy metals and polycyclic aromatic hydrocarbons, respectively, were used as reference PMs. Cytotoxic effects, activation of AhR, phosphorylation of p38 kinase and ROS generation were examined in PM‐treated HaCaT cells. The phosphorylation of p38 MAPK induced by PMs was shown to be critically important for the increases in IL‐1α and IL‐1β expression. Moreover, the mRNA and protein expression levels of MMP1 and COX2 were markedly increased in HDF cells co‐cultured with PM‐treated HaCaT cells. In conclusion, PMs induce the expression of pro‐inflammatory cytokines in keratinocytes via the p38 MAPK pathway, and these interleukins increase the expression of MMP1 and COX2 in HDF cells. These results suggest that PMs trigger skin ageing via p38 MAPK activation and interleukin secretion in epidermal keratinocytes. [ABSTRACT FROM AUTHOR]

Adiponectin plays important roles in metabolic function, inflammation and multiple biological activities in various tissues. However, evidence for adiponectin signaling in sebaceous glands is lacking, and its role remains to be clarified. This study investigated the role of adiponectin in lipid production in sebaceous glands in an experimental study of human sebocytes. We demonstrated that human sebaceous glands in vivo and sebocytes in vitro express adiponectin receptor and that adiponectin increased cell proliferation. Moreover, based on a lipogenesis study using Oil Red O, Nile red staining and thin layer chromatography, adiponectin strongly upregulated lipid production in sebocytes. In three-dimensional culture of sebocytes, lipid synthesis was markedly enhanced in sebocytes treated with adiponectin. This study suggested that adiponectin plays a significant role in human sebaceous gland biology. Adiponectin signaling is a promising target in the clinical management of barrier disorders in which sebum production is decreased, such as in atopic dermatitis and aged skin. [ABSTRACT FROM AUTHOR]

Recent studies have revealed that adiponectin can suppress cellular inflammatory signaling pathways. This study aimed to elucidate the effect of adiponectin on the unregulated production of hBD2 in UVB-induced premature senescent keratinocytes. We constructed an in vitro model of premature senescent keratinocytes through repeated exposure to low energy UVB. After repeated low energy UVB exposure, there was significant generation of reactive oxygen species (ROS) and induction of senescence-associated markers, including senescence associated beta-galactosidase activity and expression of p16INK4a and histone H2AX. In addition, the present clinical study showed higher expression of hBD2 in sun-exposed skin of elderly group, and the overexpression of hBD2 was observed by c-Fos activation in vitro. Adiponectin has the ability to scavenge ROS and consequently inhibit MAPKs and SA-markers in UVB-exposed keratinocytes. An inhibitor study demonstrated that adiponectin downregulated hBD2 mRNA expression through suppression of the AP-1 transcription factor components c-Fos via inactivation of p38 MAPK. Collectively, the dysregulated production of hBD2 by the induction of oxidative stress was attenuated by adiponectin through the suppression of p38 and JNK/SAPK MAPK signaling in UVB-mediated premature senescent inducible conditions. These results suggest the feasibility of adiponectin as an anti-photoaging and anti-inflammatory agent in the skin. [ABSTRACT FROM AUTHOR]

Atopic dermatitis ( AD) is a complicated skin condition influenced by genetic background and environmental factors. In this study, we applied Dermatophagoides farinae body extract ( Df E) to the barrier-disrupted skin of NC/ Nga mice twice a week for 8 weeks to identify the clinical and immunological factors in AD progression. Repeated application of the Df E to the skin of NC/ Nga mice showed the similar consequences for the natural course of progression in human AD, histologically and immunologically. We confirmed that the AD-like skin lesions in NC/ Nga mice did not last for the whole period of our experiment in spite of repeated topical applications of Df E twice a week. Topical Df E stimulation increased the skin m RNA expressions of Th1-, Th2- and Th17-related cytokines in the acute phase. The expression patterns of IL-4 and IL-13 in splenic T cells and skin lesions were consistent with the time course alterations of clinical features of AD-like skin symptoms. We also showed that there was a remission phase either just before or right after the chronic phase in this experimental model. Interestingly, splenic T-cell-derived IL-5 expression began to increase in the chronic phase, while skin-derived IL-5 m RNA expression increased in the acute phase. In conclusion, our results suggest that we should pay attention to the characteristics of each stage of AD progression and choose a suitable corresponding stage of animal model not only to elucidate the pathogenesis of AD but also to develop and evaluate therapeutic drugs for AD. [ABSTRACT FROM AUTHOR]

Microbial products, including lipopolysaccharides, may be involved in the pathogenesis of inflammatory skin diseases. We examined the effect of hirsutenoxime on the Toll-like receptor 4-mediated activation of Akt and nuclear factor (NF)-κB in lipopolysaccharide-stimulated keratinocytes. Hirsutenoxime, a cell signaling Akt inhibitor, and Bay 11-7085, an inhibitor of NF-κB activation, attenuated the lipopolysaccharide-induced expression of Toll-like receptor 4, activation of NF-κB and Akt, and the production of chemokines and reactive oxygen/nitrogen species. Hirsutenoxime may reduce the Toll-like receptor 4 expression-mediated NF-κB activation, which is regulated by the Akt pathway in keratinocytes exposed to lipopolysaccharides. This effect may reduce the skin inflammatory response. [ABSTRACT FROM AUTHOR]

Background Quercetin-3- O -(2″-gallate)-α-l-rhamnopyranoside (QGR) is a new quercetin derivative which is isolated from the leaves of Acer ginnala Maxim, a native plant of Korea. Quercetin has several biological effects including antioxidative, anti-inflammatory, and anti-allergic effects. However, the topical effect of QGR on atopic dermatitis (AD) like skin lesion in NC/Nga mice has not been studied. Objective To evaluate the anti-inflammatory and anti-allergic effect of QGR in a murine model of atopic dermatitis. Methods We measured inducible nitric oxide synthase (iNOS) and cyclooxygenase -2(COX-2) level in RAW264.7 cell with QGR treatment. And after induction of AD like skin lesions with Dermatophagoides farina (Df) ointment, mice were treated with QGR and control drugs. Clinical scores, interleukin (IL) 4, 5, and 13, serum IgE, eosinophil levels, iNOS and COX-2 level were evaluated. Results Results show that mRNA level of iNOS and COX-2 in vitro were decreased after QGR treatment. Topical QGR markedly decreased the iNOS and COX-2 mRNA expressions in the skin. QGR also significantly suppressed the increase in the level of total plasma IgE and eosinophils. In addition, topical application of QGR down-regulated the expressions of the cytokines, IL-4,5 and 13, which were induced by Df ointment stimulation. Conclusions In the present study, we showed that topical application of QGR ameliorated Df-induced AD-like inflammatory responses in NC/Nga mice. These results demonstrate that QGR might be beneficial in the treatment of AD. [ABSTRACT FROM AUTHOR]

Abstract: Aim of the study: The bark of Alnus species has long been used in traditional oriental medicine in the treatment of many pathological conditions, including fever, hemorrhage, diarrhea, alcoholism, various skin diseases (e.g. chronic herpes, eczema and prurigo), and inflammation. In order to assess the immunomodulatory efficacy of a novel herbal medicine in treating atopic dermatitis, we measured serum levels of several allergic and inflammatory biomarkers in NC/Nga mice before and after treatment with this experimental agent. Materials and methods: Gene and protein expression analyses of iNOS and COX-2 were quantified by real time PCR and Western blot analysis and serum levels of IL-4, -5 and -13 were also measured by ELISA, all of which were reduced after treatment with the experimental agent. Additionally, serum concentrations of IgE and blood eosinophil counts were reduced in treated mice. Results: The topical application of leaf and bark extract from Alnus japonica suppressed the development of AD-like skin lesions. The percent of blood eosinophils was decreased after treatment with leaf and bark extract from Alnus japonica. The serum IgE and Th2-related cytokine levels were decreased after treatment with leaf and bark extract from Alnus japonica compared with those treated with base cream (vehicle treated AD group). The IL-4, IL-5 and IL-13 were lower than those of vehicle treated AD group. Conclusions: We contend that leaf and bark extract from Alnus japonica may prove useful in the treatment of atopic dermatitis and other allergic skin diseases, although more in-depth clinical studies are necessary before clinical implementation. [Copyright &y& Elsevier]