• Biomolecules & Therapeutics
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• v.29 no.1
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• pp.90-97
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• 2021

Ultraviolet B (UVB) radiation causes DNA base modifications. One of these changes leads to the generation of 8-oxoguanine (8-oxoG) due to oxidative stress. In human skin, this modification may induce sunburn, inflammation, and aging and may ultimately result in cancer. We investigated whether phloroglucinol (1,3,5-trihydroxybenzene), by enhancing the expression and activity of 8-oxoG DNA glycosylase 1 (Ogg1), had an effect on the capacity of UVB-exposed human HaCaT keratinocytes to repair oxidative DNA damage. Here, the effects of phloroglucinol were investigated using a luciferase activity assay, reverse transcription-polymerase chain reactions, western blot analysis, and a chromatin immunoprecipitation assay. Phloroglucinol restored Ogg1 activity and decreased the formation of 8-oxoG in UVB-exposed cells. Moreover, phloroglucinol increased Ogg1 transcription and protein expression, counteracting the UVB-induced reduction in Ogg1 levels. Phloroglucinol also enhanced the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) as well as Nrf2 binding to an antioxidant response element located in the Ogg1 gene promoter. UVB exposure inhibited the phosphorylation of protein kinase B (PKB or Akt) and extracellular signal-regulated kinase (Erk), two major enzymes involved in cell protection against oxidative stress, regulating the activity of Nrf2. Akt and Erk phosphorylation was restored by phloroglucinol in the UVB-exposed keratinocytes. These results indicated that phloroglucinol attenuated UVB-induced 8-oxoG formation in keratinocytes via an Akt/Erk-dependent, Nrf2/Ogg1-mediated signaling pathway.

• Biomolecules & Therapeutics
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• v.24 no.5
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• pp.529-535
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• 2016

Atopic dermatitis (AD) results from gene and environment interactions that lead to a range of immunological abnormalities and breakdown of the skin barrier. Protease-activated receptor 2 (PAR2) belongs to a family of G-protein coupled receptors and is expressed in suprabasal layers of the epidermis. PAR2 is activated by both trypsin and a specific agonist peptide, SLIGKV-$NH_2$ and is involved in both epidermal permeability barrier homeostasis and epithelial inflammation. In this study, we investigated the effect of lobaric acid on inflammation, keratinocyte differentiation, and recovery of the skin barrier in hairless mice. Lobaric acid blocked trypsin-induced and SLIGKV-$NH_2$-induced PAR2 activation resulting in decreased mobilization of intracellular $Ca^{2+}$ in HaCaT keratinocytes. Lobaric acid reduced expression of interleukin-8 induced by SLIGKV-$NH_2$ and thymus and activation regulated chemokine (TARC) induced by tumor necrosis factor-a (TNF-${\alpha}$) and IFN-${\gamma}$ in HaCaT keratinocytes. Lobaric acid also blocked SLIGKV-$NH_2$-induced activation of ERK, which is a downstream signal of PAR2 in normal human keratinocytes (NHEKs). Treatment with SLIGKV-$NH_2$ downregulated expression of involucrin, a differentiation marker protein in HaCaT keratinocytes, and upregulated expression of involucrin, transglutamase1 and filaggrin in NHEKs. However, lobaric acid antagonized the effect of SLIGKV-$NH_2$ in HaCaT keratinocytes and NHEKs. Topical application of lobaric acid accelerated barrier recovery kinetics in a SKH-1 hairless mouse model. These results suggested that lobaric acid is a PAR2 antagonist and could be a possible therapeutic agent for atopic dermatitis.

• The Korea Journal of Herbology
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• v.24 no.3
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• pp.103-108
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• 2009

Objectives : This study was carried out to investigate anti-oxidative effects of Taraxaci Herba (TH) and protective effects on Human HaCaT keratinocyte. Methods : Anti-oxidative effects were measured by estimating the amount of total phenolics and flavonoids. In addition, DPPH free radical scavenging activities were estimated. Protective effects of TH on HaCaT keratinocytes against oxidative stress induced by hydrogen peroxide were also measured. Results : In our results, treatment with TH did not show cytotoxicity on HaCaT keratinocyte beneath the concentration of 200 $\mu$g/ml. 42.64$\pm$1.90 $\mu$g/ml of total phenolics and 28.09$\pm$1.84 $\mu$g/ml of flavonoids was detected from TH ethanol extract. In addition, DPPH free radical scavenging activities of TH were elevated in dose-dependent manner. In addition, The value of half maximal inhibitory concentration (IC$_{50}$) was 165.5 $\mu$g/ml. Finally, TH showed protective effect against cell death of HaCaT cell induced by hydrogen peroxide significantly. Conclusions : In conclusion, these results suggest that TH may have anti-oxidantic action in human skin and also suggest the possibility as cosmetic material.

• Journal of Life Science
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• v.32 no.1
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• pp.44-50
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• 2022

The migration and proliferation of keratinocytes are key events in re-epithelization, itself a major phase in the wound healing process. Cuscuta japonica Choisy (CJC) is used as a traditional medicine to improve liver, heart, and intestinal function, and its extracts are reported to have various biological properties such as whitening, anti-oxidancy, and an anti-acne effect. However, it is not yet known in particular whether or not CJC essential oil (CJCEO) affects skin regeneration. In the present study, we isolated CJCEO by solvent extraction and tested its effect on wound healing responses using normal human keratinocytes, namely HaCaT cells. We found that CJCEO induced proliferation as well as migration in HaCaT cells in a dose-dependent manner. Compared with a control group, CJCEO treatment at 250 ㎍/ml increased proliferation by 239.98±5.51% in HaCaT cells in a dose and migration by 124.86±6.06%. Moreover, the oil induced sprout outgrowth and, at 250 ㎍/ml, increased collagen synthesis by 148.56±15.47% in HaCaT cells. These results demonstrate that CJCEO may promote skin regeneration and wound healing by increasing the migration, proliferation, and collagen synthesis of HaCaT cells. We therefore suggest that CJCEO could be used as a cosmetic material.

• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.385-395
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• 2020

This study examined the effect of 3,4-dihydroxytoluene (DHT) on UVB-induced photoaging and determined its molecular mechanisms, using HaCaT human keratinocytes and SKH-1 hairless mice. DHT suppressed UVB-induced matrix metalloproteinase-1 (MMP-1) expression in HaCaT cells. In vivo data from mouse skin supported that DHT decreased UVB-induced wrinkle formation, epidermal thickness, and matrix metalloproteinase-13 (MMP-13) expression. DHT appeared to exert its anti-aging effects by suppressing UVB-induced Raf-1 kinase activity and subsequent attenuation of UVB-induced phosphorylation of MEK, ERK, and p90RSK in HaCaT cells. In vitro and in vivo pull-down assays revealed that DHT bound with Raf-1 in ATP-noncompetitive manner. Overall, DHT appears to anti-photoaging effects in vitro and in vivo through the suppression of Raf-1 kinase activity and may have potential as a treatment for the prevention of skin aging.

• IMMUNE NETWORK
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• v.11 no.1
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• pp.42-49
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• 2011

Background: In this study, we have investigated the effect of Korean red ginseng (KRG) extracts on the production of TNF-${\alpha}$ and IL-8 in human keratinocytes. Also, to examine the antioxidative effect of red ginseng extracts, free radical scavenging activity and superoxide dismutase (SOD) activity in human dermal fibroblasts was measured. Methods: To investigate the effect of KRG in atopic dermatitis, we measured the level of TNF-${\alpha}$ and IL-8 secretion in LPS-stimulated human keratinocytes after the treatment of KRG extracts using enzyme-linked immunosorbent assay. Anti-oxidative activity was investigated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and SOD activity. Results: The stimulation of human keratinocytes with KRG extracts shifted the LPS-induced cytokine secretion toward a more immunosuppressive response. KRG dose-dependently decreased TNF-${\alpha}$ and IL-8 production in HaCaT cells and a significant inhibition of TNF-${\alpha}$ was shown when cells were treated with 500 and $1,000{\mu}g/ml$ of KRG extracts. Additionally, KRG extracts showed DPPH radical scavenging and SOD activity in a dose-dependent manner. Particularly, SOD activities of concentrations higher than $60{\mu}g/ml$ of KRG extracts were significantly different in human dermal fibroblast cells. Conclusion: Based on this study, KRG extracts may be a useful immunosuppressive agent in the treatment of atopic dermatitis.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.1 s.60
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• pp.17-22
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• 2007

In this study, we investigated the effects of Sedum sarmentosum extract on the expression of hyaluronan synthase (HAS) genes and hyaluronan (HA) production in HaCaT keratinocytes. We also assessed water content (electrical capacitance) and transepidermal water loss (TEWL) in human skin after topical treatment with Sedum sarmentosum extract. Sedum sarmentosum extract increased expression of HAS-2 and HAS-3 genes in HaCaT cells, when assayed by real-time reverse-transcriptase polymerase chain reactions (RT-PCR). Sedum sarmentosum extract induced HA production in HaCaT cells, when determined by enzyme-linked immunosorbent assay (ELISA). Finally, treatment of Sedum sarmentosum extract on human skin increased the skin hydration and decreased TEWL when measured using Corneometer and Tewameter. Our study suggests that Sedum sarmentosum extract should be a very useful cosmetic ingredient, as a skin moisturizer.

• Journal of Environmental Science International
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• v.29 no.3
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• pp.249-255
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• 2020

Particulate matter with an aerodynamic diameter of less than 2.5 μM (PM_2.5) is one of the major environmental pollutants. Di(2-ethylhexyl) phthalate (DEHP), an endocrine disrupting chemical in PM_2.5, has been utilized for the manufacturing of polyvinyl chloride to increase the flexibility of final products. In the present study, we investigated the ecotoxicological effect of DEHP on the viability of skin keratinocytes (HaCaT). DEHP induced apoptotic cell death mediated by phosphorylation of extracellular signal-regulated kinase through the production of intracellular Reactive Oxygen Species (ROS). Interestingly, we found that DEHP induces the phosphorylation of the nuclear factor-kappa B responsible for the expression of cleaved caspase-3 as an executional cell death protease in HaCaT cells. On the basis of these results, we suggest that DEHP in PM_2.5 induces the apoptotic death of human keratinocytes via ROS-mediated signaling events.

• IMMUNE NETWORK
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• v.10 no.2
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• pp.76-81
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• 2010

Ultraviolet B (UVB) induces multiple inflammatory and carcinogenic reactions. In skin, UVB induces to secrete several kinds of inflammatory cytokines from keratinocytes and also increases angiogenic process via the modulation of vascular endothelial growth factor (VEGF) production. Interleukin-21 (IL-21) is an inflammatory cytokine and produced by activated T cells. The biologic functions of IL-21 have not yet extensively studied. In the present study, we investigate the production of IL-21 from human keratinocyte cell line, HaCaT and its biological effect after exposure to UVB. First, we confirmed the IL-21 production and its receptor expression in HaCaT. And then, the change of IL-21 and VEGF production in HaCaT by UVB irradiation was examined. Not only IL-21 but also VEGF production was enhanced by UVB irradiation. Next, to determine relationship of enhanced production of IL-21 and VEGF, we detected VEGF production after neutralization of IL-21. VEGF production was reduced by IL-21 neutralization, which indicates that the IL-21 is involved in the VEGF production. Taken together, our results suggest that IL-21 and VEGF production is enhanced by UVB irradiation in HaCaT. In addition, it seems that IL-21 plays a role in the angiogenic process in skin via the modulation of VEGF production.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.2
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• pp.83-92
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• 2021

Purpose : Keratinocytes are the main cellular components involved in wound healing during re-epithelization and inflammation. Dysfunction of tight junction (TJ) adhesions is a major feature in the pathogenesis of various diseases. The purpose of this study was to identify the various effects of a Sparassis crispa water extract (SC) on HaCaT cells and to investigate whether these effects might be applicable to human skin. Methods : We investigated the effectiveness of SC on cell HaCaT viability using MTS. The antioxidant effect of SC was analyzed by comparing the effectiveness of ABTS to that of the well-known antioxidant resveratrol. Reverse-transcription quantitative polymerase chain reaction (qRT-PCR) is the most widely applied method Quantitative RT-PCR analysis has shown that SC in HaCaT cells affects mRNA expression of tight-junction genes associated with skin moisturization. In addition, Wound healing is one of the most complex processes in the human body. It involves the spatial and temporal synchronization of a variety of cell types with distinct roles in the phases of hemostasis, inflammation, growth, re-epithelialization, and remodeling. wound healing analysis demonstrated altered cell migration in SC-treated HaCaT cells. Results : MTS analysis in HaCaT cells was found to be more cytotoxic in SC at a concentration of 0.5 mg/㎖. Compared to 100 µM resveratrol, 4 mg/㎖ SC exhibited similar or superior antioxidant effects. SC treatment in HaCaT cells reduced levels of claudin 1, claudin 3, claudin 4, claudin 6, claudin 7, claudin 8, ZO-1, ZO-2, JAM-A, occludin, and Tricellulin mRNA expression by about 1.13 times. Wound healing analysis demonstrated altered cell migration in SC-treated HaCaT cells and HaCaT cell migration was also reduced to 73.2 % by SC treatment. Conclusion : SC, which acts as an antioxidant, reduces oxidative stress and prevents aging of the skin. Further research is needed to address the effects of SC on human skin given the observed alteration of mRNA expression of tight-junction genes and the decreased the cell migration of HaCaT cells.