• 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.

• Journal of Life Science
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• v.27 no.3
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• pp.310-317
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• 2017

Mammalian cells control cellular homeostasis using a variety of defensive enzymes in order to combat against environmental oxidants and electrophiles. NF-E2-related factor-2 (NRF2) is a transcription factor that, in response to an exposure to oxidative stress, translocates into the nucleus and modulates the inducible expression of various phase II cytoprotective enzymes by binding to the antioxidant response element (ARE). In the present study, we have acquired 400 ethanol extracts of traditional medicinal plants and attempted to find out possible extract(s) that can increase the NRF2/ARE-dependent gene expression in human keratinocytes. As a result, we have identified that ethanol extracts of Rheum undulatum and Inula japonica strongly activated the ARE-dependent luciferase activity in HaCaT- ARE-luciferase cells. Exposure of ethanol extracts of Rheum undulatum and Inula japonica increased the viability and activated transcription and translation of NRF2-dependent phase II cytoprotective enzymes in HaCaT cells, such as heme oxygenase-1 (HO-1) and NAD[P]H:quinone oxidorecutase-1 (NQO1). In addition, ethanol extracts of Rheum undulatum and Inula japonica suppressed 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced generation of intracellular reactive oxygen species (ROS), thereby inhibiting the formation of 8-hydroxyguanosine (8-OHG) and 4-hydroxynonenal (4-HNE) in HaCaT cells. Together, our results demonstrate that ethanol extracts of Rheum undulatum and Inula japonica exert anti-oxidant effects via the induction of NRF2/ARE-dependent gene expression in human keratinocytes.

• Biomolecules & Therapeutics
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• v.21 no.5
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• pp.349-357
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• 2013

6'-O-galloylpaeoniflorin (GPF) is a galloylated derivate of paeoniflorin and a key chemical constituent of the peony root, a perennial flowering plant that is widely used as an herbal medicine in East Asia. This study is the first investigation of the cytoprotective effects of GPF against hydrogen peroxide ($H_2O_2$)-induced cell injury and death in human HaCaT keratinocytes. GPF demonstrated a significant scavenging capacity against the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical, $H_2O_2$-generated intracellular reactive oxygen species (ROS), the superoxide anion radical ($O_2^-$), and the hydroxyl radical (${\cdot}$OH). GPF also safeguarded HaCaT keratinocytes against $H_2O_2$-provoked apoptotic cell death and attenuated oxidative macromolecular damage to DNA, lipids, and proteins. The compound exerted its cytoprotective actions in keratinocytes at least in part by decreasing the number of DNA strand breaks, the levels of 8-isoprostane (a stable end-product of lipid peroxidation), and the formation of carbonylated protein species. Taken together, these results indicate that GPF may be developed as a cytoprotector against ROS-mediated oxidative stress.

• Archives of Pharmacal Research
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• v.24 no.4
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• pp.307-311
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• 2001

The activation of NF-$\kappa$B induced by kojic Acid, an inhibitor of tyrosinase for biosynthesis of melanin in melanocytes, was investigated in human transfectant HaCaT and SCC-13 cells. These two keratinocyte cell lines transfected with pNF-$\kappa$B-SEAP-NPT plasmid were used to determine the activation of NF-$\kappa$B. Transfectant cells release the secretory alkaline phosphatase (SEAP) as a transcription reporter in response to the NF-$\kappa$B activity and contain the neomycin phosphotransferase (NPT) gene for the dominant selective marker of geneticin resistance. NF-$\kappa$B activation was measured in the SEAP reporter gene assay using a fluorescence detection method. Kojic Acid showed the inhibition of cellular NF-$\kappa$B activity in both human keratinocyte transfectants. It could also downregulate the ultraviolet ray (UVR)-induced activation of NF-$\kappa$B expression in transfectant HaCaT cells. Moreover, the inhibitory activity of kojic Acid in transfectant HaCaT cells was found to be more potent than known antioxidants, e.g., vitamin C and N~acetyl-L-cysteine. These results indicate that kojic Acid is a potential inhibitor of NF-$\kappa$B activation in human keratinocytes, and suggest the hypothesis that NF-$\kappa$B activation may be involved in kojic Acid induced anti-melanogenic effect.

• Food Science and Preservation
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• v.31 no.2
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• pp.307-314
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• 2024

Broussonetia kazinoki twig extract (BKT) is recognized for its antioxidant and anti-cancer effects and natural whitening properties. So, it is used as a raw material for cosmetics. B. kazinoki twig is also an edible raw material. B. kazinoki has been used in Asia for paper production and oriental medicine, has anti-diabetic effects, and contains various flavonoids and alkaloids. In this study, to evaluate the efficacy of BKT on allergic skin inflammatory responses, we investigated its effects on factors related to skin inflammation in HaCaT keratinocytes and allergic responses in RBL-2H3 cells. There was no cytotoxicity of the 70% ethanol extract against HaCaT and RBL-2H3 cells. In HaCaT cells, stimulation with tumor necrosis factor-alpha (TNF-𝛼) and interferon-gamma (IFN-𝛾) increased the production of several chemokines, including thymus and activation-regulated chemokine (TARC), macrophage-derived chemokine (MDC), and regulated on activation, normal T cell expressed and secreted (RANTES). However, it was observed that this elevation was notably mitigated in a concentration-dependent manner upon treatment with BKT. Furthermore, BKT treatment demonstrated a significant reduction of 𝛽-hexosaminidase and inflammatory cytokines TNF-𝛼 and IL-4 in IgE-sensitized RBL-2H3 cells. Thus, it is expected that BKT can be used as a natural cosmetic and food ingredient that effectively suppresses allergic inflammatory reactions.

• The Korea Journal of Herbology
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• v.28 no.4
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• pp.57-62
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• 2013

Objectives : Lonicerae Japonicae Flos (LJF) has been shown anti-oxidant, anti-inflammatory, anti-viral, anti-rheumatoid properties. However, it is still largely unknown whether LJF inhibits skin injury against oxidative stress in human keratinocyte, HaCaT cells. The purpose of this study was to evaluate the protective effects of LJF against hydrogen peroxide($H_2O_2$)-induced oxidative stress in human keratinocytes, HaCaT cells. Methods : To evaluate out the protective effects of LJF on oxidative injury in HaCaT cells, an oxidative stress model of HaCaT cells was established under a suitable concentration (500 ${\mu}M$) hydrogen peroxide. HaCaT keratinocyte cells were pre-treated with LJF (0.1, 0.25 or 0.5 mg/ml), and then stimulated with $H_2O_2$. Then, the cells were harvested to measure the cell viability, DNA damage, and release of reactive oxygen species (ROS). Results : LJF (0.1, 0.25 or 0.5 mg/ml) itself did not show any significant toxicity in HaCaT cells. The treatment of $H_2O_2$ caused the oxidative stress, leading to the cell death, and DNA injury. However, pretreatment with LJF reduced cell death, and DNA injury. The stimulation of $H_2O_2$ on HaCaT cells resulted in excessive release of ROS, which is the main factor of oxidative stress. The excessive release of ROS was inhibited by LJF treatment significantly. Conclusions : These results could suggest that LJF exhibited the protective effects of HaCaT cells against $H_2O_2$-induced oxidative stress by inhibiting ROS release. It could be explained that LJF inhibit skin damages against oxidative stress. Thus, LJF would be useful for the development of drug or cosmetics treating skin troubles.

• The Korea Journal of Herbology
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• v.34 no.1
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• pp.51-57
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• 2019

Objectives : Nypa fruticans Wurmb. (NF) have been used as a traditional medicine to treat inflammatory diseases in East-South Asia. However, it is largely undiscovered whether NF water extract could exhibit anti-inflammatory activities against tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$)-induced inflammatory responses on human keratinocytes, HaCaT cells. Therefore, this study was aimed to investigate the anti-inflammatory activity of NF water extract on TNF-${\alpha}$-induced inflammatory responses in HaCaT cells. Methods : To investigate the anti-inflammatory activites of NF water extract in HaCaT cells, the inflammatory model of HaCaT cells was established under a suitable concentration (10 ng/ml) of human TNF-${\alpha}$ (hTNF-${\alpha}$). HaCaT keratinocyte cells were pre-treated with NF water extract for 1 h, and then stimulated with hTNF-${\alpha}$. Then, the cells were harvested to measure the inflammatory mediators such as inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and prostaglandin $E_2$ ($PGE_2$), and pro-inflammatory cytokine including TNF-${\alpha}$ and interleukin (IL)-6. In addition, we examined the inhibitory mechanisms of NF, mitogen activated protein kinases (MAPKs) and inhibitory kappa B alpha ($I{\kappa}-B{\alpha}$) Results : The treatment of NF inhibited the hTNF-${\alpha}$-induced elevation of iNOS, COX-2, and $PGE_2$ in HaCaT cells. In addition, NF treatment inhibited the hTNF-${\alpha}$-induced elevation of TNF-${\alpha}$ and IL-6. Furthermore, NF treatment inhibited the activation of MAPKs but not degradation of $I{\kappa}-B{\alpha}$. Conclusions : Taken together, our result suggest that treatment of NF could inhibit the hTNF-${\alpha}$-induced inflammatory responses via deactivation of MAPKs in HaCaT cells. This study could suggest that NF could be a beneficial agent to prevent skin damage or inflammation.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.20 no.1 s.32
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• pp.27-37
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• 2007

Background and Objective : Psoriasis is a chronic skin disease characterized by angiogenesis. It has been reported that growth factor as vascular endothelial growth factor (VEGF) and insulin-like growth factor (IGF)-II are overexpressed in psoriatic epidermis. This stydy was carried out for whether SB extracts have an anti-angiogenic effect for angiogenic factor. Method : To investigate the inhibitory effect of VEGF expression by the SB extracts, we performed MTS assay, western blots using HaCaT cells. HaCaT cells were pretreated with SB extracts for 1 hour followed by treatment with IGF-II. Result : SB extracts significantly reduced IGF-II induced HIF-1 ${\alpha}$ protein level via p53 and MAPK pathway in HaCaT cells. Also, SB extracts inhibited IGF-II induced VEGF mRNA and protein expression levels in the HaCaT keratinocytes. Conclusion : These results suggest that inhibition of HIF-1 ${\alpha}$ and VEGF expressions by SB extracts contributes to the anti-angiogenic effects.

• International Journal of Oral Biology
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• v.39 no.2
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• pp.97-105
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• 2014

The aim of this study was to determine the beneficial effect of propofol on human keratinocytes that have undergone hypoxia reoxygenation (H/R) injury and to investigate whether autophagy is associated with the protective mechanism. Thus, we evaluated how propofol influences the intracellular autophagy and apoptosis during the H/R process in the HaCaT cells. The cultured human keratinocyte cells were exposed to 24 h of hypoxia (5% $CO_2$, 1% $O_2$, 94% $N_2$) followed by 12 h of reoxygenation (5% $CO_2$, 21% $O_2$, 74% $N_2$). The experiment was divided into 4 groups: (1) Control=Normoxia ; (2) H/R=Hypoxia Reoxygenation ; (3) PPC+H/R=Propofol Preconditioning+Hypoxia Reoxygenation; (4) 3-MA+PPC+ H/R=3-MA-Methyladenine+Propofol Preconditioning+ Hypoxia Reoxygenation. In addition, Western blot analysis was performed to identify the expression of apoptotic pathway parameters, including Bcl-2, Bax, and caspase 3 involved in mitochondrial-dependent pathway. Autophagy was determined by fluorescence microscopy, MDC staining, AO staining, and western blot. The H/R produced dramatic injuries in keratinocyte cells. In our study, the viability of Propofol in H/R induced HaCaT cells was first studied by MTT assay. The treatment with 25, 50, and $100{\mu}M$ Propofol in H/R induced HaCaT cells enhanced cell viability in a dose-dependent manner and $100{\mu}M$ was the most effective dose. The Atg5, Becline-1, LC3-II, and p62 were elevated in PPC group cells, but H/R-induced group showed significant reduction in HaCaT cells. The Atg5 were increased when autophagy was induced by Propofol, and they were decreased when autophagy was suppressed by 3-MA. These data provided evidence that propofol preconditioning induced autophagy and reduced apoptotic cell death in an H/R model of HaCaT cells, which was in agreement with autophagy playing a very important role in cell protection.

• BMB Reports
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• v.47 no.10
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• pp.581-586
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• 2014

Epidermal growth factor (EGF) is known to play key roles in skin regeneration and wound-healing. Here, we demonstrate that Pep2-YAC, a tripeptide covering residues 29-31 in the B loop of EGF, promotes the proliferation of HaCaT keratinocytes with activity comparable to EGF. The treatment of HaCaT cells with Pep2-YAC induced phosphorylation, internalization, and degradation of EGFR and organization of signaling complexes, which consist of Grb2, Gab1, SHP2, and PI3K. In addition, it stimulated the phosphorylation of ERK1/2 at Thr 202/Tyr 204 and of Akt1 at Ser 473 and the nuclear translocation of EGFR, STAT3, c-Jun, and c-Fos. These results suggest that Pep2-YAC may be useful as a therapeutic agent for skin regeneration and wound-healing as an EGFR agonist.