• Biomolecules & Therapeutics
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• v.20 no.1
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• pp.57-61
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• 2012

The matrix metalloproteinase (MMP) family is involved in the breakdown of the extracellular matrix during normal physiological processes such as embryonic development, reproduction, and tissue remodeling, as well as in disease processes such as pathological aging, arthritis, and metastasis. Oxidative conditions generate reactive oxygen species (ROS) (e.g., hydrogen peroxide [$H_2O_2$]) in cells, which subsequently induce the synthesis of matrix metalloproteinase-1 (MMP-1). MMP-1, an interstitial collagenase, in turn stimulates an aging phenomenon. In this study, baicalein (5,6,7-trihydroxyfl avone) was investigated for its in vitro activity against $H_2O_2$-induced damage using a human skin keratinocyte model. Baicalein pretreatment signifi cantly inhibited $H_2O_2$-induced up-regulation of MMP-1 mRNA, MMP-1 protein expression and MMP-1 activity in cultured HaCaT keratinocytes. In addition, baicalein decreased the transcriptional activity of activator protein-1 (AP-1) and the expression of c-Fos and c-Jun, both components of the heterodimeric AP-1 transcription factor. Furthermore, baicalein reduced phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun-N-terminal kinase (JNK), which are upstream of the AP-1 transcription factor. The results of this study suggest that baicalein is involved in the inhibition of oxidative stress-induced expression of MMP-1 via inactivation of the ERK/JNK/AP-1 signaling pathway.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1193-1198
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• 2009

Ethylacetate and butanol fractions of leaf extracts (OLE) showed the higher contents of total phenolic compounds than hexane and water fractions. Oleuropein contents were $4.21{\pm}0.57,\;3.92{\pm}0.43,\;0.32{\pm}0.03,\;5.76{\pm}0.32$, and $32.47{\pm}0.25mg$/100g for ethanol extract, and hexane, chloroform, ethyl acetate, and butanol fraction, respectively. Treatment of ultraviolet-B (UVB) irradiated cells with 3 OLEs prepared by using ethylacetate and butanol at concentrations 0.001, 0.005, and 0.01% respectively showed significant recovery of cell viabilities. Treatment of dexametason 1 mM reduced tumor necrotic factor (TNF)-${\alpha}$ secretion by about 40%. UVB irradiated immortalized human keratinocytes (HaCaT) cells were treated with 3 different OLEs at the same concentrations. Ethylacetate fraction showed the strongest inhibition activity with respect of reduction of the elevated (TNF)-${\alpha}$. Cytotoxicity of OLEs on the B16-F1 cells was evaluated through thiazolyl blue tetrazolium bromide (MTT) assay. Ethylacetate fraction has no cytotoxicity in the range of 0.005-0.01%. A slight cytotoxicity was observed at the concentration of 0.1% butanol fraction of OLE that caused 10% decrease in cell viability.

• Molecules and Cells
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• v.42 no.2
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• pp.151-160
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• 2019

Ultraviolet (UV) radiation of the sunlight, especially UVA and UVB, is the primary environmental cause of skin damage, including topical inflammation, premature skin aging, and skin cancer. Previous reports show that activation of nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) in human skin fibroblasts and keratinocytes after UV exposure induces the expression and release of proinflammatory cytokines, such as interleukin-1 (IL-1) and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), and subsequently leads to the production of matrix metalloproteases (MMPs) and growth factor basic fibroblast growth factor (bFGF). Here, we demonstrated that TNFR2-SKEE and TNFR2-SKE, oligopeptides from TNF receptor-associated factor 2 (TRAF2)-binding site of TNF receptor 2 (TNFR2), strongly inhibited the interaction of TNFR1 as well as TNFR2 with TRAF2. In particular, TNFR2-SKE suppressed UVB- or $TNF-{\alpha}$-induced nuclear translocalization of activated $NF-{\kappa}B$ in mouse fibroblasts. It decreased the expression of bFGF, MMPs, and COX2, which were upregulated by $TNF-{\alpha}$, and increased procollagen production, which was reduced by $TNF-{\alpha}$. Furthermore, TNFR2-SKE inhibited the UVB-induced proliferation of keratinocytes and melanocytes in the mouse skin and the infiltration of immune cells into inflamed tissues. These results suggest that TNFR2-SKE may possess the clinical potency to alleviate UV-induced photoaging in human skin.

• Toxicological Research
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• v.35 no.3
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• pp.279-285
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• 2019

In this study, we investigated the therapeutic potential of Cinnamomum camphora leaves on allergic skin inflammation such as atopic dermatitis. We evaluated the effects of C. camphora leaves on human adult low-calcium high-temperature keratinocytes and atopic dermatitis mice. C. camphora leaves inhibited Macrophage-derived chemokine (an inflammatory chemokine) production in $interferon-{\gamma}$ (10 ng/mL) stimulated Human adult low-calcium high-temperature keratinocytes in a dose dependent manner. C. camphora leaves suppressed the phosphorylation of janus kinase signal transducer and activator of transcription 1. C. camphora leaves also suppressed the phosphorylation of extracellular signal-regulated kinase 1/2, a central signaling molecule in the inflammation process. These results suggest that C. camphora leaves exhibits anti-inflammatory effect via the phosphorylation of signal transducer and activator of transcription 1 and extracellular signal-regulated kinase 1/2. To study the advanced effects of C. camphora leaves on atopic dermatitis, we induced experimental atopic dermatitis in mice by applying 2,4-dinitrochlorobenzene. The group treated with C. camphora leaves (100 mg/kg) showed remarkable improvement of atopic dermatitis symptoms: reduced serum immunoglobulin E levels, smaller lymph nodes with reduced thickness and length, decreased ear edema, and reduced levels of inflammatory cell infiltration in the ears. Interestingly, the effects of C. camphora leaves on atopic dermatitis symptoms were stronger than those of hydrocort cream, a positive control. Taken together, C. camphora leaves showed alleviating effects on the inflammatory chemokine production in vitro and atopic dermatitis symptoms in vivo. These results suggest that C. camphora leaves help in the treatment of allergic inflammation such as atopic dermatitis.

• Nutrition Research and Practice
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• v.16 no.1
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• pp.1-13
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• 2022

BACKGROUND/OBJECTIVES: Bitter taste receptors are taste signaling pathway mediators, and are also expressed and function in extra-gustatory organs. Skin aging affects the quality of life and may lead to medical issues. The purpose of this study was to better understand the anti-skin aging effects of bitter taste receptors in D-galactose (D-gal)-induced aged human keratinocytes, HaCaT cells. MATERIALS/METHODS: Expressions of bitter taste receptors in HaCaT cells and mouse skin tissues were examined by polymerase chain reaction assay. Bitter taste receptor was overexpressed in HaCaT cells, and D-gal was treated to induce aging. We examined the effects of bitter taste receptors on aging by using β-galactosidase assay, wound healing assay, and Western blot assay. RESULTS: TAS2R16 and TAS2R10 were expressed in HaCaT cells and were upregulated by D-gal treatment. TAS2R16 exerted protective effects against skin aging by regulating p53 and p21, antioxidant enzymes, the SIRT1/mechanistic target of rapamycin pathway, cell migration, and epithelial-mesenchymal transition markers. TAS2R10 was further examined to confirm a role of TAS2R16 in cellular senescence and wound healing in D-gal-induced aged HaCaT cells. CONCLUSIONS: Our results suggest a novel potential preventive role of these receptors on skin aging by regulating cellular senescence and wound healing in human keratinocyte, HaCaT.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.4
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• pp.331-339
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• 2023

In this study, in vitro and clinical studies were conducted to assess the anti-inflammatory effects and skin improvement effects, including moisturizing, sebum secretion-regulating, skin barrier function enhancing, and soothing of Helianthus annuus (Sunflower) seed oil. In in vitro study using cultured human epidermal keratinocytes induced with inflammation by lipopolysaccharide, significant decreases in inflammatory cytokines interleukin-6, interleukin-8, and tumor necrosis factor alpha was revealed, indicating the anti-inflammatory effects of H. annuus (Sunflower) seed oil. Additionally, the results of clinical study on subjects with sensitive skin demonstrated improved skin hydration, regulation of sebum secretion, enhanced skin barrier function, as well as amelioration of skin redness and acne, indicating positive effects on overall skin conditions after application of H. annuus (Sunflower) seed oil containing test product for 4 weeks. Results of this study demonstrated the potential of H. annuus (Sunflower) seed oil as an ingredient for cosmetic, targeting consumers with sensitive skin.

• Journal of Biomedical Engineering Research
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• v.44 no.6
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• pp.443-449
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• 2023

The purpose of this study was to observe cell death in human keratinocytes stimulated against the infectious cytokines TNF-α and IFN-γ, and to observe the expression of Phospho-NF-κB due to phosphorylation of IkB to confirm the mechanism of inhibiting the expression of inflammatory cytokines. As a result of cell viability analysis, differences in PEMF stimulation time were observed little by little after 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours, but there was no statistical significance according to PEMF stimulation time for each time (p>0.05). No significant difference was observed in the total amount of NF-κB present in the cytoplasm and nucleus, but a significant decrease in the expression of phosphorylated NF-κB was observed in the group exposed to PEMF stimulation for 24 hours (^*p<0.05). The expression of IL-1β was observed in all inflammation-induced groups, and the concentration of IL-1β compared to α-Tubulin expression was reduced by about 54% in the PEMF-stimulated group for 24 hours compared to the control group (^***p<0.001). As a result of the study, it is shown that PEMF stimulation does not negatively affect HaCaT cells from 0 to 48 hours and can inhibit the expression of inflammatory cytokines by inhibiting the pathway of NF-κB.

• Biomedical Science Letters
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• v.6 no.2
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• pp.83-91
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• 2000

Subconfluent neonatal human epidermal keratinocytes were treated with a concentration 200 ng/$m\ell$ of human recombinant epidermal growth factor (hrEGF), human recombinant insulin-like growth factor-1 (hrIGF-1), and with a combination of hrEGF and hrIGF-1. Cytoplasmic and membrane-associated proteins were extracted and assayed. Proteins were separated by SDS-PAGE, and subjected to the western blot analysis. In the cytoplasmic fraction, the PKC concentration of keratinocyte treated with hrIGF-1 was higher than the control group, but the concentration of control group was the highest than the others in the membrane fraction. In the cytoplasmic fraction, EGF stimulated PKC-$\beta$II, -$\delta$, -$\theta$, and also stimulated PKC-$\alpha$, -$\beta$I, -$\delta$, -$\Im$ and -$\theta$ in the membrane fraction. IGF-1 stimulated PKC-$\beta$I, -$\Im$ and -$\theta$ in the cytoplasmic, PKC-$\alpha$, -$\beta$I, -$\delta$, -$\Im$, - $\varepsilon$ and -$\theta$ in the membrane. In the cells treated with a combination of EGF and IGF-1, PKC-$\alpha$, -$\beta$I, -$\Im$ and -$\theta$ in the cytoplasmic fraction, PKC-$\alpha$, -$\delta$, -$\Im$, -$\varepsilon$ and -$\theta$ in the membrane fraction were stimulated.

• Biomolecules & Therapeutics
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• v.20 no.5
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• pp.463-469
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• 2012

Atopic dermatitis is a chronic, inflammatory disease of the skin with increased transepidermal water loss. Both an abnormal inflammatory response and a defective skin barrier are known to be involved in the pathogenesis of atopic dermatitis. Protease activated receptor 2 (PAR2) belongs to a family of G-protein coupled receptors and is activated by both trypsin and a specific agonist peptide, SLIGKV-$NH_2$. PAR2 is expressed in suprabasal layers of the epidermis and regulates inflammatory responses and barrier homeostasis. In this study, we show that nordihydroguaiaretic acid (NDGA) inhibits the PAR2-mediated signal pathway and plays a role in skin barrier recovery in atopic dermatitis. Specifically, NDGA reduces the mobilization of intracellular $Ca^{2+}$ in HaCaT keratinocytes by down-regulating inflammatory mediators, such as interleukin-8, thymus and activation-regulated chemokine and intercellular cell adhesion molecule-1 in HaCaT keratinocytes. Also, NDGA decreases the protein expression of involucrin, a differentiation maker of keratinocyte, in both HaCaT keratinocytes and normal human epidermal keratinocytes. We examined NDGA-recovered skin barrier in atopic dermatitis by using an oxazolone-induced atopic dermatitis model in hairless mice. Topical application of NDGA produced an increase in transepidermal water loss recovery and a decrease in serum IgE level, without weight loss. Accordingly, we suggest that NDGA acts as a PAR2 antagonist and may be a possible therapeutic agent for atopic dermatitis.

• Journal of Periodontal and Implant Science
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• v.47 no.2
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• pp.116-131
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• 2017

Purpose: The entry of bacteria or harmful substances through the epithelial seal of human gingival keratinocytes (HGKs) in the junctional epithelium (JE) is blocked by specialized intercellular junctions such as E-cadherin junctions (ECJs). However, the influence of roughened substrates, which may occur due to apical migration of the JE, root planing, or peri-implantitis, on the development of the ECJs of HGKs remains largely unknown. Methods: HGKs were cultured on substrates with varying levels of roughness, which were prepared by rubbing hydrophobic polystyrene dishes with silicon carbide papers. The activity of c-Jun N-terminal kinase (JNK) was inhibited with SP600125 or by transfection with JNK short hairpin RNA. The development of intercellular junctions was analyzed using scanning electron microscopy or confocal laser scanning microscopy after immunohistochemical staining of the cells for E-cadherin. The expression level of phospho-JNK was assessed by immunoblotting. Results: HGKs developed tight intercellular junctions devoid of wide intercellular gaps on smooth substrates and on rough substrates with low-nanometer dimensions (average roughness $[Ra]=121.3{\pm}13.4nm$), although the ECJs of HGKs on rough substrates with low-nanometer dimensions developed later than those of HGKs on smooth substrates. In contrast, HGKs developed short intercellular junctions with wide intercellular gaps on rough substrates with mid- or high-nanometer dimensions ($Ra=505.3{\pm}115.3nm$, $867.0{\pm}168.6nm$). Notably, the stability of the ECJs was low on the rough substrates, as demonstrated by the rapid destruction of the cell junction following calcium depletion. Inhibition of JNK activity promoted ECJ development in HGKs. JNK was closely associated with cortical actin in the regulation of ECJs in HGKs. Conclusions: These results indicate that on rough substrates with nanometer dimensions, the ECJs of HGKs develop slowly or defectively, and that this effect can be reversed by inhibiting JNK.