• Archives of Pharmacal Research
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• v.28 no.7
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• pp.784-790
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• 2005

In this study, we evaluate the effects of (-)-epigallocatechin-3-gallate (EGCG) on ultraviolet B(UVB)-irradiated living skin equivalents (LSEs). Histologically, UVB irradiation induced thinning of the LSE epidermis, whereas EGCG treatment led to thickening of the epidermis. Moreover, EGCG treatment protected LSEs against damage and breakdown caused by UVB exposure. Immunohistochemically, UVB-exposed LSEs expressed p53, Fas, and 8-hydroxy-deoxyguanosine (8-OHdG), all of which are associated with apoptosis. However, EGCG treatment reduced the levels of UVB-induced apoptotic markers in the LSEs. In order to determine the signaling pathways induced by UVB, Western blot analysis was performed for both c-Jun $NH_2$-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK), which are associated with UVB-induced oxidative stress. UVB activated JNK in the epidermis and dermis of the LSEs, and EGCG treatment reduced the UVB-induced phosphorylation of JNK. In addition, p38 MAPK was also found to have increased in the UVB-exposed LSEs. Also, EGCG reduced levels of the phosphorylation of UVB-induced p38 MAPK. In conclusion, pretreatment with EGCG protects against UVB irradiation via the suppression of JNK and p38 MAPK activation. Our results suggest that EGCG may be useful in the prevention of UVB-induced human skin damage, and LSEs may constitute a potential substitute for animal and human studies.

• Journal of Photoscience
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• v.9 no.2
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• pp.482-484
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• 2002

UV irradiation activates various intracellular signaling pathways causing cell death in a DNA damage-dependent and an independent manner. As DNA photoproducts, major forms of DNA damage, are maximally formed by UV light at 260-nm, short wavelength UV (UVC) is more harmful than middle wavelength UV (UVB). However, the differences or similarities in responses of DNA damage-independent intracellular signaling molecules to UVB and UVC are not elucidated. We examined activation of signaling molecules towards apoptosis in normal human fibroblastic cells after irradiation with UVB or UVC at a dose generating the equal amount of DNA photoproducts. Both UVB and UVC induced transient phosphorylation of ERK and sustained phosphorylation of p38. Phosphorylation of p53 at Ser15 and at Ser392 residues were also observed, which were inhibited by a phosphoinositide 3-kinase inhibitor, wortmannin. In contrast, an antioxidant N-acetyl-cysteine and a p38 inhibitor SB203580 suppressed only Ser392 phosphorylation, suggesting that UV-induced oxidative stress and p38 activation were involved in the phosphorylation of this site. The apoptic signals such as mitochondrial cytochrome C release and annexin V binding were then observed. Overall, no difference was found in chronological responses of p53, MAPK, and apoptosis between UVB-irradiated and UVC-irradiated cells. These results suggested that DNA damage-independent intracellular signaling molecules similarly responded to UVB and UVC when the equal level of DNA photoproducts were generated.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.5
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• pp.520-529
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• 2014

The purpose of this study is to investigate the protective effects of Yukmijiwhang-tang(YM) water extracts against the UVB irradiation on the human keratinocyte HaCaT cells. We observed the effects of YM on the oxidative stress, gene expression of pro-inflammatory cytokine such as TNF-${\alpha}$ and IL-$1{\beta}$, and matrix metalloproteinase-9 in UVB-irradiated HaCaT cells. On the effects of oxidative stress and antioxidant function on the treatment with YM, The activity of xanthine oxidase(XO) was significantly decreased by treatment of YM in all the concentrations(p<0.01). The activity of superoxide dismutase(SOD) and catalase(CAT) was significantly increased by treatment of YM in a dose dependent manner(p<0.05 and p<0.01). DPPH radical was erased by treatment of YM under dose of $500{\mu}g/m{\ell}$ concentration. Treatment of HaCaT cells with YM had also significantly reduced intracellular ROS produced by UVB irradiation in a dose dependent manner(p<0.05, p<0.01, p<0.001). Gelatin zymography assay showed that YM downregulated the MMP-9 activity in UVB-irradiated HaCaT cells. RT-PCR analysis revealed that YM suppressed the expression of IL-$1{\beta}$ and MMP-9 however, it has no effects on the expression of TNF-${\alpha}$ and MMP-3. Our study suggests that Yukmijiwhang-tang exert protective actions on the UVB-irradiated HaCaT cells largely by anti-oxidative and anti-inflammatory processes.

• 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.

• Biomolecules & Therapeutics
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• v.22 no.4
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• pp.301-307
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• 2014

Fucodiphlorethol G (6'-[2,4-dihydroxy-6-(2,4,6-trihydroxyphenoxy)phenoxy]biphenyl-2,2',4,4',6-pentol) is a compound purified from Ecklonia cava, a brown alga that is widely distributed offshore of Jeju Island. This study investigated the protective effects of fucodiphlorethol G against oxidative damage-mediated apoptosis induced by ultraviolet B (UVB) irradiation. Fucodiphlorethol G attenuated the generation of 2, 2-diphenyl-1-picrylhydrazyl radicals and intracellular reactive oxygen species in response to UVB irradiation. Fucodiphlorethol G suppressed the inhibition of human keratinocyte growth by UVB irradiation. Additionally, the wavelength of light absorbed by fucodiphlorethol G was close to the UVB spectrum. Fucodiphlorethol G reduced UVB radiation-induced 8-isoprostane generation and DNA fragmentation in human keratinocytes. Moreover, fucodiphlorethol G reduced UVB radiation-induced loss of mitochondrial membrane potential, generation of apoptotic cells, and active caspase-9 expression. Taken together, fucodiphlorethol G protected human keratinocytes against UVB radiation-induced cell damage and apoptosis by absorbing UVB radiation and scavenging reactive oxygen species.

• Applied Chemistry for Engineering
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• v.31 no.2
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• pp.220-225
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• 2020

Hair is made of proteins containing various amino acids. Ultraviolet (UV) radiation is believed to be responsible for the most damaging effects of sunlight, and also plays an important role in hair aging. The purpose of this study was to investigate the changes in morphological and chemical structures after ultraviolet B (UVB) irradiation of human hair. The UVB-irradiated hair showed characteristic morphological and structural changes, compared to those of the normal hair. The result from a scanning electron microscope (SEM) equipped with an energy dispersive X-ray diffractometer (EDX) showed that the scale of UV-irradiated hair appeared to be rough and the amount of oxygen element was higher than that of the normal hair. Fluorescence and three dimensional (3D) topographical images were obtained by a confocal laser scanning microscope (CLSM). In 3D images, the green emission intensity of normal hair was much higher than that of fluorescing UVB-irradiated hair. The intensity of green emission reflects the intrinsic fluorescence of hair protein. Also, a fluorescent imaging method using fluorescamine reagent was used to identify the free amino groups resulting from a peptide bond breakage in UVB-irradiated hair. Strong blue fluorescence of UVB-irradiated hair, which indicates a very high level of amino groups, was observed by CLSM. Therefore, the fluorescamine as an extrinsic fluorescence could provide a useful tool to identify the peptide bond breakage in UVB-irradiated hair. Infrared image mapping was also employed to assess the cross-sections of normal and UVB-irradiated specimens to examine the oxidation of disulfide bonds. The degree of peak areas with strong absorbance for the disulfide mono-oxide was spread from the outside to the inside of hair. The spectroscopic techniques used alone, or in combination, launch new possibilities in the field of hair cosmetics.

• Journal of Radiation Protection and Research
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• v.32 no.2
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• pp.59-64
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• 2007

We induced the activation of melanocytes in the epidermis of C57BL/6 mice by ultraviolet B (UVB) irradiation and observed the effect of bamboo (Phyllostachys nigra var. henenis Strapf) leaf extract (BLE) on the formation, and decrease of UVB-induced epidermal melanocytes. C57BL/6 mice were irradiated by $UVB\;80mJ/cm^2(0.5mW/sec)$ daily for 7 days, and BLE was intraperitoneally or topically applied pre-or post-irradiation. For the estimation of change of epidermal melanocytes, light microscopic observation with dihydroxyphenylalanine (DOPA) stain was performed. Split epidermal sheets prepared from the ear of untreated mice exhibited 11-16 $melanocytes/mm^2$, and one week after UV irradiation, the applied areas show an increased number of strongly DOPA-positive melanocytes with stout dendrites. But intraperitoneal or topical treatment with BLE before each irradiation interrupted UVB-induced pigmentation and resulted in a marked reduction in the number of epidermal melanocytes as compared to radiation control skin. The number and size of DOPA-positive epidermal melanocytes were also significantly decreased in intraperitoneally injected or topically applicated group after irradiation with BLE at 3rd and 6th weeks after irradiation. The results of present study indicate that BLE is likely to be useful as inhibitor of UVB-induced pigmentation and depigmenting agent.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.1
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• pp.42-46
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• 2010

This study was performed to investigate anti-wrinkle effects of Acanthopanax senticosus (AS) on ultraviolet B (UVB)-induced photoaging with wrinkle formation. AS extract showed higher DPPH radical scavenging activity (3 ${\mu}g/mL$ as $IC_{50}$) and collagenase inhibition (1.52 mg/mL as $IC_{50}$) than those of ascorbic acid (50 ${\mu}g/mL$ and 2.17 mg/mL, respectively). Cell proliferation and type I pN collagen synthesis were increased by 11.4% and 96.4%, respectively, compared with non treatment control. In vivo, SKH-1 hairless mice were administrated AS 400 mg/kg for 10 weeks with UVB irradiation three times a week. After 10 weeks, a visual assessment and replica assay were performed on each mouse. According to visual assessment of close-up photos and skin replica, oral administration of A. senticosus affected on inhibition of wrinkle formation caused by UVB irradiation on the skin of mice as compared to the vehicle treated control mice. These results indicated that A. senticosus could protect skin wrinkle formation caused by collagen synthesis of fibroblast cells and photo-irradiation of UVB in hairless mice.

• Journal of Nutrition and Health
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• v.49 no.6
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• pp.429-436
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• 2016

Purpose: Solar ultraviolet (UV) radiation causes inflammation and matrix metalloproteinase (MMP) overexpression and extracellular matrix depletion, leading to skin photoaging such as wrinkle formation, dryness, and sagging. Activation of MMP is influenced by various molecules such as reactive oxygen species (ROS), proinflammatory cytokines, and transient receptor potential vanilloid type (TRPV)-1, which are increased in UV-irradiated skin cells. Aralia elata (AE) ethanolic extract was reported to inhibit ROS generation caused by UVB-irradiation in keratinocytes. In this study, we investigated the photoprotective effect of AE ethanolic extract on UVB-irradiated human keratinocytes (HaCaT) and human dermal fibroblasts (HDF). Methods: AE was freeze-dried, extracted in 70% ethanol, and concentrated. Skin cells were treated with AE extract for 24 h and then exposed to UVB ($55mJ/cm^2$). After 48 h of incubation, proinflammatory cytokines, MMP-1, type-1 procollagen, and TRPV-1 levels were measured by ELISA or Western blotting. Results: Treatment with AE extract ($100{\mu}g/mL$) significantly inhibited UVB-induced IL-6, IL-8, and $PGE_2$ production in HaCaT by 25.6%, 5.3%, and 70.2%, respectively, and also inhibited elevation of MMP-1 and TRPV-1 caused by UVB irradiation by 20.0% and 41.9%, respectively (p < 0.05). In HDF, AE extract treatment significantly inhibited both elevation of MMP-1 and reduction of type-1 procollagen caused by UVB irradiation (p < 0.05). In addition, type-1 procollagen was elevated by AE extract treatment in normal HDFs (p < 0.05). Conclusion: AE 70% ethanol extract has photoprotective ability via reduction of proinflammatory mediators, TRPV-1 and MMP-1 production, and elevation of collagen synthesis. Our findings suggest that AE extract might be a good natural material to protect against UVB-induced premature skin aging.

• Environmental Analysis Health and Toxicology
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• v.24 no.4
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• pp.351-357
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• 2009

To investigate the alleviative effects of jujube water extract (JWE) on the inflammation and skin barrier damage, both the irradiation of UVB and the application of squalene monohydroperoxide (Sq-OOH) were applied to the back skin of experimental animals for 4 weeks. And at the same time experimental materials were applied topically. Six weeks female SKH-1 hairless mice were divided into five groups (five animals for each group) including normal (N; saline), control (C; UVB+Sq-OOH+saline), vehicle control (VC; UVB+Sq-OOH+vehicle), positive control (PC; UVB+Sq-OOH+0.01% retinoic acid) and experimental (E; UVB+Sq-OOH+JWE) groups. The skin erythema index in the E group was significantly low compared to the C group (p<0.05). Lipid (p<0.05) and water (p<0.01) capacities in the E group were significantly high compared to the C group. In comparison with the C group, E group showed a relatively well preserved lipid lamellae in the epidermis and a relatively much less infiltration of mast cells in the dermis or hypodermis. As for the both absolute and relative weights of the spleen, PC group were significantly higher than the other groups. These results suggest that JWE have a considerably inhibitory effect on the inflammation and the skin barrier damage induced by UVB irradiation and Sq-OOH application.