• Journal of Photoscience
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• v.9 no.2
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• pp.217-220
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• 2002

Ultraviolet B (UVB) radiation may activate or deteriorate cultured human epidermal melanocytes, depending on the doses and culture conditions. In this study, we examined whether apoptosis of melanocytes can be induced by physiologic doses of UVB irradiation. PI staining for DNA condensation and flow cytometric analyses demonstrated the apoptotic cell death of melanocytes after UVB irradiation. The level of p53 and Bax revealed a dose-dependent increase with increasing dose of UVB, but the level of Bcl-2 remained unchanged. Confocal microscopic examination showed that Bax moved trom a diffuse to a punctate distribution after UVB irradiation. However, there were no changes in the pattern of Bcl-2. We next examined the downstream targets of apoptosis. Our results showed that a precursor form of caspase-3 disappeared with increasing doses of UVB. We also observed cleavage of poly(ADP-ribose) polymerase (PARP) after UVB irradiation. In addition, UVB irradiation resulted in a remarkable activation of c-Jun N-terminal kinase (JNK). These results indicate that UVB may induce apoptosis via JNK activation in human melanocytes.

• Journal of the Korean Ceramic Society
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• v.47 no.2
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• pp.169-176
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• 2010

The Fe-treated CNT/$TiO_2$ photocatalysts mixed with anatase and rutile phase have been developed for the decomposition of non-biodegradable different organic dyes like methylene blue (MB), rhodamine B (Rh.B), and methyl orange (MO) in two conditions as ultraviolet and visible light respectively. The results indicate that all the Fe-CNT/$TiO_2$ composites proved to be more efficient photocatalysts since degradation of MB at higher reaction rates, tthe decomposition rate of different dyes increases with an increase of $Fe^{3+}$ concentration in composites the highest rate of decomposition of different dyes was noted under UV irradiation. These results can indicate that the large CNT network is facilitate the electron transfer and strongly adsorb dye molecules on the texted photocatalysts, iron is reactive in the photo-Fenton process resulting in high production of OH radicals and also high activity of the photocatalyst. And Fe particles can generate more photoinduced electrons to conduction band of $TiO_2$ under visible light irradiation. The composites of Fe-CNT/$TiO_2$ photocatalysts synthesized by a sol-gel method were characterized by BET, TEM, SEM, XRD and EDX.

• Biomolecules & Therapeutics
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• v.18 no.3
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• pp.300-307
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• 2010

Photosensitized peroxidation of membrane lipids has been implicated in skin pathologies such as phototoxicity and premature aging. We have previously reported that syriacusin compounds isolated from Hibiscus Syriacus inhibited lipid peroxidation. Here, we investigated whether syriacusins could be effective inhibitor to skin aging using ultraviolet-irradiated human dermal fibroblast cells (HDFCs). Syriacusins A, B, and C inhibit the activity of human neutrophil elastase (HNE), a serine protease to degrade extracellular matrix (ECM) proteins including elastin, with $IC_{50}s$ of 8.0, 5.2, and $6.1\;{\mu}M$, respectively. No changes in cell viability were detected by syriacusins A and B in UV-B ($10\;mJ/cm^2$) irradiated HDFCs. Matrix metallo-proteinase (MMP)-1 expression in HDFCs was increased by UV-B irradiation. MMP-1 expression in UV-B irradiated HDFCs was decreased by $10\;{\mu}M$ and $20\;{\mu}M$ syriacusin A to 50% and 20% of untreated control, respectively. Syriacusin B treated with $20\;{\mu}M$ reduced MMP-1 expression in UV-B irradiated HDFCs to 60% of untreated control. Syriacusin A also inhibited MMP-2 expression accompanying the increase of type-I pro-collagen in UV-B irradiated HDFCs. These results demonstrate that syriacusin A could be a more effective compound to inhibit skin aging caused by UV irradiation. It suggests that syriacusins A and B might be developed as possible agents to treat or prevent skin aging.

• YAKHAK HOEJI
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• v.39 no.6
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• pp.585-592
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• 1995

Soil microorganisms producing immunomoduators that can restore ultraviolet B (UVB) radiation-induced suppression of the immune response were screened in vitro. Exposure of freshly isolated murine epidermal cells (EC) to $180{\;}J/m^{2}$ of UVB radiation resulted in approximately 90% impairtnent of accessory cell function, as measured by their ability to support anti-CD3 monoclonal antibody-induced T-cell mitogenesis. When the culture supenmtants of 150 actinomycete strains were exanuned for their capacity to prevent or repair the UVB-induced impairment of accessory cell function, 4 of them were identified to contain immunomodulators that can restore the decreased accessory cell finiction. The soil isolate that showed the most effective restorative activity, G40025. was selected and fturther characters Addition of 10.mu.l of the culture supernatant of G40025 grown in G-media to cultures of UVB-irradiated EC right after UVB-irradiation restored the decreased accessory cell function by 58%. The immunomodtdator produced by G40025 appeared to be stable at 100.deg. C for 10 min. Taxonomical studies by cultural, morphological, and physiological characterization showed that the soil isolate, G40025, belongs to the genus Streptomyces.

• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.466-472
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• 2019

This study was conducted to investigate anti-photoaging effects of collagen hydrolysate containing collagen tripeptides (CTP) in both HaCaT cells and SKH-1 hairless mice. CTP treatment was nontoxic to HaCaT cells and improved expression of biomarkers associated with aging of skin, such as, collagen 1A, metalloproteinase (MMP)-1, and MMP-13 after subjecting mice to ultraviolet B (UVB) irradiation. In animal studies, the depth and width of wrinkles in the skin of mice were determined upon subjecting them to UVB irradiation. However, positive effects on wrinkles on the skin of mice were seen following CTP supplementation. Collagen content and density of mouse skin were restored following CTP supplementation for 14 weeks after UVB irradiation. These results were based on the effects of CTP on protein levels of collagen 1A, MMP-1, and MMP-13. Therefore, CTP might have positive effects on the number, depth, and width of wrinkles caused by UVB irradiation in SKH-1 hairless mice.

• Journal of Radiation Protection and Research
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• v.36 no.2
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• pp.93-98
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• 2011

We induced the activation of melanocytes in the epidermis of C57BL/6 mice by ultraviolet-B (UV-B) irradiation, and observed the effect of an herbal preparation (HemoHIM, HH) on the formation, and decrease of UV-B-induced epidermal melanocytes. C57BL/6 mice were irradiated by UV-B $80\;mJ{\cdot}cm^{-2}$ ($0.5\;mW{\cdot}sec^{-1}$) daily for 7 days, and HH was intraperitoneally, orally 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 13~15 melanocytes${\cdot}mm^{-2}$, and one week after UV irradiation, the applied areas showed an increased number of strongly DOPA-positive melanocytes with stout dendrites. But intraperitoneal, oral or topical treatment with HH before each irradiation interrupted UV-B-induced pigmentation and resulted in a marked reduction in the number of epidermal melanocytes as compared to the number found in UV-B-irradiated, untreated 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 HH at 3rd and 6th weeks after irradiation. The present study suggests the HH as inhibitor of UV-B-induced pigmentation, and depigmenting agent.

• Journal of Environmental Health Sciences
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• v.33 no.2 s.95
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• pp.123-131
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• 2007

Many environmental contaminants including several metals, polycyclic aromatic hydrocarbons, and pharmaceuticals, have been identified to be phototoxic in the water environment. Concerns regarding photo-enhancement of toxicity of several environmental contaminants have been increasing because of the increased level of ultraviolet irradiation on the earth surface. However, there exist arguments that there might be certain defense mechanisms taking place in the aquatic ecosystem, which may include behavioral characteristics or genetic acclimation. This study was conducted to understand the potential responses of aquatic receptors to several phototoxic metals in the real environment, where long-term acclimation of such organisms to low dose UV-B may take place. For this purpose, water flea Daphnia magna was acclimated to environmentally relevant dose of UV-B (12 to $18uW/cm^2$) for >11 generations. The differences in developmental and life history characteristics, and toxicity responses were evaluated. Acclimation did not affect the daphnids' growth, longevity, and reproduction characteristics such as time to first brood, and brood size: After 21 d, survival of D. magna was not influenced by UV-B acclimation. When the number of young per female was compared. the daphnids acclimated for 11 generations tend to produce less number of neonates than the un-acclimated individuals but with no statistical significance (p>0.05). Four metals that were reported to be phototoxic elsewhere were employed in this evaluation, that include As, Cd. Cu, and Ni. UV-B level being applied in acclimation did increase the toxicity of Cd and Cu, significantly (p<0.05). However, the toxicities of As and Ni were not affected by irradiation of UV-B. Phototoxic responses were evaluated between the acclimated and the un-acclimated daphnids. For Cu, UV-B acclimation led to reduction of the photo-induced toxicity $(p\approx0.1)$ in daphnids. Non-acclimated Daphnia were affected by 50% at 4.18 ug/l Cu. but UV-B acclimated individuals exhibited $EC_{50}$ of 5.89 ug/l. With Cd, UV-B acclimation appeared to increase phototoxicity (p>0.05). With As and Ni, UV-B acclimation did not influence photo-induced toxicity. This observation may be in part explained by the type of reactive oxygen species that were generated by each metal. Similar to UV-B light, Cu is known to generate superoxide anion by acting as redox cycling toxicant. This is one of the first studies that employed_laboratory based UV-B acclimated test species for photoenhanced toxicity evaluation.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.1
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• pp.70-82
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• 2008

Objective : The purpose of this study is to examine the effects of Baickbujasan(BB) on the skin damage and depigmentation. Method : The inhibition of tyrosinase activity, melanogenesis and cell viability in cultured B16 melanoma cells were measured. In order to test effects of reduction of melanogenesis, B16 F-10 mouse melanoma stem line was employed to extract melanin from cultured cell, where BB was added or not, and was dissolved in alkali for colorimetric analysis. Also, in order to test skin alteration in C57BL/6 after UV irradiation, the animals were grouped into a UV urradiation group and UV irradiation after BB application group. Dopa oxidase tissue staining was excuted to invesitage the change in the distribution of active melanin cell. The distribution of active melanin cell in inner skin of iNOS after damage from UVB irradiation and the manifestation condition of P53 which takes part in natural death of keratinocyte were examined. Result : The results indicate that BB has significant effects on tyrosinase activity, and melanogenesis in vivo test. BB seems to reduce C57BL/6, external dermatological damage, for instance, erythematous papule, eczema, loss of keratinocyte, reduction in pus, and relieves dermatological damages. Conclusion : BB can be applied externally for UV protection and depigmentation.

• 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 Environmental Health Sciences
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• v.32 no.6
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• pp.566-570
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• 2006

Exposure to ultraviolet B(UVB) radiation causes skin inflammation such as pigmentation and the induction of cyclooxygenase-2(COX-2) gene expression. In this study, we investigated the effect of natural extracts from Tea, EGb 761 and Korean red ginseng(KRG), on the pigmentation and expression of COX-1 and COX-2 mRNA in UVB-irradiated C57BL/6 mice. Before UVB irradiation, the skin color was significantly showed the lightening effect by topical application of natural compounds (p<.05). In the case of UVB irradiated mice, we observed a decrease in pigmentation by compounds (p<.05). In irradiated skin, COX-1 mRNA expression is not changed following UVB irradiation, but COX-2 gene increases. Also, natural compounds lowered mRNA levels of COX-2. Therefore, these results suggest that COX-2 mRNA increases by UVB irradiation. Also, Tea, EGb 761 and KRG as a topical application may inhibit skin pigmentation and modulate COX-2 mRNA level.