• Korean Journal of Environmental Agriculture
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• v.3 no.1
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• pp.63-70
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• 1984

The terrestrial UV flux rapidly increased in late spring, as measured by the chemical actinometry at two elevations (near sea level and 1,100m above sea level) on Jeju Island. More intense UV fluxes were observed at higher altitudes. Any harmful effects of solar UV-B on the growth of soybean were not detected in UV-B-exclusion experiment. To ascertain the effect of UV radiation on vegetative growth, intact (㏖ wt 124000) and large (${\sim}120000$) phytochromes were irradiated with UV-B radiation. In intact phytochrome, the Pfr form accounts for 60% of the total phytochrome under stationary state conditions, whereas it accounts for 50% in large phytochrome. Calculated quantum yields for the forward and the backward phototransformations of phytochrome by UV were ${\phi}r=0.016$ and ${\phi}fr=0.010$ in intact phytochrome, and ${\phi}r={\phi}fr=0.012$ in large phytochrome, respectively.

• Biomolecules & Therapeutics
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• v.12 no.3
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• pp.157-164
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• 2004

DA-3711 is a novel anti-wrinkle agent containing growth factors derived from culture medium of artificial human skin. Photoprotective effect by DA-3711 against chronic UVB (ultraviolet B)-induced skin damage was investigated in hairless mice model. Methods: After hairless mice were irradiated to induce photodamage for 8 weeks with UVB, grouped mice were treated topically once a day with lotion base, DA-3711 (30% or l5%), Cylasphere retinol$^{\circed{R}}$ (2500 I.U.), NouriCel$^{\circed{R}}$ along with concomitant exposure to UVB for further 8 weeks. Then mice were sacrificed to assess photodamage-protective effect by replica analysis, biochemistry and histology. DA-3711 of 30% lotion significantly reduced UVB radiation-induced wrinkling, histological alterations and increased collagen contents. Whereas DA-3711 of l5% lotion and NouriCel$^{\circed{R}}$ treatment showed a partial protective effect on skin wrinkle, epidermal and dermal thickness, and collagen content, Cylasphere retinol$^{\circed{R}}$ showed no protective effects. These results demonstrate that topical application of DA-3711 can alleviate UVB-induced photodamage and potentially be used for reduction of UVB-induced photodamage.

• Toxicological Research
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• v.28 no.4
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• pp.241-248
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• 2012

Exposure of cells to ultraviolet B (UVB) radiation can induce production of free radicals and reactive oxygen species (ROS), which damage cellular components. In addition, these agents can stimulate the expression of matrix metalloproteinase (MMP) and decrease collagen synthesis in human skin cells. In this study, we examined the anti-photoaging effects of extracts of Tetraselmis suecica (W-TS). W-TS showed the strongest scavenging activity against 2,2-difenyl-1-picrylhydrazyl (DPPH) and peroxyl radicals, followed by superoxide anions from the xanthine/xanthine oxidase system. We observed that the levels of both intracellular ROS and lipid peroxidation significantly increased in UVB-irradiated human skin fibroblast cells. Furthermore, the activities of enzymatic antioxidants (e.g., superoxide dismutase) and the levels of non-enzymatic antioxidants (e.g., glutathione) significantly decreased in cells. However, W-TS pretreatment, at the maximum tested concentration, significantly decreased intracellular ROS and malondialdehyde (MDA) levels, and increased superoxide dismutase and glutathione levels in the cells. At this same concentration, W-TS did not show cytotoxicity. Type 1 procollagen and MMP-1 released were quantified using RT-PCR techniques. The results showed that W-TS protected type 1 procollagen against UVB-induced depletion in fibroblast cells in a dose-dependent manner via inhibition of UVB-induced MMP-1. Taken together, the results of the study suggest that W-TS effectively inhibits UVB-induced photoaging in skin fibroblasts by its strong anti-oxidant ability.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.7
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• pp.980-986
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• 1999

This study was done to ivestigate the fabrics thatminimized harmfulness of UVB(ultraviolet B) and that might product Vit. {{{{ {D }`_{3 } ^{ } }} by UVB. Twelve female subjects wearing in three different types i.e fabric A(UVB 100% protection) fabric B(UVB 50% protection) and bikinii were exposed to outdoor environment (Air Temp : 25℃, 42% R,H Air velocity : 0.13m/s UV does :6KJ/m2) Blood samples were taken 24 hours before the after the experiment in order to examine concentration of vit.{{{{ {D }`_{3 } ^{ } }} in the blood. During the experiment axillary temperature skin temperature of 7 areas(forehead Chest Upper arm, Hand Thigh Lower leg, Foot) were measured. The more irradiated areas by UVB were the more the concentration of serum 25(OH){{{{ {D }`_{3 } ^{ } }} were significantly. Mean skin temperature was significantly low levekl in wearing the fabric of UVB 50% protection (p<0.001) Axillary temperature was significantly high level in wearing the fabric of UVB 50% protection (p<0.001). Therefore the fabric of UVB 50% protection intercepts the radiation and has advantage to give off body heat over other fabrics

• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.309-313
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• 2000

To investigate the effects of different UV-B levels on growth and biochemical defense response in plants, cucumber plants were subjected to three levels of biologically effective ultraviolet-B $(UV-B_{BE})$ radiation [daily dose: 0.03 (No), 6.40 (Low) and $11.30\;(High)\;kJ{\cdot}m^{-2}$, $UV-B_{BE}$] in the growth chambers for 3 weeks during the early growth period. Enhanced UV-B radiation drastically decreased both dry weight and leaf area of cucumber. With increasing UV-B intensity, chlorophyll content was decreased, however the level of malondialdehyde was highly increased linearly. Total contents of ascorbic acid and glutathione were tended to increase by UV-B, while the ratios of dehydroascorbate/ascorbate and oxidized glutathione/reduced glutathione were significantly increased with increasing UV-B intensity in cucumber. All the enzyme activities investigated (superoxide dismutase, ascorbate peroxidase, dehydroascorbate reductase, guaiacol peroxidase etc.) in cucumber were increased by the UV-B enhancement. These results suggested that enhanced UV-B irradiation caused photooxidative stress in cucumber plant and resulted in significant reduction in plant growth. Biochemical protection responses might be activated to prevent the leaves from damaging effects of oxidative stress generated by UV-B irradiation.

• Journal of Microbiology and Biotechnology
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• v.31 no.7
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• pp.990-998
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• 2021

Melanin is a natural skin pigment produced by specialized cells called melanocytes via a multistage biochemical pathway known as melanogenesis, involving the oxidation and polymerization of tyrosine. Melanogenesis is initiated upon exposure to ultraviolet (UV) radiation, causing the skin to darken, which protects skin cells from UVB radiation damage. However, the abnormal accumulation of melanin may lead to the development of certain skin diseases, including skin cancer. In this study, the antioxidant and antimelanogenic activities of the cell-free supernatant (CFS) of twenty strains were evaluated. Based on the results of 60% 2,2-diphenyl-1-picrylhydrazyl scavenging activity, 21% 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) scavenging capacity, and a 50% ascorbic acid equivalent ferric reducing antioxidant power value, Limosilactobacillus fermentum JNU532 was selected as the strain with the highest antioxidant potential. No cytotoxicity was observed in cells treated with the CFS of L. fermentum JNU532. Tyrosinase activity was reduced by 16.7% in CFS-treated B16F10 cells (but not in the cell-free system), with >23.2% reduction in melanin content upon treatment with the L. fermentum JNU532-derived CFS. The inhibitory effect of the L. fermentum JNU532-derived CFS on B16F10 cell melanogenesis pathways was investigated using quantitative reverse transcription polymerase chain reaction and western blotting. The inhibitory effects of the L. fermentum JNU532-derived CFS were mediated by inhibiting the transcription of TYR, TRP-1, TRP-2, and MITF and the protein expression of TYR, TRP-1, TRP-2, and MITF. Therefore, L. fermentum JNU532 may be considered a potentially useful, natural depigmentation agent.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.4
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• pp.341-350
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• 2015

Skin carrys out protective role against harmful outer environment assaults including ultraviolet radiation, heavy metals and oxides. Especially, ultraviolet-B (UVB) light causes inflammatory reactions in skin such as sun burn and erythma and stimulates melanin pigmentation. Furthermore, the influx of UVB into skin cells causes DNA damage in keratinocytes and dermal fibroblasts, inhibition of extracellular matrix (ECM) synthesis which leads to a decrease in elasticity of skin and wrinkle formation. It also damages dermal connective tissue and disrupts the skin barrier function. Prolonged exposure of human skin to UVB light is well known to trigger severe skin lesions such as cell death and carcinogenesis. Haloarcula vallismortis is a halophilic microorganism isolated from the Dead Sea, Its growth characteristics have not been studied in detail yet. It generally grows at salinity more than 10%, but the actual growth salinity usually ranges between 20 to 25%. Because H. vallismortis is found mainly in saltern or salt lakes, there could exist defense mechanisms against strong sunlight. One of them is generation of additional ATP using halorhodopsin which absorbs photons and produces energy by potential difference formed by opening the chloride ion channel. It often shows a color of pink or red because of their high content of carotenoid pigments and it is considered to act as a defense mechanism against intense UV irradiation. In this study, the anti-inflammatory effect of the halophilic microorganism, H. vallismortis, extract was investigated. It was found that H. vallismortis extract had protective effect on DNA damage induced by UV irradiation. These results suggest that the extract of halophilic bacterium, H. vallismortis could be used as a bio-sunscreen or natural sunscreen which ameliorate the harmful effects of UV light with its anti-inflammatory and DNA protective properties.

• 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.

• Natural Product Sciences
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• v.18 no.1
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• pp.60-66
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• 2012

Human skin is the first line of defense for the protection of the internal organs of the body from different stimuli. Ultraviolet B (UVB) irradiation induces skin damage and inflammation through the secretion of various cytokines, which are immune regulators produced by cells. To prevent the initiation of skin inflammation, keratinocytes that have been irreversibly damaged by radiation must be removed through the apoptotic mechanism. Ixeris dentata (family: Asteraceae) is a perennial medicinal herb indigenous to Korea. It has been used in Korea, China, and Japan to treat in digestion, pneumonia, diabetes, hepatitis, and tumors. To gain insight into the anti-inflammatory effects of I. dentata, we examined its influence on UVB-induced pro-inflammatory cytokine production in human keratinocytes (HaCaT cells), by observing cells that were stimulated with UVB in the presence or absence of I. dentata. In the present study, pro-inflammatory cytokine production was determined by performing enzyme-linked immunosorbent assay, reverse transcription polymerase chain reaction, and western blot analysis to measure the activation of mitogen-activated protein kinase (MAPKs). I. dentata inhibited UVBinduced production of the pro-inflammatory cytokine interleukin (IL)-6 in a dose-dependent manner. Further, I. dentata inhibited the UVB-induced expression of cyclooxygenase (COX)-2. Furthermore, I. dentata inhibited the phosphorylation of c-Jun NH2-terminal kinase and p38 MAPKs, suggesting that it inhibits the secretion of the pro-inflammatory cytokines IL-6 and IL-8, and COX-2 expression, by blocking MAPK phosphorylation. These results suggest that I. dentate can potentially protect against UVB-induced skin inflammation.

• Journal of the Korean Applied Science and Technology
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• v.39 no.5
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• pp.644-651
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• 2022

The skin is the largest organ of the human body and protects the inside of the body. Ultraviolet rays cause various inflammatory reactions in the skin, including photoaging and oxidative damage. The purpose of this study is to investigate the protective effect of Saponaria extract by irradiating UVB on fibroblasts. In this study, the effectiveness of Saponaria showing protective activity against UVB-induced cytotoxicity, oxidative cell death, and NO and PGE₂ production was evaluated. HS68 cells were irradiated with UVB(120 mJ/cm²) and treated with Saponaria extract at various concentrations of 100, 200, and 400 ㎍/mL for 24 hours. Intracellular reactive oxygen species (ROS) generated by ultraviolet B were detected using a spectrofluorometer after DCF-DA staining. Lipid peroxidation was also analyzed by measuring the level of 8-isoprostane secreted into the culture medium. As a result, treatment with Saponaria extract effectively inhibited UVB-induced cytotoxicity. Oxidative cell damage was mediated by PGE₂ in UVB-induced HS68 fibroblasts, which was significantly inhibited by Saponaria extract treatment. In addition, it was evaluated that the protective effect of these extracts was mediated by the inhibition of intracellular ROS production and lipid peroxidation in a concentration-dependent manner. These results suggest that Saponaria extract can be used as an anti-aging functional material because it inhibits skin damage mediated by oxidative stress caused by UVB and exhibits a cellular protective effect.