• Biomolecules & Therapeutics
• /
• v.24 no.1
• /
• pp.75-84
• /
• 2016

This study was designed to investigate the cytoprotective effect of rosmarinic acid (RA) on ultraviolet B (UVB)-induced oxidative stress in HaCaT keratinocytes. RA exerted a significant cytoprotective effect by scavenging intracellular ROS induced by UVB. RA also attenuated UVB-induced oxidative macromolecular damage, including protein carbonyl content, DNA strand breaks, and the level of 8-isoprostane. Furthermore, RA increased the expression and activity of superoxide dismutase, catalase, heme oxygenase-1, and their transcription factor Nrf2, which are decreased by UVB radiation. Collectively, these data indicate that RA can provide substantial cytoprotection against the adverse effects of UVB radiation by modulating cellular antioxidant systems, and has potential to be developed as a medical agent for ROS-induced skin diseases.

• Journal of Life Science
• /
• v.8 no.3
• /
• pp.272-278
• /
• 1998

To investigate the effects of different UV-B levels on plant growth, cucumber plants were subjected to three levels of biologically effective ultraviolet-B(UV--$B^{BE}$ radiation [daily dose : 0.03(No UV-B), 6.40(Low UV-B) and 11.30 (High UV-B) kJ $m^{-2}$, UV--$B^{BE}$] in the growth chambers for 3 weeks during the early growth period. High and low levels of UV-B irradiation drastically decreased both dry weight and leaf area, but increased specific leaf weight of cucumber. Plants subjected to UV-B resulted in 30% and 20% reduction of photosynthesis rate by high and low UV-B, respectively. However, respiration rate was not affected by the UV-B. With increasing UV-B intensity, total chlorophyll contents were decreased linearly, while the contents of flavonoid were increased linearly. These results suggest that the present levels of UV-B may affect the growth of cucumber plant compared with a UV-B-free condition. It is likely that the growth of cucumber will be affected by enhanced UV-B due to ozone depletion in the near future.

• Korean Journal of Food Science and Technology
• /
• v.29 no.2
• /
• pp.355-361
• /
• 1997

This study was carried out to investigate the acute cutaneous enzymatic antioxidant activity of green tea extracts (GTE) on hairless mice skin after a signal exposure to ultraviolet B radiation. GTE has been in corporated at concentration of 5, 25, 50 and $100\;{\mu}g$ into hairless mice skin. Under exposure conditions of $1.0\;joule/cm^{2}$, impairment of cutaneous enzymatic activity was observed. Catalase and glutathione reductase were significantly influenced in dose-dependent manner by GTE, however glutathione peroxidase and superoxide dismutase were not affected. To measure inhibition effect of the GTE on lipoxygenase. $50\;{\mu}g$ GTE extract was added in vitro to arachidonis acid. GTE showed higher inhibition effect on 5-hydroxyeicosatetraenoic acid (HETE) and 8-HETE than metalolic products of 12- or 15-HETE. The addition of 5, 25, 50 and $100\;{\mu}g$ GTE inhibited the metabolite formation of 5-HETE by 32, 52, 62 and 80%, respectively, and the metabolite formation of 8-HETE by 36, 47, 70 and 84%, respectively.

• Korean Journal of Pharmacognosy
• /
• v.34 no.2 s.133
• /
• pp.156-160
• /
• 2003

$NF-{\kappa}B$ (nuclear factor-kappa B) plays a particularly central role in epidermal biology. It has been established that ultraviolet radiation (UVR) is one of the mechanisms to induce the activation of $NF-{\kappa}B$ in human skin. We previously demonstrated that melanogenic inhibitors may act through the inhibition of $NF-{\kappa}B$ activation in keratinocytes. In order to find another type of melanogenic inhibitors of $NF-{\kappa}B$ activation, various kinds of the extracts from crude drugs $(30\;{\mu}g/ml)$ were preincubated with transfectant HaCaT cells for 3 hrs and then UVR $(60\;mj/cm^2)$ was irradiated. UVR-exposed cells were incubated for another 6 hrs to measure the $NF-{\kappa}B$ activity. $NF-{\kappa}B$ activation was measured with the secreatory alkaline phosphates (SEAP) reporter gene assay using a fluorescence detection method. Among natural products, Lycium chinense, Acanthopanax senticosus, Angelica koreana, Kalopanax pictus and Asparagus cochinchinensis were the most potent inhibitors of $NF-{\kappa}B$ activation by UVR. These observations suggest that some crude drugs might act partially through the modulation of the synthesis of melanotrophic factors to decrease melanogenesis in keratinocytes.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2007.11a
• /
• pp.244.1-244.1
• /
• 2007

• Journal of Ginseng Research
• /
• v.30 no.4
• /
• pp.188-193
• /
• 2006

We induced the activation of melanocytes in the epidermis of C57BL/6 mice by ultraviolet B (UVB) irradiation and observed the effect of red ginseng (RG) on the formation, and decrease of UVB-induced epidermal mel-anocytes. C57BL/6 mice were irradiated by UVB $80mJ/cm^2$ (0.5 mW/sec) daily for 7 days, and RG 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 RG 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 mel-anocytes were also significantly decreased in intraperitoneally injected or topically applicated group after irradiation with RG at 3rd and 6th weeks after irradiation. The present study suggests the RG as inhibitor of UVB-induced pigmentation and depigmenting agent.

• Korean Journal of Agricultural Science
• /
• v.41 no.4
• /
• pp.275-281
• /
• 2014

The ozone depletion has caused plants to be exposed to an increased penetration of solar ultraviolet-B (UV-B) radiation. Enhanced UV-B radiation may have influence on biological functions of plant in many aspects including inhibition of photosynthesis. It is evident that UV-B can potentially impair the performance of all three main component processes of photosynthesis, the photophosphorylation reactions of the thylakoid membrane, the $CO_2$-fixation reactions of the Calvin cycle and stomatal control of $CO_2$ supply. Owing to these depressed reactions, the production and allocation of carbohydrates might be markedly affected, and therefore, the growth and development of plant are distinctly reduced. In this review paper, we provide basic theory and further researches in terms of photosynthesis and carbohydrate synthesis in response to elevated UV-B radiation.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.47 no.2
• /
• pp.90-98
• /
• 2023

The human eye, constantly exposed to solar radiation, can be damaged by UV radiation. In particular, ultraviolet B (UVB)-induced damage plays an important role in retinal degeneration and cell aging. In this study, we investigated the protective effects of the methanol extract of Oxya chinensis sinuosa (OCM), an edible insect known for its high protein content (64.2%), and various pharmacological effects, on human retinal pigment epithelial cells. ARPE-19 cells were treated with OCM and subsequently UVB irradiated. Our results showed that OCM effectively attenuates UVB-induced cell damage by reducing MAPK phosphorylation (JNK and p38 MAPK). Additionally, OCM increased the phosphorylation of Akt, and cell cycle regulators, including p21 and p27, in a dose-dependent manner. Moreover, OCM treatment increased ARPE-19 cell proliferation by activating the S6K1/S6 pathway. This study suggests that OCM prevents UVB-induced retinal cell damage by increasing cell proliferation via ROS reduction, suggesting its potential as a functional therapeutic superfood against retinal cell damage.

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2006.11a
• /
• pp.455-457
• /
• 2006

The effects of UV-B irradiation on the growth and photosynthetic activity were investigated in seedlings of sunflower(Helianthus annuus L.). The first leaves irradiated with UV-B were retarded in growth but simultaneously acquired a remarkably decreased chlorophyll fluorescence ratio compared with the non-irradiated leaves. The Fv/Fm ratio decreased by 13 % compared to the control after 2 d, and was kept to be lower than the control level until 5 d. From the results it is suggested that UV-B radiation may induce reduced biomass production and decrease in photosynthetic rate in sunflower plants.

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