• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.1204-1210
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• 2014

New control methods are proposed for indoor air quality by removing fine airborne dust-particles. As suspended fine dust-particles contain inorganic dust as well as fine organic bacteria, studies for simultaneous control of these contaminants are required. In this study, photocatalytic disinfection of indoor suspended microorganisms such as E. coli and Bacillus subtilis is performed by three types of photocatalysts with UVA irradiation. The UVA irradiation strength was controlled to the minimum $3{\mu}W/cm^2$, and ZnO, $TiO_2$, and ZnO/Laponite ball were used as the catalysts. The results indicate that E. coli was removed over 80 % after about 2 hours of reaction with UVA and all three types of photocatalysts, whereas only with UVA, around 50 % E. coli removal was obtained. Among the catalysts, ZnO/Laponite composite ball was found to have similar sterilizing capacity to $TiO_2$. However, in case of B. subtilis, which has thick cell wall in its spore state, disinfection was not effective under the low UVA irradiation condition, even with the catalysts. Further studies need to figure out the optimal UVA irradiation ranges as well as photocatalysts doses to control airborne dust, to provide healthy clean air environment.

• The Korean Journal of Food And Nutrition
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• v.28 no.5
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• pp.759-765
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• 2015

The effects of extracts from Lentinula edodes (L. edodes) and Aquilariae agallocha (A. agallocha) on the DNA damage response in ultraviolet A (UVA)-exposed HaCaT cells and on the allergic contact dermatitis caused by 2,4-dinitro-chlorobezene (DNCB) were investigated. When UVA-exposed cells were incubated for 24 hours in medium containing L. edodes or A. agallocha extract, the level of 8-OHdG and CPD decreased in a concentration-dependent manner. The combined treatment with both extracts potentiated the decrease in UVA-induced 8-OHdG and CPD levels as compared with those following treatment with a single extract. In addition, the two extracts showed preventive effects against the UVA-induced reduction in collagen levels. Furthermore, the blood levels of IgE, IL-6, and histamine decreased more significantly upon combined treatment with L. edodes and A. agallocha extracts as compared with those following treatment with single extracts in DNCB-induced allergic contact dermatitis in the ICR mouse. The results of the present study suggest that the components with in the extracts of L. edodes and A. agallocha can help to prevent of UVA-induced genomic instability via a decrease in DNA damage, and to decrease the DNCB-induced allergic dermatitis via modulation of relevant proteins including IgE and IL-6. Further study is needed to clarify the purified components related to the preventative effects of the two extracts against UVA- or DNCB-induced genomic damage.

• Biomolecules & Therapeutics
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• v.32 no.2
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• pp.224-230
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• 2024

Pinitol (3-O-Methyl-D-chiro-inositol) has been reported to possess insulin-like effects and is known as one of the anti-diabetic agents to improve muscle, liver, and endothelial cells. However, the beneficial effects of pinitol on the skin are not well known. Here, we investigated whether pinitol had effects on human dermal fibroblasts (HDFs), and human dermal equivalents (HDEs) irradiated with ultraviolet A (UVA), which causes various damages including photodamage in the skin. We observed that pinitol enhanced wound healing in UVA-damaged HDFs. We also found that pinitol significantly antagonized the UVA-induced up-regulation of matrix metalloproteinase 1 (MMP1), and the UVA-induced down-regulation of collagen type I and tissue inhibitor of metalloproteinases 1 (TIMP1) in HDEs. Electron microscopy analysis also revealed that pinitol remarkably increased the number of collagen fibrils with regular banding patterns in the dermis of UVA-irradiated human skin equivalents. Pinitol significantly reversed the UVA-induced phosphorylation levels of ERK and JNK but not p38, suggesting that this regulation may be the mechanism underlying the pinitol-mediated effects on UVA-irradiated HDEs. We also observed that pinitol specifically increased Smad3 phosphorylation, which is representative of the TGF-β signaling pathway for collagen synthesis. These data suggest that pinitol exerts several beneficial effects on UVA-induced damaged skin and can be used as a therapeutic agent to improve skin-related diseases.

• Journal of Photoscience
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• v.9 no.2
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• pp.338-340
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• 2002

In broom sorghum, Sorghum bicolor Moench, UV causes anthocyanin synthesis having action peaks in UVA and UVB regions. We previously reported that UV induces anthocyanin synthesis through UVB photoreceptor and phytochrome activated by UV. Furthermore, UVA and UVB amplify phytochrome-induced anthocyanin synthesis (PIAS). Our action- spectroscopic research indicated that a UV -receptor for amplification of PIAS is likely to be the same or same type of UVB photoreceptor for induction of anthocyanin synthesis. UVA-amplification of PIAS can be explained by the action of a cryptic red light signal (CRS), an amplification factor for PIAS produced by a distinct phytochrome-species activated by UVA. We suggest that UVA photoreceptors are not involved in anthocyanin synthesis in the broom sorghum.

• Journal of Photoscience
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• v.9 no.2
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• pp.150-153
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• 2002

Solar UV light is a well-known carcinogen. UVA radiation is probably carcinogenic to humans. In addition, recent investigations point to the importance of UVA irradiation in the photoaging. We investigated the mechanism of sequence- specific DNA damage using $\^$32/P-Iabeled DNA fragments in relation to carcinogenesis and aging. Furthermore, we investigated whether UVA accelerates the telomere shortening in human WI-38 fibroblasts. The exposure of double- stranded DNA fragments to 365 nm light in the presence of endogenous sensitizers produced sequence-specific cleavage at the 5' site of 5'-GG-3' and 5'-GGG-3' sequences. In addition, HPLC analysis revealed that sensitizers plus 365 nm light increased the 8-oxodG content of double-stranded DNA. We discuss the mechanisms of guanine-specific DNA damagecaused by excited photosensitizers in relation to carcinogenesis and aging.

• YAKHAK HOEJI
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• v.51 no.4
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• pp.229-234
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• 2007

We investigated antioxidative activity of the water and ethanol extracts of leaves of Acanthopanax divaricatus var. albeofructus in human dermal fibroblast (HDFs) irradiated by UVA. The irradiation of UVA did not affect the cell viability of HDFs. The antioxidative activity of the extract was investigated by xylenol orange, TBARS (thiobarbituric acid reactive substances) and antioxidant enzyme assay. Both extracts showed H202 scavenging activity and inhibited lipid peroxidation in HDF cells irradiated by UVA. The extracts also recovered enzyme activity in the same cells.

• Journal of Photoscience
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• v.9 no.3
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• pp.33-36
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• 2002

This study describes RT-PCR and in situ hybridisation protocols, and the immunohistochemical detection method that we have developed to detect and localise cells that express HO-1 in the skin. We found that HO-1 mRNA was absent in normal mouse skin, but after UVA irradiation HO-1 mRNA was expressed in the dermal fibroblasts, and strongly in basal epidermal cells. HO-1 protein was also induced strongly in dermal fibroblasts, and also in epidermal cells. In addition, the HO substrate heme was reduced in skin microsome at 72 hrs post UVA (when HO activity is high). At the same time, the HO products bilirubin and iron levels were elevated in the cutaneous tissue. Thus in addition to a dermal response, there appears to be an epidermal HO response to UVA in vivo that may be relevant for immune modulation by UVA radiation.

• Journal of Photoscience
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• v.9 no.2
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• pp.197-200
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• 2002

UVR-induced immunosuppression contributes to skin cancer. The aim was to construct accurate dose response curves for primary and secondary contact sensitivity for solar-simulated UVR (ssUVR; 290-400nm), UVA and UVB as the role of UVA in immunosuppression is controversial. We used a xenon arc source. The mice were immobilised, enabling accurate dosing. C57BL/6 mice were immunosuppressed at half the dose of ssUVR required to cause sunburn but not by higher doses (up to the sunburn dose). Thus, ssUVR causes systemic immunosuppression only over a narrow, low dose range. UVA caused suppression at low but not high doses whereas UVB induced immunosuppression at all doses tested. 8 weeks later the mice were resensitised to assess tolerance. Mice exposed to the minimum immunosuppressive dose of ssUVR prior to primary sensitisation were tolerant to re-sensitisation. However, at higher doses of ssUVR, these mice were protected from tolerance. Interestingly, while low doses of UV A caused immunosuppression, even lower doses enhanced the response to the second sensitisation. Higher doses of UVA had no affect. UVB induced tolerance in a dose related manner. Thus, ssUVR only induces immunosuppression and tolerance over a narrow dose range. Both UVA and UVB are immunosuppressive at this dose, while higher doses of UVA protect from the suppressive effects of UVB. Surprisingly very low doses of UVA enhanced memory development. Thus UVR has complex effects on the immune system depending on dose and spectrum.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.25 no.2
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• pp.59-75
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• 1999

Skin is continuously exposed to external stimuli including ultraviolet radiation, which is a major cause of skin photoaging. According to recent discoveries, UVA with a lower energy but deep-penetrating properties, compared to UVB, is likely to play a major part in causing skin photoaging. The clinical and histochemical changes of photoaging are well characterized, but the biochemical mechanisms are poorly understood partly due to the lack of suitable experimental systems. In this work, three-dimensional, reconstituted skin culture models were prepared. After certain period of maturation, the equivalent models were shown to be similar in structure and biochemical characteristics to normal skin. Mature dermal and skin equivalent models were exposed to sub-lethal doses of UVA, and the effects of UVA relevant to dermal photoaging were monitored, including the production of elastin, collagen, collagenase(MMP-1), and tissue inhibitor of metalloproteinases-1 (TIMP-1). Interestingly, dermal and skin equivalents reacted differently to acute and chronic exposure to UVA. Elastin production was increased as soon as one week after commencing UVA irradiation by chronic exposure, although a single exposure failed to do so. This early response could be an important advantage of equivalent models in studying elastosis in photoaged skin. Collagenase activity was increased by acute UVA irradiation, but returned to control levels after repeated exposure. On the other hand, collagen biosynthesis, which was increased by a single exposure, decreased slightly during 5 weeks of prolonged UVA exposure. Collagenase has been thought to be responsible for collagen degeneration in dermal photoaging. However, according to the results obtained in this study, elevated collagenase activity is not likely to be responsible for the degeneration of collagen in dermal photoagig, while reduced production of collagen may be the main reason. It can be concluded that reconstituted skin culture models can serve as useful experimental tools for the study of skin photoaging. These culture models are relatively simple to construct, easy to handle, and are reproducible Moreover the changes of dermal photoaging can be observed within 1-4 weeks of exposure to ultraviolet light compared to 4 months to 2 years for human or animal studies. These models will be useful for biochemical and mechanistic studies in a large number of fields including dermatology, toxicology, and pharmacology.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.5
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• pp.275-279
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• 2002

Nerve growth factor (NGF) is an important autocrine growth factor and also a survival factor for keratinocytes. NGF may act in the hyperproliferative condition, psoriasis. Clinically, the combination of psoralen and UVA (PUVA) has been used in the treatment of a wide variety of cutaneous disorders, such as psoriasis and vitiligo. However, the precise therapeutic mechanism of PUVA on the dermatologic diseases remains unclear. The purpose of this study was to examine whether the expression of NGF in cultured keratinocytes is influenced by PUVA. Thus, normal human keratinocytes were isolated from neonatal foreskin, and the third to fifth-passaged cells were used in this study. The cells were exposed to various doses of UVA (30, 60, 120 $mJ/cm^2)$ after adding 8-methoxypsoralen (8-MOP) to examine the expression of NGF mRNA. The RNA and protein of the cells were extracted at various time points (1, 8, 24 hours) after UVA irradiation to examine the expression of NGF mRNA and production of NGF protein. In keratinocytes, there were no differences in the expression of NGF mRNA between the different doses of UVA irradiation, however, the expression of NGF mRNA in UVA and PUVA groups tended to increase as the time increased. The expression of NGF mRNA was the highest in PUVA group, followed by UVA group and the lowest in 8-MOP group. The expressions of NGF protein at 1 and 8 hours after UVA irradiation were lower in the PUVA group than in the other groups. This study showed that the expression level of NGF protein in keratinocytes was relatively lower in the PUVA groups than in the other groups, suggesting that the therapeutic mechanism of PUVA in psoriasis is related to the decrease of NGF protein.