• Journal of Microbiology and Biotechnology
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• 제13권4호
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• pp.544-551
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• 2003

Interactive effects of UV-B and Cd on growth, pigment, photosynthesis, and lipid peroxidation have been studied in Anabaena, Microcystis, and Nostoc; all the tested cyanobacteria showed differential sensitivity to different dosage of UV-B and Cd alone as well as in combination. Phycocyanin was severely affected by UV-B and Cd by all the strains; the degree of pigment bleaching was most pronounced in Anabaena followed by Microcystis and Nostoc. $UV-B_2+Cd_2$ produced nearly 83, 78, and 65% inhibition of phycocyanin in Anabaena, Microcystis, and Nostoc, respectively. The above treatment also significantly decreased the contents of Chl ${\alpha}$ and carotenoid. Presence of capsule in Microcystis protected the phycocyanin bleaching as compared to decapsulated cells. Laboratory-grown Microcystis revealed about 75 and 80% inhibition, following $UV-B_2+Cd_2$ treatment, respectively. in capsulated and decapsulated cells. Damage caused by Cd was more pronounced than UV-B. Inhibition of photosynthesis did occur in all the test strains, being maximum in Anabaena. PS II was the most sensitive component of the electron transport chain, showing 84, 80, and 70% inhibition in Anabaena, Microcystis, and Nostoc, respectively. As compared to control, significant lipid peroxidation (6.5-fold higher) was observed in Anabaena with $UV-B_2+Cd_2$, $^{14}C-uptake$ was more susceptible to Cd and Uv-B than oxygen-evolution. Approximately 84, 80, and 76% inhibition of $^{14}C-uptake$ was observed in Anabaena, Microcystis, and Nostoc, respectively. Similarly, $UV-B_2+Cd_2$ inhibited APT content of Anabaena by 87%. This ,study suggests that inhibition of carbon fixation was due to decreased ATP content of the test cyanobacteria by UV-B+Cd, where Anabaena was the most sensitive and Nostoc the most tolerant.

• BMB Reports
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• 제32권6호
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• pp.554-560
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• 1999

TTD1BI cells are non-hypersensitive to UV irradiation and perform normal genome repair of pyrimidine dimers but fail to excise 6-4 photoproducts and, concomitantly, are unable to restore RNA synthesis levels following UV irradiation. This pointed to a detect in gene-specific repair and this study was undertaken to examine repair of 6-4 photoproducts at the gene-level. The results indicated a defect in gene-specific repair of 6-4 photoproducts in active genes, although strand-specificity of 6-4 photoproduct removal was essentially similar to that of normal cells. These findings indicate that the near normal UV resistance of TTD1BI cells may be due to the inability of these cells to remove DNA lesions preferentially, as well as to the cells opting out of the cell cycle to repair damage before resuming replication.

• 환경생물
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• 제26권1호
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• pp.1-7
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• 2008

A mathematical model for the synergistic interaction of physical and chemical environmental agents was suggested for quantitative prediction of irreversibly damaged cells after combined exposures. The model took into account the synergistic interaction of agents and was based on the supposition that additional effective damages responsible for the synergy are irreversible and originated from an interaction of ineffective sublesions. The experimental results regarding the irreversible component of radiation damage of diploid yeast cells simultaneous exposed to heat with ionizing radiation ($^{60}Co$) or UV light (254 nm) are presented. It was shown that the cell ability of the liquid holding recovery decreased with an increase in the temperature, at which the exposure was occurred. A good correspondence between experimental results and model prediction was demonstrated. The importance of the results obtained for the interpretation of the mechanism of synergistic interaction of various environmental factors is discussed.

• International Journal of Oral Biology
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• 제36권3호
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• pp.149-154
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• 2011

In the present study, total methanol extracts prepared from Alpinia katsumadai showed significant protective effects against the oxidative stress induced by hydrogen peroxide, UV-C or ${\gamma}$-ray irradiation. These protective effects were substantially increased by treatment with 20~100 ${\mu}g$/ml of the extract. The A. katsumadai total methanol preparation was further fractionated into n-hexane, dichloromethane, ethylacetate, n-butanol and water fractions. Among these five fractions, the ethylacetate and butanol fractions of A. katsumadai showed the strongest protective effects against oxidative stress induced by UV-C and ${\gamma}$-ray irradiation. These fractions also showed high DPPH radical scavenging and lipid peroxidation inhibitory activities. In addition, both fractions displayed cell proliferation activation effects, as evidenced by significant increases in colony formation. Our current data thus suggest that the mechanisms underlying the protective effects of A. katsumadai against oxidative damage may include radical scavenging, protection against cell membrane damage and stimulation of cell proliferation.

• 한국약용작물학회지
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• 제24권6호
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• pp.464-470
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• 2016

Background: Valeriana fauriei (Valerianaceae) has been used to as a traditional medicine to treat a variety of symptoms, including headache, insomnia, hypertension, and menstrual irregularity. However, the present study investigates the species' antioxidant activity and its inhibition of oxidative DNA damage, which have yet to be studied. Methods and Results: The antioxidant activity was assessed using radical scavenging assays with 1,1-diphenyl-2-picryl hydrazyl (DPPH) and, 2, 2'-azino-bis (3-ethylbenzothiazoline-6 sulfonic acid) diammonium salt (ABTS) and a reducing power assay. The total phenol content was also analyzed, and phenolic compounds were detected using HPLC/UV, whereas the inhibitory effect of Valeriana fauriei on oxidative DNA damage was measured using ${\phi}-174$ RF I plasmid DNA cleavage assay. The DPPH and ABTS radical scavenging activity were $75.17{\pm}3.55%$ and $95.83{\pm}0.63%$, repectively, and the reducing power was $93.14{\pm}1.74$ at $200{\mu}g/m{\ell}$. The total phenol content was $10.24{\pm}0.04mg/g$, whereas chlorogenic acid, catechin, caffeic acid and epicatechin were identified using HPLC/UV, and the ${\phi}-174$ RF I plasmid DNA cleavage assay indicated that V. fauriei provided protection against oxidative damage. Conclusions: The results of the present study suggest that V. fauriei has powerful antioxidant activity that can provide protective effects against the oxidative DNA damage caused by free radicals. The species, therefore, provides a valuable resource for the development of natural pharmaceutical to treat aging, cancer, and degenerative diseases.

• 한국토양비료학회지
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• 제43권3호
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• pp.400-406
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• 2010

서리태콩 (Glycine max Merr. var Seoritae)에서 광원에 따른 엽의 광합성 변화를 구명하기 위하여 콩의 제 1복엽이 완전 전개되었을 때 3일 동안 빛을 차단한 후 UV-B 와 일반광에 노출시켜 색소 함량과 엽록소 형광반응의 변화를 측정하였다. 암처리에서 엽록소 함량은 감소하고, 일반 광에서 회복하였다. 카로티노이드와 안토시아닌 함량은 UV-B 조사한 처리구에서 증가하였다. 엽록소 형광분석을 이용한 광합성 능률을 분석한 결과, 암처리가 진행 됨에 따라 Fv/Fm, F'v/F'm, ${\Phi}_{PSII}$ 및 NPQ는 감소하였다. 모든 변수들은 일반광에 노출되면서 회복하였으나 UV 처리한 것은 암처리 72시간의 수치와 큰 변화가 없었다. 이를 통하여 암처리 48시간 경과함으로 엽록체가 에티오플라스트로 전환되며, 일반광을 조사하였을 시 광합성 관련 광계가 복구되지만, UV-B의 강한 광이 조사되었을 때 광계가 회복되지 못하는 것으로 사료되었다.

• 동아시아식생활학회지
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• 제22권2호
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• pp.224-230
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• 2012

$In$ $vivo$ 동물 모델에서 10주간의 자외선 조사에 의해 유발되는 피부 손상 및 사람 피부섬유아세포에 Ginseol K-b1이 미치는 영향을 확인하고자 하였으며, 그 연구결과를 요약하면 아래와 같다. 1. 반복적인 UV 조사에 의해 7주 후부터 hairless mice의 주름이 육안으로 확인되며, Ginseol K-b1 0.0625%(w/w) 농도로 함유한 사료의 10주간 섭취는 UV 조사군에 비해 유의적 ($p$<0.05)으로 주름 생성의 정도를 억제시켰다. 피부 표피 두께 역시 Ginseol K-b1섭취군은 UV 조사군에 비해 유의적으로 작았다. 2. UV 조사는피부 수분 함량 및 탄력도를 감소시키며, Ginseol K-b1의 섭취는 표피 수분량 저하 및 탄력 감소를 유의적($p$<0.05)으로 억제하였다. 3. Ginseol K-b1은 사람 섬유아세포의 세포 증식을 유의적($p$<0.001)으로 촉진시켰으며, 저농도(1.56~6.25 ${\mu}g/mL$)에서 콜라겐 생성량을 유의적으로 증가시켰다. 이상의 결과에서 Ginseol K-b1은 피부 섬유아세포의 증식 및 콜라겐 생성을 촉진함으로써 피부 표면의 주름 생성 및 탄력 저하 억제를 통해 UV로 인한 피부 손상으로부터 피부를 보호하는 효과가 있는 것으로 보이며, 이는 화장품이 아닌 먹는 피부 미용 소재로서의 가능성이 높음을 평가할 수 있다. 그러나 세포내 신호 전달 체계에 대한 추가적인 연구가 이루어져 기작에 대한 명확한 설명이 필요할 것으로 사료된다.

• Nutrition Research and Practice
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• 제17권4호
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• pp.641-659
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• 2023

BACKGROUND/OBJECTIVES: The skin is the outermost organ of the human body and plays a protective role against external environmental damages, such as sunlight and pollution, which affect anti-oxidant defenses and skin inflammation, resulting in erythema or skin reddening, immunosuppression, and epidermal DNA damage. MATERIALS/METHODS: The present study aimed to investigate the potential protective effects of red orange complex H extract (ROC) against ultraviolet (UV)-induced skin photoaging in Skh:HR-2 mice. ROC was orally administered at doses of 20, 40, and 80 mg/kg/day for 13 weeks, along with UV irradiation of the mice for 10 weeks. RESULTS: ROC improved UV-induced skin barrier parameters, including erythema, melanin production, transepidermal water loss, elasticity, and wrinkle formation. Notably, ROC inhibited the mRNA expression of pro-inflammatory cytokines (interleukin 6 and tumor necrosis factor α) and melanogenesis. In addition, ROC recovered the UV-induced decrease in the hyaluronic acid and collagen levels by enhancing genes expression. Furthermore, ROC significantly downregulated the protein and mRNA expression of matrix metalloproteinases responsible for collagen degradation. These protective effects of ROC against photoaging are associated with the suppression of UV-induced phosphorylation of c-Jun NH2-terminal kinase and activator protein 1 activation. CONCLUSIONS: Altogether, our findings suggest that the oral administration of ROC exerts potential protective activities against photoaging in UV-irradiated hairless mice.

• International Journal of Oral Biology
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• 제45권4호
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• pp.179-189
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• 2020

Green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) is a potent antioxidant with protective effects against neurotoxicity. However, it is currently unclear whether EGCG protects neuronal cells against radiation-induced damage. Therefore, the objective of this study was to investigate the effects of EGCG on ultraviolet (UV)-induced oxidative stress and apoptosis in PC12 cells. The effects of UV irradiation included apoptotic cell death, which was associated with DNA fragmentation, reactive oxygen species (ROS) production, enhanced caspase-3 and caspase-9 activity, and poly (ADP-ribose) polymerase cleavage. UV irradiation also increased the Bax/Bcl-2 ratio and mitochondrial pathway-associated cytochrome c expression. However, pretreatment with EGCG before UV exposure markedly decreased UV-induced DNA fragmentation and ROS production. Furthermore, the UV irradiation-induced increase in Bax/Bcl-2 ratio, cytochrome c upregulation, and caspase-3 and caspase-9 activation were each ameliorated by EGCG pretreatment. Additionally, EGCG suppressed UV-induced phosphorylation of p38 and rescued UV-downregulated phosphorylation of ERK. Taken together, these results suggest that EGCG prevents UV irradiation-induced apoptosis in PC12 cells by scavenging ROS and inhibiting the mitochondrial pathways known to play a crucial role in apoptosis. In addition, EGCG inhibits UV-induced apoptosis via JNK inactivation and ERK activation in PC12 cells. Thus, EGCG represents a potential neuroprotective agent that could be applied to prevent neuronal cell death induced by UV irradiation.

• Toxicological Research
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• 제22권4호
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• pp.423-429
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• 2006

Recent reports on the photocarcinogenicity and photogerotoxicity of many compounds led to an increasing awareness for the need of a standard approach to test for photogenotoxicity. The comet assay has been recently validated as a sensitive and specific test system for the quantification of DNA damage. Thus, the objectives of this study are to investigate the utility of photo-comet assay for detecting photo-mutagens, and to evaluate its ability to predict rodent photo-carcinogenicity. Photo-comet assays were performed using L5178Y $Tk^{+/-}$ mouse lymphoma cells on five test substances (8-methoxypsoralen, chlorpromazine, lomefloxacin, anthracene and retinoic acid) that demonstrated positive results in photocarcinogenicity tests. For the best discrimination between the test substance-mediated DNA damage and the undesirable DNA damage caused by direct UV absorption, a UV dose-response of the cells in the absence of the test substances was firstly fnalized. Out of 5 test substances, positive comet results were obtained for chlorpromazine, lomefloxacin, anthracene and retinoic acid while 8-methoxypsoralen found negative. An investigation into the predictive value of this photo-comet assay for determining the photocarcinogenicity showed that photo-comet assay has relatively high sensitivity. Therefore, the photo-comet assay with mammalian cells seems to be a good and sensitive predictor of the photocarcinogenic potential of new substances.