• 한국해양환경ㆍ에너지학회지
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• 제9권4호
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• pp.187-192
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• 2006

조선소에서 배출되는 처리수, 혼합방류수 및 주변 하천수가 양식 생물에 미치는 생물 독성영향을 알아보기 위해 48시간 급성독성과 DNA 손상을 조사하였다. 조사대상 생물종으로는 조선소 주변에서 양식되고 있는 넙치, 조피볼락, 피조개, 멍게가 사용되었으며, 48 시간 노출 후 치사율을 파악하였고, DNA 손상 정도는 Comet assay을 이용하여 측정되었다. 급성독성 실험 결과, 넙치는 장평천에서 치사가 나타났고(26%), 조피볼락은 혼합방류수 1에서 치사가 나타났다(13%). 멍게는 고현천에서 10%의 치사율을 보였고, 피조개는 어느 시료에서도 치사가 나타나지 않았다. 본 연구에 사용되어진 어떠한 시료에서도 실험생물을 50%까지 치사시키는 독성이 나타나지 않아 $LC_{50}$은 계산될 수 없었다. 넙치는 장평천과 혼합방류수에서 대조구보다 유의하게 높은 DNA 손상을 보여주었고, 조피볼락은 장평천에서 유의하게 높은 DNA손상이 나타났다(p<0.05). 멍게는 세탁폐수에서 유의한 DNA손상이 나타났지만, 피조개에서는 모든 처리구에서 DNA 손상을 보이지 않았다. 치사율과 DNA 손상을 고려하였을 때 조선소의 처리수와 혼합방류수보다는 장평천에서 놀은 생물독성을 보여주는 것으로 나타났다.

• Journal of Applied Biological Chemistry
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• 제64권3호
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• pp.237-244
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• 2021

Camellia sinensis, Green tea, contains phenolic compounds that act to scavenge reactive oxygen species (ROS), such as catechin, epicatechin, etc. In contrast with the tea leaf, the bioactivity of its fruit and the fruit peels remains still unclear. This study focused on the effects of fruit and fruit peels of C. sinensis (FC and PC) against oxidative DNA damage in NIH/3T3 cells. The scavenging effects of FC and PC on ROS were assessed using 1,1-diphenyl-2-picryl hydrazyl or 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid radicals. The measurement of ROS in cellular levels was conducted by DCFDA reagent and the protein expression of γ-H2AX, H2AX, cleaved caspase-3, p53, and, p-p53 was analyzed by immunoblotting. The gene expressions of p53 and H2AX were assessed using polymerase chain reaction techniques. The major metabolites of FC and PC were quantitatively measured analyzed and the amounts of phenolic compounds and flavonoids in PC were greater than those in FC. Further, PC suppressed ROS production, which protects the oxidative stress-induced DNA damage through reducing H2AX, p53, and caspase-3 phosphorylation. These results refer that the protective effects of FC and PC are mediated by inhibition of p53 signaling pathways, probably via the bioactivity of phenolic compounds. Thus, FC and PC can serve as a potential antioxidant in DNA damage-associated diseases.

• Food Science and Biotechnology
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• 제14권5호
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• pp.614-620
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• 2005

The antioxidative effect of Ecklonia cava, a brown marine alga, was investigated on radical scavenging, including 1,1-diphenyl-2-picrylhydrazyl (DPPH), and hydroxyl and alkyl radicals, using an electron spin resonance (ESR) technique, and on the inhibition of $H_2O_2$-induced DNA damage using comet assay. E. cava was enzymatically hydrolyzed with five food industrial proteases (Alcalase, Flavourzyme, Kojizyme, Neutrase and Protamex) to prepare water-soluble extracts. All the proteolytic hydrolysates exhibited strong dose-dependent radical scavenging activities (above 80%) at a concentration of $2.5\;{\mu}g/mL$. Kojizyme extract (obtained by proteolytic hydrolysation of E. cava with Kojizyme) showed the highest hydroxyl radical scavenging activity of around 98%. In addition, the $H_2O_2$-induced DNA damage was determined using a comet assay, which was quantified by measuring the tail length. Reduction of DNA damage increased with increasing concentrations of Kojizyme extract from E. cava. These results indicated that E. cava has a potential as a valuable natural antioxidative source.

• Animal cells and systems
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• 제13권4호
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• pp.405-409
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• 2009

When DNA double-strand breaks (DSBs) were induced in mammalian cells, many DNA damage response proteins are accumulated at damage sites to form nuclear foci called IR-induced foci. Although the formation of foci has been shown to promote repair efficiency, the structural organization of chromatin in foci remains obscure. BAF53 is an actin-related protein which is required for maintenance of chromosome territory. In this study, we show that the formation of IR-induced foci by $\gamma$-H2AX and 53BP1 were reduced when BAF53 is depleted, while DSB- activated ATM pathway and the phosphorylation of H2AX remains intact after DNA damage in BAF53 knockdown cells. We also found that DSB repair efficiency was largely compromised in BAF53 knockdown cells. These results indicate that BAF53 is critical for formation of foci by $\gamma$-H2AX decorated chromatin at damage sites and the structural organization of chromatin in foci is an important factor to achieve the maximum efficiency of DNA repair.

• Molecular & Cellular Toxicology
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• 제1권1호
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• pp.32-39
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• 2005

Polycyclic aromatic hydrocarbons (PAHs) are an important class of environmentally prevalent xenobiotics that exert complex effects on the biological system and characterized as probably carcinogenic materials. Single cell gel electrophoresis assays were performed in order to evaluate DNA damage occurring in the T-and B lymphocytes, spleens (T/B-cell), bone marrow, and livers of mouse exposed to mixture of PAHs (Benzo(a)pyrene, Benzo(e)pyrene, Fluoranthene, Pyrene) at dose of 400, 800, or 1600 mg/kg body weight for 2 days. DNA damage of the cells purified from mice was increased in dose dependent manner. In the blood cells and organs, DNA damage was also discovered to vary directly with PAHs. Especially T-cells had been damaged more than B-cell. Plasma proteomes were separated by 2-dimensional electrophoresis with pH 4-7 ranges of IPG Dry strips and many proteins showed significant up-and -down expressions with the dose dependent manner. Of these, significant 4 spots were identified using matrix-assisted laser desorption/ionization-time of fight (MALDI-TOF) mass spectrometry. Identified proteins were related to energy metabolism and signal transduction.

• Preventive Nutrition and Food Science
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• 제17권2호
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• pp.116-121
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• 2012

Water extract from Pinus densiflora (WPD) was investigated for its antioxidant activity and its ability to provide protection from DNA damage. A series of antioxidant assays, including a 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging assay, a reducing power assay, a metal-chelating assay, a superoxide radical scavenging assay, and a nitrite scavenging ability, as well as a DNA damage protection assay were performed. Total phenolic content was found to be 211.32 mg Tan/g WPD. The extract scavenged 50% DPPH free radical at a concentration of 21.35 ${\mu}g/mL$. At that same concentration, the reducing power ability of WPD was higher than that of ${\alpha}$-tocopherol. The extract chelated 68.9% ferrous ion at the concentration of 4 mg/mL. WPD showed better nitrite scavenging effect at the lower pH. Meanwhile, WPD exhibited a strong capability for DNA damage protection at 1 mg/mL concentration. Taken together, these data suggest water extract from Pinus densiflora could be used as a suitable natural antioxidant.

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.852-858
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• 2004

The morbidity and mortality of colon cancer are increasing, because of the westernization of food habit. Probiotics such as lactic acid bacteria (LAB) have been known to play an important role in retarding colon carcinogenesis by possibly influencing metabolic, immunologic, and protective functions in the colon. In this study, we evaluated the effect of B. polyfermenticus SCD on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) induced DNA damage in CHO-K, cells and human lymphocytes, and on proliferation of human colon cancer cell. Using the Comet assay to detect DNA damage, we found that B. polyfermenticus SCD protected cells from the DNA damage induced by MNNG in $CHO-K_1$ cells and in human lymphocytes. B. polyfermenticus SCD was also found to inhibit the growth of colon cancer cells in a dose-dependent manner, detected by the MTT assay. These results indicate that B. polyfermenticus SCD has the potential to inhibit not only DNA damage induced by a carcinogen, but also the proliferation of colon cancer cells.

• The Plant Pathology Journal
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• 제39권5호
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• pp.449-465
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• 2023

Plants are challenged by various pathogens throughout their lives, such as bacteria, viruses, fungi, and insects; consequently, they have evolved several defense mechanisms. In addition, plants have developed localized and systematic immune responses due to biotic and abiotic stress exposure. Animals are known to activate DNA damage responses (DDRs) and DNA damage sensor immune signals in response to stress, and the process is well studied in animal systems. However, the links between stress perception and immune response through DDRs remain largely unknown in plants. To determine whether DDRs induce plant resistance to pathogens, Arabidopsis plants were treated with bleomycin, a DNA damage-inducing agent, and the replication levels of viral pathogens and growth of bacterial pathogens were determined. We observed that DDR-mediated resistance was specifically activated against viral pathogens, including turnip crinkle virus (TCV). DDR increased the expression level of pathogenesis-related (PR) genes and the total salicylic acid (SA) content and promoted mitogen-activated protein kinase signaling cascades, including the WRKY signaling pathway in Arabidopsis. Transcriptome analysis further revealed that defense-and SA-related genes were upregulated by DDR. The atm-2atr-2 double mutants were susceptible to TCV, indicating that the main DDR signaling pathway sensors play an important role in plant immune responses. In conclusion, DDRs activated basal immune responses to viral pathogens.

• Journal of Nutrition and Health
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• 제27권7호
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• pp.740-751
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• 1994

Sister chromatid exchanges(SCE) in peripheral lymphocytes is recently used as a biomarker for increased cytogenetic damage in smokers. The purpose of the investigation was to determine if there were any relationships between dietary factors and their DNA damage as measured by SCE test in a group of 62 male cigarette smokers and 36 non-smokers. As expected, smokers as compared with non-smokers had high SCE levels (10.59$\pm$0.21 versus 9.23$\pm$0.17 SCE/lymphocytes ; p<0.05). No significant relationships were observed between SCEs and age in smokers and non-smokers. In smokers, SCEs were negatively correlated with egg frequency score(r=-0.336) and total food frequency scores(r=-0.283). In non-smokers, SCEs were positively correlated with white vegetable frequency score(r=0.333) and instant food frequency score(r=0.382). There was a positive association between SCEs and the history of coffee intake of smokers(r=0.318). SCE frequency was not influenced by any other dietary factors considered ; dietary diversity and quality scores, alcohol consumption, use of processed foods and intake of burned food. No significant relationships were found between SCEs and serum cholesterol or other hematological parameters of the subjects. These results indicate that increased egg frequency score, total food frequency score which reflects dietary quality, and decreased coffee intake may reduce cancer risk by preventing smoking-induced DNA damage as reflected by sister chromatid exchanges in human lymphocytes.

• 대한화학회지
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• 제49권4호
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• pp.343-348
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• 2005