• Radiation Oncology Journal
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• 제13권2호
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• pp.113-120
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• 1995

Purpose : To investigate the effect of alkaloid fraction from Korean ginseng on radiation-induced DNA double strand breaks (dsb) formation and repair in murine lymphocytes Materials and Methods : We used the neutral filter elution technique to assay $^{60}Co\;{\gamma}$ ray-induced DNA double strand breaks formation and repair in C57BL/6 mouse spleen lymphocytes for evaluating the dose-response relationship in the presence of alkaloid fraction as a radioprotective agent. The lymphocytes were stimulated with Phytohemagglutinin (PHA, 2 u g/ml) to label $^3[H]-thymidine.$ Isotope-labelled lymphocytes in suspension were exposed to 100 Gy at $0^{\cdot}C$ in the alkaloid fraction-treated group and elution procedure was performed at PH 9.6. The extents of formation of radiation-induced DNA double strand breaks and repair were compared respectively via strand scission factor (SSF) and relative strand scission factor (RSSF). Results: Alkaloid fraction reduced the formation of double strand breaks with dose modification factor of 2 15, compared to control group Rejoining of DNA dsb appeared to take place via two components. The first fast component was completed within 20.4 minutes, but the second slow component was not completed until 220.2 minutes after irradiation. About $30\%$ of dsb formed by irradiation was ultimately unrejoined despite the administration of alkaloid fraction. The administration of alkaloid fraction had a great effect on the second slow component of repair; the half-time of fast component repair was not changed, but that of slow component was 621.8 minutes. Conclusion: Neutral filter elution assay Proved to be a very effective method to quantitate the extents of DNA dsb formation and its repair. By using this technique, we were able to evaluate the efficiency of alkaloid fraction from Korean ginseng as a valuable radioprotector. Alkaloid fraction can be used prophylactically to prevent or ameliorate the severe radiation damages in workers and neighbors around the atomic power plants. For more refined study, however, more advanced purification of alkaloid fraction wil be needed in the near future.

• Archives of Pharmacal Research
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• 제26권2호
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• pp.124-127
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• 2003

Four known prenylated flavonoids, artonins E (1) and O (2), artobiloxanthone (3), and cycloartobiloxanthone (4), were isolated from the stem bark of Artocarpus kemando by bioassayguided fractionation using the DNA strand-scission and the KB cytotoxicity assays as monitors. Compounds 1 and 3 exhibited strong DNA strand-scission activity, and all four compounds were found to be cytotoxic.

• Applied Biological Chemistry
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• 제48권3호
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• pp.222-227
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• 2005

특수미인 거대배아미와 유색미의 발아처리에 의한 항돌연변이 활성의 변화를 평가하고자, 70% 에탄올 추출물이 in vitro에서 산화적 손상에 의한 DNA strand scission을 억제하는 효과와 함께 E. coli 및 V79 배양세포에 화학적으로 유발된 돌연변이에 대한 억제효과를 측정하였다. Mitomycin C로 유발된 돌연변이에 대한 억제활성을 E. coli에서 SOS chromotest로 조사한 결과, 활성은 발아유색미(40.4%) > 발아거대배아미(37.1%) > 무발아유색미(35.5%) > 발아현미(15.7%) > 무발아거대배아미(14.0%) > 무발아현미(0.8%)의 순서였다. Mitomycin C가 유도한 DNA strand scission에 대한 억제 효과는 무발아유색미 > 무발아거대배아미 > 발아유색미 > 발아현미 > 무발아현미 > 발아 거대배아미로 나타났다. V79 세포주에서 4-NQO로 유도된 6-TG 저항성 colony의 형성을 저해하는 활성을 지표로 항돌연변이 활성을 조사한 결과, 발아거대배아미(53.2%) > 무발아유색미(40.0%) > 무발아현미(21.2%) > 발아현미(14.4%) > 무발아거대배아미(0.23%)의 순서로 돌연변이를 저해하였는데, 발아유색미는 돌연변이를 촉진하는 것으로 나타났다(-69%).

• 대한수의학회지
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• 제31권3호
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• pp.329-335
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• 1991

The filter elution technique was used to assay $^{60}Co$ $\gamma$ ray-induced DNA strand breaks(SB) in EL4 mouse leukemia cell and mouse spleen lymphocyte. The lymphocytes were stimulated with lipopolysaccharide (LPS, $20{\mu}g/ml$) to label $[^3H]$ thymidine. EL4 cells and lymphocytes in suspension were exposed at $0^{\circ}C$ to 0Gy, 1Gy, 5Gy, 10Gy or l5Gy for DNA single strand breaks(SSB) assay and 0Gy, 25Gy, 50Gy, 75Gy or 100Gy for DNA double strand breaks(DSB) assay of $^{60}Co$ radiation and elution procedure was performed at pH12.1 and 9.6. The number of DNA strand breaks increased with increasing doses of r rays. The strand scission factor(SSF) was estimated in each experiment (eluted volume 21ml). The slope of SSB EL4 cells was $0.01301{\pm}0.00096Gy^{-1}$ (n=5), the slope of SSB for lymphocytes was $0.01097{\pm}0.00091Gy^{-1}$ (n=5) and the slope of DSB for lymphocytes was $0.001707{\pm}0.0000573Gy^{-1}$ (n=5). Thus EL4 cells were more sensitive to induction of DNA SSB by ionizing radiation than lymphocytes (p<0.005). The ratio of slope of dose-response relationship (SSF versus dose) of lymphocytes DNA SSB as compared with the slope of DNA DSB was 6.4.

• 대한의생명과학회지
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• 제15권1호
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• pp.1-8
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• 2009

Human genomic DNA is continuously attacked by oxygen radicals originated from cellular metabolic processes and numerous environmental carcinogens. 2-deoxyribonolactone (dL) is a major type of oxidized abasic (AP) lesion implicated in DNA strand scission, mutagenesis, and formation of covalent DNA-protein crosslink (DPC) with DNA polymerase (Pol) ${\beta}$. We show here that human DNA polymerase (Pol)${\iota}$ and mitochondrial $Pol{\gamma}$ give rise to stable DNA-protein crosslink (DPC) formation that is specifically mediated by dL lesion. $Pol{\gamma}$ mediates DPC formation at the incised dL residue by its 5'-deoxyribose-5-phosphate (dRP) lyase activity, while $Pol{\gamma}$ cross links with dL thorough its intrinsic dRP lyase and AP lyase activities. Reactivity in forming dL-mediated DPC was significantly higher with $Pol{\gamma}$ than with $Pol{\iota}$. DPC formation by $Pol{\gamma}$, however, can be reduced by an accessory factor of $Pol{\gamma}$ holoenzyme that may attenuate deleterious effects of crosslink adducts on mitochondrial DNA. Comparative kinetic analysis of DPC formation showed that the rate of DPC formation with either $Pol{\iota}$ or $Pol{\gamma}$ was lower than that with $Pol{\beta}$. These results revealed that the activity of catalytic lyase in DNA polymerases determine the efficiency of DPC formation with dL damages. Irreversible crosslink formation of such DNA polymerases by dL lesions may result in a prolonged strand scission and a suicide of DNA repair proteins, both of which could pose a threat to the genetic and structural integrity of DNA.

• Applied Biological Chemistry
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• 제41권1호
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• pp.78-83
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• 1998

12품종의 유색미에 대한 항변이원활성 및 항암활성을 in vitro에서 일품벼를 대조구로하여 조사하였다. 각 품종별 쌀겨를 0.5%의 TFA를 포함한 80% 에탄올, 또는 n-hexane으로 추출하여 각각 색소분획과 헥산분획을 제조한 다음, SOS chromotest를 이용하여 변이원에 대한 억제활성을 측정함과 동시에 각 분획의 DNA strand scission 및 발암 promoter에 대한 억제활성을 측정하여 이들이 가지는 발암억제효과를 평가하였다. 색소분획의 항변이원활성은 LK1B4-12-1-1 >상해향혈나 > HP833-1-3-1-1 > Chokoto14 > 자광도 > 자진 > 길림흑미 > Tiwan-Tsi-C > 흑진미 > Linsia-Shoea-Dau > 수원425 >수원415의 순서였으며, 헥산분획에서는 LK1B4-12-1-1 상해향혈나 > 일품벼 > HP833-1-3-1-1 > Chokoto14 > 자광도 > 자진 > Linsia-Shoea-Dau > Tiwan-Tsi-C > 흑진미 >수원425, 길림흑미 >수원415의 순서로 활성이 나타났다. 색소분획물이 가지는 DNA strand scission에 대한 억제활성을 조사한 실험결과, HP833-1-3-1-1 > Tiwan-Tsi-C > 자진 > Chokoto14 > 수원425 > 흑진미 > LK1B4-12-1-1 > 수원415 > 자광도 > 길림흑미 > Linsia-Shoea-Dau > 상해향혈나의 순서로 활성을 보인 반면, 헥산분획에서는 LK1B 4-12-1-1 > 수원415 > 길림흑미 > Chokoto14 > 흑진미 > 자진 > 수원425 > Tiwan-Tsi-C > 상해향혈나 > Linsia-Shoea-Dau >자광도 > HP833-1-3-1-1 > 일품벼의 순서로 활성을 보였다. 발암 promoter의 단기검출법을 이용한 실험결과, 발암 promotor TPA에 대한 색소분획물의 억제활성은 Linsia-Shoea-Dau > 길림흑미 > HP833-1-3-1-1, 수원425 > 흑진미 > 자진 > Chokoto 14 > 상해향혈나 > 수원415 > LK1B4-12-1-1 > Tiwan-Tsi-C > 자광도의 순서로 나타났다.

• Animal cells and systems
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• 제9권2호
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• pp.79-85
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• 2005

Oxidized abasic residues arise as a major class of DNA damage by a variety of agents involving free radical attack and oxidation of deoxyribose sugar components. 2-deoxyribonolactone (dL) is a C1'-oxidized abasic lesion implicated in DNA strand scission, mutagenesis, and covalent DNA-protein cross-link (DPC). We show here that mammalian cell-free extract give rise to stable DPC formation that is specifically mediated by dL residue. When a duplex DNA containing dL at the site-specific position was incubated with cell-free extracts of Po ${\beta}-proficient$ and -deficient mouse embryonic fibroblast cells, the formation of major dL-mediated DPC was dependent on the presence of DNA polymerase (Pol) ${\beta}$. Formation of dL-specific DPC was also observed with histones and FEN1 nuclease, although the reactivity in forming dL-mediated DPC was significantly higher with Pol ${\beta}$ than with histones or FEN1. DNA repair assay with a defined DPC revealed that the dL lesion once cross-linked with Pol ${\beta}$ was resistant to nucleotide excision repair activity of cell-free extract. Analysis of nucleotide excision repair utilizing a model DNA substrate containing a (6-4) photoproduct suggested that excision process for DPC was inhibited because of DNA single-strand incision at 5' of the lesion. Consequently DPC mediated by dL lesion may not be readily repaired by DNA excision repair pathway but instead function as unusual DNA damage causing a prolonged DNA strand break and trapping of the major base excision repair enzyme.

• 생약학회지
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• 제44권3호
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• pp.224-229
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• 2013

Bromotopsentin (BSM) is a bisindole alkaloid compound, which is recognized as a metabolite of the marine sponge Spongosorites sp. In this study, the antioxidant activity of BSM was investigated. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, the trolox equivalent antioxidant capacity (TEAC) assay, the superoxide radical scavenging (NBT) assay, the lipid peroxidation and hydroxyl radical-induced DNA damage assays were carried out to evaluate the antioxidant activity of BSM. It was found that BSM had stronger scavenging activity on the stable free radical DPPH and superoxide radical than L-ascorbic acid with an $IC_{50}$ value of 62 and 64 ${\mu}M$, respectively. The TEAC value which indicated the total antioxidant capacity of BSM was about 0.8, which was also stronger than L-ascorbic acid. About 1.3 ${\mu}M$ of BSM induced 50% inhibition of lipid peroxidation. 60 nM of BSM exhibited a significant protective activity against DNA strand scission by hydroxyl radical on pBR322 DNA. Taken together, we suggest that BSM possesses strong antioxidant activity, and could be a valuable new addition to the list of anti-aging chemotherapeutic agents.

• Applied Biological Chemistry
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• 제46권1호
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• pp.32-38
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• 2003

시판되고 있는 두류 13종류의 70% 에탄을 추출물을 제조하여, 이들의 항산화 활성을 환원력, 지질과산화 억제 활성, superoxide radical 소저활성, hydroxyl radical 소거활성, mitomycin C로 유도된 DNA의 산화적 손상에 대한 억제활성을 지표로 조사하였다. 환원력은 예팥, 속피리, 유월콩 및 적두가 높았다. 지질과산화 억제능을 조사한 결과, linoleic acid 자동산화계를 이용한 실험계에서 모든 시료가 억제활성을 보인 반면, 토끼 적혈구막 지질과 산화에 대한 억제활성은 쥐눈이콩과 적두, 속피리에서만 관찰되었다. Superoxide radical 소거활성은 예팥, 나물콩, 적두, 쥐눈이콩에서 높게 나타났으며, hydroxyl radical 소거활성은 속피리, 청태, 예팥과 제비콩에서 높았다. Mitomycin C로 유도된 DNA의 산화적 손상에 대한 억제활성을 조사한 결과, 모든 품종들이 DNA의 산화적 손상을 억제할 수 있었으나, 특히 예팥, 쥐눈이콩, 나물콩, 녹두, 적두의 억제활성이 우수하였다. 이상의 실험결과에서 예팥, 적두, 쥐눈이콩, 속피리가 환원력, 지질과산화 억제, superoxide radical 및 hydroxyl radical 소거활성, DNA의 산화적 손상에 대한 억제활성 둥 항산화활성이 우수한 품종임을 알 수 있었다.

• Natural Product Sciences
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• 제10권6호
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• pp.277-283
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• 2004

Psammaplin A (PSA), a naturally occurring biophenolic compound has been demonstrated to deliver significant cytotoxicity to many cancer cell lines. In this article, we investigated the effect of PSA on cell cycle progression of lung cancer cells (A549). It was found that PSA could slightly perturb the cell cycle progression of A549 cells and lead to the cell cycle arrest at G2/M phase, indicating PSA might disturb the mitosis process of A549 cells. In addition, inspired by the two phenolic groups in the structure of PSA, the antioxidant activity of it has been evaluated. Although PSA was weak in scavenging the stable free radical 1,1-diphenyl-2-picrylhyrazyl (DPPH), it showed stronger ABTS radical scavenging activity than ascorbic acid in TEAC assay. Furthermore, it was found that PSA could effectively prevent DNA strand scission induced by oxidative stress. These results suggest that PSA have both cell cycle regulation and antioxidant activities. Herein, we suggest that PSA would be a very interesting and promising candidate to be developed as a multi-function drug.