• Journal of Microbiology and Biotechnology
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• 제28권4호
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• pp.527-533
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• 2018

This study compared the radioprotective effects of high-molecular-weight poly-gamma-glutamate (${\gamma}-PGA$, average molecular mass 3,000 kDa) and a reduced form of glutathione (GSH, a known radioprotector) on calf thymus DNA damage. The radiation-induced DNA damage was measured on the basis of the decreased fluorescence intensity after binding the DNA with ethidium bromide. All the experiments used $^{60}Co$ gamma radiation at 1,252 Gy, representing 50% DNA damage. When increasing the concentration of ${\gamma}-PGA$ from 0.33 to $1.65{\mu}M$, the DNA protection from radiation-induced damage also increased, with a maximum of 87% protection. Meanwhile, the maximal DNA protection when increasing the concentration of GSH was only 70%. Therefore, ${\gamma}-PGA$ exhibited significant radioprotective effects against gamma irradiation.

• 한국자원식물학회지
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• 제27권6호
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• pp.714-719
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• 2014

This study investigated DNA damage protection and anti-inflammatory activity of different solvent fractions from Aruncus dioicus var. kamtschaticus (A. dioicus) aerial parts water extract. As for DNA damage protection, distilled water ($H_2O$) fraction displayed the most powerful protection for DNA damage at a concentration of 1 mg/ml. As for anti-inflammatory activity, dichloromethane ($CH_2Cl_2$) fraction exhibited the highest NO inhibition activity, ranging from 61% to 19% ($10-40{\mu}g/ml$). Furthermore, the levels of pro-inflammatory cytokines mRNA expressions and intracellular reactive oxygen species (ROS) were employed to verify the anti-inflammatory activity of the $CH_2Cl_2$ fraction on further researches. It could be concluded that A. dioicus had a significantly effect of DNA damage protection and anti-inflammatory activity which also as an essential edible vegetable and medicinal species.

• 한국환경성돌연변이발암원학회지
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• 제19권2호
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• pp.112-115
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• 1999

The action mechanism of the inhibitory effect of some natural products on the DNA strand break and DNA damage was investigated in vitro and in vivo. In the E. coli chromosomal DNA strand break experiment in vitro, three mushroom water extracts were effective on the DNA strand breaking by daunorubicin. Phellinus linteus water extract inactivated daunorubicin, a DNA strand breaking agent, but did not protect DNA from daunorubicin-induced DNA strand breaking. Agaricus blazei water extract inhibited DNA strand breaking action of daunorubicin not only by daunorubicin inactivation, but also by DNA protection from daunorubicin. An inhibitory effect of Ganoderma lucidum water extract on the DNA strand break was based on the DNA protection rather than daunorubicin inactivation. In vivo mutagen assay system (SOS-chromotest), among three mushroom water extracts Phellinus linteus water extract was the most effective one on the inhibition of DNA damage by 4-NQO. The results suggest that all three mushroom water extracts inhibit daunorubicin-induced DNA damage and in vivo DNA damaging action of 4-NQO by the reaction of mutagen inactivation or DNA protection from the mutagen.

• 원예과학기술지
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• 제17권6호
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• pp.770-772
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• 1999

새로 육성된 품종의 보호를 위한 분자마커를 대상 작물에 전이시키는 체계를 확립하고자 본 실험을 실시하였다. 식물에서는 전혀 존재하지 않는 mouse adenosine deaminase(ADA) gene으로부터 분자마커로 활용 가능한 크기의 DNA 단편을 획득하고 이를 pBI101에 삽입하여 chimeric gene을 만들었다. 분자마커를 포함하는 형질전환된 담배를 획득하기 위해 A. tumefaciens LBA4404를 이용하여 형질전환을 실시하였다. 담배 절편체에서 형질전환된 신초를 얻기 위해 BAP $1.5mg{\cdot}L^{-1}$, kanamycin $50mg{\cdot}L^{-1}$과 cefotaxim $200mg{\cdot}L^{-1}$이 혼용된 MS배지에서 선발하였으며 신초 발생후 kanamycin의 농도를 2배, 4배로 증가시켜 chimeric gene이 완전하게 전이되어 저항성을 가진 8개체를 얻었다. 항생제에 의해 선발된 8개체를 분자마커 primer로 PCR분석하여 분자마커가 식물체의 genome내로의 전이를 확인하였다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2004년도 International Meeting of the Microbiological Society of Korea
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• pp.47-50
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• 2004

The defenses against free radical damage include specialized repair enzymes that correct oxidative damages in DNA, and detoxification systems such as superoxide dismutases. These defenses may be coordinated genetically as global responses. We hypothesized that the expression of the SOD and the DNA repair genes would inhibit DNA damage under oxidative stress. Therefore, the protection of E. coli mutants deficient in SOD and DNA repair genes $(sod^-\;xth^-\;and\;nfo^-)$ was demonstrated by transforming the mutant strain with a plasmid pYK9 which encoded Photobacterium leiognathi CuZnSOD and human AP endonuclease. The results show that survival rates were increased in $sod^+\;xth^-\;nfo^+$ cells compared to $sod^-\;xth^-\;ap^+,\;sod^-\;xth^-\;ap^-,\;and\;sod^+\;xth^-\;ap^-$ cells under oxidative stress generated from 0.1 mM Paraquat or 3 mM $H_2O_2$. The data suggested that, at least, SOD and DNA repair enzymes may have collaborate protection and repair of the damaged DNA. Additionally, both enzymes are required for protection against free radicals.

• Journal of Radiation Protection and Research
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• 제20권2호
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• pp.71-78
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• 1995

본 연구에서는 유전자 손상회복에 관여하는 단백질을 이용하여 돌연변이 생성을 억제시키는 물질로서 알려진 cobaltous chloride가 유전자 손상회복에 미치는 영향을 연구하므로서 방사선으로 인한 손상방지 및 방사선 방어효과에 대한 적용가능성을 평가하였다. Cobaltous chloride가 RecA 단백질의 기능에 미치는 영향을 조사한 결과 RecA 단백질에 의한 DNA strand exchange 반웅에 있어 cobaltous chloride 처리로 RecA 단백질이 $_{ss}DNA$로 부터 SSB 단백질과 더 효과적으로 경쟁함으로써 안정된 $RecA-_{ss}DNA$ complex의 형성을 유도하고, 증가된 ATPase활성에 의한 ATP 가수분해로 손상된 DNA의 회복이 촉진될 수 있다는 사실을 입증 해주고 있다. 또한 RecA단백질은 UV에 의해 손상된 supercoiled DNA에 더 효과적으로 결합됨이 관찰되었으며 UV 선량과도 상관관계가 있음을 확인하였다. 따라서 이와 같은 연구결과들은 방사선으로 인한 유전적인 손상방지 및 방사선 방어효과에 관한 연구에 적용될 수 있을 것으로 기대된다.

• 한국환경과학회지
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• 제23권3호
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• pp.483-492
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• 2014

DNA damage such as genotoxicity was identified with comet assay, which blood cell of a marine parrot fish (Oplegnathus fasciatus) was exposed to an acidified seawater, lowered pH gradient making of $CO_2$ gas. The gradient of pH were 8.22, 8.03, 7.81, 7.55 with control as HBSS solution with pH 7.4. DNA tail moment of fish blood cell was $0.548{\pm}0.071$ exposed seawater of pH 8.22 condition, on the other hand, DNA tail moment $1.601{\pm}0.197$ exposed acidified seawater of pH 7.55 lowest condition. The approximate difference with level of DNA damage was 2.9 times between highest and lowest of pH. DNA damage with decreasing pH was significantly increased with DNA tail moment on blood cell of marine fish (ANOVA, p < 0.001). Ocean acidification, especially inducing the leakage of sequestered $CO_2$ in geological structure is a consequence from the burning of fossil fuels, and long term effects on marine habitats and organisms are not fully investigated. The physiological effects on adult fish species are even less known. This result shown that the potential of dissolved $CO_2$ in seawater was revealed to induce the toxic effect on genotoxicity such as DNA breakage.

• 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 Radiation Protection and Research
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• 제36권4호
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• pp.190-194
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• 2011

After the first report that electrons with sub-ionization energy of DNA could cause single strand breaks or double strand breaks to DNA, there have been various studies to investigate the mechanisms of DNA damage by low-energy electrons. In this paper, we examined the possibility of using X-ray photoelectron spectroscopy (XPS) to analyze the dissociation patterns of the molecular bonds by electron irradiation on DNA thin films and tried to establish the method as a general tool for studying the radiation damage of biomolecules by low energ yelectrons. For the experiment, pBR322 plasmid DNA solution was formed into the films on tantalum plates by lyophilization and was irradiated by 5-eV electrons. Un-irradiated and irradiated DNA films were compared and analyzed using the XPS technique.

• Asian Pacific Journal of Cancer Prevention
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• 제16권15호
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• pp.6535-6539
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• 2015

This study was designed to assess, whether a new chemotherapeutic microtubule inhibitor, Epothilone B (EpoB, Patupilone), can induce DNA damage in normal ovarian cells (MM14.Ov), and to evaluate if such damage could be repaired. The changes were compared with the effect of paclitaxel (PTX) commonly employed in the clinic. The alkaline comet assay technique and TUNEL assay were used. The kinetics of DNA damage formation and the level of apoptotic cells were determined after treatment with IC50 concentrations of EpoB and PTX. It was observed that PTX generated significantly higher apoptotic and genotoxic changes than EpoB. The peak was observed after 48 h of treatment when the DNA damage had a maximal level. The DNA damage induced by both tested drugs was almost completely repaired. As EpoB in normal cells causes less damage to DNA it might be a promising anticancer drug with potential for the treatment of ovarian tumors.