• Journal of Microbiology and Biotechnology
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• v.28 no.4
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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.

• Korean Journal of Plant Resources
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• v.27 no.6
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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.

• Environmental Mutagens and Carcinogens
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• v.19 no.2
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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.

• Horticultural Science & Technology
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• v.17 no.6
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• pp.770-772
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• 1999

This study was conducted to provide a basic system to develop a molecular marker for plant cultivar protection using a recombinant DNA technology. Using Nicotiana tabacum L. plants, the potentiality in the utilization of the developed marker was examined. After homology test with several plant genomes, mouse adenosine deaminase (ADA) gene was selected as DNA source of a molecular marker for cultivar protection. As a result of the digestion of ADA gene with BamHI and Pst I, six DNA fragments were obtained, and 513 bp DNA fragment among them was selected as a possible DNA marker for cultivar protection. Selected 513 bp DNA fragment was efficiently inserted into pBI101 plasmid vector for plant transformation by using phagemid vector pBluescript II SK (+/-) as an intermediate vector. The recombinant pBI101, carrying 513 bp DNA fragment, possible markers for cultivar protection, was transformed into A. tumefaciens LBA4404. Nicotiana tabacum was transformed with A. tumefaciens LBA4404 having the recombinant pBI101 and was confirmed the transfer of 513 bp DNA fragment, a possible molecular marker for cultivar protection.

• Proceedings of the Microbiological Society of Korea Conference
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• 2004.05a
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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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• v.20 no.2
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• pp.71-78
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• 1995

To develop methods to reduce radiation risk and apply such knowledge to improvement of radiation protection, the effects of cobaltous chloride known as bioantimutagen on the function of E. coli RecA protein involved in the repair of DNA damage were examined. The results demonstrated two distinct effects of cobaltous chloride on the RecA protein function necessary for the strand exchange reaction. Cobaltous chloride enhanced the ability of RecA protein to displace SSB protein from single-stranded DNA and the duplex DNA-dependent ATPase activity. RecA protein was preferentially bound with UV-irradiated supercoiled DNA as compared with nonirradiated DNA The binding of RecA protein to UV-irradiated supercoiled DNA was enhanced in a dose-dependent manner. It is likely that studies on the factors affecting repair efficiency and the DNA repair proteins may provide information on the repair of ionizing radiation-induced DNA damage and the mechanism for DNA radioprotection.

• Journal of Environmental Science International
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• v.23 no.3
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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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• v.17 no.2
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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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• v.36 no.4
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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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• v.16 no.15
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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.