• Journal of Radiation Protection and Research
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• v.31 no.2
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• pp.65-68
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• 2006

In this study, the extent of plasmid DNA damage was observed according to concentration of BSH(Boron Sulfhydryl Hydride) and irradiation doses of neutron and ${\gamma}$-ray. The plasmid used was both pBR 322 (2870 bp) and ${\Phi}X174$ RF(5386 bp) DNA. Plasmid DNA damage by irradiation in the presence of BSH was analyzed by agarose gel electrophoresis. In the neutron experiment, DNA damage of both plasmid DNAs was increased according to increasing the concentration of BSH and neutron doses. But in the ${\gamma}$-ray experiment, there appeared no dose dependency as compared to the neutron experiment. The extent of the plasmid DNA damage in the presence of BSH was somewhat different according to irradiation by neutron or ${\gamma}$-ray.

• Development and Reproduction
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• v.1 no.2
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• pp.157-164
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• 1997

To study the regulation of porcine follicular cell apostosis by gonadotropin, steroid, and nitric oxide, we analyzed DNA fragmentation, the hallmark of apoptosis, and nitrite production of porcine granulosa cells. Dissected indiidual follicles from ovary were separated in size (small, 2-3 mm; medium, 5-6 mm; large, 7-8 mm) and isolated granulosa cells were classified morpholocally as atretic or nonatretic. Nitrite concentration was measured by mixing follicular fluids with an equal volume of Griess reagent. Follicular nitric oxide (NO) concentration of healthy follicles was higher than that of atretic follicles. Apoptotic DNA fragmentation was suppressed in non-apoptotic granulosa cells. Follicular apoptosis was induced by androgen but prevented by gonadotropin in vitro. Apoptosis was confined to the granulosa cells. But it was not clear whether apoptosis of granulosa cells were isolated, incubated with or without gonadotropin, androgen and sodium nitroprusside (SNP), respectively at $37^{\circ}C$ for 24 hrs. Cultured granulosa cells were used to extract genomic DNA and culture media was asssayed for nitrite concentration. Nitrite production of culture media was increased, while apoptotic DNA fragmentation was suppressed in PMSG, hCG, testosterone+SNP and SNP treated groups. Nitrite concentration in culture media was decreased, but apoptotic DNA fragmentation was induced in testosterone treated group. These data suggest that NO production and apoptosis may be involved of granulosa cell apoptosis induced by testosterone.

• 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.

• Archives of Pharmacal Research
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• v.22 no.1
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• pp.25-29
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• 1999

Psammaplin A, a natural bromotyrosine derivative from an associated form of two sponges (Poecillastra sp. and jaspis sp.) was found to possess the antimicrobial effect on the Gram-positive bacteria, especially on methicillin-resistant Staphylococcus aureus (MRSA). The minimal inhibitory concentration of psammaplin A against twenty one MRSAs ranged from 0.781 to 6.25 ${\mu}g/ml$, which that of ciprofloxacin was 0.391~3.125${\mu}g/ml$. Psammaplin A could not bind to penicillin binding protein, but inhibited the DNA synthesis and the DNA gyrase activity with the respective 50% (DNA synthesis) and 100% (DNA gyrase) inhibitory concentration 2.83 and 100 ${\mu}g/ml$. These results indicate that psammaplin A has a considerable antibacterial activity, although restricted to a somewhat narrow range of bacteria, probably by inhibiting DNA gyrase.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.336-344
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• 2014

Objectives: This study was performed to assay the effect of neodymium oxide on the generation of reactive oxygen species and DNA oxidative damage by intratracheal instillation. Methods: Two groups of rats were exposed to neodymium oxide($Nd_2O_3$) via intratracheal instillation with doses of 0.5 mg and 2.0 mg, respectively. At two days and at 12 weeks after exposure, the contents of neodymium oxide in the lung, liver, kidney, heart and brain, leukocyte, olive tail moment, ROS, RNS, lactate dehydrogenase, albumin, cytokine and MDA from BALF were measured. Results: Neodymium oxide contents in the liver, kidney, heart, and brain were detected at less than $1{\mu}g/g$ tissue concentration. However, in the lungs at four weeks the highest amount were detected and then found to be drastically reduced at 12 weeks. ROS and RNS in bronchoalveolar lavage increased in concentration dependently at two days, four weeks and 12 weeks after neodymium oxide instillation. However, ROS and RNS decreased with the passage of time. At two days the total number of WBC in BALF in the high concentration group was significantly increased, and at four weeks the total number of WBC were significantly increased in the low and high concentration groups(p<0.01). At two days after exposure, the LDH of the low and high concentration groups was significantly increased. At 12 weeks, only the LDH of the high concentration group was significantly increased compared to in the control group(p<0.01). As a result of Comet assay, after two days, damage to the DNA of the low and high concentration groups was observed. Conclusions: Intratracheal instillation of neodymium oxide induces the generation of ROS and DNA damage in rats.

• YAKHAK HOEJI
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• v.40 no.6
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• pp.697-704
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• 1996

Quinolone derivatives, SJ5b (ethyl 5,12-dihydro-5-dihydro-5-oxobenzoxazolo[3,2-a]quinoline-6-carboxylate) and SQ7b (3-fluoro-2-(4-methylpiperazin-1-yl)-5.12-dihydro-5-oxobenzoxa zolo[3,2-a]quinoloine carboxylic acid) showed in vitro cytotoxicities against various tumor cell lines. SJ5b and SQ7b completely inhibited the DNA relaxation activities of human placental topoisomerase II at the concentration of 15.63 and 1.95 ${\mu}$g/ml, respectively. However, unlike etoposide which stabilize the topoisomerase II-DNA complex, SQ7b did not cause topoisomerase II-mediated DNA cleavage and SJ5b weakly stabilized the topoisomerase II-DNA cleavable complex. Through both experiments. DNA relaxation assay by the increment of topoisomerase II concentration and DNA unwinding assay, it was shown that SJ5b and SQ7b did not interact with topoisomerase II itself but bound to DNA. Therefore, it was concluded that DNA binding of SJ5b and SQ7b caused the inhibition of topoisomerase II related to DNA relaxation but no or very weak stabilization of topoisomerase II-DNA cleavable complex. In addition, SJ5b and SQ7b prevented whole cell nucleic acid syntheses in HL60 cells.

• Biomolecules & Therapeutics
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• v.11 no.2
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• pp.139-144
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• 2003

Ganoderma lucidum is commonly known as medically potent mushroom, which has been widely used in China and other oriental countries for the treatment of various diseases, including cancer. In this report, we investigated the anti-oxidant and protective effect of Ganodema lucidum extract (GLE) against the DNA damage induced by free radical and U.V. In the assay of cell growth inhibition, the inhibitory cell growth rate induced by hydroxyl radical was dose-dependently decreased by GLE. This results support that GLE has a detoxifying activity against cytotoxicity of hydroxyl radical in E. coli cell. GLE also protected ColE1 plasmid DNA damage in the concentration of 200$\mu\textrm{g}$ per reaction on the DNA fragmentation assay. The nuclear tailing by hydrogen peroxide in single cell gel electrophoresis(SCGE) was decreased by GLE in the concentration of 50$\mu\textrm{g}$/ml. These data indicate that Ganoderma lucidum has an anti-oxidative activity to hydrogen peroxide. The mutation rate after irradiation of U.V. was reduced by 50$\mu\textrm{g}$/ml GLE and total number of Rif (Rifampicin) resistant mutants was decreased in a concentration dependent manner when added the GLE exogenously in a culture media. According to the results, it is likely that GLE has not only an anti-oxidative activity to hydroxyl radical but also an anti-mutagenic activity to U.V. mutagenesis.

• Environmental Analysis Health and Toxicology
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• v.20 no.4 s.51
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• pp.333-341
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• 2005

In order to know whether polychaetes could be used as an appropriate organism for the detection of genotoxicity, DNA strand breaks were evaluated in blood cells of a nereidae worm (Perinereis aibuhitensis) exposed to various aquatic chemical pollutants (e.g. Cd, Pb, Pyrene, Benaor[a]pyrene). Hydrogen peroxide increased DNA strand breaks up to the highest concentration (10 $\mu$M). Higher concentration than 0.1 $\mu$M showed a significantly more DNA damage than control. Cadmium and lead also showed higher DNA damage than control, over 1.0 and 1 $\mu$g/L, respectively. In case of pyrene, DNA damage was detected even at 0.001 $\mu$g/L. However, DNA damage decreased due to apoptosis at the highest concentration of pyrene and Pb. This study suggested that the polythaetous blood cells could be used effectively for screening genotoxic contaminants in the environment.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.5
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• pp.449-454
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• 2006

Here we present a sensitive DNA detection protocol using quantum dots (QDs) and magnetic beads (MBs) for large volume samples. In this study, QDs, conjugated with streptavidin, were used to produce fluorescent signals while magnetic beads (MBs) were used to isolate and concentrate the signals. The presence of target DNAs leads to the sandwich hybridization between the functionalized QDs, the target DNAs and the MBs. In fact, the QDs-MBs complex, which is bound using the target DNA, can be isolated and then concentrated. The binding of the QDs to the surface of the MBs was confirmed by confocal microscopy and Cd elemental analysis. It was found that the fluorescent intensity was proportional to concentration of the target DNA, while the presence of non-complementary DNA produced no significant fluorescent signal. In addition, the presence of low copies of target DNAs such as 0.5 pM in large volume samples up to 40mL was successfully detected by using a magnet-assisted concentration protocol which consequently results in the enhancement of the sensitivity more than 100-fold.

• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.272-279
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• 2021

A pump-type eDNA filtering system that can control voltage and hydraulic pressure respectively has been developed, and applied a filter case that can filter out without damaging the filter. The filtering performance of the developed system was evaluated by comparing the eDNA concentration with the conventional vacuum-pressured filtering method at the catchment conduit intake reservoir. The developed system was divided into a voltage control (manual pump system) method and a pressure control (automatic pump system) method, and the pressure was measured during filtering and the pressure change of each system was compared. The voltage control method started with 65 [KPa] at the beginning of the filtering, and as the filtering time elapsed, the amount of filtrate accumulated in the filter increased, so the pressure gradually increased. As a result of controlling the pressure control method to maintain a constant pressure according to the designed algorithm, there was a difference in the width of the hydraulic pressure fluctuation during the filtering process according to the feedback time of the hydraulic pressure sensor, and it was confirmed that the pressure was converged to the target pressure. The filtering performance of the developed system was confirmed by measuring the eDNA concentration and comparing the voltage control method and the hydraulic control method with the control group. The voltage control method obtained similar results to the control group, but the hydraulic control method showed lower results than the control group. It is considered that the low eDNA concentration in the hydraulic control method is due to the large pressure deviation during filtering and maintaining a constant pressure during the filtering process. Therefore, rather than maintaining a constant pressure during filtering, it was confirmed that a voltage control method in which the pressure is gradually increased as the filtrate increases with the lapse of filtering time is suitable for collecting eDNA. As a result of comparing the average concentration of eDNA in lentic zone and lotic zone as a control group, it was found to be 96.2 [ng µL^-1] and 88.4 [ng µL^-1l], respectively. The result of comparing the average concentration of eDNA by the pump method was also high in the lentic zone sample as 90.7 [ng µL^-1] and 74.8 [ng µL^-1] in the lentic zone and the lotic zone, respectively. The high eDNA concentration in the lentic zone is thought to be due to the influence of microorganisms including the remaining eDNA.