• YAKHAK HOEJI
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• v.51 no.4
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• pp.285-290
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• 2007

The oxidative stress causes many diseases like cancer, aging, cardiovascular disease, degenerative neurological disorders (Parkinson’s disease, and Alzheimer's disease) by damage of cell membrane, protein deformation, and damage of DNA due to the oxidation of lipid of cell membrane, protein of tissue or enzyme, carbohydrate, and DNA. It is caused by the reactive oxygen species (ROS) that is produced in the metabolic process of oxygen in cell. The superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in cell systemize the antioxidative enzymes to control the oxidative stress. In this research, it is measured that the survival rate of cell by the typical isoflavonoid of daidzein or genistein, activity of antioxidative enzyme, and ROS level, in order to study the effect of isoflavonoid over the ROS production in cell and antioxidative system. As the similar action of the isoflavonoid with the estrogen is examined, women are encouraged to get bean. In view of this trend, it is very important to find out a combination medicine that lowers the oxidative stress caused by the daidzein in the ovarian cell. In the combined treatment of the typical antioxidant of vitamin C to oxidative stress which induced by daidzein recover the control level particularly lowering the ROS in cell by 30%. However, it made no effect in the combined treatment with genistein. Therefore, the research took the combination effect of daidzein with vitamin C in order to check it effect over the antioxidative system. In conclusion, it was disclosed that the oxidative stress caused by daidzein is related to the lowering activity of SOD, and the specific combination effect of daidzein with vitamin C is related to the recovery of SOD activity.

• BMB Reports
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• v.44 no.5
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• pp.352-357
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• 2011

The effect of human MutY homolog (hMYH) on the activation of checkpoint proteins in response to hydroxyurea (HU) and ultraviolet (UV) treatment was investigated in hMYH-disrupted HEK293 cells. hMYH-disrupted cells decreased the phosphorylation of Chk1 upon HU or UV treatment and increased the phosphorylation of Cdk2 and the amount of Cdc25A, but not Cdc25C. In siMYH-transfected cells, the increased rate of phosphorylated Chk1 upon HU or UV treatment was lower than that in siGFP-transfected cells, meaning that hMYH was involved in the activation mechanism of Chk1 upon DNA damage. The phosphorylation of ataxia telangiectasia and Rad3-related protein (ATR) upon HU or UV treatment was decreased in hMYH-disrupted HEK293 and HaCaT cells. Co-immunoprecipitation experiments showed that hMYH was immunoprecipitated by anti-ATR. These results suggest that hMYH may interact with ATR and function as a mediator of Chk1 phosphorylation in response to DNA damage.

• Journal of Chest Surgery
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• v.22 no.1
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• pp.16-24
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• 1989

To investigate the effects of hydrocortisone on new-born rat cardiac endothelial cells in culture, the endothelial cells were isolated by means of enzyme-cocktail method. The cells were cultivated in Lees modified Dulbeco\ulcorner medium and 10[M or 10[M of hydrocortisone was added to the medium. The cells were harvested or coverglass and processed for thiamin pyrophosphatase reaction and Feulgen reaction. The enzymatic activities of Golgi complex, number of cells and number of large nucleated[more than tetraploid] cells were counted and discussed for their significance. The results were summarized as follows; 1. Hydrocortisone seemed to accelerate the rate of recovery of cardiac endothelial cells from isolation damage. 2. Endothelial cells treated with hydrocortisone revealed strong positive reaction to thiamine pyrophosphatase in early culture and 10 M group had stronger reaction than that of 10 AM group 3. Hydrocortisone had inhibiting effects on endothelial proliferation and the higher the concentration of the reagent was the stronger effects. 4. Hydrocortisone inhibited the appearance of large nucleate cells in endothelial cell population. 5. Hydrocortisone seemed to suppress the nuclear DNA synthesis.

• Parasites, Hosts and Diseases
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• v.56 no.1
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• pp.1-9
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• 2018

Giardia lamblia, an anaerobic, amitochondriate protozoan parasite causes parasitic infection giardiasis in children and young adults. It produces pyruvate, a major metabolic product for its fermentative metabolism. The current study was undertaken to explore the effects of pyruvate as a physiological antioxidant during oxidative stress in Giardia by cysteine-ascorbate deprivation and further investigation upon the hypothesis that oxidative stress due to metabolism was the reason behind the cytotoxicity. We have estimated intracellular reactive oxygen species generation due to cysteine-ascorbate deprivation in Giardia. In the present study, we have examined the effects of extracellular addition of pyruvate, during oxidative stress generated from cysteine-ascorbate deprivation in culture media on DNA damage in Giardia. The intracellular pyruvate concentrations at several time points were measured in the trophozoites during stress. Trophozoites viability under cysteine-ascorbate deprived (CAD) medium in presence and absence of extracellular pyruvate has also been measured. The exogenous addition of a physiologically relevant concentration of pyruvate to trophozoites suspension was shown to attenuate the rate of ROS generation. We have demonstrated that Giardia protects itself from destructive consequences of ROS by maintaining the intracellular pyruvate concentration. Pyruvate recovers Giardia trophozoites from oxidative stress by decreasing the number of DNA breaks that might favor DNA repair.

• Journal of Microbiology and Biotechnology
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• v.21 no.4
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• pp.438-447
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• 2011

Deinococcus radiodurans is extremely resistant to various genotoxic conditions and chemicals. In this study, we characterized the effect of a sublethal concentration (100 ${\mu}M$) of cadmium (Cd) on D. radiodurans using a whole-genome DNA microarray. Time-course global gene expression profiling showed that 1,505 genes out of 3,116 total ORFs were differentially expressed more than 2-fold in response to Cd treatment for at least one timepoint. The majority of the upregulated genes are related to iron uptake, cysteine biosynthesis, protein disulfide stress, and various types of DNA repair systems. The enhanced upregulation of genes involved in cysteine biosynthesis and disulfide stress indicate that Cd has a high affinity for sulfur compounds. Provocation of iron deficiency and growth resumption of Cd-treated cells by iron supplementation also indicates that CdS forms in iron-sulfur-containing proteins such as the [Fe-S] cluster. Induction of base excision, mismatch, and recombinational repair systems indicates that various types of DNA damage, especially base excision, were enhanced by Cd. Exposure to sublethal Cd stress reduces the growth rate, and many of the downregulated genes are related to cell growth, including biosynthesis of cell membrane, translation, and transcription. The differential expression of 52 regulatory genes suggests a dynamic operation of complex regulatory networks by Cd-induced stress. These results demonstrate the effect of Cd exposure on D. radiodurans and how the related genes are expressed by this stress.

• The Plant Pathology Journal
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• v.35 no.5
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• pp.521-529
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• 2019

Tomato yellow leaf curl China virus is a species of the widespread geminiviruses. The infection of Nicotiana benthamiana by Tomato yellow leaf curl China virus (TYLCCNV) causes a reduction in photosynthetic activity, which is part of the viral symptoms. ${\beta}C1$ is a viral factor encoded by the betasatellite DNA ($DNA{\beta}$) accompanying TYLCCNV. It is a major viral pathogenicity factor of TYLCCNV. To elucidate the effect of ${\beta}C1$ on plants' photosynthesis, we measured the relative chlorophyll (Chl) content and Chl fluorescence in TY-LCCNV-infected and ${\beta}C1$ transgenic N. benthamiana plants. The results showed that Chl content is reduced in TYLCCNV A-infected, TYLCCNV A plus $DNA{\beta}$ (TYLCCNV A + ${\beta}$)-infected and ${\beta}C1$ transgenic plants. Further, changes in Chl fluorescence parameters, such as electron transport rate, $F_v/F_m$, NPQ, and qP, revealed that photosynthetic efficiency is compromised in the aforementioned N. benthamiana plants. The presense of ${\beta}C1$ aggravated the decrease of Chl content and photosynthetic efficiency during viral infection. Additionally, the real-time quantitative PCR analysis of oxygen evolving complex genes in photosystem II, such as PsbO, PsbP, PsbQ, and PsbR, showed a significant reduction of the relative expression of these genes at the late stage of TYLCCNV A + ${\beta}$ infection and at the vegetative stage of ${\beta}C1$ transgenic N. benthamiana plants. In summary, this study revealed the pathogenicity of TYLCCNV in photosynthesis and disclosed the effect of ${\beta}C1$ in exacerbating the damage in photosynthesis efficiency by TYLCCNV infection.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1208-1214
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• 2011

Caffeine, a psychoactive stimulant, has been implicated in the modulation of learning and memory functions due to its action as a non-selective adenosine receptors antagonist. On the contrary, some side effects of caffeine have been reported, such as an increased energy loss and metabolic rate, decrease DNA synthesis in the spleen, and increased oxidative damage to exerted on LDL particles. Therefore, the aim of this study was to develop a safe stimulant from natural plants mixture (Aralia elata, Acori graminei Rhizoma, Chrysanthemum, Dandleion, Guarana, Shepherd's purse) that can be used as a substitute for caffeine. Thirty SD rats were divided into three groups; control group, caffeine group (15.0 mg/kg, i.p.), and natural plants mixture group (NP, 1 mL/kg, p.o.). The effect of NP extract on stimulant activity was evaluated with open-field test (OFT) and plus maze test for measurement of behavioral profiles. Plasma lipid profiles, lipid peroxidation in LDL (conjugated dienes), total antioxidant capacity (TRAP) and DNA damage in white blood, liver, and brain cells were measured. In the OFT, immobility time was increased significantly by acute (once) and chronic (3 weeks) supplementation of NP and showed a similar effect to caffeine treatment. Three weeks of caffeine treatment caused plasma lipid peroxidation and DNA damage in liver cells, whereas there were no changes in the NP group. NP group showed a higher plasma HDL cholesterol concentration compared to the caffeine group. The results indicate that the natural plants mixture had a stimulant effect without inducing oxidative stress.

• Clinical and Experimental Reproductive Medicine
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• v.44 no.3
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• pp.132-140
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• 2017

Objective: Correlations between semen parameters and sperm DNA fragmentation index (DFI) were investigated to identify characteristics of sperm without DNA damage that could be used in selecting sperm for intracytoplasmic sperm injection (ICSI). Pregnancy outcomes were compared to determine whether in vitro fertilization (IVF) or ICSI is a better choice for patients who have sperm with a high-DFI. Methods: Semen analysis was carried out in 388 patients who visited our IVF center for the first time to investigate correlations between sperm DFI and semen parameters. In addition, 1,102 IVF cycles in 867 patients were carried out in the present study; 921 cycles in the low-DFI group (DFI < 30%) and 181 cycles in the high-DFI group ($DFI{\geq}30%$). Both the low- and high-DFI groups were subdivided into IVF and ICSI cycle groups. Results: Sperm DFI showed significant inverse correlations with sperm motility (r = -0.435, p< 0.001) and morphology (r = -0.153, p< 0.05). Sperm DFI also showed significant correlations with rapid motility (r = -0.436, p< 0.001), and the kinetic parameters of average-path velocity (r = -0.403) and linearity (r = -0.412). Although there was no significant difference in the pregnancy rates between IVF (48.6%) and ICSI (44.8%) in the low-DFI group, the pregnancy rate of ICSI cycles (44.8%, p< 0.05) was significantly higher than IVF cycles (25.0%) in the high-DFI group. No significant difference was observed in the abortion rates between the low-DFI (52 of 921, 5.6%) and high-DFI groups (7 of 181, 3.8%). Conclusion: ICSI is a better choice than IVF for improving the pregnancy outcomes of patients who have sperm with a high DFI.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.53-53
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• 2023

Abeliophyllum distichum, one of the Korean endemic plant, is a significant pharmaceutical plant resource. A. distichum with phenylethanoid glycoside can use to regulate the development of cancer, DNA damage with radicals, and the generation of inflammatory mediators. In this study, we investigated whether the biomass, content of phenylethanoid glycoside, and growth rate of callus derived from A. distichum (cultivar Okhwang1, CAD) change in the absence or presence of plant hormones (2,4-Dichlorophenoxyacetic acid; 2, 4-D and 1-Naphthaleneacetic acid; NAA). The results showed that the best biomass, the growth rate of callus, and the contents of phenylethanoid glycoside were cultivated on Murashige and Skoog (MS) growth medium fortified with 1 ppm 2,4-D + 2 ppm NAA after 4 weeks. In a further study, CAD was cultivated on MS growth medium fortified with an elicitor (Methyl Jasmonate, MeJA). The results showed that CAD turned to brown color and fragile form with the elicitor. HPLC-PDA analysis revealed that the contents of phenylethanoid glycoside in the elicitor-treated group were higher than in the elicitor-non-treated group. These results are consistent with the findings of Arano-Varela H et al.,'s study which is that acteoside production can increase after the treatment of MeJA. Therefore, this study can be used to develop an effective and sustainable production of useful substances as an alternative to plant cultivation.

• Korean Journal of Head & Neck Oncology
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• v.17 no.2
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• pp.169-173
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• 2001

Objectives: The p53 tumor suppressor gene encodes a nuclear transcription factor that is critical regulator of cell growth and proliferation through its action in cell-cycle checkpoint control. The wide variety of stressful stmuli which include DNA damage, hypoxia, heat shock, metabolic changes activate the p53 protein, which in turn drives a series of events that culminate either in cell cycle arrest or apoptosis. Mutations of the p53 gene is the most common genetic alteration in human cancer. This gene is altered in approximately 40-60% of head and neck cancers. Whereas the wild-type form of the p53 protein plays a central role in cell-cycle control in response to DNA damage, most of the mutant forms are unable to do so. The high levels of p53 protein expression in tissues are related to the increased cellular proliferative activity and may be associated with the poor clinical outcome. To determine whether the expression of the p53 protein has prognostic significance and is associated with patterns of treatment failure in head and neck squamous cell carcinoma (HNSCC), We analyzed p53 overexpression in 40 cases of HNSCC. Materials and Methods: Immunohistochemical analysis with a monoclonal antibody (DO7) specific for p53 protein was used to detect expression of the protein in formalin-fixed, paraffin-embedded tumor samples from 40 HNSCC. We evaluated p53 protein expression and analyzed the relationship between the p53 overexpression and age, sex, primary tumor site, stage, survival rate, recurrence. All reported P values resulted from two-sided statistical tests. Results: Overexpression of p53 was detected in 20 cases(50%) among 40 cases of HNSCC. The p53 overexpression was not associated with age, sex, primary tumor site, stage, recurrence and survival rate. Conclusions: In our results, p53 was not significant prognostic factor in HNSCC. Based on many previous studies, It is evident that p53 has a certain role in tumorigenesis of HNSCC. So, the further study is needed to evaluate the prognostic significance of p53 in HNSCC.