• Biomedical Science Letters
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• v.11 no.2
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• pp.103-108
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• 2005

2-Deoxyribonolactone (dL) arises as a major DNA damage induced by a variety of agents, involving free radical attack and oxidation of C1'-deoxyribose in DNA. We investigated whether dL lesions can be repaired in mammalian cells and the mechanisms underlying the role of DNA polymerase $\beta$ in processing of dL lesions. Pol $\beta$ appeared to be trapped by dL residues, resulting in stable DNA-protein cross-links. However, repair DNA synthesis at site-specific dL sites occurred effectively in cell-free extracts, but predominantly accompanied by long-patch base excision repair (BER) pathway. Reconstitution of long-patch BER demonstrated that FEN1 was capable of removing the displaced flap DNA containing a 5'-dL residue. Cellular repair of dL lesions was largely dependent on the DNA polymerase activity of Pol $\beta$. Our observations reveal repair mechanisms of dL and define how mammalian cells prevent cytotoxic effects of oxidative DNA lesions that may threaten the genetic integrity of DNA.

• Journal of Pharmaceutical Investigation
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• v.6 no.2
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• pp.88-94
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• 1976

This paper attempted to investigate the effect of pretreatment with carbon tetrachloride on absorption, excretion, protein binding, and biological half-life of sulfisoxazol from rats and rabbits. Absorption of sulfisoxazol was found to decrease in severe damage rats, compared with that of normal rats, but in mild rats, absorption of sulfisoxazol was similar to that of nomal rats. Absorption of sulfisoxazol was decreased significantly in severe damage rabbit pretreated with carbon tetrachloride but in mild damage rabbit, absorption of sulfisoxazol was not influenced significantly. Pretreatment with carbon tetrachloride gave the effect on clearance of sulfisoxazol in part but protein binding percent of sulfisoxazol was not influenced by concentration of carbon tetrachloride.

• Journal of Nutrition and Health
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• v.29 no.7
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• pp.689-702
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• 1996

The purpose of this experiment was to compare the effects of tryptophan administration on nutritional status of female rats which consumed reserpine and 6% casein diet with different carbohydrate contents(87%, 65%, 44% respective). Final body weight, body weight gain, FER, plasma amino acid concentration and microsomal cytochrome P 450 content in liver were measured and microscopic structure of hepatocytes was observed. In low-protein diet, the higher the carbohydrate content of diet was, the lower the damage was in the rat's liver. Tryptophan administration after dose of reserpine induced more effective recovery from liver damage of rats in high carbohydrate diet group than that in low carbohydrate diet group. In conclusion, the general nutritional assessments such as final body weight and body weight gain provided better estimate of the degree of structural changes in hepatocytes than functional assessment such as plasma amino acid concentration or liver microsomal cytochrome P450.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2421-2427
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• 2024

In this research, the Omicron variant of the SARS-CoV-2 virus was simulated and exposed to electron radiation with up to 20 keV energy. Absorbed energy was measured for spike protein, nucleocapsid protein, and envelope of the virus. Simulations were performed by Geant4-DNA in a water environment at temperature of 20 ℃ and pressure of 1 atm. Since the viral RNA is kept inside the nucleocapsid protein, damage to this area could destroy the viral RNA strand and create an inactive virus. Our findings showed that electron beams with an energy of 2.5 keV could cause a maximum absorption dose and consequently maximum damage to the nucleocapsid and effectively be used for inactivation virus.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.50 no.3
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• pp.271-278
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• 2024

The human skin is an organ that protects the body from physical and chemical factors. The skin is the largest and most massive of the body's organs and is composed of the epidermis, dermis, and subcutaneous tissue. Constant UV exposure to the skin can cause DNA damage, oxidation of proteins, and contribute to adult diseases. Nypa fruticans Wurmb (NF), rich in phytochemicals (polyphenols and flavonoids), has been traditionally used for treating respiratory and other diseases. This study investigated the effects of NF ethyl acetate fraction (ENF) on DNA damage healing and inhibition of wrinkle-related factors in UVB-stimulated Hs68 cells. Westernblotting was used to assess the expression of DNA damage-related proteins and wrinkle-related protein factors. In addition, the wound recovery capability of ENF was confirmed through wound-healing experiments. ENF significantly suppressed the expression of DNA damage-related proteins Phosphorylated H2AX (γ-H2AX), checkpoint kinase 2 (Chk2), protein53 (p53), and Phosphorylated protein53 (p-p53). Furthermore, ENF inhibited the expression of wrinkle-related proteins matrix metalloproteinase-1 (MMP-1), matrix metalloproteinase-3 (MMP-3), and matrix metalloproteinase-9 (MMP-9). High concentrations of ENF also enhanced wound healing in Hs68 cells. ENF is thought to have the potential to heal DNA damage by significantly suppressing the expression of γ-H2AX, Chk2, p53, and p-p53, as well as to inhibit wrinkle formation by suppressing the expression of MMP-1, MMP-3, and MMP-9. These results suggest that ENF can be used as a natural resource to suppress skin damage caused by UVB by regulating the γ-H2AX, Chk2, p53, and MMP pathways in Hs68 cells induced by UVB.

• Archives of Pharmacal Research
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• v.11 no.3
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• pp.225-229
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• 1988

A ginseng protein fraction which has been reported to have radiation protective effect was purified from Korean ginseng and its effects on relative survival and chromosome aberration were studied in UV irradiated CHO-K1 cells. When the protein fraction $(100\;{\mu}g/ml)$ was added to the cells before UV irradiation at 4\;J/$m^2$,, the survival rates were increased to 53.8% from 40.6% in control. Addition of the protein $(100\;{\mu}g/ml)$ after UV irradiation at 4 and $8\;J/m^2$ raised the rates to 85.4 and 24.0% from 79.2 and 11.5% in control, respectively. When the ginseng protein $(800\;{\mu}g/ml)$ was added to the cells exposed to UV light at 10, 20, $30\;J/m^2$, the frequencies of chromosome aberration (CA) were reduced significantly to almost same level regardless of the UV dose increment and there was no significant difference between pre- and post-treatment. When the concentration of ginseng protein was increased from 200 to $800\;{\mu}g/ml$, at UV dose of 10, 20, $30\;J/m^2$ each, the CA frequencies were decreased consistently as the dose of ginseng protein increased, at all UV doses tested. Similar effects were observed in both cases of pre- and post-treatment. The data suggest that the protein may reduce cell damage caused by UV light, especially damage to DNA molecule, or play a role in repair processes of damaged DNA, to increase cell survival and reduce chromosome aberrations.

• Animal Bioscience
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• v.37 no.2
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• pp.303-314
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• 2024

Objective: Rutin, also called vitamin P, is a flavonoids from plants. Previous studies have indicated that rutin can alleviate the injury of tissues and cells by inhibiting oxidative stress and ameliorating inflammation. There is no report on the protective effects of rutin on goat rumen epithelial cells (GRECs) at present. Hence, we investigated whether rutin can alleviate lipopolysaccharide (LPS)-induced damage in GRECs. Methods: GRECs were cultured in basal medium or basal medium containing 1 ㎍/mL LPS, or 1 ㎍/mL LPS and 20 ㎍/mL rutin. Six replicates were performed for each group. After 3-h culture, the GRECs were harvested to detect the relevant parameters. Results: Rutin significantly enhanced the cell activity (p<0.05) and transepithelial electrical resistance (TEER) (p<0.01) and significantly reduced the apoptosis rate (p<0.05) of LPS-induced GRECs. Rutin significantly increased superoxide dismutase, glutathione peroxidase, and catalase activity (p<0.01) and significantly decreased lactate dehydrogenase activity and reactive oxygen species and malondialdehyde (MDA) levels in LPS-induced GRECs (p<0.01). The mRNA and protein levels of interleukin 6 (IL-6), IL-1β, and C-X-C motif chemokine ligand 8 (CXCL8) and the mRNA level of tumor necrosis factor-α (TNF-α) and chemokine C-C motif ligand 5 (CCL5) were significantly increased in LPS-induced GRECs (p<0.05 or p<0.01), while rutin supplementation significantly decreased the mRNA and protein levels of IL-6, TNF-α, and CXCL8 in LPS-induced GRECs (p<0.05 or p<0.01). The mRNA level of toll-like receptor 2 (TLR2), and the mRNA and protein levels of TLR4 and nuclear factor κB (NF-κB) was significantly improved in LPS-induced GRECs (p<0.05 or p<0.01), whereas rutin supplementation could significantly reduce the mRNA and protein levels of TLR4 (p<0.05 or p<0.01). In addition, rutin had a tendency of decreasing the protein levels of CXCL6, NF-κB, and inhibitor of nuclear factor kappa-B alpha (0.05

• Molecular & Cellular Toxicology
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• v.5 no.3
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• pp.243-249
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• 2009

Melamine, which is used to produce melamine resin for various industrial applications, has a high nitrogen content by mass. For this reason, it has been illegally added to foods to increase their apparent protein content. In the present investigation, melamine-induced oxidative damage of human lymphocyte DNA was evaluated by Comet assay. The in vitro oxidative DNA damage caused by melamine increased in a dose-dependent manner. This DNA damage was significantly inhibited by treatment with ascorbate. Moreover, the traditional Korean medicinal herb, named Acanthopanax, red ginseng and green tea markedly reduced the DNA damage. Various edible plant extracts also inhibited melamine-induced oxidative DNA damage in vitro. Melamine enhanced intracellular ROS generation, and this effect was suppressed by treatment with various antioxidants.

• Applied Microscopy
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• v.42 no.3
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• pp.129-135
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• 2012

In this study, the changes in hair quality before and after Magic straight perm have been evaluated through a hair damage measurement method. For this, a healthy high school student's (age18 years) wavy hair was selected and permed on the left and right sides. Then, the changes caused by physical methods which were applied during the fl at iron-based Magic straight perm were evaluated based on the hair damage measurement method before and after the Magic straight perm. According to the protein release test after the Magic straight perm, 1.26% in average and 0.14% was observed in Cool Magic straight perm sample. In a field emission scanning electron microscopy (FE-SEM) test, saw teeth-shaped partial desquamation of cuticle cells and impurities were observed in the warm-treated hair sample. In atomic force microscope (AFM), line-profile is a method to represent roughness data on hair. According to analysis on 3-dimensional (3D) images, the hair with Cool Magic straight perm was lower than the hair with Warm Magic perm in terms of the color change of 3D images. In addition, vertical changes were observed in the hair with Cool Magic perm. As a result, irregular surface roughness was observed. This study proposed a method to minimize hair damage by cooling down the heat with the cool hair straightener as soon as the Warm Magic was finished.

• BMB Reports
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• v.35 no.4
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• pp.353-357
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• 2002

Singlet oxygen ($^1O_2$) is highly reactive form of molecular oxygen that may harm living systems by oxidizing critical cellular macromolecules. The oxyR gene product regulates the expression of the enzymes and proteins that are needed for cellular protection against oxidative stress. In this study, the role of oxyR in cellular defense against a singlet oxygen was investigated using Escherichia coli oxyR mutant strains. Upon exposure to methylene blue and visible light, which generates singlet oxygen, the oxyR overexpression mutant was much more resistant to singlet oxygen-mediated cellular damage when compared to the oxyR deletion mutant in regard to growth kinetics, viability and protein oxidation. Induction and inactivation of major antioxidant enzymes, such as superoxide desmutase and catalase, were observed after their exposure to a singlet oxygen generating system in both oxyR strains. However, the oxyR overexpression mutant maintained significantly higher activities of anticxidant enzymes than did the oxyR deletion mutant. These results suggest that the oxyR regulon plays an important protective role in singlet oxygen-mediated cellular damage, presumably through the protection of antioxidant enzymes.