• Title, Summary, Keyword: DNA Damage

Search Result 1,311, Processing Time 0.037 seconds

Evaluation of Oxidative DNA Damage Using an Alkaline Single Cell Gel Electrophoresis (SCGE) Comet Assay, and the Protective Effects of N-Acetylcysteine Amide on Zearalenone-induced Cytotoxicity in Chang Liver Cells

  • Kang, Changgeun;Lee, Hyungkyoung;Yoo, Yong-San;Hah, Do-Yun;Kim, Chung Hui;Kim, Euikyung;Kim, Jong Shu
    • Toxicological Research
    • /
    • v.29 no.1
    • /
    • pp.43-52
    • /
    • 2013
  • Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium that are found in cereals and agricultural products. ZEN has been implicated in mycotoxicosis in farm animals and in humans. The toxic effects of ZEN are well known, but the ability of an alkaline Comet assay to assess ZEN-induced oxidative DNA damage in Chang liver cells has not been established. The first aim of this study was to evaluate the Comet assay for the determination of cytotoxicity and extent of DNA damage induced by ZEN toxin, and the second aim was to investigate the ability of N-acetylcysteine amide (NACA) to protect cells from ZEN-induced toxicity. In the Comet assay, DNA damage was assessed by quantifying the tail extent moment (TEM; arbitrary unit) and tail length (TL; arbitrary unit), which are used as indicators of DNA strand breaks in SCGE. The cytotoxic effects of ZEN in Chang liver cells were mediated by inhibition of cell proliferation and induction of oxidative DNA damage. Increasing the concentration of ZEN increased the extent of DNA damage. The extent of DNA migration, and percentage of cells with tails were significantly increased in a concentration-dependent manner following treatment with ZEN toxin (p < 0.05). Treatment with a low concentration of ZEN toxin (25 ${\mu}M$) induced a relatively low level of DNA damage, compared to treatment of cells with a high concentration of ZEN toxin (250 ${\mu}M$). Oxidative DNA damage appeared to be a key determinant of ZEN-induced toxicity in Chang liver cells. Significant reductions in cytolethality and oxidative DNA damage were observed when cells were pretreated with NACA prior to exposure to any concentration of ZEN. Our data suggest that ZEN induces DNA damage in Chang liver cells, and that the antioxidant activity of NACA may contribute to the reduction of ZEN-induced DNA damage and cytotoxicity via elimination of oxidative stress.

The effect of carrot juice, ${\beta}$-carotene supplementation on lymphocyte DNA damage, erythrocyte antioxidant enzymes and plasma lipid profiles in Korean smoker

  • Lee, Hye-Jin;Park, Yoo-Kyoung;Kang, Myung-Hee
    • Nutrition Research and Practice
    • /
    • v.5 no.6
    • /
    • pp.540-547
    • /
    • 2011
  • High consumption of fruits and vegetables has been suggested to provide some protection to smokers who are exposed to an increased risk of numerous cancers and other degenerative diseases. Carrot is the most important source of dietary ${\beta}$-carotene. Therefore, the objective of this study was to investigate whether carrot juice supplementation to smokers can protect against lymphocyte DNA damage and to compare the effect of supplementationof capsules containing purified ${\beta}$-carotene or a placebo (simple lactose). The study was conducted in a randomized and placebo-controlled design. After a depletion period of 14 days, 48 smokers were supplemented with either carrot juice (n = 18), purified ${\beta}$-carotene (n = 16) or placebo (n = 14). Each group was supplemented for 8 weeks with approximately 20.49 mg of ${\beta}$-carotene/day and 1.2 mg of vitamin C/day, as carrot juice (300 ml/day) or purified ${\beta}$-carotene (20.49 mg of ${\beta}$-carotene, 1 capsule/day). Lymphocyte DNA damage was determined using the COMET assay under alkaline conditions and damage was quantified by measuring tail moment (TM), tail length (TL), and% DNA in the tail. Lymphocyte DNA damage was significantly decreased in the carrot juice group in all three measurements. The group that received purified ${\beta}$-carotene also showed a significant decrease in lymphocyte DNA damage in all three measurements. However, no significant changes in DNA damage was observed for the placebo group except TM (P = 0.016). Erythrocyte antioxidant enzyme was not significantly changed after supplementation. Similarly plasma lipid profiles were not different after carrot juice, ${\beta}$-carotene and placebo supplementation. These results suggest that while the placebo group failed to show any protective effect, carrot juice containing beta-carotene or purified ${\beta}$-carotene itself had great antioxidative potential in preventing damage to lymphocyte DNA in smokers.

The Level of UVB-induced DNA Damage and Chemoprevention Effect of Paeoniflorin in Normal Human Epidermal Kerationcytes

  • Lim, Jun-Man;Park, Mun-Eok;Lee, Sang-Hwa;Kang, Sang-Jin;Cho, Wan-Goo;Rang, Moon-Jeong
    • Molecular & Cellular Toxicology
    • /
    • v.1 no.2
    • /
    • pp.111-115
    • /
    • 2005
  • Ultraviolet (UV) radiation to mammalian skin is known to alter cellular function via generation of Reactive Oxygen Species (ROS), DNA damage and DNA lesions, such as pyrimidine dimmers and photoproducts, which could lead to DNA mutation if they are not repaired. In this study, we have investigated the reduction of DNA damage and of apoptosis with a particular attention to genetic effect of paeoniflorin in Normal Human Epidermal Keratinocytes (NHEK). After UVB irradiation from $10\;to\;500mJ/cm^{2}$ to NHEK, Mean Tail Moments (MTM) were increased with UVB dose increase. The greatest amount of strand breaks was induced at $500mJ/cm^{2}$ of UVB. Even at the lowest dose of UVB ($10mJ/cm^{2}$), change in MTM was detected (P<0.0001). Pretreated cell with 0.1% paeoniflorin maximally reduced the level of DNA damage to about 21.3%, compared to untreated cell. In the lower concentrations less than 0.01% of paeoniflorin, MTM had a small increase but paeoniflorin still had reductive effects of DNA damage. We measured the apoptosis suppression of paeoniflorin with annexin V flous staining kit. As we observed under the fluorescence microscopy to detect apoptosis in the irradiated cell, the fluorescence intensity was clearly increased in the untreated cell, but decreased in treated cells with paeoniflorin. These results suggest that paeoniflorin reduces the alteration of cell membranes and prevents DNA damage. Therefore, the use of paeoniflorin as a free radical scavenger to reduce the harmful effects of UV lights such as chronic skin damage, wrinkling and skin cancer can be useful to prevent the formation of photooxidants that result in radical damage.

Smoking Related DNA Damage in Human Lymphocytes Assessed by the Comet Assay (단세포전기영동법으로 평가한 흡연자의 백혈구 DNA손상)

  • 선수진;정해원;한정호
    • Environmental Mutagens and Carcinogens
    • /
    • v.22 no.2
    • /
    • pp.83-89
    • /
    • 2002
  • The single cell gel electrophoresis (comet) assay is one of the useful tools for the study of genetic damage in humans exposed to environmental mutagens and carcinogens. This study was undertaken to evaluate the status of DNA damage in peripheral lymphocytes depending on their sex, age, smoking habits, and other factors in normal healthy Korean population. The 99 volunteers included in the study and out of these, 36 volunteers were smoker and 63 volunteers were non-smoker aged between 20-59 years. All individual answered a questionnaire that assessed their general information including smoking habits and the extent of the environmental tobacco smoke (ETS) exposure, and blood samples were obtained. There was a statistically significant difference in the extent of DNA damage between smoker and non-smoker (p<0.001). A significant difference was also observed between male and female (p<0.001) and amongst the different group of age (p<0.005), however, correlation analysis showed that only smoking habit was a significant factor for DNA damage. No significant effect of smoking duration, number of cigarettes smoking a day, SPY (smoke pack years) in smokers and environmental tobacco smoke exposure in non-smokers on the status of DNA damage was observed.

  • PDF

Effect of Several Drugs of DNA, RNA and Protein Damage induced by Dimethylnitrosamine in Mouse Tissues (수종약물이 Dimethylnitrosamine에 의한 DNA, RNA 및 단백질 손상도에 미치는 영향)

  • Kim, Jea-Hyun;Park, Jung-Sik;Hong, Sung-Ryul;Kweon, O-Cheul;Park, Chang-Won;Rhee, Dong-Kwon
    • YAKHAK HOEJI
    • /
    • v.35 no.6
    • /
    • pp.522-529
    • /
    • 1991
  • The purpose of this research is to evaluate effects of chloramphenicol, phenobarbital and progesterone on damage of DNA, RNA and protein which was induced by dimethylnitrosamine. $N,N-Di[^{14}C]$ methyl-nitrosamine (DMN) was used as a damaging agent and levels of DNA, RNA and protein damage in liver, brain and pancreas were compared with a control group. Pretreatment of mice with chloramphenicol increased protein damage in pancreas two times more than the control level. Liver RNA damage was increased up to 5.8 times and brain DNA damage up to 6.95 times by treatment of phenobarbital but brain RNA damage was decreased significantly down to 21% of the control group. The damage of liver RNA was significantly decreased by treatment of progesterone, although liver protein damage, pancreas RNA damage and pancreas protein damage were increased.

  • PDF

Protective Effect of Yellow-Green Vegetable Juices on DNA Damage in Chinese Hamster Lung Cell Using Comet Assay (Comet Assay를 이용한 케일, 명일엽, 당근, 돌미나리 녹즙의 Chinese Hamster Lung 세포 DNA 손상 보호 효과)

  • 전은재;김정신;박유경;김태석;강명희
    • Journal of Nutrition and Health
    • /
    • v.36 no.1
    • /
    • pp.24-31
    • /
    • 2003
  • The present study was attempted to investigate the antioxidant capacity of popular yellow-green vegetable juices (kale, Angelica keishei, carrot, small water dropwort) and to investigate the effect of vegetable juices on protecting oxidative damage to DNA in cultured Chinese hamster lung (CHL) cells. Antioxidant capacity was analyzed by TRAP assay (Total radical-trapping antioxidant potential). Cellular DNA dmamage was measured by SCGE (single-cell gel electrophoresis, also known as comet assay. Cells incubated in medium with PBS (negative control) or with various concentration of the freeze dried green juices (25, 50, 100, 250 $\mu\textrm{g}$/$m\ell$) resuspended in PBS were treated with $H_2O_2$ (200 ${\mu}{\textrm}{m}$) as an oxidative stimulus for 5 min at 4$^{\circ}C$. The physiological function of each vegetable juice on oxidative DNA damage was analyzed and expressed as tail moment (tail length X percentage migrated DNA in tail) . Kale juice had the highest TRAP value suggesting that kale has the highest antioxidant capacity followed by Angelica keishei, small water dropwort and carrot. Cells treated with $H_2O_2$ had extensive DNA damage compared with cells treated with PBS or pre-treated with vegetable juice extracts. All green juices inhibited $H_2O_2$-induced DNA damage with kale being the most effective juice among the tested juices. These results indicate that green juice supplementation to CHL cells followed by oxidative stimulus inhibited damage to cellular DNA, supporting a protective effect against oxidative damage induced by reactive oxygen species. (Korean J Nutrition 36(1) : 24-31, 2003)

THE EFFECT OF GENETIC VARIATION IN THE DNA BASE REPAIR GENES ON THE RISK OF HEAD AND NECK CANCER (DNA 염기손상 치유유전자의 변이와 두경부암 발생 위험성)

  • Oh, Jung-Hwan;Yoon, Byung-Wook;Choi, Byung-Jun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.34 no.5
    • /
    • pp.509-517
    • /
    • 2008
  • DNA damage accumulates in cells as a result of exposure to exogenous agents such as benzopyrene, cigarette smoke, ultraviolet light, X-ray, and endogenous chemicals including reactive oxygen species produced from normal metabolic byproducts. DNA damage can also occur during aberrant DNA processing reactions such as DNA replication, recombination, and repair. The major of DNA damage affects the primary structure of the double helix; that is, the bases are chemically modified. These modification can disrupt the molecules'regular helical structure by introducing non-native chemical bonds or bulky adducts that do not fit in the standard double helix. DNA repair genes and proteins scan the global genome to detect and remove DNA damage and damage to single nucleotides. Direct reversal of DNA damage, base excision repair, double strand break. DNA repair are known relevant DNA repair mechanisms. Four different mechanisms are distinguished within excision repair: direct reversal, base excision repair, nucleotide excision repair, and mismatch repair. Genetic variation in DNA repair genes can modulate DNA repair capacity and alter cancer risk. The instability of a cell to properly regulate its proliferation in the presence of DNA damage increase risk of gene mutation and carcinogenesis. This article aimed to review mechanism of excision repair and to understand the relationship between genetic variation of excision repair genes and head and neck cancer.

Suppressive Effect of Galangin on the Formation of 8-OH2'dG and DNA Single Strand Breaks by Hydrogen Peroxide ($H_2O_2$ 유도 8-OH2'dG 생성 및 DNA Single Strand Break에 미치는 Galangin의 억제효과)

  • Kim, Soo-Hee;Heo, Moon-Young
    • YAKHAK HOEJI
    • /
    • v.54 no.1
    • /
    • pp.32-38
    • /
    • 2010
  • The aim of this study was to evaluate the effect of galangin towards hydrogen peroxide-induced DNA damage. The calf thymus DNA and Chinese Hamster Lung (CHL) cells were used to measure 8-hydroxy-2'-deoxyguanosine(8-OH2'dG) as an indicator of DNA oxidative damage using high performance liquid chromatography with electrochemical detection. Hydrogen peroxide in the presence of Fe(II) ion induced the formation of 8-OH2'dG in both calf thymus DNA and CHL cells. The DNA damage effects were enhanced by increasing the concentration of Fe(II) ion and inhibited by galangin. In the single cell gel electrophoresis (Comet assay), galangin and dl-a-tocopherol showed an inhibitory effect in CHL on hydrogen peroxide induced DNA single strand breaks. Galangin showed more potent activity than dl-$\alpha$-tocopherol under our experimental conditions. These results indicate that galangin can modify the action mechanisms of the oxidative DNA damage and may act as chemopreventive agents against oxidative stress.

XPS STUDY ON DNA DAMAGE BY LOW-ENERGY ELECTRON IRRADIATION

  • Noh, Hyung-Ah;Cho, Hyuck
    • Journal of Radiation Protection and Research
    • /
    • v.36 no.4
    • /
    • pp.190-194
    • /
    • 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.

Suppressive Effect of Acanthopanax sessiliflorus Extract on the DNA and Cell Damage by Dieldrin (Dieldrin에 의한 DNA와 세포 손상에 대한 오가피 추출물의 억제효과)

  • Ryu, A-Reum;Kim, Ji-Hae;Lee, Mi-Young
    • Korean Journal of Medicinal Crop Science
    • /
    • v.20 no.4
    • /
    • pp.245-250
    • /
    • 2012
  • Dieldrin, one of the organochlorine pesticides (OCPs), induced the damages in neuroblastoma cells and DNA damages in lymphocytes. The ethanol extracts of A. sessiliflorus leaves were examined for the suppressive effects on the dieldrin-induced cell damages. Moreover, the extract was used to test whether it might inhibit the oxidative DNA damage of lymphocytes using Comet assay. The cell and DNA damage by dieldrin were suppressed in vitro upon treating A. sessiliflorus extract. This result suggests that A. sessiliflorus extract might be useful to reduce dieldrin toxicity.