• Title/Summary/Keyword: Comet-assay

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Inhibitory effects of Prunus persica flower extracts on UV-induced skin damage

  • Lee, Kang-Tae;Yoo, Young-Kyoung;Kim, Sung-Woo;Jeong, Ji-Hean;Jo, Byoung-Kee;Kim, Young-Ha;Yang, Hye-Eum;Heo, Moon-Young;Kim, Hyun-Pyo
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.27 no.1
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    • pp.73-81
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    • 2001
  • For an attempt to develop safe materials protecting UV-induced skin damage, plant extracts were evaluated for their antioxidative and free radical scavenging activities. From the results of these screening procedures, the ethanol extract of the flowers of Prunus persica was selected for further study. It was found that Prunus persica (50-200 $\mu\textrm{g}$/㎖) inhibited UVB-induced DNA damage measured by tail moment in the Single Cell Gel Electrophoresis(COMET assay) and inhibited UV-induced lipid peroxidation, expecially against UVB-induced peroxidation at higher than 10 $\mu\textrm{g}$/㎖. Also P.persica(100∼1,000 $\mu\textrm{g}$/㎖) inhibited the amount of $\^$14/C-arachidonic acid metabolites release from UVB-irradiated keratinocytes and it possessed the protective activity against UV-induced cytotoxicity of keratinocytes. All these results indicate that the flowers of P. persica extract may be beneficial for protection UV-induced skin damage when topically applied.

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Evaluation of Genotoxicity of Three Antimalarial Drugs Amodiaquine, Mefloquine and Halofantrine in Rat Liver Cells

  • Farombi E. Olatunde
    • Environmental Mutagens and Carcinogens
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    • v.25 no.3
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    • pp.97-103
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    • 2005
  • The genotoxic effect of antimalarial drugs amodiaquine (AQ), mefloquine (MQ) and halofantrine (HF) was investigated in.at liver cells using the alkaline comet assay. AQ, MQ and HF at concentrations between $0-1000{\mu}mol/L$ significantly increased DNA strand breaks of rat liver cells dose-dependently. The order of induction of strand breaks was AQ>MQ>HF. The rat liver cells exposed to AQ and HF (200 and 400 ${\mu}mol/L$) and treated with (Fpg) the bacterial DNA repair enzyme that recognizes oxidized purine showed greater DNA damage than those not treated with the enzyme, providing evidence that AQ and HF induced oxidation of purines. Such an effect was not observed when MQ was treated with the enzyme. Treatment of cells with catalase, an enzyme inactivating hydrogen peroxide, decreased significantly the extent of DNA damage induced by AQ, and HF but not the one induced by MQ. Similarly quercetin, an antioxidant flavonoid at $50{\mu}mol/L$ attenuated the extent of the formation of DNA strand breaks by both AQ and HE. Quercetin, however, did not modify the effects of MQ. These results indicate the genotoxicity of AQ, MQ and HF in rat liver cells. In addition, the results suggest that reactive oxygen species may be involved in the formation of DNA lesions induced by AQ and HF and that, free radical scavengers may elicit protective effects against genotoxicity of these antimalarial drugs.

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The Role of Mercury in the Etiology of Sperm Dysfunction in Holstein Bulls

  • Arabi, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.3
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    • pp.335-340
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    • 2006
  • A large number of toxicological substances and pharmacological and physical agents can cause reproductive intervention at the cellular and molecular level. The present study was designed to assess the effect of mercury ($HgCl_2$) at 50 to $550{\mu}M$ concentration ranges, in vitro, on the sperm membrane and DNA integrity, viability, and acrosomal status of normal bull spermatozoa. The samples were processed for sperm analyses using semen-diluting fluid (PBS, pH 7.2). We recorded a sharp increase in the lipid peroxidation/LPO rate; the highest was at $550{\mu}M$ mercury concentration, indicating a deleterious effect of mercury on the sperm membrane intactness. There was also a strong negative correlation between LPO rate and % viable spermatozoa (R = 0.987, p<0.001). Data obtained from a comet assay technique revealed that mercury is capable of inducing DNA breaks in the sperm nuclei. Interestingly, 92% of DNA breaks were double-stranded. The correlation between LPO rate and % DNA breaks was 0.984. Performing the gelatin test indicates that mercury is able to alter the integrity of acrosomal membranes showing an abnormal acrosome reaction. In this regard, a strong link was found between LPO rate and % halos (R = 0.990, p<0.001). Collectively, mercury proved to be a potent oxidant in the category of environmental factors affecting bull spermatozoa. Hence, considering the wide spread use of mercury and its compounds, these metals should be regarded with more concern.

Evaluation of the Mutagenic Properties of Two Lignans from Acanthopanax koreanum Nakai

  • Hong, Chang-Eui;Lyu, Su-Yun
    • Toxicological Research
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    • v.29 no.4
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    • pp.279-283
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    • 2013
  • Acanthopanax koreanum Nakai, a well known traditional herb grown in Jeju Island, South of Korea, has been used as a tonic and sedative agent, as well as in the treatment of diabetes and immune diseases. Mutagenicity of two lignans, syringaresinol and tortoside A isolated from A. koreanum, was assessed using Salmonella/microsome (Ames) test. Tester strains used were Salmonella typhimurium TA98, TA100, TA1535, and Escherichia coli WP2uvrA. The mutagenic activity was determined both in the absence or presence of S9 mixture. As a result, tortoside A did not cause any increase in the number of $his^+$ revertants in S. typhimurium and E. coli WP2uvrA strains in the presence or absence of S9 mix, compared to the controls. Similarly, low concentrations of syringaresinol (750 and 1,500 ${\mu}g$/plate) did not show any mutagenic properties in all bacterial strains, in the presence or absence of S9 mixture. However, in the high concentration of syringaresinol (3,000 ${\mu}g$/plate), the number of revertants were increased in TA1535 strains, in the absence of S9 metabolic activation. Therefore, in vivo experiments such as comet assay are needed to further determine the genotoxic/carciogenic potential of syringaresinol isolated from A. koreanum.

Analysis of Various Ecological Parameters from Molecular to Community Levels for Ecological Health Assessments (생태 건강성 평가로서 분자지표에서 군집지표 수준까지의 다양한 변수분석)

  • Lee, Jae-Hoon;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.43 no.1
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    • pp.24-34
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    • 2010
  • This study was carried out to analyze some influences on ecological health conditions, threaten by various stressors such as physical, chemical and biological parameters. We collected samples in 2008 from three zones of upstream, midstream and downstream, Gap Stream. We applied multi-metric fish assessment index (MFAI), based on biotic integrity model to the three zones along with habitat evaluations based on Qualitative Habitat Evaluation Index (QHEI). We also examined fish fauna and compositions, and analyzed relations with MFAI values, QHEI values, and various guild types. Chemical parameters such as oragnic matter (BOD, COD), nutrients (TP, $NH_3$-N), coli-form number (as MPN), and suspended solids (SS) were analyzed to identify the relationship among multiple stressor effects. Using the sentinel species of Zacco platypus, the population structures and condition factors were analyzed along with DNA damages related with genotoxicant effects by comet assay. This study using all these parameters showed that stream condition was degraded along the longitudinal gradient from upstream to downstream, and the downstream, especially, was impacted by nutrient enrichment and toxicant exposure from the point source, wastewater treatment plant. Overall results indicated that our approaches applying various parameters may be used as a cause-effect technique in the stream health assessments and also used as a pre-warning tool for diagnosis of ecological degradation.

What should be done for men with sperm DNA fragmentation?

  • Kim, Gi Young
    • Clinical and Experimental Reproductive Medicine
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    • v.45 no.3
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    • pp.101-109
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    • 2018
  • In an age when a small quantity of sperm can lead to pregnancy through in vitro fertilization or intracytoplasmic sperm injection, selecting healthy sperm is important. Sperm DNA fragmentation (SDF) is known to be higher in infertile men. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) and the alkaline comet test are SDF tests that directly measure DNA damage and have shown closer correlations with assisted reproduction results than indirect tools such as the sperm chromatin structure assay or the sperm chromatic dispersion test. It is difficult; however, to endorse a single test as the best test overall; instead, it is best to select a testing method based on each patient's clinical condition and goals. In a couple struggling with infertility, if the male partner has a high level of SDF, he should aim to decrease SDF through lifestyle modifications, antioxidant treatment, and ensuring an appropriate duration of abstinence, and physicians need to treat the underlying diseases of such patients. If sperm DNA damage continues despite the patient's and physician's efforts, other methods, such as micromanipulation-based sperm selection or testicular sperm extraction, should be used to select healthy sperm with nuclear DNA integrity.

Morin Protects Normal Human Dermal Fibroblasts from Ultraviolet B-induced Apoptosis (자외선 B로 유도된 아포토시스로부터 모린의 정상 인간 피부 섬유아세포 보호효과)

  • Jeong Eon Park;Ao Xuan Zhen;Mei Jing Piao;Kyoung Ah Kang;Pincha Devage Sameera Madushan Fernando;Herath Mudiyanselage Udari Lakmini Herath;Jin Won Hyun
    • Journal of Life Science
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    • v.33 no.4
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    • pp.305-314
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    • 2023
  • Ultraviolet B (UVB) irradiation causes skin diseases by inducing cellular oxidative stress, photoaging, and inflammation. This study aimed to investigate the protective effects of morin against UVB-induced oxidative stress in normal human dermal fibroblasts (NHDFs). Morin has been reported to be a potential therapeutic candidate for oxidative stress-mediated diseases, neurodegenerative diseases, and inflammation. Since morin has been identified as a potential antioxidant, we speculated that morin could alleviate UVB-induced apoptosis in NHDFs. Cell viability and intracellular reactive oxygen species (ROS) levels were measured using the MTT assay, H2DCFDA, and the DHE staining method, respectively. Lipid peroxidation and protein carbonyl formation were tested using ELISA kits. DNA fragmentation and comet assay were used to assess DNA damage. Apoptotic bodies were analyzed using Hoechst 33342 staining and TUNEL assay. The expression of apoptosis-related proteins was examined using Western blot analysis. Morin showed a cyto-protective effect by scavenging UVB-induced ROS, increasing the expression of antioxidant-related proteins and inhibiting UVB-induced oxidative alterations such as lipid peroxidation, protein carbonylation, and DNA damage. Morin protects against UVB-induced cell apoptosis by inhibiting Bcl-2-associated X protein, caspase-9, and caspase-3 expression, while increasing the expression of the anti-apoptotic protein Bcl-2. These effects of morin were conferred through decreased phosphorylation of p38 and c-Jun N-terminal kinase 1/2. The results demonstrated that morin may be developed as a preventive/therapeutic drug to be used to prevent UVB-induced skin damage.

Antidiabetic Effect of Korean Red Ginseng by Puffing Process in Streptozotocin-Induced Diabetic Rats (Streptozotocin 유발 당뇨쥐에서 팽화가공 처리한 홍삼의 항당뇨 효과)

  • Kim, Shin-Hee;Kang, Ju-Seop;Lee, Sang-Jun;Chung, Young-Jin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.6
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    • pp.701-707
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    • 2008
  • Antidiabetic effect of Korean red ginseng (RG) processed by puffing in streptozotocin (STZ)-induced diabetic (DM) rats was investigated. Five week-old SD rats were divided into four groups; normal control (NC) group, DM group, red ginseng (RG) group and puffed red ginseng (PG) group. The RG and PG groups were orally provided with RG or PG dissolved in water (500 mg/kg) respectively for seven weeks after single injection of STZ (50 mg/kg, i.v.) followed by identification of DM. NC group received saline vehicle instead of STZ. At the end of feeding of RG or PG, the changes of fasting blood glucose, serum insulin and amylase level and serum lipid profiles were evaluated. Also, oral glucose tolerance test (OGTT), comet assay and histopathological examination were performed. At 7th week, the fasting blood glucose levels of the RG and PG groups were reduced compared to the DM group by 11.54% and 20.22%, respectively. The result of OGTT did not show significant differences among DM and two red ginseng groups. While serum insulin and TG levels were predominantly improved in PG group (p<0.05), serum amylase level was increased in RG group. Alkaline comet assay for checking the oxidative damage of DNA showed that TL (tail length, ${\mu}m$) and TM (tail moment) in the blood lymphocyte of PG group significantly decreased in contrast with DM group. Histopathological results of pancreas showed that destruction of exocrine as well as endocrine might be cured by the administration of RG and PG. These results suggest that PG could exert more protection against STZ-induced toxicity than RG group.

Ethanol Extract of Ganoderma lucidum Augments Cellular Anti-oxidant Defense through Activation of Nrf2/HO-1

  • Lee, Yoo-hwan;Kim, Jung-hee;Song, Choon-ho;Jang, Kyung-jeon;kim, Cheol-hong;Kang, Ji-Sook;Choi, Yung-hyun;Yoon, Hyun-Min
    • Journal of Pharmacopuncture
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    • v.19 no.1
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    • pp.59-69
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    • 2016
  • Objectives: The mushroom Ganoderma lucidum has been widely used as a traditional herbal medicine for many years. Although several studies have focused on the anti-oxidative activity of this mushroom, the molecular mechanisms underlying its activity have not yet been clearly established. The present study investigated the cytoprotective effect of ethanol extract of Ganoderma lucidum (EGL) against oxidative stress (hydrogen peroxide, $H_2O_2$) and elucidated the underlying mechanisms in a C2C12 myoblast cell line. Methods: Oxidative stress markers were determined by using the comet assay to measure reactive oxygen species (ROS) generation and deoxyribonucleic acid (DNA) damage. Cell viability and Western blotting analyses were employed to evaluate the cellular response to EGL and $H_2O_2$ in C2C12 cells. Transfection with nuclear factor erythroid 2-related factor 2 (Nrf2)-specific small interfering ribonucleic acid (siRNA) was conducted to understand the relationship between Nrf2 expression and $H_2O_2$-induced growth inhibition. Results: The results showed that EGL effectively inhibited $H_2O_2$-induced growth and the generation of ROS. EGL markedly suppressed $H_2O_2$-induced comet-like DNA formation and phosphorylation of histone H2AX at serine 139 ($p-{\gamma}H2AX$), a widely used marker of DNA damage, suggesting that EGL prevented $H_2O_2$-induced DNA damage. Furthermore, the EGL treatment effectively induced the expression of Nrf2, as well as heme oxygenase-1 (HO-1), with parallel phosphorylation and nuclear translocation of Nrf2 in the C2C12 myoblasts. However, zinc protoporphyrin IX, a HO-1 inhibitor, significantly abolished the protective effects of EGL against $H_2O_2$-induced accumulation of ROS and reduced cell growth. Notably, transient transfection with Nrf2-specific siRNA attenuated the cytoprotective effects and HO-1 induction by EGL, indicating that EGL induced the expression of HO-1 in an Nrf2-dependent manner. Conclusion: Collectively, these results demonstrate that EGL augments the cellular anti-oxidant defense capacity through activation of Nrf2/HO-1, thereby protecting C2C12 myoblasts from $H_2O_2$-induced oxidative cytotoxicity.

Antigenotoxic and Anticarcinogenic Effects of Styela plicata (오만둥이(Styela plicata)의 항유전독성 및 대장암 억제효과에 관한 연구)

  • Seo, Bo-Young;Kim, Jung-Mi;Lee, Seung-Cheol;Park, Eun-Ju
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.7
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    • pp.839-845
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    • 2009
  • Colorectal cancer is the third most common malignant neoplasm in the world. Much attention has been focused on reducing colon cancer risk through medical properties of natural compound that could act as anticarcinogens. In this study, we evaluated the antioxidant and antigenotoxic effects of Styela plicata (S. plicata) from in vitro experiments. S. plicata extracts showed antioxidant activity measured by TRAP assay and antigenotoxic effect in $200{\mu}M$ $H_2O_2$ induced DNA damage in human leukocytes. Especially, freeze-dried S. plicata extracted with methanol showed the highest level of TRAP (0.225 mM) and inhibition of DNA damage (66.8%). Additionally we observed the effect of S. plicata on the formation of aberrant crypt foci (ACF) induced by dimethylhydrazine (DMH) and DMH induced DNA damage (by comet assay) in male SD rats. The animals were divided into three groups and fed high-fat and low fiber diet (100 g lard+20 g cellulose/kg diet) without (normal control and DMH control) or with a 3% (w/w) of lyophilized S. plicata powder (DMH+S. plicata). One week after beginning the diets, rats were treated with DMH (30 mg/kg, s.c.) for 6 weeks except for normal control group, which was treated saline instead; dietary treatments were continued for the entire experiment. Nine weeks after DMH injection, administration of S. plicata resulted in reduction of ACF numbers, to 82.7% of the carcinogen control value ($7.67{\pm}2.04$ vs. $1.33{\pm}0.53$: p<0.01). S. plicata supplementation induced antigenotoxic effect on DMH-induced DNA damage in the blood cell (% tail intensity: $6.79{\pm}0.26$ vs. $6.13{\pm}0.22$). These data indicate that S. plicata extract has antigenotoxic and anticarcinogenic effects from in vitro experiments and S. plicata exerts a protective effect on the process of colon carcinogenesis, possibly by suppressing the DMH-induced DNA damage in blood cell and the development of preneoplastic lesions in colon.