scholarly journals Normalization of DNA Damage Indices in Comet Assay for Comparing with Various Mutagenicity Tests

2004 ◽  
Vol 40 (2) ◽  
pp. 63-70 ◽  
Author(s):  
KEISUKE IWAHORI ◽  
NAOYUKI MIYATA ◽  
YASUHIRO YAMAMOTO ◽  
DAIJIRO SONE ◽  
KOTARO AOYAMA
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Mutagenicity Tests ◽  
Damage Indices

Use of the comet assay to measure DNA damage in cells exposed to photosensitizers and gamma radiation

1999 ◽  
Vol 96 (1) ◽  
pp. 143-146 ◽  
Author(s):  
J.-P. Pouget ◽  
J.-L. Ravanat ◽  
T. Douki ◽  
M.-J. Richard ◽  
J. Cadet
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Gamma Radiation ◽  
In Cells

In Vitro Genotoxicity and Molecular Docking Study of Ellagic Acid

2020 ◽  
Vol 16 (7) ◽  
pp. 1072-1082
Author(s):  
Tuba C. Dördü ◽  
Rüştü Hatipoğlu ◽  
Mehmet Topaktaş ◽  
Erman S. İstifli
Keyword(s):  
Dna Damage ◽  
Molecular Docking ◽  
Comet Assay ◽  
Treatment Period ◽  
Chromosome Aberration ◽  
Human Lymphocyte ◽  
Sister Chromatid ◽  
Ellagic Acid ◽  
Sister Chromatid Exchange ◽  
Nuclear Division

Background: Ellagic Acid (EA) is a polyphenolic compound that is classified in the natural antioxidants group. Polyphenolic compounds that exert antioxidant activity possess particular importance for scientists, food producers and consumers due to their positive effects on human health. However, despite considerable evidence that EA shows antigenotoxic activity by binding to DNA, there is no systematic genotoxicity study of this substance, which can covalently bind to DNA. This study aims to reveal the possible genotoxic activity of EA using widely accepted assays for the assessment of DNA clastogenic activity: sister chromatid exchange, chromosome aberration, micronucleus and comet assays as well as to predict the interactions among EA and DNA through molecular docking. Methods: Different assays were carried out to identify the clastogenic activity of EA on human lymphocyte DNA using Sister Chromatid Exchange (SCE), Chromosome Aberration (CA), Micronucleus (MN) and single-cell gel electrophoresis (SCGE/comet) assays. For this aim, human peripheral blood lymphocytes were treated with EA (60, 80 and 100 μg/ml) for 24 and 48 hrs in the SCE, CA and MN assays and for 1 hr in the comet assay. Furthermore, molecular docking experiments were also performed to calculate the binding energy of EA on human B-DNA structure (B-DNA dodecamer) as well as to predict noncovalent interactions among these macromolecules. Results: At the concentrations and treatment times (24- or 48-hr) tested, EA did not induce either SCE or Chromosome Aberrations (CAs) as compared to the negative and solvent controls. Although EA slightly increased the percentage of Micronucleated Binuclear (%MNBN) cells as well as the percentage of Micronucleus (%MN) in 24 or 48-hr treatment periods at all concentrations, this increase was not statistically significant as compared to both controls. The effect of EA on DNA replication (nuclear division) was determined by the Proliferation Index (PI), the Nuclear Division Index (NDI) and the Mitotic Index (MI). No statistically significant differences were observed in the PI or NDI in 24- or 48-hr treatment periods in human lymphocyte cultures treated with EA at various concentrations. EA generally had no significant effect on the MI, as observed with the PI and NDI. Discussion: Although the concentrations of 60 and 80 μg/mL at a 24-hr treatment period and the concentrations of 60 μg/mL and 100 μg/mL at 48-hr treatment period generally decreased the MI, those decreases were not statistically significant when compared to negative and solvent controls. Moreover, none of the concentrations of EA tested in this study were able to increase DNA damage determined by the tail DNA length, %DNA in tail and tail moment parameters in the comet assay. Although the amount of DNA damage in the comet assay decreased with increasing concentrations of EA, this decrease was not statistically significant as compared to both controls. However, molecular docking experiments interestingly showed that the binding free energy of EA with B-DNA was -7.84 kcal/mol-1, indicating a strong interaction between the two molecules. Conclusion : Although the findings of our study show that EA does not have genotoxic potential in human chromosomes, molecular docking experiments revealed strong hydrogen bonding between EA and B-DNA molecules. Therefore, it has been proposed that the prevailing information suggesting that the molecules that bind to DNA cause genotoxic effects should be reconsidered from a wider perspective.

Dimeric NGF Mimetic Attenuates Hyperglycaemia and DNA Damage in Mice with Streptozotocin-Induced Early-Stage Diabetes

2020 ◽  
Vol 20 (3) ◽  
pp. 453-463
Author(s):  
Svetlana Yagubova ◽  
Aliy Zhanataev ◽  
Rita Ostrovskaya ◽  
Еlena Anisina ◽  
Тatiana Gudasheva ◽  
...  
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Early Stage ◽  
Alkaline Comet Assay ◽  
Β Cells ◽  
Ghost Cells ◽  
Low Weight

Background: NGF deficiency is one of the reasons for reduced β-cells survival in diabetes. Our previous experiments revealed the ability of low-weight NGF mimetic, GK-2, to reduce hyperglycaemia in a model of advanced diabetes. The increase in DNA damage in advanced diabetes was repeatedly reported, while there were no data about DNA damage in the initial diabetes. Aim: The study aimed to establish whether DNA damage occurs in initial diabetes and whether GK-2 is able to overcome the damage. Methods: The early-stage diabetes was modelled in Balb/c mice by streptozotocin (STZ) (130 mg/kg, i.p.). GK-2 was administered at a dose of 0.5 mg/kg, i.p., subchronically. The evaluation of DNA damage was performed using the alkaline comet assay; the percentage of DNA in the tail (%TDNA) and the percentage of the atypical DNA comets (“ghost cells”) were determined. Results: STZ at this subthreshold dose produced a slight increase in glycemia and MDA. Meanwhile, pronounced DNA damage was observed, concerning mostly the percentage of “ghost cells” in the pancreas, the liver and kidneys. GK-2 attenuated the degree of hyperglycaemia and reduced the % of “ghost cells” and %TDNA in all the organs examined; this effect continued after discontinuation of the therapy. Conclusion: Early-stage diabetes is accompanied by DNA damage, manifested by the increase of “ghost cells” percentage. The severity of these changes significantly exceeds the degree of hyperglycaemia and MDA accumulation. GK-2 exerts an antihyperglycaemic effect and attenuates the degree of DNA damage. Our results indicate that the comet assay is a highly informative method for search of antidiabetic medicines.

Application of the comet assay and detection of DNA damage in haemocytes of medicinal leech affected by aluminium pollution: A case study

2009 ◽  
Vol 157 (5) ◽  
pp. 1565-1572 ◽  
Author(s):  
Zlatko Mihaljević ◽  
Ivančica Ternjej ◽  
Igor Stanković ◽  
Mladen Kerovec ◽  
Nevenka Kopjar
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Medicinal Leech

Genoprotective role of vitamin E and selenium in rabbits anaesthetized with sevoflurane

2004 ◽  
Vol 23 (8) ◽  
pp. 413-419 ◽  
Author(s):  
Cetin Kaymak ◽  
Ela Kadioglu ◽  
Hulya Basar ◽  
Semra Sardas
Keyword(s):  
Dna Damage ◽  
Vitamin E ◽  
Comet Assay ◽  
Antioxidant Supplementation ◽  
Group Iii ◽  
Sevoflurane Anaesthesia ◽  
Group I ◽  
The Mean ◽  
Group Ii

In this study, genotoxic effects of repeated sevoflurane anaesthesia were investigated in rabbits with or without antioxidant supplementation. Twenty-one New Zealand male rabbits were included in the study and randomized into three groups as: placebo treated (Group I), vitamin E supplemented (Group II) and selenium supplemented (Group III). Vitamin E and selenium were given intraperitoneally for 15 days before anaesthesia treatment. Anaesthesia was administered using 3% sevoflurane in 4 L/min oxygen for a 3-hour period and continued for 3 days. Blood samples were collected before anaesthesia (Sample 1), after the first, second and third days of sevoflurane administration (Sample 2, Sample 3 and Sample 4 respectively) and the last samples were taken 5 days after the last sevoflurane administration (Sample 5). Genotoxic damage was examined using the comet assay. The degree of damage is assessed by grading the cells into three categories of no migration (NM), low migration (LM) and high migration (HM) depending on the fraction of DNA pulled out into the tail under the influence of the electric field. The number of comets in each sample was calculated (1 × number of comets in category NM + 2 × number of comets in category LM + 3 ×number of comets in category HM) and expressed as the total comet score (TCS), which summarizes the damage frequencies. In Group I, a significant increase in the mean TCSs was observed for Samples 3 and 4 as compared with Sample 1. However, there were no significant differences between Samples 1, 2 and 5. The mean TCS of Sample 4 was significantly higher than Sample 1, 2 and 3 in Group II. Group III demonstrated no significant mean TCSs for any experimental conditions. Statistical differences were also observed between the groups with significant P values. This experimental study points out the presence of DNA damage with repeated sevoflurane anaesthesia and the genoprotective role of antioxidant supplementation on DNA damage in mononuclear leukocytes of rabbits by highly sensitive comet assay.

scholarly journals An improved method for the isolation of rat alveolar type II lung cells: Use in the Comet assay to determine DNA damage induced by cigarette smoke

2015 ◽  
Vol 72 (1) ◽  
pp. 141-149 ◽  
Author(s):  
Annette Dalrymple ◽  
Patricia Ordoñez ◽  
David Thorne ◽  
Debbie Dillon ◽  
Clive Meredith
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Cigarette Smoke ◽  
Lung Cells ◽  
Alveolar Type ◽  
Type Ii ◽  
Improved Method

Basal damage and oxidative DNA damage in children with chronic kidney disease measured by use of the comet assay

2011 ◽  
Vol 725 (1-2) ◽  
pp. 22-28 ◽  
Author(s):  
Banu Aykanat ◽  
Gonca Cakmak Demircigil ◽  
Kibriya Fidan ◽  
Necla Buyan ◽  
Kaan Gulleroglu ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Dna Damage ◽  
Kidney Disease ◽  
Comet Assay ◽  
Oxidative Dna Damage

scholarly journals Analysis of DNA damage in cells excreted in urine of cervical cancer patients using alkaline comet assay

2014 ◽  
Vol 7 (Suppl 1) ◽  
pp. P12
Author(s):  
Avani Patel ◽  
Mihir Shah ◽  
Pinaki Patel ◽  
Trupti Patel
Keyword(s):  
Cervical Cancer ◽  
Dna Damage ◽  
Comet Assay ◽  
Cancer Patients ◽  
Alkaline Comet Assay ◽  
In Cells

DNA damage and repair capacity by comet assay in lymphocytes of white-collar active smokers and passive smokers (non- and ex-smokers) at workplace

2006 ◽  
Vol 167 (2) ◽  
pp. 131-141 ◽  
Author(s):  
Maria Enrica Fracasso ◽  
Denise Doria ◽  
Paola Franceschetti ◽  
Luigi Perbellini ◽  
Luciano Romeo
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
White Collar ◽  
Repair Capacity ◽  
Dna Damage And Repair
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