scholarly journals Chromatin in fractal globule state: evidence from comet assay

2015 ◽  
Vol 31 (2) ◽  
pp. 97-103
Author(s):  
K. S. Afanasieva ◽  
M. I. Chopei ◽  
A. V. Sivolob
Keyword(s):  
Comet Assay ◽  
Fractal Globule

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

Genotoxicity evaluation in vitro by comet assay of compound and crude extract obtained from P. Pubescens Benth.

Planta Medica ◽  
2015 ◽  
Vol 81 (11) ◽  
Author(s):  
VHS Souza ◽  
A Paula OHohne ◽  
R Grando ◽  
N de Cassia de Almeida Queiroz ◽  
GM Pastore ◽  
...  
Keyword(s):  
Comet Assay ◽  
Crude Extract

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.

scholarly journals Validation of the in vitro comet assay for DNA cross-links and altered bases detection

2021 ◽  
Author(s):  
Damián Muruzabal ◽  
Julen Sanz-Serrano ◽  
Sylvie Sauvaigo ◽  
Bertrand Treillard ◽  
Ann-Karin Olsen ◽  
...  
Keyword(s):  
Comet Assay ◽  
Human Health Risk ◽  
High Sensitivity ◽  
Dna Lesions ◽  
Dna Glycosylase ◽  
Vitro Assay ◽  
Cytotoxic Compound ◽  
Endonuclease Iii ◽  
Cross Links

AbstractMechanistic toxicology is gaining weight for human health risk assessment. Different mechanistic assays are available, such as the comet assay, which detects DNA damage at the level of individual cells. However, the conventional alkaline version only detects strand breaks and alkali-labile sites. We have validated two modifications of the in vitro assay to generate mechanistic information: (1) use of DNA-repair enzymes (i.e., formamidopyrimidine DNA glycosylase, endonuclease III, human 8-oxoguanine DNA glycosylase I and human alkyladenine DNA glycosylase) for detection of oxidized and alkylated bases as well as (2) a modification for detecting cross-links. Seven genotoxicants with different mechanisms of action (potassium bromate, methyl methanesulfonate, ethyl methanesulfonate, hydrogen peroxide, cisplatin, mitomycin C, and benzo[a]pyrene diol epoxide), as well as a non-genotoxic compound (dimethyl sulfoxide) and a cytotoxic compound (Triton X-100) were tested on TK-6 cells. We were able to detect with high sensitivity and clearly differentiate oxidizing, alkylating and cross-linking agents. These modifications of the comet assay significantly increase its sensitivity and its specificity towards DNA lesions, providing mechanistic information regarding the type of damage.

Effects of melatonin on N-nitroso-N-methylurea-induced carcinogenesis in rats and mutagenesis in vitro (Ames test and COMET assay)

1999 ◽  
Vol 138 (1-2) ◽  
pp. 37-44 ◽  
Author(s):  
Sergei A Musatov ◽  
Vladimir N Anisimov ◽  
Véronique André ◽  
Carole Vigreux ◽  
Thierry Godard ◽  
...  
Keyword(s):  
Comet Assay ◽  
Ames Test

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
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