Use of sensitive methods for detection of DNA damage on human lymphocytes exposed to p,p′-DDT: Comet assay and new criteria for scoring micronucleus test

2007 ◽  
Vol 42 (6) ◽  
pp. 607-613 ◽  
Author(s):  
Goran Gajski ◽  
Sanda Ravlić ◽  
Željka Capuder ◽  
Vera Garaj-Vrhovac
2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Ronaldo Carvalho-Silva ◽  
Alanna Cibelle Fernandes Pereira ◽  
Rúbens Prince dos Santos Alves ◽  
Temenouga N. Guecheva ◽  
João A. P. Henriques ◽  
...  

Garcinia mangostana,popularly known as “mangosteen fruit,” originates from Southeast Asia and came to Brazil about 80 years ago where it mainly grows in the states of Pará and Bahia. Although mangosteen or its extracts have been used for ages in Asian folk medicine, data on its potential genotoxicity is missing. We, therefore, evaluated genotoxicity/mutagenicity of hydroethanolic mangosteen extract [HEGM, 10 to 640 μg/mL] in established test assays (Comet assay, micronucleus test, andSalmonella/microsome test). In the Comet assay, HEGM-exposed human leukocytes showed no DNA damage. No significant HEGM-induced mutation in TA98 and TA100 strains ofSalmonella typhimurium(with or without metabolic activation) was observed and HEGM-exposed human lymphocytes had no increase of micronuclei. However, HEGM suggested exposure concentration-dependent antigenotoxic potential in leukocytes and antioxidant potential in the yeastSaccharomyces cerevisiae. HEGM preloading effectively protected against H2O2-induced DNA damage in leukocytes (Comet assay). Preloading of yeast with HEGM for up to 4 h significantly protected the cells from lethality of chronic H2O2-exposure, as expressed in better survival. Absence of genotoxicity and demonstration of an antigenotoxic and antioxidant potential suggest that HEGM or some substances contained in it may hold promise for pharmaceutical or nutraceutical application.


2002 ◽  
Vol 40 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Shawna M. Jackman ◽  
Geraldine M. Grant ◽  
Christopher J. Kolanko ◽  
David A. Stenger ◽  
Joginder Nath

2017 ◽  
Vol 324 ◽  
pp. 781-788 ◽  
Author(s):  
Cristina Araujo Matzenbacher ◽  
Ana Letícia Hilario Garcia ◽  
Marcela Silva dos Santos ◽  
Caroline Cardoso Nicolau ◽  
Suziane Premoli ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Márcia Fernanda Correia Jardim Paz ◽  
André Luiz Pinho Sobral ◽  
Jaqueline Nascimento Picada ◽  
Ivana Grivicich ◽  
Antonio Luiz Gomes Júnior ◽  
...  

This study aimed to evaluate DNA damage in patients with breast cancer before treatment (background) and after chemotherapy (QT) and radiotherapy (RT) treatment using the Comet assay in peripheral blood and the micronucleus test in buccal cells. We also evaluated repair of DNA damage after the end of RT, as well as the response of patient’s cells before treatment with an oxidizing agent (H2O2; challenge assay). Fifty women with a mammographic diagnosis negative for cancer (control group) and 100 women with a diagnosis of breast cancer (followed up during the treatment) were involved in this study. The significant DNA damage was observed by increasing in the index and frequency of damage along with the increasing of the frequency of micronuclei in peripheral blood and cells of the buccal mucosa, respectively. Despite the variability of the responses of breast cancer patients, the individuals presented lesions on the DNA, detected by the Comet assay and micronucleus Test, from the diagnosis until the end of the oncological treatment and were more susceptible to oxidative stress. We can conclude that the damages were due to clastogenic and/or aneugenic effects related to the neoplasia itself and that they increased, especially after RT.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4353-4353
Author(s):  
Janusz Blasiak ◽  
Jozef Drzewoski ◽  
Tomasz Poplawski ◽  
Agnieszka Czechowska

Abstract Imatinib (STI571) is a 2-phenylaminopyrimidine derivative used mostly in the treatment of chronic myeloid leukaemia. It targets specifically the BCR/ABL oncogenic tyrosine kinase, inhibiting its activity. Using the alkaline comet assay we showed that STI571 at concentrations ranging from 0.05 to 2 μM induced DNA damage in human leukemic K562 cells expressing the BCR/ABL oncogene, whereas it had no effect in normal human lymphocytes. Because the extent of DNA damage observed in the neutral and pH 12.1 versions of the comet assay was much lesser than in the alkaline version, we concluded that the drug induced DNA alkali-labile sites rather than strand breaks. Imatinib did not induce DNA strand breaks in the direct interaction with DNA as examined by the plasmid relaxation assay. K562 cells were unable to repair H2O2-induced DNA damage during a 120-min incubation, if they had been preincubated with STI571, whereas normal lymphocytes did so within 60 min. Pre-treatment of K562 cells with vitamins A, C and E reduced the extent of DNA damage evoked by STI571. Similar results brought experiments with the nitrone spin traps POBN and PBN, suggesting that free radicals may be involved in the formation of DNA lesions induced by STI571 in K562 cells. These cells exposed to imatinib and treated with endonuclease III, formamidopyrimidine-DNA glycosylase and 3-methyladenine-DNA glycosylase II, the enzymes recognizing oxidized and alkylated bases, displayed greater extent of DNA damage than those not treated with these enzymes.


2017 ◽  
Vol 17 (1) ◽  
pp. 7-22 ◽  
Author(s):  
Geonildo Rodrigo Disner ◽  
Sabrina Louise Moraes Calado ◽  
Helena Cristina Silva Assis ◽  
Marta Margarete Cestari

Polycyclic aromatic hydrocarbons are one of the most important organic pollutants in environmental studies. The aim of this study was to assess the naphthalene acute toxicity in two fish species, Astyanax lacustris (LLcust, 1875) and Geophagus brasiliensis (Quoy & Gaimard, 1824). The fish were exposed to naphthalene (0.005, 0.03, 0.3, and 3 mgL-1) in water and after that the piscine micronucleus test in erythrocytes, comet assay in blood, liver and gill cells, glutathione S–transferase (GST) activity in the liver, and accumulation of naphthalene in the bile were performed. The susceptibility of the two species was similar and naphthalene was not genotoxic in all tested tissues. The liver GST activity may have been responsible for less damage observed in the liver while the highest DNA damage occurred in blood cells. However, low concentrations of naphthalene in water can stimulate apparent benefits, such as less DNA damage, which would be a compensatory response to an imbalance of homeostasis. The naphthalene is absorbed and can accumulate in the gall bladder, a greater accumulation of PAH was observed in A. lacustris, while G. brasiliensis did not differ from the control. The naphthalene concentrations are not genotoxic to the tested species, although they can potentially accumulate into the body.Keywords: Comet assay. Ecotoxicology. Fish. Genotoxicity. Hormesis.


Genetika ◽  
2016 ◽  
Vol 48 (2) ◽  
pp. 617-627
Author(s):  
Stefan Dacic ◽  
Ninoslav Djelic ◽  
Milena Radakovic ◽  
Nada Lakic ◽  
Aleksandar Veselinovic ◽  
...  

Certain in vivo studies have shown that the application of adhesives directly onto the open pulp or on a thin layer of dentin causes inflammation and pulpal abscesses. This reaction is related to toxic effects of monomers from adhesives. It has been confirmed that after proper illumination the adhesives become less toxic. The aim of the study was to examine genotoxicity of non-polymerised, partly polymerised and polymerised adhesives on isolated human lymphocytes using the alkaline Comet assay. Adper Single bond2 and Adper Easy One/3M ESPE adhesive photopolymerisation was performed by Elipar Highlight 3M ESPE halogen lamp for 0, 10 and 40 sec, at final concentrations of 100, 200, 500 and 1000 ?g/mL. With both adhesives, photopolymerisation at 0 and 10 seconds showed statistically significant increase in DNA damage in comparision to the negative control (solvent). On the other hand, after 40 seconds of photopolymerisation of both adhesives in all tested concentrations, the degree of DNA damage in Comet assay had no significant difference (P>0.05, ?2 test) compared to the negative control. Therefore, only the 40 seconds of photopolymerisation prevented genotoxic effects of both adhesives in the Comet assay.


Author(s):  
Rima Thiyam ◽  
Mangamoori Lakshmi Narasu

Objective: The objective of the present study was to investigate the growth inhibitory effect, apoptosis initiation and genotoxic effect of zerumbone (ZER), a phytochemical and cisplatin, a chemotherapeutic drug on human colorectal cancer cell line COLO205 and normal human lymphocytes.Methods: The antiproliferative activity of ZER and cisplatin (positive control) on COLO205 cells and lymphocytes was analysed by 3( 4, 5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide (MTT) assay. Morphological analysis of the cells was studied by using inverted phase contrast microscope. Propidium iodide staining method was used to observe the apoptotic morphological changes in the treated cells. Finally comet assay was conducted to observe the extent of DNA damage induced by ZER and cisplatin on COLO205 and lymphocytes.Results: ZER and cisplatin exhibited growth inhibition in a dose and time dependent manner against COLO205 with no considerable effect on lymphocytes. The IC50 values of ZER on COLO205 for 24h, 48h and 72h were 19 µg/ml, 10 µg/ml and 5 µg/ml. Comparatively the IC50 values of cisplatin on COLO205 for 24h, 48h and 72h were 38 µg/ml, 24 µg/ml and 15 µg/ml.  Morphological changes such as cell shrinkage, membrane blebbing and nuclear condensation were observed in COLO205 while no significant change was observed in lymphocytes. Fluorescence imaging studies confirmed apoptotic cell death in treated COLO205 cells while no significant cell death was observed in treated lymphocytes. Comet assay revealed significant DNA damage in treated COLO205 cells.Conclusion: The present study demonstrated the cytotoxic and genotoxic effect of ZER and cisplatin on COLO205 cells. These drugs showed no significant effect on lymphocytes.


Sign in / Sign up

Export Citation Format

Share Document