scholarly journals Evaluation of DNA damage in tobacco associated human buccal cells using comet assay

2021 ◽  
Vol 94 (2) ◽  
pp. 214-219
Author(s):  
Shanmugam Mohanapriya ◽  
Thangadurai Maheswaran ◽  
Nalliapan Ganapathy ◽  
Thukanayakanpalayam Ragunathan Yoithappr ◽  
Janardhanam Dineshshankar ◽  
...  

Aim and objective. To assess the DNA damage in tobacco associated human buccal cells using comet assay. Methods. The study included 75 study subjects, which were divided into 3 groups on the basis of tobacco usage. Group I - 25 individuals with no history of tobacco usage, Group II - 25 individuals with tobacco usage but without oral lesions and Group III - 25 individuals with tobacco associated oral lesions. Cytological smears collected from these individuals were used to assess the tobacco associated DNA damage by measuring the tail length in the comet assay method. Results. The average tail length was found to be 1.46 µm in the normal mucosa, 2.86 µm in tobacco users without oral lesions, 3.86 µm in the lesional sites of tobacco users and 3.67 µm in the non-lesional sites of these individuals. Factors like age, gender, duration and different forms of tobacco habit had their own impact on the oral mucosa. Conclusion. Comet assay helps assess the subclinical genetic changes of oral mucosa even before the clinical manifestations of the precancerous lesions appeared due to tobacco usage. Thus, comet assay may bloom out as a novel adjuvant tool for the prevention of oral cancer in the near future.

Author(s):  
Ahmet Cihat Öner ◽  
Adnan Ayan

This study was aimed to evaluate DNA fragmentation by using Comet assay in naturally infected sheep with Anaplasmosis before and after treatment with the Comet method, which shows DNA damage specifically. In the study, blood samples were collected from 10 Anaplosmosis infected and 10 healthy sheep. The anaplosmosis was diagnosed by clinical signs and symptoms. The infection was confirmed by Giemsa staining. The blood was collected from control group and infected group before and after the treatment, from the vena jugularis with the appropriate method. The DNA fragmentation was checked by using the Comet assay of blood cells. The data were analysed throught ANNOVA one-way. The result showed higher DNA fragmentation in sick animals diagnosed with anaplasmosis; tail length and tail moment values were found to be statistically significantly higher than the control group. When the data obtained after imidocarb (IMD) application were compared with obtained during the disease, a decreased DNA damage and tail moment was determined, however, these values higher than control. In this study, DNA damage and the extent of this damage were investigated by the Comet assay method using a healthy control group before and after treatment in animals with Anaplasmosis. When the findings obtained from the study were evaluated, it was seen that Anaplasma agents caused DNA damage and with the imidocarb application given for treatment, DNA damage was reduced and results close to healthy individuals were obtained.


2019 ◽  
Vol 18 ◽  
pp. e191430
Author(s):  
Garima Rawat ◽  
Aadithya B Urs ◽  
Anita Chakravarti ◽  
Priya Kumar

Aim: DNA damage associated with Oral Squamous Cell Carcinoma (OSCC) and potentially malignant disorders (PMDs) is produced due to carcinogenic agents or increased oxidative stress. Comet assay can assist in early detection and evaluation of the amount of DNA damage; lymphocytesare the most commonly used cells for performing comet assay. Utilisation of buccal epithelial cells in comet assay can be a minimally invasive and rapid method.  The present study compared the efficacy of comet assay in assessing DNA damage in buccal cells over peripheral blood leucocytes (PBLs) in oral potentially malignant and malignant disorders. Methods: The study included fifty five patients each of Leukoplakia, Oral Submucous Fibrosis (OSMF) and OSCC along with fifty five healthy individuals as control. Buccal epithelial cells were collected from all the selected subjects. DNA damage was evaluated bymeasuring the mean tail length (µm). Results: A significantly increased mean tail length (µm) and higher DNA damage were found in OSCC (26.1096 + 1.84355) and there was a progressive stepwise increase in mean tail length from control(8.4982 + 0.93307) to PMD [leukoplakia (14.6105 + 0.71857); OSMF (12.5009 + 1.12694)] to OSCC.The mean tail length in different habit groups was greater than controls, though no significant difference was noted between habit groups. The mean tail length of buccal cells was significantly greater than the mean tail length of PBLs in all study groups and controls. Conclusion: Hence, use of comet assay on buccal epithelial cells can prove to be beneficiary for evaluation of DNA damage.


2004 ◽  
Vol 23 (8) ◽  
pp. 413-419 ◽  
Author(s):  
Cetin Kaymak ◽  
Ela Kadioglu ◽  
Hulya Basar ◽  
Semra Sardas

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.


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.


2018 ◽  
Vol 28 (5) ◽  
pp. 9-18
Author(s):  
Carmen Martínez-Valenzuela ◽  
Stefan Waliszewski ◽  
María Elena Calderón-Segura ◽  
Mario Caba ◽  
Enrique Meza ◽  
...  

Pesticides constitute a heterogeneous category of chemicals designed for the control of pests affecting cultivated plants. Frequently, they are classified according to their chemical structure, organic and non-organic pesticides. Biomonitoring studies using somatic cells have been conducted to evaluate the possible genotoxic risk of occupationally exposed workers to pesticides. The aim of this study was to assess the genotoxic effects of pesticides in pilots occupationally exposed to these chemicals during aerial application in agricultural fields. The study groups comprised 30 pilots who applied aerial pesticides and 30 controls. The alkaline Comet Assay was performed on freshly collected peripheral whole blood lymphocytes. The nonparametric Mann-Whitney test was applied to compare the equality of two population medians. Additionally, a comparison of two groups according to age and years of work as quantitative variables and a one-way analysis of variance (Anova) with Tukey’s post hoc test were applied. To corroborate differences between groups, a regression analysis was performed to calculate the degree of correlation, expressing their magnitude by R2. Statistical significances were set at a p value of <0.05. The median of comet frequency, tail length (159.6 ± 16.8) and tail moment (16.75 ± 3.13) reveals statistically significant differences (p < 0.001) between exposed pilots and controls. The pilot group divided according to age reveals Deoxyribonucleic acid (DNA) damage which increases significantly when age of participant increases. Neither smoking nor alcohol consumption could be statistically linked to DNA damage. 


2013 ◽  
Vol 33 (3) ◽  
pp. 224-229 ◽  
Author(s):  
T Zhang ◽  
Q Zhao ◽  
Y Zhang ◽  
J Ning

The present study investigated the genotoxic effects of flumorph in various organs (brain, liver, spleen, kidney and sperm) of mice. The DNA damage, measured as comet tail length (µm), was determined using the alkaline comet assay. The comet assay is a sensitive assay for the detection of genotoxicity caused by flumorph using mice as a model. Statistically significant increases in comet assay for both dose-dependent and duration-dependent DNA damage were observed in all the organs assessed. The organs exhibited the maximum DNA damage in 96 h at 54 mg/kg body weight. Brain showed maximum DNA damage followed by spleen > kidney > liver > sperm. Our data demonstrated that flumorph had induced systemic genotoxicity in mammals as it caused DNA damage in all tested vital organs, especially in brain and spleen.


2001 ◽  
Vol 121 (12) ◽  
pp. 1093-1098
Author(s):  
Junji Miyakoshi ◽  
Masami Yoshida ◽  
Yosiaki Tarusawa ◽  
Toshio Nojima ◽  
Kanako Wake ◽  
...  

2014 ◽  
Vol 03 (03) ◽  
pp. 137-142
Author(s):  
Rijied Thompson Swer ◽  
Dyutimoy Datta ◽  
Mary Hydrina D'Silva

Abstract Background and Objectives: The role of genomic instability resulting from chromosomal aberrations, gene mutations due to deletions, translocations and single gene defects is a known phenomenon leading to DNA damage. A deficient repair process is also attributed to the perpetuation of this damage. Placental insufficiency in pregnancy during late embryonic or early fetal period resulting in DNA damage gives rise to malformed phenotypes. An attempt was made to study the extent of DNA damage in non syndromic congenital malformations. Materials and Methods: A total of 20 children were studied. 10 of them, between 10 days to 5 years of age, presenting with non syndromic congenital anomalies formed the cases. An equal number of children matched for age criteria formed the controls. Lymphocytes collected from peripheral blood of these children were subjected to the standard comet assay, an highly sensitive, reliable, relatively inexpensive and reproducible single cell layer electrophoretic technique, where damaged DNA migrates out of the cell towards the anode forming a comet. The length of the tail is a measure of the DNA damage. Results: The malformations observed were those of urogenital, craniofacial and nervous systems. The mean comet tail lengths were 24.744 μm, 20.649 μm and 27.402 μm respectively. Comparing this to the mean tail length in controls with 1.992 μm, there was high statistical significance (P value <0.0001). Conclusion: Gene mutations, particularly involving Sex Region Determining (SRD) genes and Superoxide Dismutase (SOD) enzyme imbalances, have been implicated in these congenital malformations. Thus the comets seen in this study reflect the DNA damage due to the gene defects.


2018 ◽  
Vol 7 (03) ◽  
pp. 153-156
Author(s):  
Priyadharshini NA ◽  
Parkash Chand ◽  
Vishnu Bhatt S.

Abstract Background & aim : Early diagnosis of neonatal sepsis is important for effective management and recovery. The available methods for diagnosis were not useful in predicting outcome. In the present study the technique of single cell gel electrophoresis [comet assay] which measures DNA damage was used to predict the outcome of neonatal sepsis. Material & methods : Comet Assay [single cell gel electrophoresis, SCGE] was used as a tool to assess the DNA damage in 3 5 term neonates with sepsis .The comet parameters were compared between those who recovered and expired due to sepsis neonatorum. Results were analysed using independent student t test with SPSS software version 19. p values <0.05 was taken as significant. Results : Comet length [174.57 ± 46.66pm] and Tail length [ 114.63 ± 52.92pm] are the prime indicator of DNA damage and were significantly [p Z < .05 ] higher among the expired cases when compared to the recovered cases [113.70 ±32.72 and 46.40±37.57 respectively]. Receiver Operating Characteristic [ROC] curve for comet length and tail length showed comet length and tail length are high. Area under the curve [AUC] 0.867 with cut off value of 140.06pm [71.4% sensitivity, 85.7% specificity] and 0.862 with cut off value of 63.12pm [85% sensitivity, 71.4% specificity] respectively. Conclusion :Weconclude that SCGE can be used for predicting mortality in neonatal sepsis


2019 ◽  
Vol 12 (2) ◽  
pp. 163-172 ◽  
Author(s):  
D. Rašić ◽  
D. Želježić ◽  
N. Kopjar ◽  
D. Kifer ◽  
M. Šegvić Klarić ◽  
...  

The study aimed to check whether ochratoxin A (OTA) and citrinin (CIT) increase DNA damage in the kidney and liver of male Wistar rats (alkaline comet assay), clarify the oxidative nature of DNA damage (hOGG1-modified comet assay), and verify whether resveratrol (RSV) could ameliorate OTA+CIT-induced genotoxicity. Rats were treated orally with OTA (0.125 and 0.250 mg/kg bodyweight (bw)) and CIT (2 mg/kg bw), OTA+CIT combinations and OTA+CIT+RSV (0.250+2+20 mg/kg bw) for 21 days. Both alkaline and hOGG1-modified comet assay showed that DNA damage was more severe in rat kidneys than in liver following mycotoxin treatment. Alkaline comet assay revealed a higher intensity of DNA damage, particularly as measured by tail intensity in the kidneys. Both tail length and tail intensity were OTA dose-dependent, but in combined OTA+CIT treatment these values were similar to CIT alone and lower than in animals treated with single OTA, possibly due to induction of apoptosis. hOGG1-modified comet showed that OTA+CIT evoked greater oxidative DNA damage than single mycotoxins. RSV did not reduce DNA damage measured by alkaline comet assay, but hOGG1-modified comet showed that RSV ameliorated OTA+CIT genotoxicity in the kidneys. Apart from oxidative stress, other mechanisms of DNA damage are involved in OTA and CIT genotoxicity. In rat kidneys RSV can reduce but not overcome oxidative DNA damage induced by combined OTA and CIT.


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