Comet Assay

Background: This study investigated the possible protective effects of bilberry extract after exposing rat eyes to ultraviolet-B (UV-B) radiation. Methods: Four groups of rats were included in this study, each consisting of 10 Wistar rats. The first group acted as the control, and the second group was exposed to UV-B, 5 KJ/m2 (λm = 300 nm), for 15 minutes. The third group was orally administered bilberry extract (160 mg twice per day) for two weeks before exposure to the UV-B, while the fourth group was administered the same dose of bilberry extract for two weeks before euthanisation. A comet assay was used to examine DNA damage, while the malondialdehyde (MDA) level and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), activities were measured in the lens. Results: After exposing the rats to UV-B radiation, the mean percentage tail DNA and tail moment were significantly increased (P < 0.001) when compared to the control group. In the same context, the lens tissue MDA levels and CAT activity were also significantly increased (P < 0.001). The supplementation of the bilberry extract was found to improve the comet assay parameters and enzymatic activity of the rat lens tissue. Conclusion: The administration of bilberry led to a decrease in the oxidative stress in the lens tissues and DNA damage induced by UV-B radiation in the lenses of Wistar rats.
Vaccinium myrtillus ; DNA ; Comet Assay ; Malondialdehyde

Comet Assay ; DNA Damage ; Humans ; Occupational Exposure ; Population Surveillance ; methods

OBJECTIVETo explore the feasibility of single-cell gel electrophoresis (SCGE) as one of lab tests to examine DNA breakage for the diagnosis of Fanconi anemia (FA). Case Record A 4-year-and-10-month old boy presented with cryptorchism, deformities of both thumbs and esotropia of right eye. He developed thrombocytopenia and anemia when he was 3 year- and -2-month old. He was clinically diagnosed as FA.

METHODS AND RESULTSDNA breakage of peripheral white blood cells from the patient and his parents was examined with SCGE. The percentages of cells with chromosome breakage (comet-tail positive cells) were 100%, 90% and 52% for the patient,his father and mother, respectively, while that were only 2% and 5% in two normal same-age children (P <0. 001). The micronucleus-positive lymphocytes was 6.74% in the patient, being also much higher than normal value (0.40%).

CONCLUSIONSCGE disclosed DNA breakage in the patient with FA, suggesting that it could be used as a test for determining DNA breakage of FA.

Child, Preschool ; Comet Assay ; Fanconi Anemia ; diagnosis ; Humans ; Male

Comet Assay ; DNA Damage ; DNA Repair ; In Situ Hybridization, Fluorescence ; methods

Animals ; Comet Assay ; DNA Damage ; drug effects ; Lymphocytes ; drug effects ; Male ; Organometallic Compounds ; toxicity ; Rats

OBJECTIVETo investigate the genetic instability in patients with Dyskeration congenita.

METHODSThe spontaneous chromosome instability of lymphocytes from 4 DC patients, 29 FA patients and 24 healthy volunteers was assessed with comet assay. The percent of DNA in comet head (HeadDNA%）, the percent of DNA in comet tail (TailDNA%）, tail moment (TM), olive tail moment (OTM), the comet cell percentage (CCP) were compared between groups. And the results of MMC test, PNH clones and karotype were analysed additionally. The correlation between TM, OTM, CCP and the severity degree of bone marrow failure in DC group were evaluated.

RESULTS①PNH clones and karotype abnormalities were not found in 4 DC patients. ②TM (6.77 ± 0.90), OTM（6.19 ± 0.80) and CCP [(46.00 ± 5.03) %] in DC were significantly higher than those in normal control group [0.61 ± 0.49, 0.66 ± 0.42, (5.91 ± 3.19)%, P<0.05], however, not distinguished from FA patients [7.81 ± 3.58, 6.65 ± 2.21, (56.03 ± 13.47) %, P ≥ 0.05]. The aberrant cell percent at the MMC concentration of 80 μg/L in DC group was significantly lower than that in FA group [(21.00 ± 3.16) % vs (31.97 ± 6.33)%, P=0.003]. ③The correlation between TM, OTM, CCP and the severity of bone marrow failure in DC group were not found (P>0.05).

CONCLUSIONDC patients were of significantly increased genetic instability and normal DNA repair, which was different from that in FA patients. And there was no correlation between the degree of genetic instability and the severity of bone marrow failure in DC patients presenting as aplastic anemia.

Case-Control Studies ; Chromosomal Instability ; Comet Assay ; Dyskeratosis Congenita ; genetics ; Fanconi Anemia ; genetics ; Humans ; Lymphocytes ; Pancytopenia

OBJECTIVEThis paper aims to evaluate the genotoxicity in peripheral blood lymphocytes of rats after exposure to sunlight at different time points of day in a tropical region of Brazil (5 degrees S, 42 degrees W).

MATERIALS AND METHODSThirty Wistar-Hannover rats, three months old, were randomly divided into three groups of 10 animals each: Group I [control, without exposure to ultraviolet (UV) radiation], Group II (exposed to sunlight during 08:00 a.m. to 10:00 a.m.), and Group III (exposed to sunlight during 10:00 a.m. to 12:00 a.m.). After a week of exposure, peripheral blood samples were taken from the tail of these animals to prepare smears on two slides per animal. In 24 h after exposure to sunlight in Group III, a new collection was obtained to observe the repair activity. The alkaline comet assay was used in this study to evaluate the genotoxic activity of sunlight (P < 0.05).

RESULTSThere was no statistical difference between Group I and II (P = 0.672). On the other hand, the exposure to sunlight in Group III showed genotoxic action in comparison to the other groups (P < 0.0001). Also, there was no significant repair in Group III R (P = 0.407).

CONCLUSIONThis study has shown a genotoxic potential of sunlight (UVA-B) in lymphocytes of mammals from 10:00 a.m. to 12:00 a.m., due to a higher intensity of UV in this tropical region.

Animals ; Comet Assay ; DNA Damage ; Lymphocytes ; radiation effects ; Rats ; Rats, Wistar ; Sunlight

OBJECTIVETo investigate whether long working in the high-altitude area can damage sperm DNA in men.

METHODSWe enlisted 51 service men stationed on the plateau in an observation group and another 53 living in the low-altitude area in a control group. We detected and compared the damages to sperm DNA in the semen samples from the two groups using single cell gel electrophoresis and the sperm chromatin dispersion test.

RESULTSThe percentages of total, G1, G2 and G3 comet cells and abnormal sperm of the observation group were (5.56 +/- 3.98)%, (3.72 +/- 1.85)%, (1.57 +/- 1.07)%, (0.27 +/- 0.34)% and (16.59 +/- 12.07)%, respectively, before stationed on the plateau, but significantly increased at 6 months of plateau life ([11.15 +/- 8.59]%, [5.97 +/- 3.26]%, [3.83 +/- 2.13%, [1.35 +/- 1.53]% and [22.03 +/- 15.33]%, P<0.05). The percentages of G2 comet cells and abnormal sperm were decreased to (3.32 +/- 1.83)% and (20.54 +/- 15.52)% at 12 months, but still significantly higher than the baseline (P<0.05).

CONCLUSIONLong working on the plateau may damage sperm DNA, but its influence on male fertility deserves further investigation. Therefore, it is important to reinforce reproductive health protection for males working on the plateau.

Adolescent ; Adult ; Altitude ; Comet Assay ; DNA Damage ; Humans ; Male ; Sperm Count ; Spermatozoa ; metabolism ; Young Adult

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 microg/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 microg/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.
Eleutherococcus* ; Biotransformation ; Comet Assay ; Escherichia coli ; Immune System Diseases ; Korea ; Lignans* ; Salmonella typhimurium