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

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

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

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

BACKGROUND/AIMS: The role of Helicobacter pylori in gastric carcinogenesis is unclear, but H. pylori infection is thought to predispose carriers to gastric cancer. The aim of this study was to investigate the relationship between the extent of DNA damage in normal gastric epithelial cells and H. pylori-positive and -negative gastritis according to histological diagnosis. We also compared the percentage of cometed cells on the surface of the gastric epithelial cells to the percentage beneath the gastric mucosal cells using serial incubations times. METHODS: The comet assay is a rapid, efficient and reproducible measure of DNA damage in single cell and it was used in this study. DNA damage was evaluated in 52 cases using alkaline single cell gel electrophoresis (comet assay). Comparisons were made between 19 normal individuals, 19 patients with H. pylori-positive and -negative gastritis and 14 mixed cases with different histology gradings to determine if there was a relationship between histological diagnosis and DNA damage (comet percentage). RESULTS: The comet percentages in specimens from cases with normal histology were significantly higher than the comet percentages in specimens from cases with H. pylori-positive gastritis. In addition, there was a significant increase in the percentage of cometed cells on the surface of gastric epithelial cells in both normal and H. pylori-infected cells compared to the subsequent gastric cell layers of the same specimen. CONCLUSIONS: A relationship between the comet percentage and the histological diagnosis was observed.
Comet Assay ; DNA ; DNA Damage ; Electrophoresis ; Epithelial Cells ; Gastritis ; Helicobacter ; Helicobacter pylori ; Humans ; Stomach Neoplasms

High consumption of fruits and vegetables has been suggested to provide some protection to smokers who are exposed to an increased risk of numerous cancers and other degenerative diseases. Carrot is the most important source of dietary beta-carotene. Therefore, the objective of this study was to investigate whether carrot juice supplementation to smokers can protect against lymphocyte DNA damage and to compare the effect of supplementation of capsules containing purified beta-carotene or a placebo (simple lactose). The study was conducted in a randomized and placebo-controlled design. After a depletion period of 14 days, 48 smokers were supplemented with either carrot juice (n = 18), purified beta-carotene (n = 16) or placebo (n = 14). Each group was supplemented for 8 weeks with approximately 20.49 mg of beta-carotene/day and 1.2 mg of vitamin C/day, as carrot juice (300 ml/day) or purified beta-carotene (20.49 mg of beta-carotene, 1 capsule/day). Lymphocyte DNA damage was determined using the COMET assay under alkaline conditions and damage was quantified by measuring tail moment (TM), tail length (TL), and% DNA in the tail. Lymphocyte DNA damage was significantly decreased in the carrot juice group in all three measurements. The group that received purified beta-carotene also showed a significant decrease in lymphocyte DNA damage in all three measurements. However, no significant changes in DNA damage was observed for the placebo group except TM (P = 0.016). Erythrocyte antioxidant enzyme was not significantly changed after supplementation. Similarly plasma lipid profiles were not different after carrot juice, beta-carotene and placebo supplementation. These results suggest that while the placebo group failed to show any protective effect, carrot juice containing beta-carotene or purified beta-carotene itself had great antioxidative potential in preventing damage to lymphocyte DNA in smokers.
beta Carotene ; Capsules ; Comet Assay ; Daucus carota ; DNA ; DNA Damage ; Erythrocytes ; Fruit ; Lymphocytes ; Plasma ; Vegetables ; Vitamins

This study aims to explore the temporal pattern of DNA breaks induced by nanosecond electric pulses (nsEP) in cisplatin-sensitive and cisplatin-resistant human ovarian cancer cells. Human ovarian cancer cells A2780 (cisplatin-sensitive subline) and C30 (cisplatin-resistant subline) were exposed to nsEP. Sham exposed groups were shame exposed to nsEP. Cell viability was determined using CCK-8 assay after 0 h, 4 h, 8 h, 12 h and 24 h, respectively, and the percentage of dead cells was calculated. The DNA break was detected with the alkaline single cell gel electrophoresis (comet assay), and the 75th percentiles of TL (tail length), TM (tail moment) and OTM (Olive tail moment) were measured. Cell viability displayed an early decrease and late increase, with the valley value seen at 8 h. Percentages of cell death and comet-formed in A2780 cells were higher than those in C30 cells (P < 0.05) at 8 h, respectively. TL, TM and OTM in C30 cells were less than those in A2780 cells (P < 0.05). The percentage of comet-formed correlated with that of cell death in either A2780 (r = 0.997, P < 0.05) or C30 (r = 0.998, P < 0.05) cells. DNA breaks induced by nsEP in cisplatin-sensitive cells differred from that in resistant cells, and DNA break resulted in fraction of cell death.
Cell Survival ; Cisplatin ; Comet Assay ; DNA Breaks ; DNA, Neoplasm ; Electricity ; Female ; Humans ; Ovarian Neoplasms ; pathology

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