DNA Damage Index Research Articles

Determination of the Effect of Thymoquinone on DNA Damage in Kidney Cells Treated to High Glucose Depending on Time and Dosage by Comet Assay

The purpose of this study was to assess the anti-genotoxic potential of thymoquinone (TQ) against DNA damage in NRK-52E cells treated with high glucose using the comet assay technique single cell gel electrophoresis method. Cells were propagated by regular passages in in vitro conditions. TQ proliferative concentration (10μM) and IC25 (3rd-hour: 550 mM, 12th-hour: 240 mM, 24th-hour: 200 mM) and IC50 (3rd-hour: 760 mM, 12th-hour: 400 mM, 24th-hour: 280 mM) values for each hour of high glucose and were determined separately with MTT method. At these concentrations, the cells were divided into control(C), Thymoquinone (TQ), high glucose(G) and high glucose plus thymoquinone (GT) groups; It was incubated with the indicated substances for 3, 12, 24 hours. DNA damage was evaluated by applying the comet assay protocol and the results were calculated as DNA damage index (DDI). While DDI levels were observed to be significantly higher (p<0.05) in all groups administered high glucose compared to the control, a significant decrease was determined in all groups in which TQ was added along with high glucose. It was determined that high concentrations of glucose had genotoxic effects on kidney cells, and TQ administration together with high glucose, depending on concentration and time, had a significant effect on reducing DNA damage. However, it was concluded that the application of only thymoquinone significantly increased the DDI value compared to the control, and this was a data worth investigating in future studies. Additionally, TQ inhibited DNA damage. These results demonstrated the importance of TQ against nephrotic syndrome with its high antioxidant properties.

In vitro effect of Lenzites betulinus mushroom against therapy-induced DNA damage in peripheral blood lymphocytes of patients with acute coronary syndrome

Ethnopharmacological relevanceAcute coronary syndrome (ACS) represents a group of diseases that are the result of reduced blood flow to the heart. There are natural products, based on mushrooms, used traditionally in the treatment of cardiovascular diseases. Aim of the studyAssessment of the potential protective effect of L. betulinus mushroom against therapy-induced DNA damage in lymphocytes of patients with ACS in relation to the phytochemical properties of the mushroom. Materials and methodsThe study included 30 ACS patients and 30 healthy controls. The genotoxic potential of acetone and ethanol extract of L. betulinus was evaluated using the comet assay. The contents of minerals were determined by inductively coupled plasma optical emission spectrometry. Determination of sugars and organic acids was performed using a DIONEX ICS 3000 DP liquid chromatography system. Analysis of fatty acids was performed at Focus GC coupled with PolarisQ mass spectrometer. The total phenolic and flavonoid contents in the mushroom extracts were measured using spectrophotometric methods. The qualitative and quantitative content of polyphenolic compounds was investigated by the UHPLC-DADMS/MS method. ResultsThe comet assay showed that both mushroom extracts did not increase the level of DNA damage in the lymphocytes of healthy individuals, while they significantly decreased the %DNA damage and genetic damage index (p < 0.0005) in the therapy-induced lymphocytes of patients. The mushroom was very rich in phytochemical composition. The results showed that the most abundant components in the mushroom were phosphorus, potassium, sodium, sulfur, and calcium among minerals and glucose, fructose, galactose, sorbitol, and turanose among carbohydrates. Among organic acids were present in higher concentrations malic, citric, and maleic acids, while among fatty acids, the most abundant were trans-linoleic, cis-oleic, palmitic, docosahexaenoic and eicosadienoic acids. The results showed that the highest amount of total phenols and flavonoids in the mushroom extracts were obtained in the acetone extract. The most abundant polyphenolic compounds were chlorogenic acid and quercetin in both extracts of mushroom. ConclusionsThis study indicates that L. betulinus can be considered a mushroom with a high nutritional and functional value. Extracts of the mushroom were not genotoxic in tested concentrations in cultured human lymphocytes of healthy individuals, while in ACS patients they manifested a protective effect against therapy-induced DNA damage. The acetone extract showed a stronger protective effect against therapy-induced DNA damage, which is consistent with its phytochemical composition.

Phytochemical profile and determination of cytotoxicity, acute oral toxicity, genotoxicity, and mutagenicity of aqueous and ethanolic extracts of Pseudobombax marginatum (A. St.-Hil.) A. Robyns

ABSTRACT Pseudobombax marginatum, popularly known as “embiratanha,” is widely used by traditional communities as anti-inflammatory and analgesic agent. This study aimed to determine the phytochemical profile as well as cytotoxicity, acute oral toxicity, genotoxicity, and mutagenicity attributed to exposure to aqueous (AqEx) and ethanolic (EtEx) extracts of embiratanha bark. Phytochemical screening was conducted using thin-layer chromatography (TLC). Cell viability was analyzed using MTT assay with human mammary gland adenocarcinoma (MDA-MB-231) and macrophage (J774A.1) cell lines, exposed to concentrations of 12.5, 25, 50, or 100 µg/ml of either extract. For acute oral toxicity, comet assay and micronucleus (MN) tests, a single dose of 2,000 mg/kg of either extract was administered orally to Wistar rats. TLC analysis identified classes of metabolites in the extracts, including cinnamic acid derivatives, flavonoids, hydrolyzable tannins, condensed tannins, coumarins, and terpenes/steroids. In the cytotoxicity assay, the varying concentrations of extracts derived from embiratanha induced no significant alterations in the viability of MDA-MB-231 cells. The lowest concentration of EtEx significantly increased macrophage J774A.1 viability. However, the higher concentrations of AqEx markedly lowered macrophage J774A.1 viability. Animals exhibited no toxicity in the parameters analyzed in acute oral toxicity, comet assay, and MN tests. Further, EtEx promoted a significant reduction in DNA damage index and DNA damage frequency utilizing the comet assay, while the group treated with AqEx exhibited no marked differences. Thus, data demonstrated that AqEx or EtEx of embiratanha may be considered safe at a dose of 2,000 mg/kg orgally under our experimental conditions tested.

Analysis and quantification of double-stranded DNA breaks in blood lymphocytes by detection of γ-H2AX foci during a body mass increase

The research aims to investigate the relationship of body mass index indicators on the appearance and nature of damage to the genetic material of lymphocyte cells in patients with diagnosed obesity without concomitant pathological conditions. The research methods included anthropometry, biochemical blood examination, immunofluorescence analysis, and static data processing. Characterization of nuclear damage was assessed by studying the phosphorylated histone protein γ-H2AX loci in circulating lymphocytes (computational tool – AKLIDES). The study sample comprised 235 adult patients, categorized into four groups based on body mass index, with randomization conducted for age and sex matching between the groups. BMI increased with higher degrees of obesity. DNA damage in lymphocytes showed significant differences among groups, particularly in overweight patients. Correlations between BMI and various DNA damage indices suggest a relationship between body weight and genetic material breakage in circulating lymphocytes. The analysis of the data revealed that the number of deoxyribonucleic acid double-strand breaks per lymphocyte as well as the number of nuclei with break foci and the break diameter itself correlated with the body mass index and in some cases with the waist/hip index as well as the waist/height index. The results of the work can be used to improve treatment protocols for obese patients, as well as implemented in preventive programs to prevent the development of overweight and type 2 diabetes mellitus.

Lycopene prevents cell death in NRK-52E cells by inhibition of high glucose-activated DNA damage and apoptotic, autophagic, and necrotic pathways.

This study aims to investigate the effects of lycopene on apoptotic, autophagic, and necrotic pathways, oxidative status, and DNA damage in diabetic nephropathy at the molecular level. The sample of the study includes seven groups: lycopene (L), high glucose (G), high glucose + lycopene (GL), and control (C) groups tested at 12 and 24 h. The expression levels of genes in oxidative, apoptotic, autophagic, and necrotic cell death pathways are determined by reverse transcription-quantitative polymerase chain reaction analysis. The comet assay method is used for the analysis of DNA damage. It is observed that adding lycopene to high glucose for protective purposes reduces the expression of genes related to apoptosis, autophagy, and necrosis, as well as the DNA damage index, compared to cells given high glucose alone. Lycopene can be a safe and effective alternative agent.

Top-down Nanoscavengers for the protection of organophosphate-challenged cells

BackgroundOrganophosphates (OPs) can directly poison various types of mammalian cells, only with several awkward bottom-up antagonists. A top-down nanoscavenger was developed to radically and etiologically prevent cell damage, while insufficient subcellular or molecular blocking mechanisms were explored. MethodsThe top-down nanoscavengers were first developed and carefully characterized. EL4 cells were then adopted as model cells to clarify the protective effects and mechanisms of nanoscavengers. After detecting the cell viability and apoptosis, oxidative stress and mitochondrial injury markers, DNA damage index as well as relevant apoptotic factors were sequentially examined to clarify what damage the top-down nanoscavengers inhibited. ResultsThe well-characterized nanoscavengers exerted a top-down and etiological protective effects on EL4 cell viability via radically eliminating OPs and blocking OP-cell interactions. As a result, the intracellular oxidative stress-related markers including ROS production and abnormal antioxidants, mitochondrial injuries as well as DNA damage were inhibited. Accordingly, above damage-induced apoptosis was also blocked. ConclusionIn conclusion, this study clarified the protective mechanisms of a novel enzyme-based nanoscavengers for OP-challenged cells and provided a potent antidote for OP poisoning.

Cytosine–phosphate–guanine oligodeoxynucleotides alleviate radiation-induced kidney injury in cervical cancer by inhibiting DNA damage and oxidative stress through blockade of PARP1/XRCC1 axis

BackgroundRadiotherapy can cause kidney injury in patients with cervical cancer. This study aims to investigate the possible molecular mechanisms by which CpG-ODNs (Cytosine phosphate guanine-oligodeoxynucleotides) regulate the PARP1 (poly (ADP-ribose) polymerase 1)/XRCC1 (X-ray repair cross-complementing 1) signaling axis and its impact on radiation kidney injury (RKI) in cervical cancer radiotherapy.MethodsThe GSE90627 dataset related to cervical cancer RKI was obtained from the Gene Expression Omnibus (GEO) database. Bioinformatics databases and R software packages were used to analyze the target genes regulated by CpG-ODNs. A mouse model of RKI was established by subjecting C57BL/6JNifdc mice to X-ray irradiation. Serum blood urea nitrogen (BUN) and creatinine levels were measured using an automated biochemical analyzer. Renal tissue morphology was observed through HE staining, while TUNEL staining was performed to detect apoptosis in renal tubular cells. ELISA was conducted to measure levels of oxidative stress-related factors in mouse serum and cell supernatant. An in vitro cell model of RKI was established using X-ray irradiation on HK-2 cells for mechanism validation. RT-qPCR was performed to determine the relative expression of PARP1 mRNA. Cell proliferation activity was assessed using the CCK-8 assay, and Caspase 3 activity was measured in HK-2 cells. Immunofluorescence was used to determine γH2AX expression.ResultsBioinformatics analysis revealed that the downstream targets regulated by CpG-ODNs in cervical cancer RKI were primarily PARP1 and XRCC1. CpG-ODNs may alleviate RKI by inhibiting DNA damage and oxidative stress levels. This resulted in significantly decreased levels of BUN and creatinine in RKI mice, as well as reduced renal tubular and glomerular damage, lower apoptosis rate, decreased DNA damage index (8-OHdG), and increased levels of antioxidant factors associated with oxidative stress (SOD, CAT, GSH, GPx). Among the CpG-ODNs, CpG-ODN2006 had a more pronounced effect. CpG-ODNs mediated the inhibition of PARP1, thereby suppressing DNA damage and oxidative stress response in vitro in HK-2 cells. Additionally, PARP1 promoted the formation of the PARP1 and XRCC1 complex by recruiting XRCC1, which in turn facilitated DNA damage and oxidative stress response in renal tubular cells. Overexpression of either PARP1 or XRCC1 reversed the inhibitory effects of CpG-ODN2006 on DNA damage and oxidative stress in the HK-2 cell model and RKI mouse model.ConclusionCpG-ODNs may mitigate cervical cancer RKI by blocking the activation of the PARP1/XRCC1 signaling axis, inhibiting DNA damage and oxidative stress response in renal tubule epithelial cells.

Differential dose-response effect of cyclosporine A in regulating apoptosis and autophagy markers in MCF-7 cells.

Cyclosporine A (CsA) is an immunosuppressant primarily used at a higher dosage in transplant medicine and autoimmune diseases with a higher success rate. At lower doses, CsA exhibits immunomodulatory properties. CsA has also been reported to inhibit breast cancer cell growth by downregulating the expression of pyruvate kinase. However, differential dose-response effects of CsA in cell growth, colonization, apoptosis, and autophagy remain largely unidentified in breast cancer cells. Herein, we showed the cell growth-inhibiting effects of CsA by preventing cell colonization and enhancing DNA damage and apoptotic index at a relatively lower concentration of 2µM in MCF-7 breast cancer cells. However, at a higher concentration of 20µM, CsA leads to differential expression of autophagy-related genes ATG1, ATG8, and ATG9 and apoptosis-associated markers, such as Bcl-2, Bcl-XL, Bad, and Bax, indicating a dose-response effect on differential cell death mechanisms in MCF-7 cells. This was confirmed in the protein-protein interaction network of COX-2 (PTGS2), a prime target of CsA, which had close interactions with Bcl-2, p53, EGFR, and STAT3. Furthermore, we investigated the combined effect of CsA with SHP2/PI3K-AKT inhibitors showing significant MCF-7 cell growth reduction, suggesting its potential to use as an adjuvant during breast cancer therapy.

Association between the use of muscle-building supplements and DNA damage in resistance training practitioners

ObjectivesLittle is known about the relationship between the supplements used for sport and safety, especially regarding the induction of genotoxicity. Therefore, more knowledge about a DNA damage possibly caused using sport supplements is necessary. The aim of this study was to investigate the potential association between the use of muscle-building supplements and DNA damage in resistance training practitioners. MethodsMuscle-building supplements were classified into three categories based on evidence of efficacy and safety: Strong Evidence to Support Efficacy and Apparently Safe (SESEAS); Limited or Mixed Evidence to Support Efficacy (LMESE), and Little to No Evidence to Support Efficacy and/or Safety (LNESES). DNA damage was evaluated by the comet assay (DNA damage index and frequency) and buccal micronucleus by the cytome assay (micronuclei and nuclear buds). In the sequence, the adjusted analysis of covariance was performed. This study included 307 individuals ages 37.99 ± 13.95 y (52.1% men), of which 157 consumed supplements. ResultsThe results of the comet assay revealed that participants who used supplements had higher DNA damage indexes (P = 0.018) and damage frequency (P = 0.045) than those who reported using no supplements. Moreover, the comet assay also indicated that the participants who used supplements classified into the SESEAS category presented the highest DNA damage index (P = 0.025) and frequency (P = 0.044) compared with those who used no supplements. However, we found no significant difference in the micronuclei and nuclear buds in the evaluated groups (P > 0.05). ConclusionSupplement use is not associated with permanent damage, suggesting that SESEAS supplements are safe for consumption.

Indices of Inflammation, Oxidative Stress and DNA damage in T2DM patients with and without Insulin Therapy

Background: Type 2 Diabetes Mellitus is a metabolic disorder associated with excessive free radical generation and oxidative stress. Pharmacological interventions of T2DM targets on glycemic control and reduce the circulatory levels of oxidative stress and inflammation. Aim: The study compared the levels of oxidative stress, inflammation and the extent of DNA damage in T2DM patients undergoing different treatment modalities. Methods: 150 subjects recruited for this study belonged to the age group of 35-65 years. Participants were grouped as healthy controls (n=50), diabetics treated with oral hypoglycemic agent metformin (n=50) and diabetics undergoing combined therapy of insulin and metformin (n = 50). All the participants underwent the assessment of anthropometric measures, baseline blood pressure and blood samples were analysed for FBS, HbA1c, MDA, TAC, Hs-CRP and DNA damage. Results: Analysis using one-way ANOVA showed that despite the same age and duration of T2DM, patients in insulin therapy group had significantly higher levels of oxidative stress, inflammation and DNA damage when compared to T2DM patients treated with metformin alone. Further, significant correlations were observed for the above parameters with the duration of T2DM.Conclusion: The study concludes that oxidative stress, systemic inflammation and cellular senescence are more prominent in T2DM patients undergoing insulin therapy. Poor glycemic control observed in these patients could be attributed to increased insulin resistance as a consequence of oxidative stress and inflammation.

Combined treatment of disulfiram with PARP inhibitors suppresses ovarian cancer.

Due to the difficulty of early diagnosis, nearly 70% of ovarian cancer patients are first diagnosed at an advanced stage. Thus, improving current treatment strategies is of great significance for ovarian cancer patients. Fast-developing poly (ADP-ribose) polymerases inhibitors (PARPis) have been beneficial in the treatment of ovarian cancer at different stages of the disease, but PARPis have serious side effects and can result in drug resistance. Using PARPis in combination with other drug therapies could improve the efficacy of PRAPis.In this study, we identified Disulfiram as a potential therapeutic candidate through drug screening and tested its use in combination with PARPis. Cytotoxicity tests and colony formation experiments showed that the combination of Disulfiram and PARPis decreased the viability of ovarian cancer cells. The combination of PARPis with Disulfiram also significantly increased the expression of DNA damage index gH2AX and induced more PARP cleavage. In addition, Disulfiram inhibited the expression of genes associated with the DNA damage repair pathway, indicating that Disulfiram functions through the DNA repair pathway. Based on these findings, we propose that Disulfiram reinforces PARPis activity in ovarian cancer cells by improving drug sensitivity. The combined use of Disulfiram and PARPis provides a novel treatment strategy for patients with ovarian cancer.

Biochemical studies and expression of Atg7/LC3 autophagy genes in mephalan-induced testicular dysfuntion

Autophagy is an intracellular lysosomal degradation pathway and plays a very important role in maintaining intracellular homeostasis. This present study demonstrates the biochemical status and expression of ATG7/LC3 autophagic genes in Melphalan-induced testicular dysfunction. Twenty make Swiss albino mice were maintained under standard conditions of humidity (50 ± 5%), temperature (25 ± 2° C) with free access to food and water. The mice were divided into five groups (n=5 each) and treated by intraperitoneal injection as follows; Group I: vehicle-treated control; Group II: 1 mg/kg/bwt MEP; Group III: 3mg/kg/bwt MEP; Group IV: 5mg/kg/bwt MEP. Histopathological and histochemical evaluation by light microscopy, biochemical assays and sperm parameters evaluation are the various investigation depicted in this study. Result shows a rise percentage of DNA damage and teratozoospermia Index (TZI); decrease of protein concentration and total antioxidant capacity (TAC). Testosterone concentration was depleted. The result also shows a significant decrease of Luteinizing Hormone (LH) level across the groups when compared to the control. This study confirms oxidative stress by increased ROS and MDA levels in the testes of the melphalan-treated mice and defective antioxidants response as evident from diminished activities of antioxidant enzymes. The autophagic gene markers showed an upstream Atg7 gene and downstream of LC3-II/LC3-I ratio. Autophagy is mediated by the expression of Atg7 and LC3 genes and these varying mRNA expression led to autophagic defect.

Trypanosoma cruzi: Does the intake of nanoencapsulated benznidazole control acute infections?

Chagas Disease (CD) affects around eight million people worldwide. It is considered a neglected disease that presents few treatment options with efficacy only in the acute phase. Nanoparticles have many positive qualities for treating parasite infections and may be effectively and widely employed in clinical medicine. This research aimed to evaluate the nanoencapsulated benznidazole treatment in animals experimentally infected with Trypanosoma cruzi. To analyze the treatment efficacy, we evaluated survival during thirty days, parasitemia, genotoxicity, and heart and liver histopathology. Thirty-five female Swiss mice were organized into seven groups characterizing a dose curve: A – Negative control (uninfected animals), B – Positive control (infected animals), C – Benznidazole (BNZ) 100 mg/kg (infected animals), D – 5 mg/kg Benznidazole nanocapsules (NBNZ) (infected animals), E − 10 mg/kg Benznidazole nanocapsules (infected animals), F – 15 mg/kg Benznidazole nanocapsules (infected animals), G – 20 mg/kg Benznidazole nanocapsules (infected animals). The animals were infected with the Y strain of T. cruzi intraperitoneally. The treatment was administered for eight days by oral gavage. It was possible to observe that the treatment with the highest NBNZ dose presented efficacy similar to the standard benznidazole drug. The 20 mg/kg NBNZ dose was able to reduce parasitemia, increase survival, and drastically reduce heart and liver tissue damage compared to the 100 mg/kg BNZ dose. Moreover, it showed a lower DNA damage index than the BNZ treatment. In conclusion, the nanoencapsulation of BNZ promotes an improvement in parasite proliferation control with a five times smaller dose relative to the standard dose of free BNZ, thus demonstrating to be a potential innovative therapy for CD.

Comet assay in Aegla platensis (Decapoda: Anomura) using a non-lethal hemolymph field sampling for in situ monitoring of freshwater genotoxicity.

This study aimed to apply the comet assay on Aegla platensis crabs as a suitable non-destructive approach for in situ monitoring of freshwater genotoxicity. Animals were captured during four sampling periods in a stream under minor anthropogenic impacts in Southern Brazil. Crabs were captured with a hand net, then the hemolymph samples were collected, and the animals were released into the stream after a 20-min recovery time. Hemolymph samples were transported to the laboratory and used to perform the alkaline comet assay. Results showed an intermediate level in the DNA damage index (range 107.3-165.0 arbitrary unit). No significant differences were observed among the different sampling periods. Hemolymph was successfully used as a non-lethal source of biological samples, and the comet assay using A. platensis proved to be a feasible approach for genotoxicity studies.

Brain DNA damaging effects of volatile anesthetics and 1 and 2 Gy gamma irradiation in vivo: Preliminary results

Although both can cause DNA damage, the combined impact of volatile anesthetics halothane/sevoflurane/isoflurane and radiotherapeutic exposure on sensitive brain cells in vivo has not been previously analyzed. Healthy Swiss albino male mice (240 in total, 48 groups) were exposed to either halothane/sevoflurane/isoflurane therapeutic doses alone (2h); 1 or 2gray of gamma radiation alone; or combined exposure. Frontal lobe brain samples from five animals were taken immediately and 2, 6, and 24h after exposure. DNA damage and cellular repair index were analyzed using the alkaline comet assay and the tail intensity parameter. Elevated tail intensity levels for sevoflurane/halothane were the highest at 6h and returned to baseline within 24h for sevoflurane, but not for halothane, while isoflurane treatment caused lower tail intensity than control values. Combined exposure demonstrated a slightly halothane/sevoflurane protective and isoflurane protective effect, which was stronger for 2 than for 1gray. Cellular repair indices and tail intensity histograms indicated different modes of action in DNA damage creation. Isoflurane/sevoflurane/halothane preconditioning demonstrated protective effects in sensitive brain cells in vivo. Owing to the constant increases in the combined use of radiotherapy and volatile anesthetics, further studies should explore the mechanisms behind these effects, including longer and multiple exposure treatments and in vivo brain tumor models.

P19-12 Assessment of indices of oxidative DNA damage, inflammation and lung function in chronic exposure to wood dust

P19-12 Assessment of indices of oxidative DNA damage, inflammation and lung function in chronic exposure to wood dust

Monolayer (2D) or spheroids (3D) cell cultures for nanotoxicological studies? Comparison of cytotoxicity and cell internalization of nanoparticles

Two-dimensional (2D) cell culture monolayers are commonly used for toxicological assessments of nanomaterials. Despite their facile handling, they exhibit several constraints due to their structural and complexity differences with three-dimensional (3D) in vitro cell models, such as spheroids. Here, we conducted a comparative nanotoxicological study of fibroblasts (L929) and melanoma (B16-F10) cells, grown in 2D and 3D arrangements. The cytotoxicity, reactive oxygen species (ROS) production, genotoxicity, cell morphology complexity, and uptake of silver nanoparticles (AgNPs) and folic acid-functionalized upconversion nanoparticles (FA-UCNPs) were compared in the two culture arrangements. AgNPs cytotoxicity was higher in spheroids than in monolayer cultures. Furthermore, apoptotic cell percentages and ROS production were higher in 3D than in 2D cell cultures. More importantly, 2D cultures required twice the concentration of AgNPs than the 3D cell models to reach a considerable DNA damage index (c.a. 200). Therefore, spheroids are more sensitive to the genotoxic effects of AgNPs. FA-UCNPs exerted negligible cell toxicity in 2D and 3D cell models. Moreover, AgNPs induced disaggregation and downsizing of spheroids in a facile and concentration-dependent manner. Internalization of FA-UCNPs in spheroids was 20% higher than in the 2D cell arrangements. Collectively, our findings, demonstrated that spheroids are a more sensitive model than monolayers for the assessment of nanoparticle biocompatibility and internalization.

Monitoring DNA Damage in Suez Pufferfish (Lagocephalus suezensis) from the Northeastern Mediterranean

Industrial effluents, agricultural runoff, and municipal wastewaters contain unknown substances and complex mixtures that are released into the environment and can lead to contamination of surface and subsurface waters. Such activities have endangered the existence of ecosystems and their inhabitants. Changes in the genome caused by genotoxic agents led to mutations and pose a burden to the populations of fish species. In the present study, we have used the alkaline Comet assay to detect the genotoxicity in Suez pufferfish (Lagocephalus suezensis) sampled from two different gulfs (Iskenderun and Mersin Bay), Northeastern Mediterranean. At the end of the study, the damage frequency (%), arbitrary unit and genetic damage index (%) were evaluated in gill and liver cells of L. suezensis by comet assay. The DNA damage in the gill and liver cells of L. suezensis in the present study were observed with a higher level of DNA damage in gill cells compared to liver cells in both the Iskenderun and Mersin Bays. The highest level of DNA damage (55.01±1.02%), arbitrary unit (143.01±7.21) and genetic damage index (1.43±0.07 %) were found in gill cells of L. suezensis from Mersin Bay. Statistically significant differences were found between DNA damage, Arbitrary unit and genetic damage index values of the two locations (p &lt; 0.001). In conclusion, this study indicates that comet assay gives sensitive results in monitoring the pollution, especially the pollution of the gulf, and thus it might be used as a standard method in regularly monitoring the pollution of the coastal ecosystem.

Background DNA damage is higher in summer than winter in both free-living and captive birds.

Although stress can cause overall damage to the genome, it is currently unknown whether normal background damage to DNA varies throughout the annual cycle. If DNA damage did vary seasonally, it would have major implications on environmental-genomic interactions. We measured background DNA double-stranded breaks using the neutral comet assay in fivetissues (nucleated red blood cells, abdominal fat, hippocampus, hypothalamus, and liver) in fourcohorts of house sparrows (Passer domesticus): free-living summer, captives on a summer light cycle, free-living winter, and captives on a winter light cycle. The experiment was designed to answer threequestions: (1) Is red blood cell DNA damage representative of other tissues? (2) Is DNA damage in captive birds representative of DNA damage in free-living birds? (3) Does DNA damage show seasonality? We found that (1) blood is a representative tissue, (2) captive animals are representative of free-living animals, and (3) DNA damage is higher in the summer than in the winter. These data indicate that red blood cells can be an index of DNA damage throughout the body and that background levels of DNA damage show substantial seasonal variation. The latter result suggests the possibility that underlying molecular mechanisms of DNA damage and/or repair also change seasonally.

Safety of 222 nm UVC Irradiation to the Surgical Site in a Rabbit Model.

For the prevention of surgical site infection (SSI), continuous disinfection could be helpful. Short wavelength ultraviolet radiation C (UVC) is highly bactericidal but shows cytotoxicity. Radiation of UVC with a wavelength of 222 nm to the skin is considered to be safe because it only reaches the stratum corneum. However, the safety of 222 nm irradiation to the surgical field not covered with skin is unknown. The purpose of this study was to examine the safety of 222 nm UVC irradiation on a surgical field in a rabbit model. Five types of tissue were surgically exposed and irradiated with 222 or 254 nm UVC. Immunohistological assessment against cyclobutane pyrimidine dimer (CPD), an index of DNA damage by UVC, was performed. The CPD-positive cell rate was significantly higher in the 254 nm group than in the other groups in all tissues. A 222 nm group showed significantly more CPD than control in fat tissue, but no significant difference in all other tissues. In fat tissue collected 24 h after irradiation, the 254 nm group showed higher CPD than the other groups, while the 222 nm group had reduced to the control level. These data suggest that 222 nm UVC irradiation could be a new method to safely prevent SSI.