Increase In Tail DNA Research Articles

Toxicity evaluation of silver nanoparticles synthesized from naringin flavonoid on human promyelocytic leukemic cells and human blood cells.

Increasing applications of silver nanoparticles (AgNPs) in multiple products like cosmetics, medicines, drugs, paints, and other new materials have raised concern for their toxic effects on living beings and the surrounding environment. In the present study, cytotoxicity and genotoxicity of AgNPs synthesized using plant flavonoid (Naringin) as a reducing agent were investigated on human promyelocytic leukemic (HL-60) cells and human blood as an in vitro model. The LC50 of AgNPs was found to be 4.85µM. Dose-dependent increase in cell death and caspase activity was observed in the presence of AgNPs. The comet assay showed a 60%-70% (p < .05) increase in tail DNA at 0.48 and 0.96µM AgNPs. CBMN in PBMCs also confirmed the genotoxic potential of AgNPs-induced DNA damage. AgNPs resulted in 1.5-1.54 fold (p < .05) increase in the level of ROS in HL-60 cells after 12h of exposure. AgNP showed toxicity in human cells through ROS generation and cellular damage through membrane dysfunction, caspase activation, apoptosis, and DNA damage.

Evaluation of herbicidal and fungicidal activities of six natural components and their phenoxyacetic acids derivatives and assessment of human health risk posed by oral exposure to them

ABSTRACT In the present study, we isolated linalool, geraniol, carvacrol, thymol, menthol and eugenol; synthesised their phenoxyacetic acid derivatives; and assessed their phytotoxic and genotoxic potentials against weeds and agricultural crops. Moreover, the fungicidal activity of both categories of compounds against 12 fungi was examined. Finally, using probabilistic assessment based on Risk Quotient (RQ) by the Monte Carlo simulation (MCS) method, we examined human health risks via oral exposure to these compounds. Toxic potencies to plants demonstrated that all parameters and related indices including germination percentage, mean germination time, germination rate, root length, shoot length, seedling length and vigour index dose-dependently decreased in both weeds and agricultural crops. Based on the comet assay, DNA damage was observed in the root meristems of the plants. Consequently, a significant decrease was observed in head DNA, whereas a significant increase in tail DNA was observed in response to treatments. Besides, the natural components and semisynthetic molecules showed a broad spectrum of fungicidal traits. However, eugenol and eugenoxyacetic acid inhibitory effects on the growth of the tested fungi were similar to that of benomyl. Our probabilistic health risk assessment indicated di minimis risk for natural components and their phenoxyacetic acid derivatives. Sensitivity analysis showed that concentrations of residues of the compounds had the most significant effect on risk. Current findings could offer a platform for developing sustainable approaches to reduce chemical residues and their consequent risks to the environment and human health.

Curcuma aeruginosa Roxb. exhibits cytotoxicity in A-549 and HeLa cells by inducing apoptosis through caspase-dependent pathways.

The aim of the current study was to examine the efficacy of the leaf, stem and rhizome ofCurcuma aeruginosa Roxb. for their phytochemical content, antioxidant and anti-cancer activities. The different parts of C. aeruginosa were subjected to sequential extraction to give three fractions viz., hexane, ethyl acetate and methanol extract. The cytotoxic effectand the mode of action against A-549 humanlung adenocarcinoma and HeLa celllines were examined. C. aeruginosa presented no significant toxic effect in normal human lung cells (L-132). The methanol extracts were found to be the most cytotoxic and further investigation was carried out to understand the effects. The methanol extracts induced DNA damage after 24h with significant increase in tail DNA and tail moment when compared to untreated control. Up-regulation in the expression of thecaspase -8 and -3activity was observed after 48h of treatment. The mechanism of cell death and apoptosis induced by the methanol extracts on A549 and HeLa cells were studied using fluorescent staining. Bioactive compounds detected from the HPLC revealed phenol and flavonoid compounds: Gallic acid, quercetin, caffeic acid, kaempferol, rutin, coumaric acid and naringenin. GC-MS results identified the presence of sesquiterpenoids: α-curcumene, curzerene curcumenol, curzerenone epicurzerenone, caryophyllene oxide and diterpenoid, andrographolide. These compounds are known for inducing apoptosis in human cancer cells through caspase - dependent pathways. Therefore, C. aeruginosa and its potential to induce apoptosis in cancer cells suggest that they have potential in medical applications.

Genotoxic and cytotoxic potential of Bisphenol A in the early developing stages of chick embryo (Gallus gallus domesticus) evidenced by HET-MN and Comet assay

Bisphenol-A (BPA) is ubiquitously present in the environment and consumer products and is a crucial environmental contaminant known to cause significant health risks to various organisms. The present study aims to evaluate the genotoxicity effect of BPA in developing chick embryos. Fertile chicken eggs were treated with increasing concentrations of BPA (1, 10, 20, 30, 40 and 50 mM/egg) on embryonic days (ED) 8, 9 and 10. On ED11, the number of viable embryos was recorded and LD50 values were calculated for 24 h (ED 10), 48 h (ED 9) and 72 h (ED 8). HET-MN (Hens egg test for micronucleus assay) and comet assay were performed on the 11th-day to evaluate the cytotoxicity and genotoxicity potential of BPA. Experiments were performed in three different time points i.e. 24 h, 48 h and 72 h of exposure. Results showed an increased mortality rate in a dose and time-dependent manner. Significant alterations of cellular dynamics erythropoiesis and PCE/NCE ratio were observed. Also, significant induction of total MN and other nuclear abnormalities was observed. A decrease in head DNA content, increase in tail DNA, olive tail moment and damage indexes were detected upon exposure. Thus, the results confirmed the genotoxic and cytotoxic potential of Bisphenol-A that caused genetic alterations extensively during the early development of embryos.

Appraisal of immediate and late effects of mobile phone radiations at 2100MHz on mitotic activity and DNA integrity in root meristems of Allium cepa.

The present study evaluated the potential of 2100MHz radiofrequency radiations to act as cytotoxic and genotoxic agent. Fresh onion (Allium cepa L.) roots were exposed to electromagnetic field radiations (EMF-r) for different durations (1h and 4h) and evaluated for mitotic index (MI), phase index, chromosomal aberrations, and DNA damage. DNA damage was investigated with the help of the comet assay by assessing various parameters like % head DNA (HDNA), % tail DNA (TDNA), tail moment (TM), and olive tail moment (OTM). Effects of EMF-r exposure were also compared with that of methyl methanesulfonate (MMS; 90μM), which acted as a positive control. The post-exposure effects of EMF-r after providing the test plants with an acclimatization period of 24h were also evaluated. Compared to the control, a significant increase in the MI and aberration percentage was recorded upon 4h of exposure. However, no specific trend of phase index in response to exposure was detected. EMF-r exposure incited DNA damage with a significant decrease in HDNA accompanied by an increase in TDNA upon exposure of 4h. However, TM and OTM did not change significantly upon exposure as compared to that of control. Analysis of the post-exposure effects of EMF-r did not show any significant change/recovery. Our data, thus, suggest the potential cytotoxic and genotoxic nature of 2100MHz EMF-r. Our study bears great significance in view of the swiftly emergent EMF-r in the surrounding environment and their potential for inciting aberrations at the chromosomal level, thus posing a genetic hazard.

GENOTOXICITY OF CERIUM OXIDE NANOPARTICLE IN ZEBRAFISH AND GREEN MUSSEL PERNA VIRIDIS USING ALKALINE COMET ASSAY

Cerium oxide nanoparticles or nanoceria has versatile application in biomedical, solar cells and gas sensors. Increasing utilization of nanoceria has raised concerns over its release to environment and potential exposure. In vitro studies have shown its genotoxic potential, but reports on aquatic life are very limited. In this study, zebrafish (Danio rerio) and green mussel (Perna viridis) was exposed to different concentration 10, 20, 50 µg/l of nanoceria for 24, 72, and 120 h and the genotoxic response was measured using comet assay. The results showed significant (p < 0.05) increase in tail DNA (TDNA) and olive tail moment (OTM) as measured using comet assay in exposed animals as compared to control. The highest TDNA and OTM were measured after 120 h of exposure with 50 µg/l of nanoceria in zebrafish as well as in green mussel. The results of this study demonstrate that short-term exposure to nanoceria causes a genotoxic response in zebrafish and green mussel, hence its environmental release should be carefully monitored. Article DOI: https://dx.doi.org/10.20319/lijhls.2019.43.118127 This work is licensed under the Creative Commons Attribution-Non-commercial 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.

The Protective Effect of Whole Honey and Phenolic Extract on Oxidative DNA Damage in Mice Lymphocytes Using Comet Assay.

In this study, the antioxidant activity and the protective effect against hydrogen peroxide-induced DNA damage were assessed for five honeys of different botanical origin. Seven phenolic acids were detected in the honey samples. Ferulic acid was the most abundant phenolic acid detected in longan honey, jujube honey and buckwheat honey. Ellagic acid, p-hydroxybenzoic acid and protocatechuic acid were the main phenolic acids detected in vitex honey. Of all honey samples tested, the highest total phenolic content and antioxidant activity were found in buckwheat honey, whereas the lowest total phenolic content and antioxidant activity were found in locust honey. Treatment with hydrogen peroxide induced a 62% increase in tail DNA in mice lymphocytes, and all studied honeys significantly inhibited this effect (P<0.05). The buckwheat honey with higher antioxidant capability also exhibited super protective effect than others. Phenolic extracts of honey displayed greater protective effects than whole honey in comet assay. The hydrogen peroxide-generated increase in 8-hydroxy-2-deoxyguanosine (8-OHdG) was effectively inhibited by the honeys studied (P<0.05). Moreover, a dose-effect relationship between honey concentration and its protective effect was clearly observed in this study. It can be deduced that phenolic acids of honey can penetrate into lymphocytes and protect DNA from oxidative damage by scavenging hydrogen peroxide and/or chelating ferrous ions.

Genotoxicity of two heavy metal compounds: lead nitrate and cobalt chloride in Polychaete Perinereis cultrifera

The present study explores the in vivo and in vitro genotoxic effects of lead nitrate, [Pb(NO3)2] a recognized environmental pollutant and cobalt chloride (CoCl2), an emerging environmental pollutant in polychaete Perinereis cultrifera using comet assay. Despite widespread occurrence and extensive industrial applications, no previous published reports on genotoxicity of these compounds are available in polychaete as detected by comet assay. Polychaetes were exposed in vivo to Pb(NO3)2 (0, 100, 500, and 1000μg/l) and CoCl2 (0, 100, 300, and 500μg/l) for 5days. At 100μg/l Pb(NO3)2 concentration, tail DNA (TDNA) values in coelomocytes were increase by 1.16, 1.43, and 1.55-fold after day 1, day 3, and day 5, whereas, OTM showed 1.12, 2.33, and 2.10-fold increase in in vivo. Pb(NO3)2 showed a concentration and time-dependent genotoxicity whereas CoCl2 showed a concentration-dependent genotoxicity in in vivo. A concentration-dependent increase in DNA damage was observed in in vitro studies for Pb(NO3)2 and CoCl2. DNA damage at 500μg/L showed almost threefold increase in TDNA and approximately fourfold increase in OTM as compared to control in in vitro. Our studies suggest that Pb(NO3)2 and CoCl2 have potential to cause genotoxic damage, with Pb(NO3)2 being more genotoxic in polychaete and should be used more carefully in industrial and other activities. Graphical abstract.

Oxidative Stress and Genotoxicity of Zinc Oxide Nanoparticles to Pseudomonas Species, Human Promyelocytic Leukemic (HL-60), and Blood Cells

In the present study, toxicity of commercial zinc oxide nanoparticles (ZnO NPs) was studied on the bacterium Pseudomonas sp., human promyelocytic leukemia (HL-60) cells, and peripheral blood mononuclear cells (PBMC). The toxicity was assessed by measuring growth, cell viability, and protein expression in bacterial cell. The bacterial growth and viability decreased with increasing concentrations of ZnO NP. Three major proteins, ribosomal protein L1 and L9 along with alkyl hydroperoxides reductase, were upregulated by 1.5-, 1.7-, and 2.0-fold, respectively, after ZnO NP exposure. The results indicated oxidative stress as the leading cause of toxic effect in bacteria. In HL-60 cells, cytotoxic and genotoxic effects along with antioxidant enzyme activity and reactive oxygen species (ROS) generation were studied upon ZnO NP treatment. ZnO NP exhibited dose-dependent increase in cell death after 24-h exposure. The DNA-damaging potential of ZnO NP in HL-60 cells was maximum at 0.05mg/L concentration. Comet assay showed 70-80% increase in tail DNA at 0.025 to 0.05mg/L ZnO NP concentration. A significant increase of 1.6-, 1.4-, and 2.0-fold in ROS level was observed after 12h. Genotoxic potential of ZnO NPs was also demonstrated in PBMC through DNA fragmentation. Thus, ZnO NP, besides being an essential element having antibacterial activity, also showed toxicity towards human cells (HL-60 and PBMC).

Assessment of the DNA Damage in Human Sperm and Lymphocytes Exposed to the Carcinogen Food Contaminant Furan with Comet Assay

The aim of this work was to assess the damage of DNA in human blood cell and spermin vitro under the influence of furan. These cells were administered 0-600 μM of furan at 37 and 32oC for 30 and 60 min, respectively. A significant increase in tail DNA%, tail length and moment indicating DNA damage was observed at increasing doses when compared to the controls. The treatment with 300 and 600 μM of furan showed a maximum increase of 86.74 ± 2.43 and 93.29 ± 8.68 compared to the control tail DNA% in lymphocytes. However, only 600 μM of furan showed a maximum increase of 94.71 ± 6.24 compared to the control tail DNA% in sperm. The results suggested that furan caused DNA damage in lymphocytes at increasing doses, but appeared to have not the same effect on human sperm at the low doses. Genotoxic activity had an impact on the risk assessment of furan formed on the food for human cells. Therefore, it would be important to further investigate these properties of furan as the food mutagen.

DNA damage in human germ cell exposed to the some food additives in vitro.

The use of food additives has increased enormously in modern food technology but they have adverse effects in human healthy. The aim of this study was to investigate the DNA damage of some food additives such as citric acid (CA), benzoic acid (BA), brilliant blue (BB) and sunset yellow (SY) which were investigated in human male germ cells using comet assay. The sperm cells were incubated with different concentrations of these food additives (50, 100, 200 and 500μg/mL) for 1h at 32°C. The results showed for CA, BA, BB and SY a dose dependent increase in tail DNA%, tail length and tail moment in human sperm when compared to control group. When control values were compared in the studied parameters in the treatment concentrations, SY was found to exhibit the highest level of DNA damage followed by BB>BA>CA. However, none of the food additives affected the tail DNA%, tail length and tail moment at 50 and 100μg/mL. At 200μg/mL of SY, the tail DNA% and tail length of sperm were 95.80±0.28 and 42.56±4.66, for BB the values were 95.06±2.30 and 39.56±3.78, whereas for BA the values were 89.05±2.78 and 31.50±0.71, for CA the values were 88.59±6.45 and 13.59±2.74, respectively. However, only the highest concentration of the used food additives significantly affected the studied parameters of sperm DNA. The present results indicate that SY and BB are more harmful than BA and CA to human sperm in vitro.

Protective effect of (-)-epigallocatechin-3-gallate on capsaicin-induced DNA damage and oxidative stress in human erythrocyes and leucocytes in vitro.

The aim of this study is to show that protective effects of the main catechin (-)-epigallocatechin-3-gallate (EGCG) against capsaicin (CAP) induced oxidative stress and DNA damage in human blood in vitro. Superoxide dismutase, catalase, glutathione peroxidase and malondialdehyde (MDA) level were studied in erythrocytes and leucocytes with increased concentrations of CAP. DNA damage in leucocytes was measured by the comet assay. Human blood cells have been administered with doses between 0 and 200μM of CAP and/or EGCG (20μM) for an hour at 37°C. Treatment with CAP alone has increased the levels of MDA and decreased antioxidant enzymes in human blood cells. A significant increase in tail DNA%, mean tail length and tail moment indicating DNA damage has been observed at the highest dose of CAP treatment when compared to controls. Treatment of cells with CAP plus EGCG prevented CAP-induced changes in antioxidant enzyme activities and MDA level and mean tail lenght indicating DNA damage. A significant increase in mean tail lenght was observed at high doses of CAP. These data suggest that EGCG can prevent toxicity to human erythrocytes and leucocytes caused by CAP, only at low doses.

Protective effects of selenium on mercury-induced DNA damage in mussel haemocytes

Little is known of the antioxidant role of selenium (Se) in aquatic invertebrates. We investigated the effects of Se on mercury-induced DNA damage in haemocytes from Mytilus edulis using alkaline single cell gel electrophoresis, that is, the Comet assay. The basal percentage tail DNA value for mussel haemocytes was 9.8 ± 0.2% (mean ± S.E.M., n = 70). Exposing mussels to Hg 2+ (nominal concentration 20 μg L −1) for three days led to an increase in tail DNA to 61.1 ± 1.8% ( n = 10). With added Se (as selenite, nominal concentration 4 μg L −1), Hg-induced DNA damage was reduced to 39.5 ± 3.1% ( n = 10). Se pre-exposure also provided some protection against Hg-induced DNA damage (% tail DNA = 51.0 ± 2.9%, n = 10). Basal glutathione peroxidase (GPx) activity in cell-free haemolymph was 93.7 ± 3.5 nmol min −1 mg −1 (mean ± S.E.M., n = 70). Increases in GPx activity were seen when Se was added during and/or after exposure to Hg. For example, a 3–4-fold increase was seen after three days exposure to Hg in the presence of added Se. Interestingly GPx activity doubled after three days in the presence of added Se alone, but was unchanged after exposure to HgCl 2 alone. These results suggest that the availability of Se in the natural environment could affect the antioxidant status of mussels, and consequently could affect levels of DNA damage.

In vivo genotoxicity of hard metal dust: induction of micronuclei in rat type II epithelial lung cells.

Inhalation of hard metal dust (WC-Co particles) has been associated with an increased risk for lung cancer in occupational settings. In vitro, WC-Co was genotoxic in human lymphocytes producing DNA strand breaks and micronuclei. The aim of the present study was to evaluate the in vivo genotoxic effects of WC-Co dust in rat type II pneumocytes. DNA breaks/alkali-labile sites (alkaline comet assay) and chromosome/genome mutations (micronucleus test) were assessed after a single intra-tracheal (i.t.) instillation of WC-Co, including dose-effect and time trend relationships. In addition, the alkaline comet assay was performed on cells obtained after broncho-alveolar lavage (BAL) and on peripheral blood mononucleated cells (PBMC). As pulmonary toxicity parameters, protein content, lactate dehydrogenase activity, total and differential cell count in BAL fluid were evaluated in parallel. In type II pneumocytes, WC-Co induced a statistically significant increase in tail DNA (12 h time point) and in micronuclei (72 h) after a single treatment with 16.6 mg WC-Co/kg body wt, a dose that produced mild pulmonary toxicity. This observation provides the first evidence of the in vivo mutagenic potential of hard metal dust. In PBMC, no increase in DNA damage or micronuclei was observed. This study indicates the potential to detect chromosome/genome mutations (micronuclei) in relevant target cells (type II pneumocytes) after i.t. instillation of a particle mixture.