Cadmium sulfide quantum dots (CdS QDs) are being developed for sensors, fluorescent probes, and other platforms and are attracting increasing attention. Given the growing demand for QDs, it is clear ...that there is a need to understand their potential toxicity to organisms. However, little is known regarding the genotoxicity of CdS QDs to humans. Therefore, this study used CdS QDs as the research object, cultured human peripheral blood lymphocytes, and randomly divided them into a control group, CdS I group (CdS QDs), and CdS II group (CdS QDs coated with thioglycolic acid). After cultivation, we measured the olive tail distance, tail length, tail DNA%, lymphocyte micronucleus rate, and aneuploid rate. The comet test results indicated that the indices of the QD group were significantly larger than those of the control group (
< 0.05). The results of the micronucleus and chromosome aberration tests showed that the lymphocyte micronucleus rate and chromosome aneuploid rate in the QD group were significantly increased (
< 0.05) compared with those in the control group. In conclusion, CdS QDs have certain genotoxicity to human peripheral blood lymphocytes, and the DNA damage caused by CdS QDs encapsulated with thioglycolic acid is less severe than that caused by nonencapsulated CdS QDs.
Biological activity of 2-tert-butyl-1,4-benzoquinone (TBQ) and its derivatives, 2-tert-butyl-5-(2-propylthio)-1,4-benzoquinone, 2-tert-butyl-5- -(propylthio)-1,4-benzoquinone, ...2-tert-butyl-5,6-(ethylenedithio)-1,4-benzoquinone, 2-tert-butyl-5-(phenylthio)-1,4-benzoquinone and 2-tert-butyl-6-(phenylthio)- 1,4-benzoquinone, were tested for their antioxidant, antibacterial, toxic, cytotoxic and genotoxic potential. Using the DPPH test, all derivatives showed good antioxidant activity, better than ascorbic acid, and the 2-tert- -butyl-5-(propylthio)-1,4-benzoquinone derivative showed the strongest effect. Better antibacterial potential was observed against Gram-positive bacteria in the broth microdilution method in which the 2-tert-butyl-5-(phenylthio)-1,4- -benzoquinone derivative showed the strongest activity (MIC = 15.6 ?M). The results of toxicity tests, using the Brine shrimp test, indicated that the derivatives lose their toxic potential compared to TBQ, except for 2-tert-butyl-6- -(phenylthio)-1,4-benzoquinone, which showed a 3 times stronger effect. Cytotoxicity was assessed by the MTT assay in 24 and 72 h treatments in MRC-5, HS 294T and A549 cell lines in threefold decreasing gradient (11, 33 and 100 ?M). Modifications potentiate the cytotoxic effect, and the strongest effect was observed with the 2-tert-butyl-5,6-(ethylendithio)-1,4-benzoquinone derivative. In addition, the genotoxic potential was examined in the MRC-5 cell line using the comet assay. All tested derivatives of TBQ showed a genotoxic effect at all applied subtoxic concentrations. In general, the chemical modifications of TBQ enhanced its biological activity.
The main aim of this study is to investigate the effect of fragmentation of electrospun carbon nanofibers (eCNFs) obtained at different temperatures, i.e., at 750 °C, 1000 °C, 1500 °C, 1750 °C and ...2000 °C on the cellular response in vitro. In order to assess the influence of nanofibers on biological response, it was necessary to conduct physicochemical, microstructural and structural studies such as SEM, XPS, Raman spectroscopy, HRTEM and surface wettability of the obtained materials. During the in vitro study, all samples made contact with the human chondrocyte CHON-001 cell lines. The key study was to assess the genotoxicity of eCNFs using the comet test after 1 h or 24 h. Special attention was paid to the degree of crystallinity of the nanofibers, the dimensions of the degradation products and the presence of functional groups on their surface. A detailed analysis showed that the key determinant of the genotoxic effect is the surface chemistry. The presence of nitrogen-containing groups as a product of the decomposition of nitrile groups has an influence on the biological response, leading to mutations in the DNA. This effect was observed only for samples carbonized at lower temperatures, i.e., 750 °C and 1000 °C. These results are important with respect to selecting the temperature of thermal treatment of eCNFs dedicated for medical and environmental functions due to the minimization of the genotoxic effect of these materials.
Iron oxide-Fe
2
O
3
nanoparticles-NPs and microparticles-MPs widely used in medical applications were comparatively investigated for
in vitro
mutagenicity and
in vivo
cytotoxicity/genotoxicity using ...the Ames test in
Salmonella typhimurium
strains (125, 250, 500, 750, 1,000 µg/mL) and chromosome aberration/comet assays in
Allium cepa
(all concentrations but 1,000 µg/mL), for the first time. Neither of the particles was mutagenic in all the bacterial strains in the media without (-S9) mix. However, with the S9 mix, a significant increase was determined in the reverting colonies in some concentrations in TA 97a. In TA 102, all the concentrations but 125 µg/mL also revealed a significant increase. These effects were regarded as weak mutagens since they were < twofold of the negative value. In the Allium test, almost all concentrations of NPs and MPs significantly decreased mitotic index (MI) compared to the negative control at all treatment times (down to 6.06% at 250 µg/mL and 6.40% at 750 µg/mL at 48 h, respectively). The frequency of aberrations significantly increased following all concentrations of NPs in all treatment periods (the highest was 62.03%). However, only a few concentrations of MPs induced significant aberrations (the highest was 32.18%). In the comet assay, while the two lowest concentrations of NPs were more effective in DNA damage, Fe
2
O
3
MPs significantly increased DNA damage at more treatment points at both treatment periods. Both particles were also characterized morphologically and physicochemically
.
The results revealed that further investigations using different organisms and test systems are necessary for the safer usage of these particles.
Graphical abstract
Objective: To evaluate the genotoxic effect on workers exposed to X-rays in the Radiology Service of the Luis N. Sáenz National Hospital PNP. Materials and methods. The type of study was ...observational, prospective, cross-sectional, analytical, using the comet assay as an analysis technique. The study population was 20 workers exposed to X-rays and 20 people without exposure. Results The mean length of migration of damaged DNA in the control group was 1.28 ± 0.38 µm and 10.39 ± 9.44 µm for the exposed group, the means of the groups were compared, obtaining p = 0.001 significant. The correlation analysis for DNA damage, years of exposure and dose received, a significant correlation was found (p <0.05). For the correlation of DNA damage with age, no statistical significance was found (p> 0.05). Conclusions X-rays at low permissible doses can cause damage to DNA integrity, correlating with the first years of exposure of personnel working in the radiology service. Keywords: Genotoxic, exposure, X-ray, comet test.
Seven types of atmospheric dusts (road dust, soil dust, brake dust, desert dust, pellet ash and coke and certified material NIST1648a – urban dust) have been tested for their genotoxicity on ...specimens of Echinogammarus veneris, a small aquatic amphipod. Experiments were carried out in vivo, by exposing the animals for 24 h to water containing 25 mg/L of dust. Each dust has been chemically analyzed for ions, elemental carbon, organic carbon and for the soluble and insoluble fractions of elements. Non-specific damages to DNA have been evaluated by the comet test, while oxidative damages have been estimated by coupling the comet test with formamido pyrimidine DNA glycosylase reaction. The animal tissues have been acid digested and analyzed for their elemental content to evaluate the bioaccumulation. All the considered dusts have caused a significant non-specific DNA damage, while the oxidative stress was shown only by dust types containing high concentration of elements. Furthermore, the oxidative damage has shown a positive correlation with the total bio-accumulated elemental concentration. For all the dust samples, the correlation with bio-accumulation in the tissues was more satisfactory for the insoluble fraction than for the soluble fraction of elements. Elements contained in solid particles seem then to be the main responsible bioaccumulation and for the oxidative stress.
•E. veneris is a suitable bio-indicator of DNA damages caused by atmospheric dusts.•Non-specific and oxidative DNA damages were evaluated on haemocyte cells.•The insoluble fraction of elements is bio-accumulated in the gammarid tissue.•Oxidative stress is mainly related with the insoluble fraction of elements in PM.
2,4-Dichlorophenoxyacetic acid (2,4-D) is a synthetic plant growth regulator that is highly toxic to most broad leaved plants and relatively nontoxic to monocotyledonous plants; is frequently used as ...weed killer. The study aimed to investigate cytogenetic effects of different concentrations of 2,4-D (0.67, 1.34, 2.01, 2.68, 3.35 and 4.02 mg/L) on
Allium cepa
bulblets’ root tips treated for 24 and 48 h. The results showed six types of structural aberrations: C-mitosis, stickiness, laggards, bridges, fragments and multipolarity that varied numerically compared to control. It significantly affected mitotic index (MI) at 24 and 48 h treatment. In the
Allium
test, MI increased significantly at three lower concentrations (0.67, 1.34, 2.01 mg/L) after treatment with 2,4-D for 24 h and decreased significantly at higher concentration. Whereas, 2,4-D treatment for 48 h increased MI at all concentrations with significantly decreased MI at the highest concentration. The experiment was extended using comet test that did not reveal significant difference among treatments except for application of 4.02 mg/L 2,4-D for 48 h; where cell damages were verified by comet test. Rest of the concentrations for any duration of time were not damaging and toxic to cells. The results showed, visible mitodepressive action of 4.02 mg/L 2,4-D when treated for 48 h that had tendency to become toxic if the roots had been in touch with 2,4-D for a longer time.
Contemporary lifestyle is commonly associated with chronic stress, an environmental factor contributing to development of various psychological and somatic disorders. Increased levels of ...glucocorticoids, observed in the chronic stress, induce the production of reactive oxygen species leading to genotoxicity. The aim of this study was to investigate whether chronic administration of oxytocin (OXY) 10 IU/400 μL/day, s.c., for 14 days, a hormone presumed to exert antioxidant effect, may prevent DNA damage in the comet assay of peripheral blood lymphocytes of Wistar rats treated chronically with corticosterone (CORT) 100 mg/L ad libitum, per os, for 21 days, as well as, to influence some plasma oxidative stress parameters, i.e. levels of total lipid hydroperoxide (LOOH), and malondialdehyde (MDA), and the activity of antioxidative enzyme superoxide dismutase (SOD). Even though there was no reduction in overall number of damaged cells after oxytocin treatment only, the marked increase in total comet score (TCS) after incubation with H2O2 in CORT group compared to controls, was absent in the CORT + OXY experimental group. Furthermore, significant decrease of highly damaged cells compared to corticosterone group was noted. Chronic oxytocin administration thus protected lymphocytes from high intensity damage that leads to cellular death. In addition, treatment with OXY along with CORT, significantly decreased concentration of LOOH in plasma, and increased SOD compared to CORT treatment only. This finding corresponds well with current reports on beneficial effects of OXY in conditions of HPA axis hyperactivity, and supports the hypothesis of OXY-mediated antioxidant action.
•Oxytocin decreased high damaged cells after incubation with H2O2 in CORT + OXY group.•Increase in high damaged cells induced by H2O2 was not noted in OXY-treated rats.•Oxytocin decreases plasma LOOH concentration in CORT + OXY treated animals.•Oxytocin increases plasma activity of SOD in CORT + OXY treated animals.
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