Ana Valenta Sobot

Ionising radiation damages DNA directly and indirectly through increased production of reactive oxygen species. Although telomeres have been reported as indicators of radiosensitivity, their maintenance in response to occupational exposure to low radiation doses is still a matter of debate. In this work we aimed to investigate telomere length and structure in hospital workers occupationally exposed to X-rays and to relate these findings to oxidation of biomolecules and chromosome aberrations. Blood samples of exposed participants and matching controls were taken during periodical check-ups. Chromosome aberrations and telomere length and structure were analysed in peripheral blood lymphocytes using Q-FISH, whereas oxidative stress parameters [pro/antioxidant balance (PAB), lipid peroxidation, and 8-oxo-dG] were measured in plasma samples. Based on the CA findings we divided the exposed group into two subgroups, of which one had chromosome aberrations in the first division metaphases ...

Yellow gentian (Gentiana lutea L.), a medicinal plant widely used in traditional medicine, displays multiple biological effects, ranging from beneficial to toxic. Since many promising applications have been reported so far, our aim was to evaluate its potential concentration- and time- dependent cytotoxic and genotoxic effects in vitro. To that end we exposed human peripheral blood mononuclear cells to 0.5, 1, and 2 mg/mL of yellow gentian root extract (YGRE) to determine its effects on oxidative stress parameters [pro/antioxidant balance (PAB) and lipid peroxidation], DNA damage (alkaline comet assay and chromosome aberrations), and cell viability (trypan blue exclusion test). Cell viability decreased with increasing concentrations and treatment duration. Only the lowest YGRE concentration (0.5 mg/mL) increased oxidative stress but produced minor DNA damage and cytotoxicity. At higher concentrations, redox parameters returned to near control values. The percentage of chromosome abe...

Traditional methods in cell proliferation studies are based on immunohistochemical detection of proliferating cells in the target tissue. Since they are time consuming, optimization of novel, more efficient methods is important for large scale proliferation studies. In this study, we aimed to optimize the isolation of single epithelial rat forestomach cells for flow cytometry. As a marker of cellular proliferation we used the Ki-67 antibody to detect this nuclear protein expressed in proliferating cells. We also performed immunohistochemical detection of Ki-67 positive cells and propidium iodide staining to validate the results. 3-tert- butyl -4-hydroxyanisole was used as the positive control to ensure cellular proliferation. The results showed that isolation of epithelial cells with collagenase, trypsin and cell strainer ensures great cell viability (>95%) and the purity of the samples. Flow cytometry and immunostaining with the Ki-67 antibody indicated that 3-tert- butyl-4-hydr...

In this work we present biological effects of silver nanoparticles (AgNPs) synthesized by picosecond laser ablation of silver in deionized water. We examined induction of chromosomal aberrations, lymphocyte micronuclei, appearance and recovery of double strand breaks (DSBs) of DNA, cell proliferation potential, concentration of lipid peroxidation products and insulin-like growth factor 1 (ILGF-1). We found that AgNPs sized from 3nm to 8nm induce cell cytostasis, which is accompanied with its clastogenic action on DNA, while AgNPs, sized 2nm behaves contrary stimulating cell proliferation by enhancing ILGF-1 concentration.

The aim of this study was to identify palatable additives which have a significant protective action against soft tissue changes in the oral cavity caused by Swedish smokeless tobacco ("snus"), and that satisfy existing legal requirements. Although the cancer risk from snus is extremely low, long term use may result in highly undesirable keratotic lesions and associated epithelial abnormalities in the oral cavity. The rat forestomach, which is vulnerable to the irritative action of non-genotoxic compounds like butylated hydroxyanisole, propionic acid as well as snus, was chosen as an experimental model. Studied toxicological endpoints included histopathology and cellular proliferation based on DNA incorporation of bromodeoxyuridine. After 6 weeks' exposure, blueberries (bilberries) and an extract from the common milk thistle were found to exert a highly significant inhibition of cell proliferation induced by snus in the rat forestomach epithelium, indicating a potential protection with respect soft tissue changes in the human oral cavity.

Silver nanoparticles (AgNPs) have been recognized for widespread biological applications due to their antimicrobial and anti-inflammatory effect, especially in dentistry and for wound healing. Many features determine their beneficial or toxic potential, such as their synthesis type, size, morphology, coating, and concentration. Most synthesis types rely on the use of synthetic chemicals, which contributes to their toxicity. We present an environmentally friendly method for “green” synthesis of AgNPs from the silver target by pulsed laser ablation in liquid (PLAL) using citrate as the stabilizing agent. Since AgNPs already have many dental applications, we examined their antibacterial effect against supragingival biofilm-forming bacteria and bacterial strains known to cause resistant dental infections. Their impact on human fibroblast cells’ cytotoxicity, proliferation (measured by XTT and Ki-67 immunofluorescence), pro/antioxidant balance, and lipid peroxidation (measured by PAB and...

The study of cell proliferation is a useful tool in the fields of toxicology, pathophysiology and pharmacology. Cell proliferation and its degree can be evaluated using 5-bromo-2′-deoxyuridine which is incorporated into the newly synthesized DNA. The aim of this study was the optimization of subcutaneous application of 5-bromo-2′-deoxyuridine implantation for continuous and persistent marking of proliferating cells in the rat forestomach. 3-

Root of Gentiana lutea commercially available as gentian root, a natural antidote for different types of poisons, possess antioxidative, immunomodulatory, cytoprotective and anti-inflammatory, and adverse, genotoxic and mutagenic effects. It has monoterpenes loganic acid, swertiamarin, gentiopicroside and sweroside as most abundant constituents. In this study, we assessed the toxicity of monoterpenes’ reactive molecular fragments using in silico prediction by VEGA-QSAR platform. Further, we compared the data obtained with in vitro geno- and cyto- toxicity testing of the above monoterpenes and the G. lutea root extract (GE), on human primary unstimulated and mitogen-stimulated peripheral blood mononuclear cells (PBMCs). Viability was assessed by TB and XTT tests after 48 h treatmen. DNA damage was evaluated by alkaline comet assay on unstimulated cells, whereas cytokinesis-block micronucleus assay was employed on mitogen-stimulated PBMCs. Stability of compounds throughout treatment w...

In this paper we present the data of lymphocyte radiosensitivity testing used for characterization of radiosensitive cellular phenotype and diagnostics of ataxia-telangiectasia disease. We point out the advantage of lymphocyte micronucleus test (CBMN) over other cellular tests for assessment of radiosensitivity: the first advantage of CBMN is that primary patient cells are used (less than 1 ml), the second one is that the results of testing are obtained within 3 days and there is no need for establishing a patient-derived cell line, which requires additional time and application of more expensive methods. The third advantage of CBMN method is that it gives information about proliferative ability of cells, which can recognize dysfunctional ataxia-telangiectasia mutated protein. The results are fast and accurate in diagnostics of ataxia-telagiectasia diseases.

Carbon nanotubes are unique one-dimensional macromolecules with promising applications in biology and medicine. Since their toxicity is still under debate, here we present a study investigating the genotoxic properties of purified single wall carbon nanotubes (SWCNTs), multiwall carbon nanotubes (MWCNTs), and amide functionalized purified SWCNTs on cultured human lymphocytes employing cytokinesis block micronucleus assay and enumeration of gamma H2AX foci as a measure of double strand breaks (DSBs) of the DNA in normal human fibroblasts. SWCNTs induce micronuclei (MN) formation in lymphocytes and decrease the proliferation potential (CBPI) of cells. In a fibroblast cell line the same dose of SWCNTs induces gamma H2AX foci 2.7-fold higher than in a control. Amide functionalized purified SWCNTs behave differently: they do not disturb the cell proliferation potential of harvested lymphocytes, but induce micronuclei to a higher extent than SWCNTs. When applied on fibroblasts, amide functionalized SWCNTs also induce gamma H2AX foci, 3.18-fold higher than the control. The cellular effects of MWCNTs display the broad spectrum of clastogenic properties seen as the highest incidence of induced lymphocyte micronuclei and anaphase bridges among nuclei in binucleated cells. Surprisingly, the incidence of induced gamma H2AX foci was not as high as was expected by the micronucleus test, which indicates that MWCNTs act as clastogen and aneugen agents simultaneously. Biological endpoints investigated in this study indicate a close relationship between the electrochemical properties of carbon nanotubes and observed genotoxicity.

Backgroun/Aim. Constant production of free radicals and antioxidants (AO) in cells is a part of normal cellular function. Their imbalance might take a part in pathophysiology of many diseases, including Parkinson?s disease (PD). Evaluation of the disease status, prooxidant-antioxidant balance (PAB) and antioxidants are being widely estimated. The aim of this study was to examine potential interaction between several AO variables: glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and PAB, and clinicopathologic features of patients with PD, particularly the Hoehn and Yahr (H&Y) stage. Methods. A multivariate analysis of variance (MANOVA) was conducted to analyze mean differences between clinicopathologic characteristics (gender, age at examination, duration of the disease, and the H&Y stage) and AO variables of PD patients and those of age/sex matched healthy controls. The study included 91 patients with idiopatic PD patients and 20 healthy persons. Results. The multivaria...

The aim of this study was to evaluate the effects of two nutraceuticals Amazon Megamin and Immunarc forte in radiorecovery of human lymphocytes after exposure to ionizing radiation in vitro. The incidences of micronuclei, cell proliferation, apoptosis and lipid peroxidation products were examined in cultured human peripheral blood lymphocytes before and after ionizing radiation in a present of nutraceuticals in vitro. Results showed that Amazon Megamin and Immunarc forte possess antioxidant properties; they act by eliminating the toxic metabolites, scavenging the free radicals and decreasing lipid peroxidation. The obtained results indicated that the studied nutraceuticals can help in prevention of the development of injurious caused by ionizing irradiation and, therefore, they encourage studies on their radioprotective properties.

Carbon nanotubes are unique one-dimensional macromolecules with promising application in biology and medicine. Since their toxicity is still under debate, here we describe an investigation of genotoxic properties of purified single-walled carbon nanotubes (SWCNT), multiwall carbon nanotubes (MWCNT), and amide-functionalized purified SWCNT. We used two different cell systems: cultured human lymphocytes where we employed cytokinesis-block micronucleus test and human fibroblasts where we investigate the induction of DNA double-strand breaks (DSBs) employing H2AX phosphorylation assay.