Lubica Hunakova

Slovak Academy of Sciences, Presburg, Bratislavský, Slovakia

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Publications (6)17.96 Total impact

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    ABSTRACT: Salvia officinalis (SO) and Thymus vulgaris (TV) are medicinal plants well known for their curative powers. However, the molecular mechanisms responsible for these abilities of sage and thyme have not been fully understood yet. In this study we investigated the composition and the quantitative estimation of plant extracts, the protective effects of plant extracts against hydrogen peroxide- and 2,3-dimethoxy-1,4-naphthoquinone-induced DNA damage, and levels of enzymatic and non-enzymatic antioxidants (superoxide dismutase, glutathione peroxidase, glutathione) in human HepG2 cells. To measure antioxidative activity of plant extracts we used three assays: 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The results showed that the oxidant-induced DNA lesions were significantly reduced in cells pre-treated with the plant extracts studied. The observed DNA-protective activity could be explained by both elevation of GPx activity in cells pre-treated with SO and TV and antioxidant activity of SO and TV.
    Food Chemistry 12/2013; 141(3):2198-206. · 3.26 Impact Factor
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    ABSTRACT: Application of autologous bone marrow mononuclear cells to "no option" patients with advanced critical limb ischemia (CLI) prevented major limb amputation in 73% patients during the 6-month follow-up. We examined which properties of bone marrow stromal cells also known as bone-marrow derived mesenchymal stem cells of responding and non-responding patients are important for amputation-free survival. Mesenchymal stem cells of 41 patients with CLI unsuitable for revascularisation were isolated from mononuclear bone marrow concentrate used for their treatment. Based on the clinical outcome of the treatment, we divided patients into two groups: responders and non-responders. Biological properties of responders' and non-responders' mesenchymal stem cells were characterized according to their ability to multiply, to differentiate in vitro, quantitative expression of cell surface markers, secretion of 27 cytokines, chemokines and growth factors, and to the relative expression of 15 mesenchymal stem cells important genes. Secretome comparison between responders (n=27) and non-responders (n=14) revealed significantly higher secretion values of IL-4, IL-6 and MIP-1b in the group of responders. The expression of cell markers CD44 and CD90 in mesenchymal stem cells from responders was significantly higher compared to non-responders (p<0.01). The expression of mesenchymal stem cells surface markers that was analyzed in 22 patients did not differ between diabetic (n=13) and non-diabetic (n=9) patient groups. Statistically significant higher expression of E-cadherin and PDX-1/IPF1 genes was found in non-responders, while expression of Snail was higher in responders. The quality of mesenchymal stem cells shown in the expression of cell surface markers, secreted factors and stem cell genes plays an important role in therapeutic outcome. Paracrine mechanisms are main drivers in the induction of reparatory processes in CLI patients. Differences in mesenchymal stem cells properties are discussed in relation to their involvement in the reparatory process.
    PLoS ONE 09/2013; 8(9):e73722. · 3.53 Impact Factor
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    ABSTRACT: This paper presents comparisons of biological impacts of the oxidants H2O2 and t-BHP on human liver cells, and shows modulation of these effects by the phenolic compound carvacrol. To understand better how these oxidants exert their effect on DNA and on the activity of the enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), we measured intracellular antioxidant glutathione (iGSH) and intracellular reactive oxidative species (iROS). DNA lesions corresponded to single-strand DNA breaks, alkali-labile lesions and formamido-pyrimidine-DNA-glycosylase(FPG)-sensitive sites. Pre-treatment of cells with carvacrol substantially decreased the number of H2O2-induced DNA lesions, but the number of t-BHP-induced DNA lesions was not reduced. Activities of both SOD and GPx were stimulated significantly by carvacrol and were reduced by the combined effect of carvacrol and oxidants. H2O2 and t-BHP alone influenced the level of antioxidant enzymes differently. While H2O2 did not markedly change the activity of SOD or GPx, lower concentrations of t-BHP stimulated activity of SOD and mainly GPx. The level of iROS was increased by both oxidants and decreased by carvacrol applied either alone or with oxidants. The level of iGSH was not influenced in any of the treatments tested. Our results show that although both oxidants induced oxidative stress and damaged cellular DNA, their influences on other molecular processes were different. The protective effect of carvacrol against DNA-damaging effects of H2O2 was unambiguous, but reduction by carvacrol of the DNA-damaging effect of t-BHP was not observed. These results suggest that the phenolic compound carvacrol contributes to the defence mechanisms of the human organism, but these beneficial effects are dependent on the origin and source of the actual oxidative stress.
    Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis 07/2013; · 4.44 Impact Factor
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    ABSTRACT: BACKGROUND: Engineered mesenchymal stromal cells (MSC) were used in many preclinical studies of gene directed enzyme/prodrug therapy. We aimed to compare the efficacy of two most frequently used systems, and evaluate extent of bystander effect mediated by therapeutic MSC towards cell lines derived from different tumours. METHODS: Two approaches were compared: (1.) Herpes simplex virus thymidine kinase (TK)/ganciclovir (GCV) and (2.) yeast cytosine deaminase fused with uracil phosphoribosyltransferase (CD::UPRT)/5-fluorocytosine (5-FC). Cytotoxic effect mediated by therapeutic MSC was evaluated in direct co-culture by fluorimetric assay. Expression profile of tumour cells was analysed by qPCR, and the ability of gap-junctional intercellular communication (GJIC) was evaluated by dye transfer assay. RESULTS: Both systems were effective only on glioblastoma cells (8-MB-BA). CD::UPRT-MSC/5-FC system showed efficiency on melanoma A375 cells. We decreased sensitivity of 8-MG-BA cells and A375 cells to CD::UPRT-MSC/5-FC system by pharmacologic inhibition of thymidylate synthase, and we achieved similar result in A375 cells by inhibition of thymidine phosphorylase. Although we demonstrated functional GJIC in A375 cells, TK-MSC were ineffective in mediating bystander effect similarly to HeLa cells, which were relatively resistant also to CD::UPRT-MSC/5-FC treatment. TK-MSC/GCV treatment had strong cytotoxic effect on MDA-MB-231 cells (breast carcinoma), but CD::UPRT-MSC/5-FC treatment failed due to overexpression of ABCC11 gene. Transfection of MDA-MB-231 cell line with small interference RNA specific to ABCC11 led to significantly increased sensitivity to CD::UPRT-MSC/5-FC approach. CONCLUSIONS: GJIC, expression of enzymes involved in drug metabolism and ABC transporters correlate with the response of tumour cells to treatment by MSC expressing prodrug-converting genes. Copyright © 2012 John Wiley & Sons, Ltd.
    The Journal of Gene Medicine 11/2012; 14(12). · 1.95 Impact Factor
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    ABSTRACT: Lung cancer represents the most frequent cause of cancer-related deaths in the industrialized countries. The aim of this study was to analyze the lung cancer incidence and mortality and the possible reasons for any differences discovered in two neighboring Central European countries-the Slovak Republic. We used linear regression model when analyzing incidence and mortality; the trends are presented with corresponding 95 % confidence intervals (CI) and p-value with null hypothesis being constant with time. Statistically significant increase of age-standardized incidence (0.707/100,000/year, 95 % CI 0.107-1.307, p = 0,025) and mortality (1.339/100,000/year, 95 % CI 1.050-1.629, p < 0.0001) of the lung cancer was revealed in males in the Slovak Republic (1980-1991). On the contrary, values of both indicators were stabilized in the Czech Republic. Since year 1991-2005 a statistically highly significant decrease of both incidence and mortality values was observed in males, which was greater in the Slovak Republic. Peak of the curve was not reached in women population, while incidence and mortality values have significantly continuous growth in both countries. According to the lung cancer incidence and mortality trends in both countries (in correlation with smoking prevalence) we consider the support of efforts to change the attitude towards smoking predominantly in women and younger generation to be the most accurate action to reduce these trends.
    Clinical and Translational Oncology 07/2012; 14(9):659-66. · 1.28 Impact Factor
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    ABSTRACT: Experimental evidences suggest that most essential oils possess a wide range of biological and pharmacological activities that may protect tissues against oxidative damage. In this study, we investigated DNA-protective effect of borneol, a component of many essential oils, against oxidative DNA damage induced in primary cultures of rat hepatocytes. Borneol was added to drinking water of Sprague-Dawley rats and DNA resistance against oxidative agents was compared in hepatocytes originated from control and borneol-treated rats. Oxidative stress induced by visible light-excited methylene blue (MB/VL) or 2,3-dimethoxy-1,4-naphthoquionone (DMNQ) resulted in increased levels of DNA lesions measured by the modified single cell gel electrophoresis. Borneol (17 or 34 mg/kg body weight) added to drinking water of rats for 7 days reduced the level of oxidative DNA lesions induced in their hepatocytes by MB/VL or DMNQ. To explain the increased resistance of DNA towards oxidative stress, we measured the base-excision repair (BER) capacity in liver cell extracts of control and borneol-supplemented rats on DNA substrate of HepG2 cells containing oxidative damage. Our results showed that administration of borneol in drinking water had no effect on incision activity of hepatocytes isolated from supplemented rats. The spectrophotometric assessment of enzymatic antioxidants superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and the flow cytometric assessment of total intracellular glutathione (iGSH) in primary hepatocytes of borneol-supplemented rats showed no changes in SOD and GPx activities but higher iGSH content particularly in hepatocytes of higher borneol dose (34 mg/kg) supplemented rats in comparison to control animals. Despite the fact that borneol had no effect either on BER of oxidative DNA damage or on the levels of antioxidant enzymes and manifested no reducing power and radicals scavenging activity, it increased significantly the level of non-enzymatic antioxidant iGSH which could reduce the oxidative DNA lesions induced by MB/VL or DMNQ.
    Mutagenesis 04/2012; 27(5):581-8. · 3.50 Impact Factor