Katarina Tokarova

Dr. Katarina Tokarova

Department of Animal Physiology, Faculty of Biotechnology and Food Sciences, Slovak University of Agriculture in Nitra
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Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 August 2021 in Systems Biology in Reproductive Medicine
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Journal Article
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MĎMichal Ďuračka
Michal Ďuračka
LBLjubica Belić
Ljubica Belić
KTKatarina Tokarova
Katarina Tokarova
JŽJana Žiarovská
Jana Žiarovská
Miroslava KačániováMiroslava Kačániová
Miroslava Kačániová
Eva TvrdáEva Tvrdá
Eva Tvrdá
Although bacterial contamination of ejaculates may cause difficulties in cattle reproduction, standard protocols for a routine microbiological analysis of bovine semen are still missing. Understanding of the mechanisms of bacterial damage to spermatozoa may contribute to the prevention and management of bacteriospermia in the future. Therefore, this study was designed to investigate bacterial profiles of fresh bovine ejaculates (n = 30), while at the same time we focused on assessing the relationships between bacteriospermia and selected sperm quality parameters as well as an array of oxidative stress and inflammatory markers. The samples were divided into three quality groups according to the sperm motility: Excellent (EX) – over 90% > Good (GO) – between 89% and 80% > Moderate (MO) – under 80%. The results showed a significant increase in reactive oxygen species (ROS) generation in the GO group when compared to the EX group. In the MO group, a deterioration of almost all quality parameters was observed when compared to the EX group. In particular, sperm motility, mitochondrial membrane potential, ROS production and IL-6 concentration exhibited a significant decline. Pearson correlation analysis revealed positive associations among bacterial load and the presence of leukocytes in semen (r = 0.965), malondialdehyde concentration (r = 0.816) and DNA fragmentation (r = 0.784). MALDI-TOF MS Biotyper analysis showed a prevalence of the Staphylococcus genus. The quantification of bacterial colonies revealed a significantly increased (P < 0.01) bacterial load in the MO group when compared with the EX as well as the GO group. Overall, our results suggest that sperm quality may be affected by both, bacterial composition, and bacterial load. It appears that an increased presence of bacterial species triggers the immune response, causes oxidative stress, and thereby contributes to sperm structural alterations while diminishing their fertilization ability. Abbreviations: EX: Excellent; GO: Good; MO: Moderate; MOT: Motility; ROS: Reactive Oxygen Species; MMP: Mitochondrial Membrane Potential; IL-1: Interleukin 1; IL-6: Interleukin 6; IL-8: Interleukin 8; IL–12: Interleukin 12; CRP: C-reactive protein; DNA: Deoxyribonucleic acid; MALDI-TOF MS: Matrix-assisted Laser Desorption/Ionization–Time of Flight Mass Spectrometry; LPO: Lipid peroxidation; CFU: Colony-forming units MDA: Malondialdehyde; CASA: Computer-assisted Sperm Analysis; WS: Working solution; RIPA: Radio–immunoprecipitation assay; TBARS: Thiobarbituric Acid Reactive Substances; BHB: D–β–hydroxybutyrate.

31 August 2022 in Research in Veterinary Science
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Journal Article
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RDRudolf Dupak
Rudolf Dupak
JHJana Hrnkova
Jana Hrnkova
NŠNikoleta Šimonová
Nikoleta Šimonová
JKJán Kováč
Ján Kováč
EIEva Ivanišová
Eva Ivanišová
MCMarcela Capcarova
Marcela Capcarova

1 October 2021 in Molecules
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Journal Article
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DFDaniela Figurová
Daniela Figurová
KTKatarina Tokarova
Katarina Tokarova
HGHana Greifová
Hana Greifová
NKNikola Knizatova
Nikola Knizatova
AKAdriana Kolesárová
Adriana Kolesárová
Norbert LukáčNorbert Lukáč
Norbert Lukáč
The inflammatory reaction accompanies in part or in full any disease process in the vascularized metazoan. This complicated reaction is controlled by regulatory mechanisms, some of which produce unpleasant symptomatic manifestations of inflammation. Therefore, there has been an effort to develop selective drugs aimed at removing pain, fever, or swelling. Gradually, however, serious adverse side effects of such inhibitors became apparent. Scientific research has therefore continued to explore new possibilities, including naturally available substances. Amygdalin is a cyanogenic glycoside present, e.g., in bitter almonds. This glycoside has already sparked many discussions among scientists, especially about its anticancer potential and related toxic cyanides. However, toxicity at different doses made it generally unacceptable. Although amygdalin given at the correct oral dose may not lead to poisoning, it has not yet been accurately quantified, as its action is often affected by different intestinal microbial consortia. Its pharmacological activities have been studied, but its effects on the body’s inflammatory response are lacking. This review discusses the chemical structure, toxicity, and current knowledge of the molecular mechanism of amygdalin activity on immune functions, including the anti-inflammatory effect, but also discusses inflammation as such, its mediators with diverse functions, which are usually targeted by drugs.

16 November 2021 in Life
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Journal Article
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Filip TirpákFilip Tirpák
Filip Tirpák
MHMarko Halo
Marko Halo
KTKatarina Tokarova
Katarina Tokarova
ŁBŁukasz Binkowski
Łukasz Binkowski
JVJaromír Vašíček
Jaromír Vašíček
Peter MassányiPeter Massányi
Peter Massányi
The composition of seminal plasma of individual sires varies and so does the fertilizing ability. Micro and macro elements along with seminal enzymes, hormones, proteins, and lipids contained in seminal plasma are essential for the proper physiological function of spermatozoa. However, elevated levels against the normal physiological values, especially in the case of trace metals, result in the production of reactive oxygen species. The deficiency of antioxidants in the seminal plasma that could scavenge free radicals causes an impairment of spermatozoa quality. Ejaculates were obtained from 19 stallions. The fresh semen was analyzed to evaluate qualitative parameters of spermatozoa in terms of the motility, viability, and integrity of DNA. Separated seminal plasma underwent the assessment of the chemical and biochemical composition and RedOx markers. Based on the obtained concentrations of individual chemical elements, the correlation analysis suggested a negative impact of Cu in seminal plasma on the SOD, GPx, and LPO. Contrary, positive correlation was detected between FRAP and motility features. While Cu negatively correlated with sperm motion parameters, the adverse effect on viability was suggested for Cd. Our data suggest that seminal plasma has a potential due to its availability to become the potential biomarker of the reproductive health of farm animals.

12 September 2022 in Antioxidants
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Filip TirpákFilip Tirpák
Filip Tirpák
MHMarko Halo
Marko Halo
MTMarian Tomka
Marian Tomka
TSTomáš Slanina
Tomáš Slanina
KTKatarina Tokarova
Katarina Tokarova
Peter MassányiPeter Massányi
Peter Massányi
This study monitored the chemical and biochemical composition of bovine seminal plasma (SP). Freshly ejaculated semen (n = 20) was aliquoted into two parts. The first aliquot was immediately assessed to determine the sperm motion parameters. Another motility measurement was performed following an hour-long co-incubation of spermatozoa with SP at 6 °C. The other aliquot was processed to obtain the SP. Seminal plasma underwent the analyses of chemical composition and quantification of selected proteins, lipids and RedOx markers. Determined concentrations of observed parameters served as input data to correlation analyses where associations between micro and macro elements and RedOx markers were observed. Significant correlations of total oxidant status were found with the content of Cu and Mg. Further significant correlations of glutathione peroxidase were detected in relation to Fe and Hg. Furthermore, associations of chemical elements and RedOx markers and spermatozoa quality parameters were monitored. The most notable correlations indicate beneficial effects of seminal Fe on motility and Mg on velocity and viability of spermatozoa. On the contrary, negative correlations were registered between Zn and sperm velocity and seminal cholesterol content and motility. Our findings imply that seminal plasma has a prospective to be developed as the potential biomarker of bull reproductive health.

19 December 2023 in Life
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Journal Article
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NŠNikola Štefunková
Nikola Štefunková
HGHana Greifová
Hana Greifová
TJTomas Jambor
Tomas Jambor
KTKatarina Tokarova
Katarina Tokarova
LZLucia Zuščíková
Lucia Zuščíková
Norbert LukáčNorbert Lukáč
Norbert Lukáč
Bisphenol A (BPA) is an endocrine-disruptive chemical that is widely utilized in the production of polycarbonate plastic and epoxy resin, which are used to make a wide range of consumer products, food and drink containers, and medical equipment. When the potential risk of BPA emerged, it was substituted by allegedly less harmful substitutes such as bisphenols S, F, B, and AF. However, evidence suggests that all bisphenols can have endocrine-disruptive effects, while the extent of these effects is unknown. This study aimed to determine effect of BPA, BPAF, BPB, BPF, and BPS on viability and steroidogenesis in human adrenocortical carcinoma cell line in vitro. The cytotoxicity of bisphenols was shown to be considerable at higher doses. However, at low concentrations, it improved viability as well as steroid hormone secretion, indicating that bisphenols have a biphasic, hormetic effect in biological systems. The results are consistent with the hypothesis that bisphenols selectively inhibit some steroidogenic enzymes. These findings suggest that bisphenols have the potential to disrupt cellular steroidogenesis in humans, but substantially more detailed and systematic research is needed to gain a better understanding of the risks associated with bisphenols and their endocrine-disrupting effect on humans and wildlife.