65 results on '"Hirka G"'
Search Results
2. The Surface Antigen Phenotype of Human Embryonal Carcinoma Cells: Modulation Upon Differentiation and Viral Infection
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Andrews, P. W., Marrink, J., Hirka, G., von Keitz, A., Sleijfer, D. Th., Gönczöl, E., Herfarth, Ch., editor, Senn, H.-J., editor, Baum, M., editor, Diehl, V., editor, Gutzwiller, F., editor, Rajewsky, M. F., editor, Wannenmacher, M., editor, Oosterhuis, J. Wolter, editor, Walt, Heinrich, editor, and Damjanov, Ivan, editor
- Published
- 1991
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3. The Surface Antigen Phenotype of Human Embryonal Carcinoma Cells: Modulation Upon Differentiation and Viral Infection
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Andrews, P. W., primary, Marrink, J., additional, Hirka, G., additional, von Keitz, A., additional, Sleijfer, D. Th., additional, and Gönczöl, E., additional
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- 1991
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4. Toxicological examinations of a new acaricide. Dose selection for a carcinogenicity study
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Hirka, G., primary, Béres, E., additional, and Sebestyén, I., additional
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- 1998
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5. The effect of MB-599 on liver cytochrome P450 and UDP-glucuronyl transferase enzymes
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Szakonyi, I.P., primary, Hirka, G., additional, Monostory, K., additional, Jemnitz, K., additional, and Pap, L., additional
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- 1998
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6. Differentiation-dependent human immunodeficiency virus long terminal repeat regulatory elements active in human teratocarcinoma cells
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Zeichner, S L, primary, Hirka, G, additional, Andrews, P W, additional, and Alwine, J C, additional
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- 1992
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7. Differentiation of human embryonal carcinoma cells induces human immunodeficiency virus permissiveness which is stimulated by human cytomegalovirus coinfection
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Hirka, G, primary, Prakash, K, additional, Kawashima, H, additional, Plotkin, S A, additional, Andrews, P W, additional, and Gönczöl, E, additional
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- 1991
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8. Use of cell and tissue cultures in genetic toxicology
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Hirka, G
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- 1982
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9. In vitro toxicity study of eye irritation potential of agrochemicals
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Tavaszi, J., Budai, P., and Hirka, G.
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- 2006
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10. Comparison of fibroblast and hepatocyte cultures for detectability of mutagenic activity
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Béres, E., Hirka, G., and Schmidt, K.
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- 1982
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11. 90-day oral toxicity study in rats of a protein-rich powder derived from Xanthobacter sp. SoF1.
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Choi B, Glávits R, Murbach TS, Endres JR, Hirka G, and Szakonyiné IP
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- Animals, Male, Female, Administration, Oral, Rats, Dose-Response Relationship, Drug, Bacterial Proteins toxicity, No-Observed-Adverse-Effect Level, Powders, Rats, Wistar
- Abstract
Xanthobacter sp. SoF1 (SoF1) is an autotrophic hydrogen-oxidizing bacteria that produces protein-rich biomass and has potential to be an alternative protein source that is more environmentally sustainable than animal and plant derived proteins. A protein-rich powder derived from SoF1 was the test material in a 90-day repeated-dose oral toxicity study to explore major toxic effects, demonstrate target organs, and provide an estimate of a no-observed-adverse-effect level (NOAEL). Daily doses of 0 (vehicle only), 375, 750, and 1500 mg/kg bw/day of the test material were administered by gavage to 10 Han:WIST rats/sex/group. An additional group was administered 1290 mg/kg bw/day whey protein concentrate as positive control. No treatment-related adverse effects were observed, and no target organs were determined after 90/91 days of consecutive administration of the test item. A NOAEL of 1500 mg/kg bw/day was determined., (© 2024 AIBMR Life Sciences. Journal of Applied Toxicology published by John Wiley & Sons Ltd.)
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- 2024
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12. An evaluation of the genotoxicity and 90-day repeated dose oral toxicity in rats of Porphyridium purpureum.
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Murbach TS, Glávits R, Endres JR, Hirka G, Vértesi A, Béres E, and Pasics Szakonyiné I
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- Animals, Administration, Oral, Male, Rats, Female, Cricetulus, Mice, Cricetinae, Dose-Response Relationship, Drug, Cell Line, Micronucleus Tests, Mutagenicity Tests, Porphyridium drug effects, Porphyridium genetics, No-Observed-Adverse-Effect Level, Chromosome Aberrations chemically induced, Chromosome Aberrations drug effects
- Abstract
Interest in microalgae products for use in food is increasing, as demands for sustainable and cost-effective food choices grow due to the escalating global population and increase in climate-related struggles with agriculture. Toxicological assessments of some species of microalgae have been conducted, but there were little data available for the oral consumption of the red microalgae Porphyridium purpureum and no data on genotoxicity. This article articulates a genotoxicity assessment and a 90-day repeated dose oral toxicity study in rats performed according to OECD guidelines. Under the experimental conditions applied, the test item did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used in the bacterial reverse mutation test. Similarly, the test item did not induce structural chromosomal aberrations in V79 hamster lung cells. The test item also did not cause chromosomal damage in bone marrow of mice in the mammalian micronucleus test. The no observed adverse effect level (NOAEL) of the 90-day repeated dose oral toxicity study in rats was determined to be the highest dose tested, 3000 mg/kg bw/day. These data add to the body of evidence regarding the safety of P. purpureum for human consumption., (© 2024 John Wiley & Sons Ltd.)
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- 2024
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13. A 90-day preclinical toxicological evaluation in rats of a highly purified and concentrated mulberry leaf extract.
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Murbach TS, Glávits R, Endres JR, Hirka G, and Pasics Szakonyiné I
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- Animals, Male, Female, Rats, Dose-Response Relationship, Drug, Toxicity Tests, Subchronic, Administration, Oral, Body Weight drug effects, 1-Deoxynojirimycin toxicity, 1-Deoxynojirimycin analogs & derivatives, Organ Size drug effects, Morus chemistry, Plant Extracts toxicity, Plant Leaves chemistry, No-Observed-Adverse-Effect Level, Rats, Wistar
- Abstract
Mulberry (genus Morus) leaves have long been used as a human food, especially in Asia, and animal feed. More recently, mulberry leaf extracts have been introduced as a convenient way to consume mulberry for non-nutritional functional effects. Reducose® 5% is an Morus alba leaf extract that has been highly purified and standardized to a content of 5 ± 0.5% 1-deoxynojirimycin, a naturally present polyhydroxylated piperidine alkaloid analog of D-glucose. This extract has previously been evaluated in acute and subacute (28-day) oral toxicity studies in which no adverse effects of the test item were observed in mice or rats, respectively. Due to continued and growing interest in the extract in multinational markets, we have now further investigated potential toxic effects in subchronic (90-day) oral toxicity study in male and female Han:WIST rats. The test item was administered at doses of 850, 1700, and 2550 mg/kg bw/day, and did not cause adverse effects in clinical signs, body weight development, clinical pathology, gross pathology, or histopathology in comparison to the vehicle-control group. The no-observed-adverse-effect-level was determined to be 2550 mg/kg bw/day. These results add to the existing body of both preclinical and clinical work relevant to the safety of the extract and of interest to regulators in various global markets., (© 2024 John Wiley & Sons Ltd.)
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- 2024
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14. Evidence for safety of the dietary ingredient agmatine sulfate as assessed by mutagenicity and genotoxicity studies.
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Gilad VH, Béres E, Vértesi A, Hirka G, and Gilad GM
- Abstract
Agmatine, 1-Amino-4-guanidinobutane, is a ubiquitous naturally occurring molecule present in low amounts in a wide variety of foodstuff. Clinical trials have demonstrated the safety of oral agmatine sulfate and have led to its development as an effective dietary ingredient for promoting resilient nerve functions. Although clearly required, the mutagenic and genotoxic effects of agmatine have not been previously reported. The present study, therefore, undertook to assess the safety profile of agmatine using currently accepted in vitro and in vivo mutagenicity and genotoxicity tests. The test item was G-Agmatine®, a proprietary brand of agmatine sulfate. Using the bacterial reverse mutation assay (Ames test), the study found that G-Agmatine® has no mutagenic effects. It had no clastogenic effects as observed by the in vitro chromosomal aberration test using Chinese Hamster lung cells. And it lacked genotoxic effects as evidenced by the lack of increased frequency of micronucleated polychromatic immature erythrocytes following oral administration in the mouse micronucleus test. Taken together with previously published data, results of the present study further support the safety of agmatine sulfate as a dietary ingredient., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests. GAD M. GILAD, PhD reports was provided by Gilad&Gilad LLC. GAD M. GILAD, PhD reports a relationship with Gilad&Gilad LLC that includes: employment and equity or stocks. GAD M. GILAD, PhD has patent licensed to Gad M. Gilad. Gad M. Gilad reports a relationship with Gilad&Gilad LLC that includes: employment, equity or stocks, and funding grants. VARDA H. Gilad reports a relationship with Gilad&Gilad LLC that includes: employment, equity or stocks, and funding grants. GAD M. GILAD has patents issued to Gad M. Gilad. Varda H. Gilad has patents issued to Varda H. Gilad. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier B.V.)
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- 2024
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15. An evaluation of the genotoxicity and 90-day repeated-dose toxicity of a CBD-rich hemp oil.
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Clewell A, Glávits R, Endres JR, Murbach TS, Báldi PT, Renkecz T, Hirka G, Vértesi A, Béres E, and Szakonyiné IP
- Abstract
Currently, there is much interest in the sales and study of consumable Cannabis sativa L. products that contain relatively high levels of cannabidiol (CBD) and low levels of Δ-9-tetrahydrocannabinol. While there are published safety evaluations for extracts containing low concentrations of CBD, toxicological assessments for those with higher concentrations are still scant in the public domain. In this paper, genotoxicity tests and a 90-day repeated-dose toxicity study of an ethanolic extract of C. sativa containing ~85% CBD were performed following relevant OECD guidelines. No increased gene mutations were observed in a bacterial reverse mutation assay compared to controls up to the maximum recommended concentration of the guideline. An in vitro chromosomal aberration assay showed no positive findings in the short-term (3 h) treatment assays. Long-term treatment (20 h) showed an increased number of cells containing aberrations at the highest dose of 2 μg/mL, which was outside of historical control levels, but not statistically significantly different from the controls. An in vivo micronucleus study showed no genotoxic potential of the test item in mice. A 90-day repeated-dose gavage study using 0, 75, 125, and 175 mg/kg bw/day showed several slight findings that were considered likely to be related to an adaptive response to consumption of the extract by the animals but were not considered toxicologically relevant. These included increases in liver and adrenal weights compared to controls. The NOAEL was determined as 175 mg/kg bw/day, the highest dose tested (equivalent to approximately 150 mg/kg bw/day of CBD)., (© 2023 John Wiley & Sons Ltd.)
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- 2023
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16. A 90-day toxicity study of tripeptide, arginine-alanine-lysine.
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Dunn M, Glávits R, Murbach TS, Modica V, Endres JR, Hirka G, and Pasics Szakonyiné I
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- Humans, Rats, Animals, Arginine toxicity, No-Observed-Adverse-Effect Level, Administration, Oral, Toxicity Tests, Subchronic, Lysine toxicity, Alanine toxicity
- Abstract
There is a growing global interest in using peptides in the health industry for pharmaceuticals, cosmetics, and natural food products. Peptides contain two or more linked amino acids, whereas more than 50 amino acids are classified as polypeptides. Although there is a growing level of interest in the use of peptides in the health and wellness industry, there is a lack of literature pertaining to a specific tripeptide derived from arginine, alanine, and lysine (RAK) that is of interest for human dietary use. Therefore, a 90-day repeated-dose toxicity study was performed in rats to evaluate the subchronic oral toxicity of RAK. Eighty Han:WIST rats were administered RAK by gavage at doses of 0, 250, 500, or 1000 mg/kg bw/day. There were no mortalities or other treatment related effects, and no target organs were identified. A no-observed-adverse-effect-level (NOAEL) of 1000 mg/kg bw/day, the highest dose tested, was determined. This study will contribute to the body of research in regard to the safety of the use of RAK., (© 2023 John Wiley & Sons Ltd.)
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- 2023
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17. Toxicology and digestibility of Chlamydomonas debaryana green algal biomass.
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Murbach TS, Glávits R, Jayasena S, Moghadam Maragheh N, Endres JR, Hirka G, Goodman RE, Vértesi A, Béres E, and Pasics Szakonyiné I
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- Mice, Rats, Humans, Animals, Biomass, No-Observed-Adverse-Effect Level, Chromosome Aberrations, Mammals, Chlorophyta, Chlamydomonas metabolism
- Abstract
There is an economic interest, both for food security and for the non-meat-eating population, in the development of novel, sustainable sources of high-quality protein. The green algae Chlamydomonas reinhardtii has already been developed for this purpose, and the closely related species, Chlamydomonas debaryana, is a complementary source that also presents some additional advantages, such as reduced production cost. To determine whether C. debaryana may have a similar safety profile to that of C. reinhardtii, a wild type strain was obtained, designated TS04 after confirmation of its identity, and subjected to a battery of preclinical studies. Genetic toxicity was evaluated using a bacterial reverse mutation test, an in vitro mammalian chromosomal aberration test, and an in vivo mammalian micronucleus test in a mouse model. No genotoxic potential (e.g., mutagenicity and clastogenicity) was observed in these tests under the employed conditions up to maximum recommended concentrations or doses. To assess general toxicity, a 90-day repeated-dose oral toxicity study was conducted in rats. No mortality or adverse effects were observed, and no target organs were identified up to the maximum feasible dose, due to solubility, of 4,000 mg/kg bw/day. The no-observed-adverse-effect level was determined as the highest dose tested. A digestibility study in simulated gastric fluid was conducted and determined that TS04 has low allergenic potential, exhibiting rapid digestion of proteins. Due to the negative results of our evaluation, it is reasonable to proceed with further development and additional investigations to contribute towards a safety assessment of the proposed use in food for human consumption., (© 2023 John Wiley & Sons Ltd.)
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- 2023
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18. Safety evaluation of Veillonella atypica FB0054 with genotoxicity and subchronic toxicological studies.
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Preece KE, Glávits R, Murbach TS, Endres JR, Hirka G, Vértesi A, Béres E, and Szakonyiné IP
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- Rats, Humans, Animals, Micronucleus Tests, Comet Assay, Toxicity Tests, Subchronic, Mutagenicity Tests, Mammals, DNA Damage, Veillonella
- Abstract
Veillonella atypica is a nonmotile, nonsporulating anaerobic bacteria commonly found in various human biofilms. V. atypica FB0054 was isolated from the gastrointestinal tract of marathon runners, who have increased amounts of this species after athletic events. Interestingly, the consumption of this strain by rodents has been shown to increase their treadmill endurance, leading to the hypothesis that consumption of this species may improve athletic performance in humans as well. Further evaluation, in humans, of the usefulness of this strain should be preceded by safety studies. Therefore, the genotoxic and subchronic toxicological potential was evaluated as a contribution to this effort. Genotoxicity investigation was performed using the in vivo comet assay and in vivo mammalian micronucleus assay due to the anaerobic characteristic of the strain. A 90-day, repeated-dose oral toxicity study was performed in rats up to 2200 mg/kg bw/d to investigate general toxicity and identify any target organs. Mitsuoka buffer, a solution shown to preserve the viability of anaerobic bacteria, was used as the vehicle. All three studies revealed no toxicological effects from exposure to FB0054 was isolated from the gastrointestinal tract of marathon runners, who have increased amounts of this species after athletic events. Interestingly, the consumption of this strain by rodents has been shown to increase their treadmill endurance, leading to the hypothesis that consumption of this species may improve athletic performance in humans as well. Further evaluation, in humans, of the usefulness of this strain should be preceded by safety studies. Therefore, the genotoxic and subchronic toxicological potential was evaluated as a contribution to this effort. Genotoxicity investigation was performed using the in vivo comet assay and in vivo mammalian micronucleus assay due to the anaerobic characteristic of the strain. A 90-day, repeated-dose oral toxicity study was performed in rats up to 2200 mg/kg bw/d to investigate general toxicity and identify any target organs. Mitsuoka buffer, a solution shown to preserve the viability of anaerobic bacteria, was used as the vehicle. All three studies revealed no toxicological effects from exposure to FB0054 at the highest doses tested., (© 2022 John Wiley & Sons Ltd.)
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- 2023
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19. Toxicological evaluation of protein powder derived from Cupriavidus necator.
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Modica V, Glávits R, Murbach TS, Endres JR, Hirka G, Vértesi A, Béres E, and Pasics Szakonyiné I
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- Rats, Male, Humans, Female, Animals, Rats, Wistar, Powders toxicity, No-Observed-Adverse-Effect Level, Mutagenicity Tests, Mammals, Cupriavidus necator
- Abstract
Microorganisms have the potential to produce nutrient-rich products that can be consumed as food or feed. The protein-rich powder derived from heat treatment of the whole-cell biomass of polyhydroxybutyrate-deficient Cupriavidus necator, a metabolically versatile organism that uses elements found in the air, is an example of such a product. To assess the safety of the protein powder for use as a nutritional ingredient in human food, in accordance with internationally accepted standards, its genotoxic potential and repeated-dose oral toxicity were investigated. A bacterial reverse mutation test, an in vitro mammalian chromosomal aberration test, and an in vivo mammalian micronucleus test were performed. No evidence of mutagenicity or genotoxicity was found. Additionally, a 90-day repeated-dose oral toxicity study in rats was completed, in which a total of 100 male and female Wistar rats were exposed by gavage to daily doses of 1000, 2000, or 3000 mg/kg bw/day of the test material. Following 90 days of continuous exposure, no mortality or treatment-related adverse effects were observed and no target organs were identified. Therefore, a no observed adverse effect level was determined at 3000 mg/kg bw/day, the highest dose tested., (© 2023 John Wiley & Sons Ltd.)
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- 2023
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20. Evaluation of the genotoxic potential of protoporphyrin IX and the safety of a protoporphyrin IX-rich algal biomass.
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Murbach TS, Glávits R, Moghadam Maragheh N, Endres JR, Hirka G, Goodman RE, Lu G, Vértesi A, Béres E, and Pasics Szakonyiné I
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- Animals, Biomass, DNA Damage, Mammals metabolism, Rats, Proteomics, Protoporphyrins metabolism, Protoporphyrins toxicity
- Abstract
Chlamydomonas reinhardtii is a nonpathogenic, nontoxigenic green algae used as a sustainable source of protein in foods. In order to mimic meat-like qualities, a strain rich in protoporphyrin IX (PPIX), an endogenous heme/chlorophyll precursor, was developed using an evolution and selection strategy, and investigations were carried out to evaluate the safety of the novel strain, C. reinhardtii (red), strain TAI114 (TAI114). Digestibility and proteomic evaluations were conducted to determine whether any potentially allergenic or toxic proteins occurred as the result of the mutation process. The genotoxic potential of pure PPIX was evaluated using a bacterial reverse mutation test, an in vitro mammalian chromosomal aberration test, and an in vivo mammalian micronucleus test. Finally, the novel TAI114 biomass was evaluated for general toxicity and identification of target organs in a 90-day repeated-dose oral toxicity study in rats. All proteins were rapidly degraded in pepsin at pH 2.0 suggesting low allergenic potential. The proteomic evaluation indicated that TAI114 biomass contains typical C. reinhardtii proteins. PPIX was unequivocally negative for genotoxic potential and no target organs or adverse effects were observed in rats up to the maximum feasible dose of 4000 mg/kg bw/day TAI114 biomass, which was determined to be the no-observed-adverse-effect-level (NOAEL). These results support the further development and risk characterization of TAI114 biomass as a novel ingredient for use in the meat analogue category of food., (© 2022 John Wiley & Sons, Ltd.)
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- 2022
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21. Comparative bioavailability study following a single dose intravenous and buccal administration of remdesivir in rabbits.
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Szente L, Renkecz T, Sirok D, Stáhl J, Hirka G, Puskás I, Sohajda T, and Fenyvesi É
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- Adenosine Monophosphate analogs & derivatives, Administration, Buccal, Administration, Intravenous, Alanine analogs & derivatives, Animals, Antiviral Agents pharmacokinetics, Biological Availability, Furans, Humans, Pyrroles, Rabbits, Triazines, SARS-CoV-2, COVID-19 Drug Treatment
- Abstract
As remdesivir, the first FDA-approved drug for SARS-CoV-2 infection, can be used only for hospitalized patients due to intravenous administration, there is an urgent need of effective oral antiviral formulations to be used at early stage of infection in an outpatient setting. The present paper reports on the comparative pharmacokinetics of the electrospun nanofiber remdesivir/sulfobutyl ether beta-cyclodextrin formulation after intravenous and buccal administration. It was postulated that oral transmucosal administration avoids remdesivir from metabolic transformation and intact remdesivir can be detected in plasma, but only the active metabolite GS-441524 could be experimentally detected at a significantly lower plasma level, than that provided by the intravenous route. In buccally treated animals, the metabolite GS-441524 appeared only at 1 h after treatment, while in intravenously treated animals, GS-441524 was possible to quantify even at the first time-point of blood collection. Further optimization of formulation is required to improve pharmacokinetics of remdesivir-sulfobutyl ether beta-cyclodextrin formulation upon buccal administration., (Copyright © 2022. Published by Elsevier B.V.)
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- 2022
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22. A toxicological evaluation of 8-28 nm gold nanocrystals.
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Modica V, Glávits R, Murbach TS, Endres JR, Hirka G, Vértesi A, Béres E, and Szakonyiné IP
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- Animals, Cell Line, Cricetinae, Female, Lung cytology, Male, Mice, Micronucleus Tests, No-Observed-Adverse-Effect Level, Rats, Rats, Wistar, Gold chemistry, Gold toxicity, Metal Nanoparticles chemistry, Metal Nanoparticles toxicity
- Abstract
Gold nanocrystals (AuNC) are gold nanoparticles (AuNP) relatively homogenous in size at 8-28 nm with clean surfaces and crystalline structures. There are concerns and a lack of consensus in the scientific literature and major regulatory bodies regarding not only the safety of nanoparticles when consumed by humans, but exactly how to determine their safety and whether evidence from a nanoparticle with one set of physiochemical properties extends to one with a different set. Additionally, there are few general long-term toxicity data on AuNP. To our knowledge, the potential toxicity of AuNC specifically, with the above characteristics, or otherwise, has not been investigated in preclinical studies; thus, we conducted a battery of genetic toxicity tests and an oral repeated-dose toxicity test to further explore their safety. AuNC were not mutagenic or clastogenic in bacterial reverse mutation and in vitro mammalian chromosomal aberration tests, respectively, and did not exhibit in vivo genotoxicity in a micronucleus test in mice. In a 60-day, repeated-dose oral toxicity study, rats were administered 0, 2.5, 5, or 10 mg/kg bw/day of AuNC by gavage. No toxicity was identified. Therefore, a no observed adverse effect level was determined as 10 mg/kg body weight/day., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)
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- 2022
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23. Development and Validation of an LC-MS-MS Method for the Quantification of Cyanate in Rat Plasma and Its Application to Toxicokinetic Bioanalysis.
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Renkecz T, Scopchanova S, Hirka G, and Szakonyiné IP
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- Animals, Chromatography, Liquid, Humans, Rats, Reproducibility of Results, Toxicokinetics, Cyanates, Tandem Mass Spectrometry
- Abstract
Cyanate has been recognized as a uremic toxin that can adversely affect the clinical status of patients with chronic kidney disease. Besides, its toxicity has been under investigation in mammalian toxicology. If such studies are supplemented with toxicokinetic sampling and bioanalysis, additional information can be acquired about the systemic exposure. In order to serve this need, a liquid chromatography with tandem mass spectrometry (LC-MS-MS) method was elaborated and validated for the quantification of cyanate in rat plasma using its isotope-labeled analog for internal standard. Cyanate was converted to a product compatible with reverse-phase LC-MS-MS via a two-step derivatization reaction with the reagent-anthranilic acid. It was observed that this reagent solution contains the reaction products even if prepared freshly in ultrapure water. The phenomenon was interpreted as the presence of urea and its reactivity with anthranilic acid. Contrary to previous research results where fresh anthranilic acid solution was recommended to use, we have found that the aging of the reagent solution is a crucial factor to eliminate the interference. Thereafter, the optimal pH was selected for the plasma sample and processing conditions. Bioanalytical validation and incurred sample reanalysis confirmed the reliability of the method when the intermediate reaction product was used for detection. Only one freeze-thaw cycle stability could be proven, which highlighted the need to collect two sample aliquots whenever possible. Real samples were analyzed in a toxicity study to evaluate systemic exposure of potassium cyanate at three dose levels. Further on, this method might be adapted to provide additional information about the pathophysiological concentration of cyanate in patients with chronic kidney disease for therapeutic support., (© The Author(s) 2020. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2021
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24. A toxicological evaluation of lithium orotate.
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Murbach TS, Glávits R, Endres JR, Hirka G, Vértesi A, Béres E, and Szakonyiné IP
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- Administration, Oral, Animals, Cell Line, Chromosome Aberrations chemically induced, Cricetulus, DNA Damage drug effects, Dose-Response Relationship, Drug, Mice, Micronucleus Tests, No-Observed-Adverse-Effect Level, Organometallic Compounds administration & dosage, Rats, Toxicity Tests, Subacute, Dietary Supplements toxicity, Organometallic Compounds toxicity
- Abstract
Lithium orotate, the salt of lithium and orotic acid, has been marketed for decades as a supplemental source of lithium with few recorded adverse events. Nonetheless, there have been some concerns in the scientific literature regarding orotic acid, and pharmaceutical lithium salts are known to have a narrow therapeutic window, albeit, at lithium equivalent therapeutic doses 5.5-67 times greater than typically recommended for supplemental lithium orotate. To our knowledge, the potential toxicity of lithium orotate has not been investigated in preclinical studies; thus, we conducted a battery of genetic toxicity tests and an oral repeated-dose toxicity test in order to further explore its safety. Lithium orotate was not mutagenic or clastogenic in bacterial reverse mutation and in vitro mammalian chromosomal aberration tests, respectively, and did not exhibit in vivo genotoxicity in a micronucleus test in mice. In a 28-day, repeated-dose oral toxicity study, rats were administered 0, 100, 200, or 400 mg/kg body weight/day of lithium orotate by gavage. No toxicity or target organs were identified; therefore, a no observed adverse effect level was determined as 400 mg/kg body weight/day. These results are supportive of the lack of a postmarket safety signal from several decades of human consumption., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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25. A toxicological evaluation of geranylgeraniol.
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Preece K, Glávits R, Foster JR, Murbach T, Endres JR, Hirka G, Vértesi A, Béres E, and Szakonyiné IP
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- Administration, Oral, Animals, Diterpenes administration & dosage, Female, Male, Mutagenicity Tests, Mutagens administration & dosage, No-Observed-Adverse-Effect Level, Rats, Toxicity Tests, Subchronic, Bixaceae chemistry, Carotenoids chemistry, Diterpenes toxicity, Mutagens toxicity, Plant Extracts chemistry
- Abstract
Geranylgeraniol (GGOH) is an isoprenoid compound found in annatto seeds and an intermediate of the mevalonate pathway found within organisms serving various functions. Toxicological studies on its safety profile are not readily available. To assess the safety of GGOH, a molecularly distilled, food grade annatto oil, consisting of approximately 80% trans-GGOH, was subjected to a bacterial reverse mutation test, an in vitro mammalian chromosomal aberration test, and an in vivo mammalian micronucleus test in order to investigate its genotoxic potential and a 90-day repeated-dose oral toxicity study in rats in order to investigate its potential subchronic toxicity and identify any target organs. No evidence of mutagenicity or genotoxic activity was observed under the applied test systems. In the 90-day study, male and female Hsd. Han Wistar rats were administered daily doses of 0, 725, 1450, and 2900 mg/kg bw/day by gavage. Treatment-related adverse effects were observed in the forestomach at all dose levels and in the liver at the intermediate- and high-dose levels. Based on these results, the lowest observed adverse effect level (LOAEL) for local effects and the no observed adverse effect level (NOAEL) for systemic effects were determined as 725 mg/kg bw/day., (Copyright © 2021 Elsevier Inc. All rights reserved.)
- Published
- 2021
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26. Assessment of toxicological potential of sodium carboxymethyl beta-glucan, a novel beta-glucan.
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Preece KE, Glávits R, Murbach TS, Endres JR, Hirka G, Vértesi A, and Szakonyiné IP
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- Administration, Oral, Animals, Escherichia coli drug effects, Female, Male, Mutagenicity Tests, No-Observed-Adverse-Effect Level, Rats, Wistar, Saccharomyces cerevisiae chemistry, Salmonella typhimurium drug effects, Toxicity Tests, Subacute, beta-Glucans administration & dosage, Rats, beta-Glucans toxicity
- Abstract
In this experimental work, sodium carboxymethyl beta-glucan (CMBG), a chemically altered beta-glucan, is evaluated for mutagenicity and sub-acute oral toxicity. Specifically, the tested material was CM-Glucan Nu, a food grade powder ≥90% CMBG derived from Saccharomyces cerevisiae. A bacterial reverse mutation test was performed and resulted in no mutagenicity. A 28-day, repeated-dose, oral (gavage) toxicity test on rats was performed at dose levels of 0, 500, 1000, and 2000 mg/kg bw/day. No mortality, target organs or other treatment related effects were observed. The no observed adverse effect level (NOAEL) was 2000 mg/kg bw/day, the highest dose tested, for both male and female Han:WIST rats., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2021
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27. Safety assessment of a novel thermostable phytase.
- Author
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Nováková J, Vértesi A, Béres E, Petkov S, Niederberger KE, Van Gaver D, Hirka G, and Balázs Z
- Abstract
A novel 6-phytase (Phytase TSP, trade name OptiPhos® PLUS) with improved thermostability has been developed for use in animal feed. The safety of the new phytase was evaluated by testing for genotoxicity and subchronic toxicity. In in vitro and in vivo genotoxicity assays Phytase TSP concentrate was not mutagenic and did not induce biologically or statistically significant increases in the frequency of micronucleated polychromatic erythrocytes. In a subchronic toxicity study, male and female rats administered 100, 500 or 1000 mg/kg body weight/day of Phytase TSP concentrate via oral gavage for 90 days had no mortalities, and no treatment-related effects on body weight, food consumption, clinical observations or ophthalmology. Furthermore, there were no changes in haematology, clinical chemistry, urinalysis, gross pathology, organ weights or histopathology that could be attributed to the test article. Several endpoints exhibited statistically significant effects, but none was dose-related or considered to be of toxicological relevance. Based on these results, Phytase TSP concentrate (OptiPhos® PLUS) was not genotoxic and the No Observed Adverse Effect Level (NOAEL) for male and female rats was 1000 mg/kg body weight/day., Competing Interests: All authors or their employing institutions have a financial relationship with the sponsor of the studies and manuscript, Huvepharma NV, Antwerp, Belgium. Spas Petkov and Davy Van Gaver are employed by Huvepharma. Katherine E. Niederberger and Zoltán Balázs are consultants to Huverpharma. Jana Nováková, Adél Vértesi, Erzsébet Béres, and Gábor Hitka are employees of contract research organisations that conducted the studies under the sponsorship of Huverpharma., (© 2020 The Author(s).)
- Published
- 2020
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28. A toxicological evaluation of monomethylsilanetriol (MMST) stabilized in acacia gum, a novel silicon preparation.
- Author
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Preece KE, Glávits R, Murbach T, Endres JR, Hirka G, Vértesi A, Béres E, and Szakonyiné IP
- Subjects
- Administration, Oral, Animals, Cell Line, Cricetinae, Cricetulus, Dose-Response Relationship, Drug, Female, Gum Arabic administration & dosage, Male, Mice, Rats, Rats, Wistar, Silicon administration & dosage, Gum Arabic toxicity, Mutagenicity Tests methods, No-Observed-Adverse-Effect Level, Silicon toxicity
- Abstract
Monomethylsilanetriol (MMST), a silicon-containing compound, has been sold in dietary supplements. However, toxicological studies on its safety profile are not readily available. To assess the safety of MMST stabilized in acacia gum, a novel delivery form of MMST, in accordance with internationally accepted standards, the genotoxic potential and repeated-dose oral toxicity of Living Silica® Acacia Gum Stabilized Monomethylsilanetriol (formerly known as Orgono Acacia Gum Powder®), a food grade product consisting of 80 ± 10% acacia gum and 2.8% (SD ± 10%) elemental silicon from MMST, was investigated. A bacterial reverse mutation test, an in vitro mammalian chromosomal aberration test, an in vivo mammalian micronucleus test, and a 90-day repeated-dose oral toxicity study in rats were performed. No evidence of mutagenicity or genotoxic activity was observed under the applied test systems. In the 90-day study, male and female Hsd.Han Wistar rats were administered daily doses of 0, 500, 1000, and 2000 mg/kg bw/day by gavage. No mortality or treatment-related adverse effects were observed, and no target organs were identified. Therefore, the no observed adverse effects level (NOAEL) was determined as 2000 mg/kg bw/day (201 mg MMST/kg bw/day), the highest dose tested., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
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29. A toxicological evaluation of a fulvic and humic acids preparation.
- Author
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Murbach TS, Glávits R, Endres JR, Clewell AE, Hirka G, Vértesi A, Béres E, and Pasics Szakonyiné I
- Abstract
Humic substances are ubiquitous in soils and waters. These complex superstructures are derived from the decomposition of dead plant and animal matter and are vital to soil health. Their heterogenous composition is specific to their site of origin and is comprised of weakly bound aggregates of small organic compounds that can sequester minerals and make them available to plants. As such, they may possess potential nutritional value for humans, and extractions of fulvic and humic acids can be produced that could be suitable for such purposes. For this reason, we evaluated the toxicological profile of a specific preparation (blk. 333) of fulvic and humic acids derived from a lignite deposit in Alberta, Canada and found it to lack genotoxic potential in a bacterial reverse mutation test, in vitro mammalian chromosomal aberration test, and in vivo mammalian micronucleus test. No general or organ toxicity was observed in Wistar rats following 90 days of continuous exposure, and a no observed adverse effect level (NOEAL) was determined at 2000 mg/kg bw/day, the highest tested dose. Our results suggest the feasibility of further evaluation for development of the preparation as a nutritional supplement in food., Competing Interests: Authors Timothy Murbach, John Endres, and Amy Clewell are salaried employees of AIBMR Life Sciences, Inc. (Seattle, WA, USA). AIBMR was contracted by the study sponsor, as an independent third party, to determine appropriate study protocols and dose selections, place the studies, approve the study plans, and monitor the toxicological studies herein described and to analyze and interpret the resulting data and prepare the manuscript. Author Gábor Hirka is owner and Managing Director at Toxi-Coop Zrt. (with test facilities in Budapest (90-day study) and Balatonfüred (genotoxicity studies), Hungary); authors Adél Vértesi, Erzsébet Béres, and Ilona Pasics Szakonyiné are salaried employees of Toxi-Coop; and author Róbert Glávits is an independent contractor to Toxi-Coop. Toxi-Coop was contracted by AIBMR to develop the study plans and conduct, analyze and interpret, and report the results of the toxicological studies herein described. The authors declare no additional conflicts of interest in regard to the research, authorship, and/or publication of this article., (© 2020 The Author(s).)
- Published
- 2020
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30. A Toxicological Evaluation of Germanium Sesquioxide (Organic Germanium).
- Author
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Reddeman RA, Glávits R, Endres JR, Murbach TS, Hirka G, Vértesi A, Béres E, and Szakonyiné IP
- Abstract
A battery of OECD- and GLP-compliant toxicological studies was performed to assess the safety of a highly purified germanium sesquioxide, an organic form of the naturally occurring, nonessential trace element germanium. Germanium dioxide and germanium lactate citrate (inorganic germaniums) have been shown to induce renal toxicity, whereas germanium sesquioxide (an organic germanium) has been shown to have a more favorable safety profile. However, past toxicity studies on germanium sesquioxide compounds have not clearly stated the purity of the tested compounds. In the studies reported herein, there was no evidence of mutagenicity in a bacterial reverse mutation test or an in vitro mammalian chromosomal aberration test. There was no genotoxic activity observed in an in vivo mammalian micronucleus test at concentrations up to the limit dose of 2000 mg/kg bw/day. In a 90-day repeated-dose oral toxicity study in Han:WIST rats conducted at doses of 0, 500, 1000, and 2000 mg/kg bw/day by gavage, there were no mortalities, treatment-related adverse effects, or target organs identified. The no-observed-adverse-effect-level (NOAEL) was determined to be 2000 mg/kg bw/day., Competing Interests: AIBMR Life Sciences, Inc. was contracted by the study sponsor, as an independent third party, to determine appropriate study protocols and dose selections, place the studies, approve the study plans, and monitor the toxicological studies herein described and to analyze and interpret the resulting data and prepare the manuscript. Toxi-Coop Zrt. was contracted by AIBMR to develop the study plans and conduct, analyze and interpret, and report the results of the toxicological studies herein described. The authors declared no additional conflicts of interest regarding the research, authorship, and/or publication of this article., (Copyright © 2020 Robin A. Reddeman et al.)
- Published
- 2020
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31. A Toxicological Evaluation of Methylliberine (Dynamine®).
- Author
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Murbach TS, Glávits R, Endres JR, Clewell AE, Hirka G, Vértesi A, Béres E, and Szakonyiné IP
- Abstract
Methylliberine (CAS 51168-26-4), a methoxiuric acid, is a caffeine metabolite present at low levels in various Coffea plants; however, very little has been published regarding this compound and we could find no toxicological data in the public domain. Therefore, we undertook the toxicological investigation of a pure, synthetic form of methylliberine in order to evaluate its potential health hazards as a food ingredient. A (1) bacterial reverse mutation test, (2) in vitro mammalian chromosomal aberration test, (3) in vivo mammalian micronucleus test, and (4) 90-day repeated-dose oral toxicity study in rats with a 28-day recovery period were conducted. No in vitro mutagenic or clastogenic activity was observed in the presence or absence of metabolic activation up to the maximum OECD recommended test concentrations. No genotoxicity was observed in the mammalian micronucleus study up to the highest dose tested of 700 mg/kg bw. In the 90-day study, methylliberine was administered to Han:WIST rats at doses of 0, 75, 112, 150, 187, and 225 mg/kg bw/day. No mortality or morbidity was observed and no toxicologically relevant clinical effects or effects on clinical pathology parameters were observed. In male animals, test item-related effects on body weight and sexual organs, which were not reversible after a 28-day recovery period without treatment, were observed in the high-dose group. Body weight development was also slightly and reversibly depressed in the 187 mg/kg bw/day male group. No toxicological effects were observed in females. The NOAEL for females was determined to be 225 mg/kg bw/day, the highest dose tested, while the NOAEL for males was determined to be 150 mg/kg bw/day. Future studies are encouraged to corroborate the safety, and assess efficacy, of methylliberine in humans., Competing Interests: AIBMR Life Sciences, Inc. (Seattle, WA, USA) was contracted by the study sponsor, as an independent third party, to determine appropriate study protocols and dose selections, place the studies, approve the study plans, and monitor the toxicological studies herein described and to analyze and interpret the resulting data and prepare the manuscript. Toxi-Coop Zrt. (with test facilities in Budapest (90-day study) and Balatonfüred (genotoxicity studies), Hungary) was contracted by AIBMR to develop the study plans and conduct, analyze and interpret, and report the results of the toxicological studies herein described. The authors declare no additional conflicts of interest in regard to the research, authorship, and/or publication of this article., (Copyright © 2019 Timothy S. Murbach et al.)
- Published
- 2019
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32. A Toxicological Evaluation of Mango Leaf Extract ( Mangifera indica ) Containing 60% Mangiferin.
- Author
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Reddeman RA, Glávits R, Endres JR, Clewell AE, Hirka G, Vértesi A, Béres E, and Szakonyiné IP
- Abstract
A battery of OECD- and GLP-compliant toxicological studies was performed on mango leaf extract ( Mangifera indica ) containing 60% mangiferin (MLE). No evidence of genotoxicity was found in a bacterial reverse mutation test (Ames). While evidence of clastogenic activity was noted in an in vitro chromosomal aberration test, an in vivo mammalian micronucleus test showed no findings up to the limit dose (2000 mg/kg bw). A 90-day repeated dose oral toxicity study was conducted in rats using doses of 0 (vehicle control), 500, 1000, and 2000 mg/kg bw/day. Based on the lack of mortality or toxic effects in the 90-day study, the NOAEL for MLE in Han:Wist male and female rats was determined to be 2000 mg/kg bw/day, the highest dose tested., Competing Interests: AIBMR Life Sciences, Inc., was contracted by the study sponsor, as an independent third party, to determine appropriate study protocols and dose selections, place the studies, approve the study plans, monitor the toxicological studies herein described, analyze and interpret the resulting data, and prepare the manuscript. TOXI-COOP Zrt. was contracted by AIBMR to develop the study plans and to conduct, analyze, interpret, and report the results of the toxicological studies herein described. The authors declared no additional conflicts of interest in regard to the research, authorship, and/or publication of this article.
- Published
- 2019
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33. Toxicological Evaluation of a Mixture of Astragalus membranaceus and Panax notoginseng Root Extracts (InnoSlim®).
- Author
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Murbach TS, Glávits R, Endres JR, Hirka G, Vértesi A, Béres E, and Szakonyiné IP
- Abstract
Astragalus spp. and Panax spp. have a long history of traditional human use. A blend, InnoSlim®, of highly purified and fractionated root extracts from Astragalus membranaceus and Panax notoginseng has now been developed for human consumption; however, the unique constituent content of this blend has not been specifically evaluated with respect to safety. Therefore, the toxicological potential of the blend was formally investigated in a series of studies-genetic toxicity was evaluated in a bacterial reverse mutation test followed by an in vivo mammalian micronucleus test, and general toxicity was evaluated in a 28-day repeated-dose oral toxicity study in rats. No evidence of mutagenicity was observed in the bacterial tester strains used, and no evidence of in vivo chromosomal damage resulting in increased frequency of micronucleated cells was observed in male Crl:NMRI BR mice. No mortality or toxic effects were observed, and no target organs were identified, in male and female Han:WIST rats exposed to 0, 400, 800, or 1200 mg/kg bw/day of the blend by gavage for 28 consecutive days. The highest dose-1200 mg/kg bw/day-was determined to be the NOAEL. Based on these results, extrapolation towards a safe human consumption level can be explored.
- Published
- 2019
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34. Toxicological evaluations of colostrum ultrafiltrate.
- Author
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Thiel A, Glávits R, Murbach TS, Endres JR, Reddeman R, Hirka G, Vértesi A, Béres E, and Szakonyiné IP
- Subjects
- Administration, Oral, Animals, Female, Male, Mice, No-Observed-Adverse-Effect Level, Pregnancy, Rats, Rats, Wistar, Ultrafiltration, Colostrum chemistry, Dairy Products analysis, Dairy Products toxicity
- Abstract
Colostrum has been consumed safely for many years as a food collected directly from cows. More recently, an ultrafiltrated bovine colostrum product has been developed; however, its safety in toxicology studies has not been extensively evaluated. To assess the safety of bovine colostrum ultrafiltrate, in accordance with internationally accepted standards, the genotoxic potential was investigated in a bacterial reverse mutation test, an in vitro chromosomal aberration test, and an in vivo mammalian micronucleus test. No mutagenicity or genotoxic activity was observed in these three tests. A 90-day repeated-dose oral toxicity study in Hsd.Han Wistar rats was conducted at doses of 0, 1050, 2100, and 4200 mg/kg bw/day by gavage. After 90 days of continuous exposure, no mortality or treatment-related adverse effects were observed, and no target organs were identified. The no-observed-adverse-effect level (NOAEL) was determined to be 4200 mg/kg bw/day, the highest dose tested., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2019
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35. A comprehensive toxicological safety assessment of an extract of Ageratum conyzoides.
- Author
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Palmer PA, Bryson JA, Clewell AE, Endres JR, Hirka G, Vértesi A, Béres E, Glávits R, and Szakonyiné IP
- Subjects
- Administration, Oral, Animals, Cell Line, Cricetinae, Female, Male, Mice, Plant Extracts administration & dosage, Plant Extracts isolation & purification, Rats, Rats, Wistar, Ageratum chemistry, Food Safety, Plant Extracts toxicity
- Abstract
A battery of toxicological studies was conducted to aid in the safety assessment of an ethanolic extract of Ageratum conyzoides for use as an ingredient in food. In accordance with internationally accepted standards, a bacterial reverse mutation test, an in vitro mammalian chromosomal aberration test, an in vivo mammalian micronucleus test, and a 90-day repeated-dose oral toxicity study in rats were performed. In the first three applied test systems, no evidence of mutagenicity, clastogenicity or genotoxicity was revealed. Ageratum conyzoides did not cause mortality or toxic changes in Hsd.Han Wistar rats in the 90-day repeated dose oral (gavage) toxicity study at doses of 500, 1000 and 2000 mg/kg bw/d. The NOAEL was determined to be 2000 mg/kg bw/d for both male and female rats, the highest dose tested., (Copyright © 2019. Published by Elsevier Inc.)
- Published
- 2019
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36. An Assessment of the Genotoxicity and Subchronic Toxicity of a Supercritical Fluid Extract of the Aerial Parts of Hemp.
- Author
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Marx TK, Reddeman R, Clewell AE, Endres JR, Béres E, Vértesi A, Glávits R, Hirka G, and Szakonyiné IP
- Abstract
A battery of toxicological studies was conducted on a supercritical CO
2 extract of the aerial parts of the Cannabis sativa plant, containing approximately 25% cannabinoids. No evidence of genotoxicity was found in a bacterial reverse mutation test (Ames), in an in vitro mammalian chromosomal aberration test, or in an in vivo mouse micronucleus study. A 14-day repeated oral dose-range finding study conducted in Wistar rats at 1000, 2000, and 4000 mg/kg bw/day resulted in effects where a NOAEL could not be concluded. Based on those results, a 90-day repeated dose oral toxicity study was performed in rats using doses of 100, 360, and 720 mg/kg bw/day, followed by a 28-day recovery period for two satellite groups. Significant decreases in body weight, body weight gain, and differences in various organ weights compared to controls were observed. At the end of the recovery period, many of the findings were trending toward normal; thus, the changes appeared to be reversible. The NOAEL for the hemp extract in Hsd.Han Wistar rats was considered to be 100 mg/kg bw/day for males and 360 mg/kg bw/day for females.- Published
- 2018
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37. A Toxicological Assessment of Creatyl-l-Leucine.
- Author
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Reddeman RA, Glávits R, Endres JR, Murbach TS, Hirka G, Vértesi A, Béres E, and Szakonyiné IP
- Subjects
- Animals, Cell Line, Cricetulus, Erythrocytes drug effects, Escherichia coli drug effects, Escherichia coli genetics, Female, Male, Mice, No-Observed-Adverse-Effect Level, Rats, Wistar, Salmonella typhimurium drug effects, Salmonella typhimurium genetics, Toxicity Tests, Leucine analogs & derivatives, Leucine toxicity
- Abstract
A battery of toxicological studies was conducted to investigate the genotoxicity and repeated-dose oral toxicity of creatyl-l-leucine, a synthetic compound, in rats in accordance with internationally accepted guidelines. There was no evidence of mutagenicity in a bacterial reverse mutation test and in an in vitro mammalian chromosomal aberration test. There was no genotoxic activity observed in an in vivo mammalian micronucleus test at concentrations up to the limit dose of 2,000 mg/kg bw/d. Creatyl-l-leucine did not cause mortality or toxic effects in Hsd.Han Wistar rats in a 90-day repeated-dose oral (gavage) toxicity study at doses of 1,250, 2,500, and 5,000 mg/kg bw/d. The no observed adverse effect level from the 90-day study was determined to be 5,000 mg/kg bw/d, the highest dose tested, for both male and female rats.
- Published
- 2018
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38. A Toxicological Evaluation of Chlamydomonas reinhardtii, a Green Algae.
- Author
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Murbach TS, Glávits R, Endres JR, Hirka G, Vértesi A, Béres E, and Szakonyiné IP
- Subjects
- Animals, Dose-Response Relationship, Drug, Female, Humans, Male, Micronucleus Tests, No-Observed-Adverse-Effect Level, Rats, Chlamydomonas reinhardtii physiology, Food Safety
- Abstract
There is a current worldwide interest in developing novel sustainable nonanimal nutritional sources, and one such source is the green algae Chlamydomonas reinhardtii, the only green algae that has been studied as a model organism for many biological processes ranging from photosynthesis to flagellar movement. However, its potential as a safe nutritional source for use in various foods has not been thoroughly investigated. To assess the safety of C reinhardtii for use as a nutritional human food ingredient, in accordance with internationally accepted standards, the genotoxic potential and repeated-dose oral toxicity of the dried C reinhardtii (THN 6) algal biomass was investigated. The following studies were conducted: (1) a bacterial reverse mutation test, (2) an in vitro mammalian chromosomal aberration test, (3) an in vivo mammalian micronucleus test, and (4) a 28-day repeated-dose oral toxicity study in rats. No evidence of mutagenicity or genotoxic activity was observed in the first 3 tests under the applied test systems. In the 28-day study, male and female Hsd.Han Wistar rats were exposed to daily doses of 0, 1,000, 2,000, and 4,000 mg/kg bw by gavage. Following 28 days of continuous exposure, no mortality or treatment-related adverse effects were observed and no target organs were identified. Therefore, a no observed adverse effect level was concluded as 4,000 mg/kg bw/day, the highest dose tested.
- Published
- 2018
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39. A 28-day oral toxicology study of an aqueous extract of Polypodium leucotomos (Fernblock ® ).
- Author
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Murbach TS, Glávits R, Hirka G, Endres JR, Clewell AE, and Szakonyiné IP
- Abstract
Fernblock
® is a standardized commercial aqueous extraction of the leaves of the tropical fern Polypodium leucotomos promoted as an orally active photoprotective substance. In a previous battery of toxicological tests on Fernblock® , no genotoxicy was observed and no oral toxicity was observed up to 1200 mg/kg bw/day. The current study was conducted in Hsd.Han Wistar rats using doses of 0, 2000, 3500, and 5000 mg/kg bw/day Fernblock® by gavage for 28 consecutive days. No mortality or toxic effects were observed and no target organs were identified. The no observed adverse effect level was determined to be 5000 mg/kg bw/day, the highest dose tested.- Published
- 2017
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40. A 28-Day Repeated Dose Toxicological Study of an Aqueous Extract of Morus Alba L.
- Author
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Marx TK, Glávits R, Endres JR, Palmer PA, Clewell AE, Murbach TS, Hirka G, and Pasics I
- Subjects
- Animals, Female, Male, No-Observed-Adverse-Effect Level, Plant Leaves, Rats, Toxicity Tests, Subacute, Morus, Plant Extracts toxicity
- Abstract
Morus alba L. (white mulberry) leaves are one of the oldest recognized traditional Chinese medicines. More recently, M alba leaves and their constituents, particularly iminosugars (or azasugars), have garnered attention for their ability to maintain normal blood glucose concentrations, an effect identified in both animal studies and human clinical trials. Reducose (Phynova Group Limited) is a commercial water-soluble extract of M alba leaves standardized to 5% 1-deoxynojirimycin (DNJ), an iminosugar with α-glucosidase inhibition properties. Although there is an extensive history of consumption of M alba leaves by humans and animals worldwide, suggesting that the leaves and their extracts have a relatively good safety profile, we are unaware of safety assessments on an extract containing a higher amount of DNJ than that occurs naturally. The current 28-day repeated dose oral toxicity study in rats, conducted according to Organisation for Economic Co-operation and Development guidelines, was carried out to assess the safety of Reducose. Male and female Hsd.Han Wistar rats (4 groups of 10 animals/sex) were administered Reducose via gavage at doses of 0, 1,000, 2,000 and 4,000 mg/kg body weight (bw)/d. No treatment-related mortality or adverse effects (per clinical observations, body weight/weight gain, food consumption, ophthalmoscopy, clinical pathology, gross pathology, organ weights, or histopathology) were observed, and no target organs were identified. The no observed adverse effect level was determined to be 4,000 mg/kg bw/d for both male and female rats, the highest dose tested., (© The Author(s) 2016.)
- Published
- 2016
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41. A Comprehensive Toxicological Safety Assessment of an Extract of Olea Europaea L. Leaves (Bonolive™).
- Author
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Clewell AE, Béres E, Vértesi A, Glávits R, Hirka G, Endres JR, Murbach TS, and Szakonyiné IP
- Subjects
- Animals, Chromosome Aberrations, Dose-Response Relationship, Drug, Female, Male, Mice, Mutagenicity Tests, No-Observed-Adverse-Effect Level, Rats, Rats, Wistar, Olea chemistry, Plant Extracts toxicity, Plant Leaves chemistry
- Abstract
A battery of toxicological studies was conducted to investigate the genotoxicity and repeated-dose oral toxicity of Bonolive™, a proprietary water-soluble extract of the leaves of the olive tree (Olea europaea L.), in accordance with internationally accepted protocols. There was no evidence of mutagenicity in a bacterial reverse mutation test and in an vitro mammalian chromosomal aberration test nor was any genotoxic activity observed in an in vivo mouse micronucleus test at concentrations up to the limit dose of 2000 mg/kg bw/d. Bonolive™ did not cause mortality or toxic effects in Crl:(WI)BR Wistar rats in a 90-day repeated-dose oral toxicity study at doses of 360, 600, and 1000 mg/kg bw/d. The no observed adverse effect level in the 90-day study was 1000 mg/kg bw/d for both male and female rats, the highest dose tested., (© The Author(s) 2015.)
- Published
- 2016
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42. A 90-Day Oral Toxicological Evaluation of the Methylurate Purine Alkaloid Theacrine.
- Author
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Clewell A, Hirka G, Glávits R, Palmer PA, Endres JR, Murbach TS, Marx T, and Pasics Szakonyiné I
- Abstract
A 90-day repeated-dose oral toxicological evaluation was conducted according to GLP and OECD guidelines on the methylurate purine alkaloid theacrine, which is found naturally in certain plants. Four groups of Hsd.Brl.Han Wistar rats (ten/sex/group) were administered theacrine by gavage doses of 0 (vehicle only), 180, 300, and 375 mg/kg bw/day. Two females and one male in the 300 and 375 mg/kg bw/day groups, respectively, died during the study. Histological examination revealed centrilobular hepatocellular necrosis as the probable cause of death. In 375 mg/kg bw/day males, slight reductions in body weight development, food consumption, and feed efficiency, decreased weight of the testes and epididymides and decreased intensity of spermatogenesis in the testes, lack or decreased amount of mature spermatozoa in the epididymides, and decreased amount of prostatic secretions were detected at the end of the three months. At 300 mg/kg bw/day, slight decreases in the weights of the testes and epididymides, along with decreased intensity of spermatogenesis in the testes, and lack or decreased amount of mature spermatozoa in the epididymides were detected in male animals. The NOAEL was considered to be 180 mg/kg bw/day, as at this dose there were no toxicologically relevant treatment-related findings in male or female animals.
- Published
- 2016
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43. A comprehensive toxicological safety assessment of an aqueous extract of Polypodium leucotomos (Fernblock(®)).
- Author
-
Murbach TS, Béres E, Vértesi A, Glávits R, Hirka G, Endres JR, Clewell AE, and Szakonyiné IP
- Subjects
- Administration, Oral, Animals, Dose-Response Relationship, Drug, Drug Administration Schedule, Female, Male, Mice, Micronucleus Tests, Plant Extracts administration & dosage, Rats, Plant Extracts toxicity, Polypodium chemistry
- Abstract
A battery of toxicological studies was conducted in accordance with internationally accepted standards to investigate the genotoxicity and repeated-dose oral toxicity of Fernblock(®), a commercial aqueous extraction of the leaves of the tropical fern Polypodium leucotomos used for its oral and topical photoprotective properties. No evidence of mutagenicity was observed in a bacterial reverse mutation test or in vitro mammalian chromosomal aberration test nor was any genotoxic activity observed in an in vivo mouse micronucleus test. Two repeated-dose oral toxicity studies were conducted in male and female Wistar rats. In the first study, no mortality or toxic effects were observed and no target organs were identified at doses administered for 14 days by gavage up to the maximum dose of 5000 mg/kg bw/day. Based on these results, a 90-day study was conducted at 0, 300, 600, and 1200 mg/kg bw/day. No mortality or treatment-related adverse effects were observed and no target organs were identified. The NOAEL from the 90-day study was determined to be 1200 mg/kg bw/day, the highest dose tested., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2015
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44. A toxicological safety assessment of a standardized extract of Sceletium tortuosum (Zembrin®) in rats.
- Author
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Murbach TS, Hirka G, Szakonyiné IP, Gericke N, and Endres JR
- Subjects
- Alkaloids analysis, Animals, Blood Cell Count, Blood Chemical Analysis, Body Weight drug effects, Dose-Response Relationship, Drug, Eating drug effects, Female, Male, Medicine, African Traditional, Rats, Rats, Wistar, Aizoaceae toxicity, Plant Extracts toxicity
- Abstract
A well-characterized standardized hydroethanolic extract of a traditionally recognized mak (mild) variety of Sceletium tortuosum, a South African plant with a long history of traditional ingestion, is marketed under the trade name Zembrin(®) as an ingredient for use in functional foods and dietary supplements. It is standardized to contain 0.35-0.45% total alkaloids (mesembrenone and mesembrenol ≥60%, and mesembrine <20%). A 14-day repeated oral toxicity study was conducted at 0, 250, 750, 2500, and 5000 mg/kg bw/day. A 90-day subchronic repeated oral toxicity study was conducted at 0, 100, 300, 450, and 600 mg/kg bw/day. Because S. tortuosum has a long history of human use for relieving stress and calming, a functional observation battery, including spontaneous locomotor activity measured using LabMaster ActiMot light-beam frames system, was employed. Several parameters, such as locomotion, rearing behavior, spatial parameters, and turning behavior were investigated in the final week of the study. No mortality or treatment-related adverse effects were observed in male or female Crl:(WI)BR Wistar rats in the 14- or 90-day studies. In the 14- and 90-day studies, the NOAELs were concluded as 5000 and 600 mg/kg bw/d, respectively, the highest dose groups tested., (Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
45. The effect of ergothioneine on clastogenic potential and mutagenic activity: genotoxicity evaluation.
- Author
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Schauss AG, Béres E, Vértesi A, Frank Z, Pasics I, Endres J, Aruoma OI, and Hirka G
- Subjects
- Animals, Biotransformation, Cell Line, Chromatography, High Pressure Liquid, Chromatography, Liquid, Chromosome Aberrations drug effects, Cricetinae, Dose-Response Relationship, Drug, Ergothioneine chemistry, Erythrocytes drug effects, Female, Lung cytology, Male, Mass Spectrometry, Mice, Micronucleus Tests methods, Mutagens chemistry, DNA Damage drug effects, Ergothioneine toxicity, Mutagens toxicity
- Abstract
L-(+)-ergothioneine has antioxidant and anti-inflammatory properties in vitro and in vivo and has uses as a dietary supplement and as an ingredient in foods, cosmetics, and as a pharmaceutical additive. The clastogenic potential and mutagenic of ergothioneine were assessed in vitro and in vivo. Ergothioneine concentrations up to 5000 μg/mL, with and without metabolic activation, was tested in the chromosome aberration assay with CHL cells and found not to induce structural chromosome aberrations. In the in vivo mammalian erythrocyte micronucleus test, ergothioneine was administered orally to male mice at doses up to 1500 mg/kg for potential genotoxic activity. No increase in the frequency of micronucleated polychromatic erythrocytes was observed. Overall, ergothioneine was not genotoxic in these studies and provides additional experimental evidence supporting the safety of its use as a potential dietary supplement.
- Published
- 2011
- Full Text
- View/download PDF
46. Evaluation of the safety of the dietary antioxidant ergothioneine using the bacterial reverse mutation assay.
- Author
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Schauss AG, Vértesi A, Endres JR, Hirka G, Clewell A, Qureshi I, and Pasics I
- Subjects
- Escherichia coli genetics, Humans, Mutagenicity Tests methods, Salmonella typhimurium genetics, Antioxidants toxicity, Ergothioneine toxicity, Escherichia coli drug effects, Salmonella typhimurium drug effects
- Abstract
The dietary antioxidant L-(+)-ergothioneine was tested for its potential mutagenic activity using the bacterial reverse mutation assay. The experiments were carried out using histidine-requiring auxotrophic strains of Salmonella typhimurium (Salmonella typhimurium TA98, TA100, TA1535 and TA1537), and the tryptophan-requiring auxotrophic strain of Escherichia coli (Escherichia coli WP2 uvrA) in the presence and absence of a post-mitochondrial supernatant (S9) prepared from livers of phenobarbital/β-naphthoflavone-induced rats. The revertant colony numbers of vehicle control plates with and without S9 Mix were within the corresponding historical control data ranges. The reference mutagen treatments (positive controls) showed the expected, biologically relevant increases in induced revertant colonies in all experimental phases in all tester strains. No biologically relevant increases were observed in revertant colony numbers of any of the five test strains following treatment with L-(+)-ergothioneine at any concentration level, either in the presence or absence of metabolic activation (S9 Mix) in the performed experiments. On the basis of the data reported, it can be concluded that L-(+)-ergothioneine did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used. Thus L-(+)-ergothioneine has no mutagenic activity on the applied bacteria tester strains under the test conditions used in this study. Research is continuing to define the role of L-(+)-ergothioneine in disease pathophysiology. Further studies on its safety are suggested., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
47. Safety evaluation of an açai-fortified fruit and berry functional juice beverage (MonaVie Active(®)).
- Author
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Schauss AG, Clewell A, Balogh L, Szakonyi IP, Financsek I, Horváth J, Thuroczy J, Béres E, Vértesi A, and Hirka G
- Subjects
- Animals, Chromosome Aberrations, Female, Male, Mice, Mice, Inbred BALB C, Micronucleus Tests, Mutation, Random Allocation, Rats, Rats, Wistar, Toxicity Tests, Vitamin K analysis, Antioxidants toxicity, Arecaceae chemistry, Beverages toxicity, Fruit chemistry
- Abstract
The safety of an açai (Euterpe oleracea Mart.) pulp enriched fruit and berry juice, MonaVie Active®, fortified with the functional ingredient, glucosamine, was studied. The beverage was found not to be mutagenic, clastogenic, cytotoxic, or genotoxic, as determined by the bacterial reverse mutation assay, chromosomal aberration assay, mouse micronucleus assay, and mammalian cell gene mutation (L5178Y) assay. The single dose LD50 based on a 14-day acute oral toxicity study is greater than 20,000 mg/kg bw, the highest dose tested. In a repeat dose 90-day oral subchronic toxicity study by gavage, 220 animals were randomly assigned to a control group, an untreated group, or one of three experimental groups (10, 20 and 40 g/kg bw). No treatment-related significant changes in body weight, food and water consumption, ophthalmology, organ weights, urinanalysis, hematological and clinical chemistry, or gross pathology, were observed in surviving animals compared to the control groups. Three animals died midway through the observation period (male, 20 g/kg bw/day; male 40 g/kg bw/day; and, female, 10 g/kg bw/day). These animals died without preceding clinical symptoms, histopathological lesions, or evidence of injury to tissue or organs except for signs of suffocation/aspiration congestion, which was concluded to be due to problems with the gavage administration of the fluid test article, and not due to the test article itself. The NOEAL was determined to be 40 g/kg bw/day for male and female rats, which was the highest dose tested. Phylloquinone (vitamin K1) content averaged 21.7 μg/100 g, comparable to amounts found in iceberg lettuce. In conclusion, the results provide additional experimental evidence that MonaVie Active® juice is non-toxic., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
48. Evaluation of a Hungarian acaricide original molecule based on its environmental toxicological studies.
- Author
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Szamosi D, Oláh B, Hirka G, Pap L, and Gáty S
- Subjects
- Animals, Bacteria drug effects, Bacteria growth & development, Biodegradation, Environmental, Daphnia drug effects, Environmental Pollutants metabolism, Evaluation Studies as Topic, Fishes, Heterocyclic Compounds metabolism, Hungary, Insecticides metabolism, Plant Development, Plants drug effects, Acari drug effects, Environmental Pollutants toxicity, Heterocyclic Compounds toxicity, Insecticides toxicity
- Abstract
The results of the environmental toxicological investigations and their results of a new hungarian acaricide molecule (SZI-121) developed by the CHINOIN were summarized. The toxicological effects of the test item on different ecotoxicological test systems were investigated in the following tests: Bacterium, alga, and plant growth inhibition tests, acute immobilization and 21 days reproduction tests on Daphnia magna, acute fish test, closed bottle test, mobility, aerob degradation and adsorption/desorption tests on three different soils. No toxic effect was found in the bacterium, alga, plant growth inhibition and acute fish tests in the highest concentrations used. In the Daphnia immobilization test 0.14 mg/l LC50 value was established in the concentration range of 0.0128-40 mg/l applied. The test item showed similar characteristics as the reference item during the mobility test in soils, the adsorption/desorption study and the degradation investigations. In order to determine the environmental degradation rate further degradation investigations, as well as the nitrogen mineralization test and the model of concentration change in natural waters were performed.
- Published
- 2000
49. Results of the general toxicity and genetic studies of an insecticide intermediate.
- Author
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Béres E, Pasics I, Pap L, Hirka G, Sebestyén I, Oláh B, and Stáhl J
- Subjects
- Animals, CHO Cells, Chromosome Aberrations, Cricetinae, Eye drug effects, Female, Male, Rabbits, Rats, Salmonella typhimurium drug effects, Salmonella typhimurium genetics, Skin drug effects, Insecticides toxicity, Mutagens toxicity
- Abstract
Methyl-chrysanthemate is one of the intermediates of pyrethroid type insecticides. The acute toxicity of the test item was investigated in rats after single oral, dermal and inhalation applications. The irritation effect was determined by Draize method. Buehler method was applied to evaluate the sensitization potential of the test item. The mutagenic effect was assessed on Salmonella typhimurium strains. Furthermore metaphase chromosome aberration assay was performed on CHO cell line to check the structural chromosome aberrations.
- Published
- 2000
50. DNA-binding proteins that interact with the 19-base pair (CRE-like) element from the HCMV major immediate early promoter in differentiating human embryonal carcinoma cells.
- Author
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Rideg K, Hirka G, Prakash K, Bushar LM, Nothias JY, Weinmann R, Andrews PW, and Gönczöl E
- Subjects
- Antibodies, Monoclonal metabolism, Base Sequence, Binding Sites, Binding, Competitive, Cell Differentiation, Cyclic AMP metabolism, Humans, Leucine Zippers, Molecular Sequence Data, Tumor Cells, Cultured, Carcinoma, Embryonal pathology, Cytomegalovirus genetics, DNA-Binding Proteins metabolism, Genes, Immediate-Early, Neoplasm Proteins metabolism, Promoter Regions, Genetic
- Abstract
The pluripotent human embryonal carcinoma (EC) cell line NTERA-2 provides a useful tool for investigating cell differentiation in a way that is pertinent to the development of the early human embryo. The major immediate early (MIE) gene of human cytomegalovirus (HCMV), which is not transcribed in undifferentiated NTERA-2 EC cells but is transcribed in their differentiated derivatives, offers a model with which to study the developmental regulation of gene activity during the differentiation of these cells. We have investigated the regulatory activity of the cAMP response elements (CRE) and the activation protein (AP1) site found within several repeated 19-base-pair (bp) elements from the HCMV MIE promoter, and the developmental regulation of nuclear DNA-binding factors that interact with these sites. The 19-bp CRE but not the AP1 site is responsive to cAMP in undifferentiated NTERA-2 EC and its activity is enhanced upon differentiation. Nuclear proteins of the CREB, Fos, and Jun families bind to these sites, but, surprisingly, their levels only show limited regulation during NTERA-2 differentiation. This contrasts with results obtained with murine EC cells. However, additional and apparently novel proteins with molecular weights between 80,000 and 90,000, and binding specificities for both CRE and AP1 sites, were detected in undifferentiated EC cells. The activity of these proteins decreased markedly after differentiation, indicating their involvement in negative regulation of the CRE/AP1-like site in undifferentiated EC cells. This suggests novel members able to interact via leucine zippers with other members of the Jun-Fos-CREB family of DNA binding proteins that are also involved in this regulation.
- Published
- 1994
- Full Text
- View/download PDF
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