Search NEL Online

Journal Article 2014; 35(Suppl 2): 158-168 PubMed PMID: 25638381 Citation  Keywords:  Animals, Benzo(a)pyrene:administration & dosage, Carcinogens:administration & dosage, DNA Adducts:administration & dosage, Flavonols:administration & dosage, Male, Rats, Rats, Wistar,.   

trong>OBJECTIVES:trong> Flavanol dihydromyricetin (DHM) has been shown to counteract acute ethanol (EtOH) intoxication and reduce excessive EtOH consumption. Since this flavonoid is being considered for human use, the in vivo study of DHM interactions with the cytochrome P450 (CYP) multienzyme system in the respect of metabolic activation of a model food-born carcinogen, benzo[a]pyrene (BaP), is of high importance. Flavonoids of known properties, alpha-naphthoflavone (ANF) and beta-naphthoflavone (BNF) were included into the study to compare their and DHM effects on BaP-DNA adduct formation. METH0 DS: The flavonoids were administered by oral gavage either 72 hrs prior or simultaneously with a single dose of BaP to experimental rats. The expression of CYP1A1/2 enzymes was examined based on the enzymatic activity with a marker substrate, 7-ethoxyresorufin, and on Western blots. The nuclease P1 version of the 32P-postlabeling assay was used to detect and quantify covalent DNA adducts formed by BaP.

trong>RESULTS:trong> Treatment of rats with a single dose of DHM or ANF prior to or simultaneously with BaP did not produce an increase in levels of CYP1A1 and in formation of BaP-DNA adducts in liver. BNF, a known inducer of CYP1A1, showed a synergistic effect on BaP-mediated CYP1A1 induction and BaP activation in liver. Contrary to that, in small intestine the stimulatory effect of BNF on both parameters was not detected. Animal pre-treatment with DHM or ANF before BaP administration resulted in a significant elevation of BaP-DNA adducts, namely in the distal part of small intestine, while the CYP1A1 mediated 7-ethoxyresorufin-O-deethylation (EROD) was decreased markedly. It is important to note that under all regimens of animal treatment, DHM or ANF produced the higher inhibitory effect on the BaP-DNA adduct formation and BaP-induced EROD activity of CYP1A1 when administered simultaneously than sequentially with BaP. Our data show that DHM or ANF did not enhance the BaP-activation leading to BaP-mediated genotoxicity (the formation of BaP-DNA adducts) in rat liver, however, in small intestine the pretreatment of rats with these flavonoids may enhance BaP genotoxicity.

trong>CONCLUSIONS:trong> The data indicate that the intake of DHM prior to or simultaneously with the administration of BaP may increase the risk of a BaP-induced tumorigenesis in small intestine.

...

Read abstract  Full text PDF

Journal Article 2014; 35(Suppl 2): 141-148 PubMed PMID: 25638378 Citation  Keywords:  Animals, Electron Transport Complex II:drug effects, Formazans:metabolism, Interferon-gamma:pharmacology, Mice, Mice, Inbred C57BL, Peritoneum:cytology, Pyrimidines:pharmacology, Spleen:cytology,.   

trong>OBJECTIVES:trong> Formation of formazan is a commonly used measure of cytotoxicity of compounds. It is a product of reduction of tetrazolium salts such as 4-[3- (4-iodophenyl)-2- (4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST-1) and 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyltetrazolium chloride. The extent of substrates reduction reflects the activity of enzymes succinate dehydrogenase (SDH; respiratory complex II) and lactate dehydrogenase (LDH), respectively. The aim of present study was a) to investigate formazan formation under the conditions of in vitro stimulation of cells with interferon-γ (IFN-γ) and lipopolysaccharide (LPS), and b) to analyse possible interference of pyrimidine analogues with formazan production.

trong>METHODS:trong> Peritoneal cells and splenocytes were obtained from C57BL/6 mice. They were cultured at 37 degrees C, 5% CO2 in humidified incubator. Levels of formazan were determined at the interval of 24 h of culture using the WST-1 and LDH assays. Nitric oxide (NO) was activated by IFN-γ plus LPS and assayed by Griess reagent 24 h afterwards. Pyrimidines were applied concomitantly with immunostimulatory agents.

trong>RESULTS:trong> IFN-γ enhanced concentration of SDH-produced formazan by macrophages (not by splenocytes) by approximately 50%. The activity of LDH remained unaffected. LPS was ineffective in both cases. While pyrimidines with NO-inhibitory properties suppressed the IFN-γ-enhanced levels of SDH-produced formazan, they did not change the LDH-dependent formazan production.

trong>CONCLUSION:trong> IFN-γ augments the SDH-produced formazan by macrophages. It does not change the LDH-dependent formazan formation. The enhancing effect may have a significant impact upon the appropriate interpretation of cytotoxic properties of drugs investigated under the conditions of immune stimulation of cells.

...

Read abstract  Full text PDF

Journal Article 2014; 35(Suppl 2): 133-140 PubMed PMID: 25638377 Citation  Keywords:  Animals, Cosmetics:toxicity, Eye Diseases:chemically induced, Humans, In Vitro Techniques, Irritants:toxicity, Skin Diseases:chemically induced,.   

trong>BACKGROUND:trong> The aim of this study was to compare human and animal skin irritation data with results of selected in vitro methods, including HET-CAM test, Neutral Red Release Assay, Neutral Red Uptake Assay and EpiOcular eye irritation test and with already existing data of eye irritation obtained from animal experiments.

trong>METHODS:trong> Chemicals employed in previous skin irritation validation studies and commercially available cosmetic formulations were subjected to further testing using in vitro methods Neutral Red Release (NRR) assay, Neutral Red Uptake (NRU) assay, HET-CAM test and EpiOcular assay.

trong>RESULTS:trong> The study revealed that skin irritants are not necessarily eye irritants; specifically volatile or solid materials may be misclassified. NRR assay provided false negative results in case of substances with fixative effect or not removable under standard washing procedure, emphasizing the role of microscopical evaluation as a crucial additional endpoint. Although overpredictive, HET-CAM test provided the lowest false negative rate. The most aggressive cosmetic formulation was correctly identified by EpiOcular assay, in accordance with NRU and NRR assays results, while HET-CAM test correctly identified the mildest formulation.

trong>CONCLUSIONS:trong> Each of the in vitro methods is related to a specific endpoint of ocular irritation and provides only partial information on the mode of action of the tested material. Despite good reproducibility of individual in vitro assays, only the weight-of-evidence approach and results of multiple selected in vitro tests can allow for estimation of eye irritation hazard in vivo.

...

Read abstract  Full text PDF

Journal Article 2014; 35(Suppl 2): 99-104 PubMed PMID: 25638373 Citation  Keywords:  Animals, Antibodies:immunology, Bacterial Infections:prevention & control, Cell Line, Chickens, Egg Yolk:immunology, Epithelial Cells:immunology, Humans, Immunoglobulin Fab Fragments:immunology, Immunoglobulins:immunology, Inflammation:immunology, Lung:im.   

trong>OBJECTIVES:trong> As an alternative therapeutic approach for the prevention and treatment of bacterial infections with P. aeruginosa of cystic fibrosis (CF) patients, chicken yolk antibodies (IgY) could be used. The most significant advantage of IgY, in contrast to mammalian IgG, consists in the fact, that when bound to the antigen, they usually do not induce inflammatory reaction. In addition, the simplicity of egg production and the ease of IgY preparation makes this kind of antibody an excellent tool for passive immunization. Thus, the aim of our project was to study the effect of IgY and its Fab fragment on the potential induction of pro-inflammatory reactions in lung epithelial cells.

trong>METHODS:trong> Chicken IgY were prepared from pooled egg yolks. Fab fragmens of IgY were purified from the papain digest of IgY using DEAE-Sephacel ion exchange chromatography. Their purity was verified by SDS electrophoresis in polyacrylamide gel. Immortalized human cell lines, CuFi (CF patient) and NuLi (healthy subject), and A549 (human adenocarcinoma cells) were exposed to IgY, Fab, OVA, LPS (positive control), PBS (negative control), and human and goat IgG for 24 hours. The concentration of pro-inflammatory cytokines TNF-α, IL-1β, IL-6 and GM-CSF were determined in cell media using the BioPlex method, which enables the quantification of multiple analytes simultaneously in one sample.

trong>RESULTS:trong> Our results show that i) the Fab fragment induced levels of some proinflammatory cytokines, when compared to the PBS control, whereas ii) chicken IgYs did not induce any notable production of pro-inflammatory cytokines in contrast to intense effect of LPS on TNF-α and GM-CSF. In summary, our data show that levels of all cytokines are comparable with physiological values in human serum except of IL-1β, which concentration in cell medium was markedly elevated by Fab fragment.

trong>CONCLUSIONS:trong> The present data indicate that IgY are not inflammatory for lung cells and thus they are possibly applicable for prevention of airway bacterial infections.

...

Read abstract  Full text PDF

Journal Article 2014; 35(Suppl 2): 93-98 PubMed PMID: 25638372 Citation  Keywords:  Animals, Astacoidea:drug effects, Embryo, Nonmammalian:drug effects, Herbicides:toxicity, Prometryne:toxicity,.   

trong>OBJECTIVES:trong> The aim of this study is to assess the toxicity of prometryne in early life stages of marbled crayfish (Procambarus fallax f. virginalis) on the basis of mortality, early ontogeny, growth rate, and histopathology during and at the end of the test.

trong>DESIGN:trong> The early life stages of marbled crayfish were exposed to prometryne at four concentrations, 0.51, (reported concentration in Czech rivers), 144, 1440, and 4320 μg x l(-1) for 53 days and compared to crayfish in a non-treated control group. RESU LTS: Prometryne in concentration 144, 1444 and 4320 μg x l(-1) caused decrease of weight and specific growth rates of crayfish. Crayfish exposed the highest concentration 4320 μg x l(-1) showed delay in ontogeny development. All crayfish groups exposed to prometryne showed histopathological changes in gill. On the basis of histopathological changes the values of LOEC = 0.51 μg x l(-1) and NOEC = for 0.10 μg x l(-1) of prometryne for marbled crayfish juveniles was estimated.

trong>CONCLUSIONS:trong> Chronic exposure of prometryne on early life stages of crayfish has affected their mortality, growth rate, and histology. Some of the changes were observed only at higher exposures (144, 1444 and 4320 μg x l(-1)), but histopathological changes in gills were observed also in crayfish exposed to the real environmental concentration in Czech rivers (i.e. 0.51 μg x l(-1)), which is about 9 times lower than maximal concentration (4.40 μg x l(-1)) reported in surface waters of Greece. Concentrations of prometryne in World rivers have been reported to generally vary in the range of 0.1-4.40 μg x l(-1).

...

Read abstract  Full text PDF

Journal Article 2014; 35(Suppl 2): 71-80 PubMed PMID: 25638369 Citation  Keywords:  Animals, Antioxidants:pharmacology, Carotenoids:pharmacology, Carps:metabolism, Chloramines:pharmacology, Diet, Oxidative Stress:drug effects, Sulfonamides:pharmacology, Tosyl Compounds:pharmacology,.   

trong>OBJECTIVES:trong> In fish aquaculture, disinfectants are used against bacterial and protozoal infections. These compounds cause oxidative stress that may stimulate the generation of reactive oxygen species, and subsequently the alteration in antioxidant systems of exposed organisms. Antioxidants like carotenoids present in microalgae increase carp resistance to oxidative stress after chemical treatment.

trong>DESIGN:trong> The aim of these experiments was to prove increased resistance of common carp (Cyprinus carpio L.) juveniles fed on experimental diets with microalgae biomass supplement (Algadiets) to oxidative stress caused by a disinfectant chloramine-T. In indoor experiments fish were fed on laboratory-prepared extruded diets containing supplement of Chlorella spp. (cf. C. vulgaris Beijerinck) biomass which contains antioxidants (carotenoids) like lutein. The young-of-the-year-old fish were acclimatized and fed on basal diet (control group) and the on diets containing 1, 2, 5 and 10% (w/w) of spray-dried Chlorella biomass (Algadiet 1, 2, 5 and 10) for 14 days followed by 6 weeks. Consequently, fish were treated daily with chloramine-T (Chl-T) at concentration of 10 mg x l(-1) for 1 h in three consecutive days. After this treatment, the indices of oxidative stress and antioxidant enzyme activity were assayed in fish gill, muscle and hepatopancreas.

trong>RESULTS:trong> The fish fed on different Algadiets had increased antioxidant enzyme activities of glutathione peroxidase, glutathione reductase and catalase in flesh after the exposure to Chl-T. Higher activities of superoxide dismutase, glutathione peroxidase and glutathione reductase were also observed in the hepatopancreas in all tested concentrations compared to the control group fed on the basal diet. The increased production and activity of antioxidant enzymes confirmed improved protection ability of fish tissues against oxidative damage when microalgae biomass was supplemented to the fish diet which was more pronounced by higher microalgae supplement in Algadiet 5 and 10 where the content of carotenoids was 105 mg and 214 mg per kilogram of fed, respectively.

trong>CONCLUSION:trong> The results show the positive effect of carotenoids from microalgae biomass to maintain the antioxidant capacity which increases resistance of fish to oxidative stress.

...

Read abstract  Full text PDF

Journal Article 2014; 35(Suppl 2): 64-70 PubMed PMID: 25638368 Citation  Keywords:  Animals, Anti-Bacterial Agents:toxicity, Ciprofloxacin:toxicity, Oxidative Stress:drug effects, Toxicity Tests, Subchronic, Zebrafish,.   

trong>OBJECTIVES:trong> The aim of this study was to assess the impact of ciprofloxacin in Danio rerio on growth, on the development of histopathological changes in selected organs (gills, kidney, liver), and on the activity of some oxidative stress markers during a 28-day toxicity test.

trong>METHODS:trong> Juvenile growth tests were performed on D. rerio according to OECD guideline No. 215. Fish at the age of 30 days were exposed for 28 days to a range of concentrations of ciprofloxacin (0.7 μg x L(-1)--environmental concentration, 100, 650, 1100 and 3 000 μg x L(-1)).

trong>RESULTS:trong> There were no significant differences between the specific growth rates of fish from the test groups and from the control group. Histopathological examination revealed no pathological changes in organs of fish exposed to any ciprofloxacin concentration. The activity of glutathione S-transferase increased at the ciprofloxacin concentrations of 0.7 and 100 μg x L(-1) compared to the control. A significant decrease in glutathione reductase activity was obtained in fish exposed to ciprofloxacin at 1100 and 3000 μg x L(-1); a significant decrease in glutathione peroxidase activity was also found, but at all tested concentrations except for 100 μg x L(-1). A decrease in the concentration of thiobarbituric acid reactive substances was noted only at 100 μg x L(-1) compared to the control.

trong>CONCLUSIONS:trong> According to our results, all tested concentrations of ciprofloxacin, including the environmental concentration, had an influence on oxidative stress markers and detoxifying enzymes in exposed fish, but did not affect fish growth or cause the development of histopathological changes in the fish organism.

...

Read abstract  Full text PDF

Journal Article 2014; 35(Suppl 2): 51-56 PubMed PMID: 25638366 Citation  Keywords:  Animals, Astacoidea:drug effects, Environmental Exposure:adverse effects, Herbicides:toxicity, Toxicity Tests, Subchronic, Triazines:toxicity, Water Pollutants, Chemical:toxicity, Water Pollution, Chemical:adverse effects,.   

trong>OBJECTIVES:trong> The aim of the study was to investigate effects of the triazine herbicide metribuzin on signal crayfish Pacifastacus leniusculus Dana by determining oxidative stress (thiobarbituric acid reactive substances) and antioxidant indices (total superoxide dismutase, catalase, glutathione reductase) in hepatopancreas, muscle, and gill as well as assessing their histopathology.

trong>DESIGN:trong> Crayfish were exposed to metribuzin concentrations of 0.52 μg x l(-1) (realistic environmental concentration) and 3.06 mg x l(-1) (10% 96hLC50) for 10 and 30 days followed by a 30-day depuration period without exposure to metribuzin.

trong>RESULTS:trong> In the thiobarbituric acid reactive substances, superoxide dismutase, and catalase were observed differences in all examined tissues compared to the control group. Differences from control were observed in glutathione reductase activity in hepatopancreas after 10 days for both exposure concentrations and after 30 days at 3.06 mg x l(-1). Histological examination revealed extensive focal autolytic disintegration of tubular epithelium in hepatopancreas of crayfish exposed to metribuzin for 30 days.

trong>CONCLUSIONS:trong> Chronic exposure of metribuzin resulted in oxidative damage to cell lipids, in changes of antioxidant activity in crayfish tissue, and pathological changes in hepatopancreas. The results suggest that selected oxidative stress biomarkers, antioxidant enzymes, and pathologies of hepatopancreas may have potential as biomarkers for monitoring residual triazine herbicides in the aquatic environment.

...

Read abstract  Full text PDF