The influence of experimental administration of low zearalenone doses on the expression of Th1 and Th2 cytokines and on selected subpopulations of lymphocytes in intestinal lymph nodes

The aim of this study was to characterize the immune response taking place in ileocecal lymph nodes (ICLN) in control (n=15) and zearalenone (ZEN)-treated (n=15) pigs. The experiment was carried out over 42 days; a dose of 0.1 mg kg⁻¹ feed day⁻¹ of ZEN was administered to the animals. The dose used in the experiment was at a level where no adverse effects are observed (NOAEL) in the ovaries, uterus and vagina. ICLN samples for analysis were collected on the 14th, 28th and 42nd day of the experiment. The analysis of cytokine concentration in the tissues showed that pigs treated with ZEN had an increased level of cytokines produced by helper Th1 lymphocytes (IL-2, IL-12 and IFN- γ) on the 28th day of the experiment. The level of cytokines produced by helper Th2 lymphocytes (IL-4 and IL-10) was characterized by a statistically non-significant upward trend, as compared with the control group. Flow cytometry showed a linear decrease in the percentage of CD21+ B, CD2+ T and CD4+CD8- T cells and an increase in the percentage of CD8+CD4- and TCRγδ + T cells in pigs treated with ZEN. Both ZEN and α-ZEL (α-zearalenone) concentrations increased over time in the liver, but only ZEN concentration increased in ICLN. The results obtained demonstrate that a NOAEL concentration of ZEN shifts the immune response in pig ICLN towards Th1/Th17, probably with a simultaneous activation of M1 macrophages. Moreover, we observed an increase in humoral cytokine secretion; this can be explained by a negative feedback loop and a phenotypic switch of macrophages from M1 to M2, as well as a switch of immune response from Th1 to Th2 type. ZEN can therefore influence the process of cytokine secretion and the percentage of lymphocytes in ileocecal lymph nodes

Influence of fresh garlic (Allium sativum L.) juice on zebrafish (Danio rerio) embryos developmental effects

A higher sensitivity and the cytotoxic effects of garlic have been previously reported on culture cells. No studies, however, have investigated the developmental toxicity of fresh garlic in zebrafish model. In this study freshly made garlic juice, which chemically is a combination of sulphur containing compounds, was evaluated to investigate the developmental toxicity during a 5-day assay using zebrafish embryos, starting from 2 h post fertilization. The results showed that toxicity endpoints such as the hatching rate, survival rate, malformation rate and growth rate had a significant dose-response relationship with increasing concentrations of garlic juice. The average hatching rate and time to hatch of zebrafish exposed to lower concentrations (0.001% and less) were significantly increased around 48-60 h of treatment (P < 0.05), strongly emphasizing the acceleration of hatchability caused by garlic juice. Mortality was also increased with exposure to garlic, exhibiting the maximal toxicity after 12 h of exposure to the concentration of 0.08%. A significant reduction in the heart rate by 35.5% was recorded due to the higher concentrations of juice (above 0.01%) starting form 36-hour exposure (P < 0.05). Growth retardation, pericardial oedema with heart malformations, deformity of yolk, lack of pigmentation and body malformation have been noticed at the concentration of 0.03% starting from 48 h of exposure. No severe malformations in any of the experimental zebrafish were produced at concentrations less than 0.01% of garlic juice. The results indicate that developing zebrafish are sensitive to garlic juice and further studies are required to investigate the molecular basis of the observed effects that garlic constituents exert upon aquatic vertebrates

Influence of fresh garlic (Allium sativum L.) juice on zebrafish (Danio rerio) embryos developmental effects

A higher sensitivity and the cytotoxic effects of garlic have been previously reported on culture cells. No studies, however, have investigated the developmental toxicity of fresh garlic in zebrafish model. In this study freshly made garlic juice, which chemically is a combination of sulphur containing compounds, was evaluated to investigate the developmental toxicity during a 5-day assay using zebrafish embryos, starting from 2 h post fertilization. The results showed that toxicity endpoints such as the hatching rate, survival rate, malformation rate and growth rate had a significant dose-response relationship with increasing concentrations of garlic juice. The average hatching rate and time to hatch of zebrafish exposed to lower concentrations (0.001% and less) were significantly increased around 48-60 h of treatment (P < 0.05), strongly emphasizing the acceleration of hatchability caused by garlic juice. Mortality was also increased with exposure to garlic, exhibiting the maximal toxicity after 12 h of exposure to the concentration of 0.08%. A significant reduction in the heart rate by 35.5% was recorded due to the higher concentrations of juice (above 0.01%) starting form 36-hour exposure (P < 0.05). Growth retardation, pericardial oedema with heart malformations, deformity of yolk, lack of pigmentation and body malformation have been noticed at the concentration of 0.03% starting from 48 h of exposure. No severe malformations in any of the experimental zebrafish were produced at concentrations less than 0.01% of garlic juice. The results indicate that developing zebrafish are sensitive to garlic juice and further studies are required to investigate the molecular basis of the observed effects that garlic constituents exert upon aquatic vertebrates

The expression of mitochondrial, cytoplasmic and extracellular superoxide dismutase in the colonic wall of pigs suffering from swine dysenteria

The expression of 3 types of peroxide dismutase (SOD1, SOD2 and SOD3) was studied with Real-Time PCR in the colonic wall of domestic pig suffering from swine dysentery. The expression of enzymes was studied separately in the mucosa and the muscular membrane. It was found that in the mucosa the expression of SOD1 (cytoplasmic) did not change, while the levels of expression of mitochondrial SOD2 and extracellular SOD3 were raised in inflamed colon. More dramatic changes were seen in the muscular mebrane where expression of SOD1 rose twice, this of SOD2 rose ca. 5-fold and the expression of SOD3 rose dramatically, even 30-fold.The obtained data are contradictory to findings in other types of colonic inflammation, which were studied either in the whole colonic wall, or in mucosa alone. The results show a very strong reaction of antioxidant systems in the muscular membrane in the enteritis

Zebrafish: an animal model for research in veterinary medicine

The zebrafish (Danio rerio) has become known as an excellent model organism for studies of vertebrate biology, vertebrate genetics, embryonal development, diseases and drug screening. Nevertheless, there is still lack of detailed reports about usage of the zebrafish as a model in veterinary medicine. Comparing to other vertebrates, they can lay hundreds of eggs at weekly intervals, externally fertilized zebrafish embryos are accessible to observation and manipulation at all stages of their development, which makes possible to simplify the research techniques such as fate mapping, fluorescent tracer time-lapse lineage analysis and single cell transplantation. Although zebrafish are only 2.5 cm long, they are easy to maintain. Intraperitoneal and intracerebroventricular injections, blood sampling and measurement of food intake are possible to be carry out in adult zebrafish. Danio rerio is a useful animal model for neurobiology, developmental biology, drug research, virology, microbiology and genetics. A lot of diseases, for which the zebrafish is a perfect model organism, affect aquatic animals. For a part of them, like those caused by Mycobacterium marinum or Pseudoloma neutrophila, Danio rerio is a natural host, but the zebrafish is also susceptible to the most of fish diseases including Itch, Spring viraemia of carp and Infectious spleen and kidney necrosis. The zebrafish is commonly used in research of bacterial virulence. The zebrafish embryo allows for rapid, non-invasive and real time analysis of bacterial infections in a vertebrate host. Plenty of common pathogens can be examined using zebrafish model: Streptococcus iniae, Vibrio anguillarum or Listeria monocytogenes. The steps are taken to use the zebrafish also in fungal research, especially that dealing with Candida albicans and Cryptococcus neoformans. Although, the zebrafish is used commonly as an animal model to study diseases caused by external agents, it is also useful in studies of metabolic disorders including fatty liver disease and diabetes. The zebrafish is also a valuable tool as a model in behavioral studies connected with feeding, predator evasion, habituation and memory or lateralized control of behavior. The aim of the present article is to familiarize the reader with the possibilities of Danio rerio as an experimental model for veterinary medicine

The role of galanin during bacterial infection in larval zebrafish

Galanin is a peptide that is conserved among different species and plays various roles in an organism, although its entire role is not completely understood. For many years, galanin has been linked mainly with the neurotransmission in the nervous system; however, recent reports underline its role in immunity. Zebrafish (Danio rerio) is an intensively developing animal model to study infectious diseases. In this study, we used larval zebrafish to determine the role of galanin in bacterial infection. We showed that knockout of galanin in zebrafish leads to a higher bacterial burden and mortality during Mycobacterium marinum and Staphylococcus aureus infection, whereas administration of a galanin analogue, NAX 5055, improves the ability of fish to control the infection caused by both pathogens. Moreover, the transcriptomics data revealed that a lower number of genes were regulated in response to mycobacterial infection in gal−/− mutants compared with their gal+/+ wild-type counterparts. We also found that galanin deficiency led to significant changes in immune-related pathways, mostly connected with cytokine and chemokine functions. The results show that galanin acts not only as a neurotransmitter but is also involved in immune response to bacterial infections, demonstrating the complexity of the neuroendocrine system and its possible connection with immunity

The effect of T-2 toxin on percentages of CD4plus, CD8plus, CD4plusCD8plus and CD21plus lymphocytes, and mRNA expression levels of selected cytokines in porcine ileal Peyer’s patches

The immune system is one of the main toxicity targets of the T-2 toxin. In view of scant research data demonstrating the effect of T-2 on cellular and humoral responses in gut-associated lymphoid tissue (GALT), this study set out to investigate the effects of chronic exposure to low doses of the T-2 toxin (200 μg T-2 toxin kg⁻¹ feed) on percentages of CD4⁺ and CD8⁺ T lymphocytes, CD4⁺/CD8⁺ double-positive T lymphocytes, CD21⁺ B cells, and IL-2, IFN-γ, IL-4 and IL-10 mRNA expression levels in porcine ileal Peyer’s patches. The investigated material comprised ileum sections sampled from piglets (aged 8-10 weeks, body weight of 15-18 kg) on days 14, 28 and 42 of the experiment. After 42 days of exposure to T-2, a significant drop in the quantity of the IL-10 product was observed (R=0.94; S.E. 0.49-0.79; p<0.001). A gradual decrease in the amount of IL-4 and IFN-γ cytokine transcripts was found throughout the experiment, but the reported trend was not significant. On experimental days 14 and 42, a significant increase in the percentage of CD8⁺ T lymphocytes was observed in comparison with the control (p=0.04 and p=0.05, respectively), whereas on day 28, a significant decrease in the percentage of the above subpopulation was noted (p=0.00). The percentage of CD21⁺ B cells in the experimental group decreased steadily in comparison with the control, and the observed drop was significant on days 28 and 42 (p=0.06 and p=0.00, respectively). On days 14 and 28, the percentages of CD4⁺ and CD8⁺ T lymphocytes were lower in the experimental animals than in the control group, and the drop reported on day 28 was statistically significant (p=0.03)

Is the activity-based anorexia model a reliable method of presenting peripheral clinical features of anorexia nervosa?

Anorexia nervosa (AN) causes the highest number of deaths among all psychiatric disorders. Reduction in food intake and hyperactivity/increased anxiety observed in AN are also the core features of the activity-based anorexia animal model (ABA). Our aim was to assess how the acute ABA protocol mimics common AN complications, including gonadal and cardiovascular dysfunctions, depending on gender, age, and initial body weight, to form a comprehensive description of ABA as a reliable research tool. Wheel running, body weight, and food intake of adolescent female and male rats were monitored. Electrocardiography, heart rate variability, systolic blood pressure, and magnetic resonance imaging (MRI) measurements were performed. Immediately after euthanasia, tissue fragments and blood were collected for further analysis. Uterine weight was 2 times lower in ABA female rats, and ovarian tissue exhibited a reduced number of antral follicles and decreased expression of estrogen and progesterone receptors. Cardiovascular measurements revealed autonomic decompensation with prolongation of QRS complex and QT interval. The ABA model is a reliable research tool for presenting the breakdown of adaptation mechanisms observed in severe AN. Cardiac and hormonal features of ABA with underlying altered neuroendocrine pathways create a valid phenotype of a human disease