Curcumin modulates neurogliogenesis and purinergic receptor expression in neural precursor cells infected with Toxoplasma gondii.

Toxoplasma gondii is an obligate intracellular parasite that causes toxoplasmosis, and its congenital transmission is of paramount concern. During embryonic development, infection with the parasite causes irreversible damage to the still-forming fetus's central nervous system (CNS). In the pathogenesis of neurotoxoplasmosis, purinergic receptors prejudice neuroprotection, neuroinflammation, and activation of microbicide mechanisms against the parasitic vacuole. This study used curcumin as a treatment for neural precursor cells (NPCs) infected with T. gondii. The congenital toxoplasmosis induction consisted of maternal infection with the VEG strain, and NPCs were obtained from the telencephalon of mouse embryos. Curcumin at increasing concentrations was administered in vitro to analyze NPC metabolic activity, cell number, and size, as well as neurogliogenesis, proving to be effective in recovering the size of infected NPCs. Curcumin partially re-established impaired neurogenesis. Purinergic A1, A2A, and P2X7 receptors may be related to neuroprotection, neuroinflammatory control, and activation of mechanisms for inducing the parasite's death. ERK 1/2 was highly expressed in infected cells, while its expression rates decreased after the addition of the treatment, highlighting the possible anti-inflammatory action of curcumin. These findings suggest that curcumin treats neurological perturbations induced by toxoplasmosis.

Impact of free curcumin and curcumin nanocapsules on viability and oxidative status of neural cell lines.

Curcumin is an active polyphenol substance found in the highest concentrations in the roots of Curcuma longa. Its health benefits have led to recent increases in the consumption of curcumin. It has anti-inflammatory and antioxidant activities and is a potent neuroprotective against diseases of the brain. Nevertheless, its low bioavailability and its relative difficulty crossing the blood-brain barrier limit curcumin's use for these purposes. Curcumin-loaded nanoparticles may be an effective treatment for several diseases although there is a paucity of studies reporting its safety in the central nervous system (CNS). Therefore, this study aimed to identify non-neurotoxic concentrations of free curcumin and two nanoformulations of curcumin. Cell lines BV-2 and SH-SY5Y, both originating from the CNS, were evaluated after 24, 48, and 72 h of treatment with free curcumin and nanocapsules We measured viability, proliferation, and dsDNA levels. We measured levels of reactive oxygen species and nitric oxide as proxies for oxidative stress in culture supernatants. We found that free curcumin was toxic at 10 and 20 µM, principally at 72 h. Nanoformulations were more neurotoxic than the free form. Safe concentrations of free curcumin are between 1-5 µM, and these concentrations were lower for nanoformulations. We determined the ideal concentrations of free curcumin and nanocapsules serving as a basis for studies of injuries that affect the CNS.

Addition of chromium propionate in dog food: metabolic, immunological, and oxidative effects.

Chromium is a trace element essential in metabolising carbohydrates, lipids, and proteins and is involved in other biological functions. Therefore, this study determined whether chromium propionate supplementation in dogs improves haematologic, metabolic, immune/inflammatory, and antioxidant biomarkers. A commercial product (Labex® Chromium) containing 0.4% chromium was used at 500 g/ton of food, which provided an additional calculated amount of 2 mg of chromium per kg of food. We used ten beagles divided into two treatments: the chromium group (supplemented with 0.380 mg of chromium/dog/day; T-CHR) and the control group comprised dogs fed a basal diet (no chromium supplementation). The experiment included two periods of 28 days, with an interval of 15 days, i.e. the dogs in the control group in the first period were in the chromium group in the second period (all dogs underwent all treatments in a crossover design). Dogs supplemented with chromium had higher serum mineral levels on days 14 and 28 (P ≤ 0.001). The group in the chromium group showed significantly higher numbers of total leukocytes and lymphocytes and concentrations of total protein, globulin, thio-proteins, and catalase activity in blood than the control group. Serum urea concentrations and TBARS (lipid peroxidation) were lower (P ≤ 0.05) in the chromium group. Tendencies towards lower concentrations of reactive oxygen species were observed on day 28 in the T-CHR group (P = 0.10). Chromium supplementation increased the concentration of cytokines in serum (tumour necrosis factor-alpha [TNF-α], IFN-γ, and IL-10) and C-reactive protein (P ≤ 0.05). Dogs in the chromium group had higher gamma globulin concentrations than controls (P ≤ 0.001). These findings suggest that supplementation with chromium propionate (2 mg/kg) in food positivity modulates metabolic, antioxidant, and immune indicators in dogs.

Encapsulated pepper blend in the diet of confined Holstein bullocks: effect on ruminal volatile fatty acid profiles, growth performance, and animal health.

Dairy bulls in feedlots have been a viable alternative for dairy producers to reinforce the family's income. Aspects such as balanced diets and proper management are essential for these animals to develop and allow an economic return fully. Plant extracts are performance enhancers and ruminal and intestinal health promoters. Therefore, this study aims to evaluate whether the addition of encapsulated pepper (EP) blend (Capsicum annuum, Capsicum frutescens, and Capsicum chinense - rich in capsaicin) interferes with the volatile fatty acid profile in the rumen and enhances the growth performance of Holstein bullocks in a feedlot. For the experiment, 24 whole bullocks were used, distributed into three treatments, with eight replicates per treatment (one animal as an experimental unit, kept in an individual stall): groups T0, T200, and T400, receiving 0 mg, 200 mg, and 400 mg EP/kg of concentrate, respectively. Knowing the intake of concentrate and the average body weight during the experiment, we calculated the dose in mg/kg/day of the EP; that is, the T200 animals consumed 2.45 mg EP/kg (body weight -BW)/day; and T400 consumed 4.9 mg EP/kg BW/day. The animals from T400 presented a more significant weight gain between days 15 and 45 of confinement compared to T0 (P=0.05). This same treatment (T400) had a trend of lower weight gain between days 46 and 90 (P=0.09). Likewise, the T400 group had higher feed efficiency than T0 between days 15 and 45. Furthermore, the treatments affected the white blood cell count, with the T400 bullocks showing a higher number of neutrophils and lymphocytes. Higher levels of C-reactive protein (CRP) were measured in the serum of steers from both groups that consumed pepper (P<0.01). Interaction between treatment × day was observed for the activity of glutathione enzymes (GST and GPx) and levels of lipoperoxidation (LPO) (characterized by antioxidant stimulation) associated with the reduction in serum LPO; similar antioxidant enzymes behavior was observed in the liver. In the small intestine (jejunum), the activities of antioxidant enzymes (GST and GPx) were lower in the two groups of cattle that consumed EP, and LPO was lower. The treatments affected the concentration of acetic acid in the rumen fluid, presenting lower levels in T400 compared to T200 and similar T0 (P≤0.05). There was an interaction of day vs. treatment for propionic acid, presenting a higher concentration on day 45 at T400 than T0. These results, therefore, allow us to conclude that adding 400 mg of pepper extract can be an excellent additive for weight gain at the beginning of the experiment; however, over time, this dose of additive negatively affects weight gain. Both EP doses stimulated serum and tissue antioxidant responses, reducing lipoperoxidation. However, the 400 mg EP/kg concentrate suggests a pro-inflammatory response (leukocytosis and elevated CRP), s probably related to the high dose (i.e., between 1.7 and 2.4 g/animal/day).

Resveratrol impacts in oxidative stress in liver during Trypanosoma cruzi infection.

Trypanosoma cruzi is the causative agent of Chagas disease, infecting the heart, intestines and liver tissues. There is growing evidence that oxidative stress, defined as a persistent imbalance between highly oxidative compounds and antioxidant defenses, is a marker of tissue inflammation; it is related to immune responses such as damage, as well as to strand breaks in DNA contributing to disease progression. Antioxidant agents help mitigate the damage caused by inflammation, preventing or slowing damage to cells caused by free radicals. In this sense, resveratrol (RSV) is an important polyphenol that demonstrates antioxidant effects. It reverses damage caused by several infectious diseases. The aim of the present study was to determine whether treatment with RSV would prevent or minimize oxidative damage caused by T. cruzi. The animals were divided into four groups (n = 5): A) control; B) control + RSV; C) infected and D) infected + RSV. The infected groups received 1 x 104 Y strain trypomastigotes via intraperitoneal injection; after confirmation of infection, the mice received RSV 100 mg/kg for seven days orally. On the 8th day post-infection, we collected liver tissue for analysis of oxidant/antioxidant status: superoxide dismutase (SOD), catalase (CAT), and glutathione s-transferase (GST) activities, as well as reactive oxygen species (ROS), non-protein thiols (NPSH), thiols, carbonyl protein, thiobarbituric acid reactive substance (TBARS), and finally, the nitrite/nitrate ratio (NOx) levels were determined. The administration of RSV did not exert direct effect on parasitemia. The infection produced high levels of TBARS, NOx, and ROS levels in liver tissue, suggesting cellular injury with production of free radicals in animals infected by T. cruzi. RSV positively modulated SOD and aumenting GST activities enzymes in infected animals. Protein thiols levels in infected animals were lower than those of control. Taken together, the data suggest T. cruzi causes hepatic oxidative stress, and RSV 100 mg/kg for seven days it's dosen't seem minimized these negative effects in the acute phase of disease.

Involvement of ectonucleotidases and purinergic receptor expression during acute Chagas disease in the cortex of mice treated with resveratrol and benznidazole.

Chagas disease (CD) is caused by the parasite Trypanosoma cruzi. CD affects people worldwide, primarily in tropical areas. The central nervous system (CNS) is an essential site for T. cruzi persistence during infection. The protozoan may pass through the blood-brain barrier and may cause motor and cognitive neuronal damage. Once in the CNS, T. cruzi triggers immune responses that the purinergic system can regulate. Treatment for CD is based on benznidazole (BNZ); however, this agent has negative side-effects and is toxic to the host. For this reason, we investigated whether resveratrol (RSV), a potent antioxidant and neuroprotective molecule, would modulate purinergic signaling and RSV alone or in combination with BNZ would prevent changes in purinergic signaling and oxidative damage caused by T. cruzi. We infected mice with T. cruzi and treated them with RSV or BNZ for 8 days. Increases in ATP and ADP hydrolysis by NTPDase in the total cortex of infected animals were observed. The treatment with RSV in infected group diminished ATP, ADP, and AMP hydrolysis compared to infected group. The combination of RSV + BNZ decreased AMP hydrolysis in infected animals compared to the INF group, exerting an anti-inflammatory effect. RSV acted as a neuroprotector, decreasing adenosine levels. Infected animals presented an increase of P2X7 and A2A density of purine receptors. RSV reduced P2X7 and A2A and increased A1 density receptors in infected animals. In addition, infected animals showed higher TBARS and reactive oxygen species (ROS) levels than control. RSV diminished ROS levels in infected mice, possibly due to antioxidant properties. In short, we conclude that resveratrol could act as a neuroprotective molecule, probably preventing inflammatory changes caused by infection by T. cruzi, even though the mice experienced high levels of parasitemia.

Addition of a blend of essential oils (cloves, rosemary and oregano) and vitamin E to replace conventional chemical antioxidants in dog feed: effects on food quality and health of beagles.

This study aimed to produce dog food containing natural antioxidants (blend of essential oils and vitamin E) to replace synthetic antioxidants and determine the effects on food conservation and animal health sequentially. The foods were produced in a commercial factory, and the antioxidants were added at the oil bath stage. Ten adult beagle dogs were used, divided into two treatments; control treatment (CON; synthetic antioxidant feed [butylhydroxytoluene]) and test treatment (NAT; natural antioxidant feed; blend of essential oils from clove, rosemary, oregano, and vitamin E). The dogs were weighed at the beginning and end of each experimental period, and there were no treatment effects for body weight. In both treatments, food conservation efficiency was observed, demonstrating the feasibility of using natural sources as antioxidants in dog food because chemical and oxidative variables did not differ regardless of the antioxidant used during production. The animals' metabolic and haematological variables were not influenced by the treatments; however, a reduction in the number of lymphocytes was observed over time only in the dogs of the NAT group. There was also a day effect for total leukocyte, neutrophil and erythrocyte counts only in NAT animals, which means a significant increase (p ≤ 0.05) in the variables on d 28. There was an effect of the treatment and an interaction treatment x day for the total bacterial count, whereas a decrease in the bacterial count (p < 0.05) was observed in NAT dogs' faeces on day 28. Dogs fed the NAT diet had lower reactive oxygen species (ROS) (p ≤ 0.05) to minimise oxidative stress. In group NAT, the NPSH and glutathione S-transferase levels were increased, which may explain the decrease in ROS levels. It was concluded that natural antioxidants in dog feed, in addition to promoting feed conservation, stimulate levels of systemic antioxidants and minimise the impacts caused by free radicals in the dogs' blood.

Neuroprotective role of resveratrol mediated by purinergic signalling in cerebral cortex of mice infected by Toxoplasma gondii.

The central nervous system of the intermediate host plays a central role in lifelong persistence of Toxoplasma gondii as well as the pathogenesis of congenital toxoplasmosis and reactivated infection in immunocompromised individuals. The purinergic system has been implicated in a wide range of immunological pathways for controlling intracellular responses to pathogens, including T. gondii. In the present study, we investigated the effect of resveratrol (RSV) on ectonucleotidases, adenosine deaminase (ADA), and purinergic receptors during chronic infection by T. gondii. For this study, Swiss mice were divided into control (CTL), resveratrol (RSV), infected (INF), and INF+RSV groups. The animals were orally infected with the VEG strain and treated with RSV (100 mg/kg, orally). Ectonucleotidase activities, P2X7, P2Y1, A1, and A2A purinergic receptor density, ROS, and thiobarbituric acid reactive substances levels were measured in the cerebral cortex of mice. T. gondii infection increased NTPDase and reduced ADA activities. Treatment with RSV also affected enzymes hydrolysing extracellular nucleotides and nucleosides. Finally, RSV affected P1 and P2 purinergic receptor expression during T. gondii infection. Overall, RSV-mediated beneficial changes in purinergic signalling and oxidative stress, possibly improving cerebral cortex homeostasis in T. gondii infection.

Effect of heat treatment on pre-stocking of Turkey eggs and its impact on incubation and hatching.

Egg stocking is used to meet housing demands in the hatchery industry. Stocking periods longer than 10 days of occur commonly, despite the fact that this practice causes productive losses during the incubation process. To minimize these losses, eggs are heated before incubation to stimulate the embryo, thereby reducing the range of birth intervals. The objective of this study was to determine whether heat treatment (37.5 °C) prior to incubation would improve hatching rates. We also determined the heat-exposure time necessary to improve productivity. We stored 5376 Nicholas pedigree eggs, aged between 40 and 51 weeks, for seven days. These eggs were distributed in three groups: groups 1 and 2 received 4 and 6 h of heat treatment, respectively; group 3 was used as control (no heat treatment, remaining at 17 °C). After heat treatment, the eggs were stored for 7 days at 17 °C, together with eggs from the control group. We found significant variation in the cumulative dispersion of birds born during the hatch window; greater numbers of birds were born in group 1 that underwent the 4-h heat treatment with a 24-h hatch window and in group 3 that underwent the 6-h heat treatment with a 12-h hatch window. Hatch rate, yolk retention and the relationship between average chick weight/average egg weight did not differ between treatments. These data suggest that heat treatment modulates the hatch window; nevertheless, the treatment did not influence the average weight the chicks, the number of chicks born, the percentage of hatching or yolk retention.

Nitric oxide levels in brain, liver, and gills of silver catfish (Rhamdia quelen) exposed to the antiparasitic eprinomectin.

Nitric oxide (NO) is a mediator and biomarker of pro- and anti-inflammatory processes. Excessive levels of NO for long periods have been associated with inflammation and tissue damage. The metabolism and synthesis of NO is usually measured indirectly, as metabolites and enzymes involved in reactions, often as the nitrite/nitrate (NOx) level. The aim of the present study was to measure the NOx levels in vital organs of juvenile silver catfish (Rhamdia quelen) exposed to various levels of eprinomectin in the water. The fish were exposed for 24 and 48 h to start concentration (0 h) of eprinomectin in water (0.0, 1.12, 1.80, and 3.97 µg/L). The eprinomectin concentrations in water were lower at 24 h (0.0, 0.85, 1.14, and 1.15 µg/L) and 48 h (0.0, 0.39, 0.69, and 1.28 µg/L), due to the process of eprinomectin metabolization. Subsequently, the fish were left for 48 h of recovery in eprinomectin-free water. NO levels were measured indirectly, as NOx levels in brain, liver, and gill tissue. Within 24 h of exposure, there was no significant increase in NOx levels in the organs evaluated at any of the concentrations tested. However, increases in NOx levels did occur at 48 h of exposure in all organs, particularly at the two highest concentrations of eprinomectin (1.80 and 3.97 µg/L). The transfer of fish to eprinomectin-free water did not result in reversal of NOx levels after 48 h of recovery, especially in fish that had been exposed to the two highest concentrations in the brain and liver tissues, and for the highest concentration in the gills. We conclude that silver catfish exposed to eprinomectin for up to 48 h present possible cerebral, hepatic, and branchial inflammatory process associated with increased tissue NOx levels, and that recovery for 48 h in water without antiparasitic is insufficient for the fish to recover from the poisoning.

Reduction of stool bacterial counts and prevention of diarrhea using an oral homeopathic product in newborn lambs.

Lamb farming is generally a secondary activity for farmers, and many breeding systems suffer from management failures that impair production. One reason for decline in performance is enteritis, usually affecting newborn lambs. Enteritis can be fatal, especially in dairy herds. Generally, lambs are fed sucrose or unprocessed milk from sheep or cow that is heated and fed to animals two or three times a day in baby bottles. However, on most farms, milk temperature differs among feeds, as often the process of alteration among diet adaptations is deficient, contributing to enteritis and consequent diarrhea. Therefore, the objective of the present study was to verify the administration of the homeopathic product (Dia 100®) in newborn and bottle-fed lambs, in order to prevent or minimize the occurrence of diarrhea. We studied 60 lambs, divided into two groups with ten repetitions each (n = 30) and during the nursing period (1-45 days of life). Animals in the treated group received the homeopathic product (36 g) orally divided into three doses (1, 7 and 14 days of life). We measured weight gain, mortality, bacterial counts (Escherichia coli and total coliforms) in feces, hematological analysis (leukocytes, hematocrit, hemoglobin and erythrocytes) and biochemical analyses (glucose, triglycerides, cholesterol, albumin, globulin, urea and total protein) at four time-points. There were no differences in weight gain between groups (P > 0.05); however, there was a higher mortality rate in the control group (13%) than in the treated group (6%). E. coli counts were significantly higher in the stools of control group lambs on days 15 and 45 of the experiment (P < 0.05). Total leukocyte counts were greater in treated animals due to greater numbers of lymphocytes on day 15 of the experiment (P < 0.05). In the treated group, we found higher serum levels of total protein, urea (day 15), globulin and triglycerides (days 15 and 30). In the period of administration of the homeopathic product, there was substantial and significant reduction of cases of diarrhea (up to day 14); however, after this period, there were no difference between groups. Based on these results, we concluded that the homeopathic product had moderate efficacy in terms of control of diarrhea. The treated lambs made better use of nutrients, contributing to the development of their immune responses.

Resveratrol-mediated reversal of changes in purinergic signaling and immune response induced by Toxoplasma gondii infection of neural progenitor cells.

The effects of Toxoplasma gondii during embryonic development have not been explored despite the predilection of this parasite for neurons and glial cells. Here, we investigated the activation of the purinergic system and proinflammatory responses during congenital infection by T. gondii. Moreover, neuroprotective and neuromodulatory properties of resveratrol (RSV), a polyphenolic natural compound, were studied in infected neuronal progenitor cells (NPCs). For this study, NPCs were isolated from the telencephalon of infected mouse embryos and subjected to neurosphere culture in the presence of EGF and FGF2. ATP hydrolysis and adenosine deamination by adenosine deaminase activity were altered in conditions of T. gondii infection. P2X7 and adenosine A2A receptor expression rates were augmented in infected NPCs together with an increase of proinflammatory (INF-γ and TNF-α) and anti-inflammatory (IL-10) cytokine gene expression. Our results confirm that RSV counteracted T. gondii-promoted effects on enzymes hydrolyzing extracellular nucleotides and nucleosides and also upregulated P2X7 and A2A receptor expression and activity, modulating INF-γ, TNF-α, and IL-10 cytokine production, which plays an integral role in the immune response against T. gondii.

Evaluation of cytotoxicity, genotoxicity and ecotoxicity of nanoemulsions containing Mancozeb and Eugenol.

Mancozeb is a fungicide widely used in agriculture, mostly against the pathogen Glomerella cingulata responsible for the rot of ripe grape, but presents high toxicity. Strategies are sought to reduce the toxicity of this fungicide and alternative treatments are welcome. An alternative could be the use of clove oil, which has Eugenol as its major compound, and has antifungal potential against G. cingulata, however, Eugenol is susceptible to degradation processes which may compromise its efficacy. The nanoencapsulation of Mancozeb and Eugenol is a possible strategy to overcome the limitations of toxicity, solubility and instability of these compounds. Therefore, the objective of this study is to develop nanoemulsions containing Mancozeb (0.1 mg/mL) and Eugenol (33 mg/mL), isolated or associated, and evaluate the safety of these formulations through cytotoxicity, genotoxicity and ecotoxicity tests. Nanoemulsions were developed by the spontaneous emulsification method, cytotoxicity and genotoxicity were evaluated in healthy human cells through MTT, Dichlorofluorescein diacetate and Picogreen tests, and ecotoxicity assessment was carried out using the chronic toxicity test in springtails. After preparation, the physicochemical characterization of the nanoemulsions were performed which presented mean particle size between 200 and 300 nm, polydispersity index less than 0.3, negative zeta potential and acid pH. The nanoencapsulation was able to avoid the reduction of the cell viability caused by Mancozeb, while Eugenol was shown to be safe for cell use in both free and nanostructured forms, however the association of the two active compounds showed toxicity in the higher doses of Mancozeb. In the ecotoxicity tests, both free Mancozeb and Eugenol forms presented high toxic potential for soil, whereas the nanoencapsulation of these compounds did not cause a reduction in number of springtails. Therefore, from the tests performed, it was possible to observe that nanoencapsulation of Mancozeb and Eugenol is a safe alternative for the application of these compounds mainly in agriculture.

Post-weaning piglets fed with different levels of fungal mycotoxins and spray-dried porcine plasma have improved weight gain, feed intake and reduced diarrhea incidence.

Mycotoxins are responsible for economic losses in the swine production industry, especially during post-weaning, when piglets are physiologically immature. Spray-dried porcine plasma (SDPP), added to pig diets, may help reduce losses due to mycotoxins. This work investigates the effects of SDPP in post-weaning piglets fed with diets containing natural contaminants or with more contaminants (co-contamination by mycotoxins). Fifty-six castrated weaned piglets were used in a randomized 2 (0 and 6% of SDPP) x 2 (natural contamination or co-contamination with mycotoxin) factorial design, with seven experimental units of two piglets each. The natural contaminants were 0.95 µg/kg aflatoxins +450 µg/kg fumonisins. The co-contaminated diet contained 300 µg/kg aflatoxins +8000 µg/kg fumonisins. Animals were fed 15 days with experimental diets. Feed intake, weight gain, feed efficiency, diarrhea incidence, and economic feasibility of SDPP treatement were evaluated in three periods of five days each. There was no interaction (P < 0.05) between mycotoxins levels and SDPP. Feed intake, weight gain and feed efficiency were higher (P < 0.05) in diets supplemented with SDPP. Animals fed with SDPP showed lower (P < 0.05) diarrhea incidence in the 1-10 day and 1-15 day periods. The experimental dose of mycotoxins reduced (P < 0.05) weight gain at 11-15 days. SDPP proved to be economical feasible over the total experimental period (1-15 days). Spray-dried plasma improved weight gain, feed intake and reduced diarrhea incidence in piglets post-weaning, but did not correlate with various levels of mycotoxins.

Listeria monocytogenes impairs enzymes of the phosphotransfer network and alters antioxidant/oxidant status in cattle brain structures.

Several evidences have suggested the involvement of enzymes belonging to the phosphotransfer network, formed by creatine kinase (CK), pyruvate kinase (PK) and adenylate kinase (AK), as well the oxidative stress on the pathogenesis of infectious diseases associated with the central nervous system (CNS). Thus, the aim of this study was to evaluate whether listeriosis alters the brain energy metabolism and/or causes oxidative stress in different brain structures of cattle experimentally infected by Listeria monocytogenes. The cytosolic CK activity was inhibited in the cerebral cortex, cerebellum, brainstem and hippocampus of infected animals compared to uninfected animals, while the mitochondrial CK activity was increased. The PK activity was inhibited in all brain structures of infected animals, while the AK activity was unchanged. Na+, K+-ATPase activity decreased in the cerebral cortex, cerebellum and hippocampus of animals infected by L. monocytogenes. Regarding the oxidative strees variables, the cerebellum and brainstem of infected animals showed increased thiobarbituric acid reactive substances, while the catalase activity was inhibited. Glutathione S-transferarase was inhibited in the cerebral cortex and brainstem of infected animals, and it was increased in the cerebellum. L. monocytogenes was quantified in the liver (n = 5/5) and cerebral cortex (n = 4/5) of the infected cattle. Based on these evidences, the nucleocytoplasmic communication between CK isoenzymes was insufficient to avoid an impairment of cerebral bioenergetics. Moreover, the inhibition on brain PK activity caused an impairment in the communication between sites of ATP generation and ATP utilization. The lipid peroxidation and alteration on antioxidant status observed in some brain structures were also involved during the disease. In summary, these alterations contribute to disease pathogenesis linked to CNS during cattle listeriosis.

Surface immunoglobulins of erythrocytes and platelets in dogs naturally infected by Rangelia vitalii.

Rangelia vitalii is a protozoan of the Babesiidae family that parasitizes domestic and wild dogs in South American countries. The main laboratory findings in blood samples from animals infected by R. vitalii are anemia and thrombocytopenia. The aim of this study was to detect IgM and IgG immunoglobulins on the surface of red blood cells and platelets, as well as to determine the percentage of reticulated platelets and reticulocytes in dogs naturally infected by R. vitalii. Blood samples from twenty dogs seen at the Veterinary Hospital of the Federal University of Santa Maria (UFSM) were divided into two groups: the diseased group consisted of blood samples from 10 animals with the diagnosis of rangeliosis, and the healthy group (control) consisted of samples from 10 healthy animals. All diseased dogs showed normocytic normochromic anemia but showed no differences (p > 0.05) in reticulocyte counts compared to healthy dogs. Moreover, IgM and IgG immunoglobulins were detected on the surface of the plasma membrane of red blood cells from both groups, but the amounts did not differ between groups (p > 0.05). Thrombocytopenia in infected animals was classified as severe. The percentage of reticulated platelets was higher (p < 0.001) in diseased dogs than in healthy animals. Diseased animals showed more IgM immunoglobulins bound to the surface of platelets than did the healthy group (p < 0.001). However, the amount of IgG bound to the surface of platelets was not different between groups. In conclusion, we showed that R. vitalii caused immune-mediated thrombocytopenia since IgM immunoglobulins were found on the surface of platelets of diseased dogs. We suggest that the binding of immunoglobulins on platelet surfaces contributes to early destruction of these cells and, consequently, alterations in hemostasis. An increase in reticulated platelets was noted in response to thrombocytopenia, indicating active thrombopoiesis.

Secnidazole for control of giardiasis in dairy calves.

The aim of this study was to verify whether secnidazole, given in a single oral dose (10 mg/kg), decreases or eliminates the excretion of Giardia duodenalis cysts. Holstein calves were raised from birth to 15 ±â€¯2 days of age in individual stalls. Subsequently, 12 calves were grouped and housed in collective stalls. After seven days (day of life 21), we collected stool samples directly from the rectal ampulla in order to determine the degree of parasitic infection. Fecal examination was performed by a centrifugal-flotation technique, which allows for visualization and quantification of G. duodenalis cysts. After division into control and treatment groups, six animals were treated with one 400 mg secnidazole capsule. The first stool collection following treatment was performed on day 5 and the second on day 30. This experiment was repeated at 15 days, with a total of 24 calves studied. Animals on the farm where the experiment was conducted often suffer from giardiasis, despite hygiene care (disinfection) and adequate facilities. All 24 calves were excreting G. duodenalis cysts prior to starting treatment. Five days after receiving the treatment, animals in the experiment group were Giardia-negative, i.e., they did not excrete parasite cysts, whereas calves in the control group continued to excrete cysts. After 30 days of treatment, the stool of most treated animals (83.3%) remained free of G. duodenalis cysts. Therefore, we believe that secnidazole was 100% effective in eliminating the excretion of Giardia duodenalis cysts.

Ecotoxicological effects of fipronil, neem cake and neem extract in edaphic organisms from tropical soil.

Veterinary medicines are widely applied for the treatment and prevention of animal diseases. Consequently, animal manure contains significant amounts of environmental pollutants that are potential sources of environmental pollution when inappropriately applied in soils. This work aimed to evaluate ecotoxicological effects of doses of commercial fipronil, neem cake and neem extract in the survival and reproduction of earthworms (Eisenia andrei), enchytraeidae (Enchytraeus crypticus) and springtails (Folsomia candida) in Oxisol and tropical artificial soil (TAS). Applications of fipronil, neem cake and extract in soil were carried out according to standardized ISO methodologies by using a random experimental design with five replicates. Toxic effects of fipronil for springtails in Oxisol and TAS were observed with LC50 of 0.26 mg kg-1 (0.18-0.35 mg kg-1) and 0.29 mg kg-1 (0.22-0.37 mg kg-1), respectively. It was not observed significant toxic effects of fipronil for earthworms and enchytraeidae in both soils. However, significant amounts of juvenile earthworm and adult enchytraeidae decreased in fipronil doses higher than 10 mg kg-1. Neem cake and extract were not toxic for earthworms and enchytraeidae but, significant amounts of juvenile springtails decreased in neem cake doses from 500 to 1000 mg kg-1. It can be concluded that the use of veterinary medicines containing synthetic compounds for preventing diseases in animals needs to be controlled to avoid environmental pollution after applying manure in soil. Veterinary medicines containing natural compounds as neem cake and extract are eco-friendly and could be efficiently applied in soil in a sustainable way.

Hepatic xanthine oxidase activity and purine nucleosides levels as physiological mediators to analyze a subcutaneous treatment with (PhSe)2 in mice infected by Toxoplasma gondii.

The aim of this study was to evaluate the levels of purine nucleosides and xanthine oxidase (XO) activity in the liver of mice chronically infected by Toxoplasma gondii and treated with diphenyl diselenide (PhSe)2. For this experiment, forty Swiss mice were used. Twenty animals were orally infected by approximately 50 bradizoites of a cystogenic ME-49 strain of T. gondii, and the same number of uninfected mice was used as a control group. Ten infected and ten uninfected mice were subcutaneously treated twice (days 1 and 20 post-infection (PI)) with 5 µmol kg-1 of (PhSe)2. On day 30 PI, liver samples were collected to measure the levels of hypoxanthine (HYPO), xanthine (XAN), uric acid (UA), and XO activity. Infected animals showed increased (P < 0.05) levels of hepatic XAN and UA, as well as XO activity compared to uninfected animals. The use of (PhSe)2 in healthy mice increased the levels of all nucleosides, but decreased XO activity compared to healthy untreated animals. The group of infected and treated animals showed increased XAN and UA levels, and XO activity compared to the healthy control group, however infected and treated mice showed a decrease in the XO activity compared to the infected untreated group. We conclude that chronic infection caused by T. gondii can induce hepatic changes, such as increased UA levels and XO activity, that can increase the pro-oxidative profile. The (PhSe)2 treatment of healthy animals altered the levels of nucleosides, possibly due to low XO activity that decreased nucleoside degradation. Finally, (PhSe)2 treatment decreased XO activity in the infected group and increased nucleoside levels; however it was unable to reduce the UA levels found during the infection.

Aflatoxins produced by Aspergillus parasiticus present in the diet of quails increase the activities of cholinesterase and adenosine deaminase.

The aim of this study was to evaluate the effects of aflatoxins on cholinesterases (acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), and adenosine deaminase (ADA) activities in quails. For this, twenty male quails were randomly distributed into two groups (n = 10 each): the group A was composed by quails that received feed without aflatoxin (the control group); while the group B was composed by quails that received feed contaminated with 200 ppm/kg of feed of aflatoxin. On day 20, the animals were euthanized to measure the activities of AChE (total blood and brain), BChE (serum) and ADA (serum, liver, and brain), as well as for histopathological analyses (liver and intestine). AChE, BChE, and ADA levels increased in animals intoxicated by aflatoxin compared to the control group. The presence of aflatoxin lead to severe hydropic degeneration of hepatocytes and small focus of hepatocyte necrosis. In conclusion, aflatoxins poisoning increased AChE, BChE, and ADA activities, suggesting the involvement of these enzymes during this type of intoxication, in addition to the fact that they are well known molecules that participate in physiological and pathological events as inflammatory mediators. In summary, increased AChE, BChE and ADA activities contribute directly to the inflammatory process and tissue damage, and they might be involved in disease development.