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The aim of this study was to evaluate the anesthetic efficacy of tea tree oil (TTO; Melaleuca alternifolia) and its three main compounds: terpinen-4-ol, γ-terpinene, and α-terpinene, in silver catfish (Rhamdia quelen). We also aimed to investigate which of these compounds may be responsible for the anesthetic effect, as well as the effect of prolonged exposure on oxidative parameters. Fish were exposed to 100, 300, 500, 800, and 1000 μL L− 1 of TTO, and the corresponding concentrations of terpinen-4-ol, γ-terpinene, and α-terpinene in TTO; anesthesia induction time was recorded based on fish behavior. Anesthesia induction time with 300–1000 μL L− 1 TTO was 185–1.512 s, and with terpinen-4-ol was 103–630 s; for both, the recovery time was 134–673 s. The monoterpenes α-terpinene and γ-terpinene were incapable of causing sedation and anesthesia in R. quelen, but presented with an antagonistic effect when used in association with terpinen-4-ol. Based on this evidence, it can be concluded that terpinen-4-ol itself caused an anesthetic effect, and therefore, can be considered the compound responsible for the anesthetic effect of TTO. Long-term (6 h) exposure to TTO (25 μL L− 1) and terpinen-4-ol (42 μL L− 1) reduced thiobarbituric acid-reactive substances levels in the liver, and terpinen-4-ol (42 and 20 μL L− 1) reduced lipid hydroperoxide in the liver and kidney. Glutathione-S-transferase activity demonstrated an increase in the liver of silver catfish exposed to terpinen-4-ol (20 and 42 μL L− 1), and increased in the kidney of silver catfish exposed to TTO at concentration of 25 μL L− 1 compared to the control group. In summary, TTO and terpinen-4-ol may be recommended to induce faster anesthesia, and may be suitable as sedatives for transport, because they improved the antioxidant status of silver catfish.

Nanoencapsulated Melaleuca alternifolia essential oil (tea tree oil, TTO) is a natural alternative treatment, with 100% therapeutic efficacy in fish experimentally infected with Pseudomonas aeruginosa, and has also potent protective effects linked with antioxidant properties. However, the pathways responsible for the antioxidant capacity remain unknown. Thus, this study evaluated whether the inhibition of seric xanthine oxidase (XO) activity can be considered a pathway involved in the antioxidant capacity of nanoencapsulated TTO in fish experimentally infected with P. aeruginosa. Seric samples from fish infected with P. aeruginosa showed increased XO activity, as well as increased uric acid and reactive oxygen species (ROS) levels. In contrast, the prophylactic treatment with nanoencapsulated TTO prevented these infection-induced alterations. Based on the evidence obtained, the upregulation of seric XO activity induced pro-oxidative effects in the serum of fish experimentally infected with P. aeruginosa, due to excessive formation of uric acid, which stimulates the release of ROS. This treatment was able to prevent the upregulated seric XO activity and, consequently, the excessive formation of uric acid and ROS. In summary, inhibition of seric XO activity can be considered a pathway involved in the antioxidant capacity of nanoencapsulated TTO in fish experimentally infected with P. aeruginosa.

The purinergic system is recognized to modulate extracellular adenosine triphosphate (ATP) and related nucleotides through the activities of triphosphate diphosphohydrolase (NTPDase), 5'-nucleotidase, and adenosine deaminase (ADA), thereby playing an essential role in the immunoregulation of inflammatory and immune responses. Thus, the aim of this study was to evaluate whether the purinergic system can improve the inflammatory response in fish experimentally infected with Streptococcus agalactiae through the modulation of seric NTPDase, 5'-nucleotidase and ADA activities. Seric NTPDase (ATP as substrate) and 5'-nucleotidase activities increased in silver catfish experimentally infected with S. agalactiae compared with the uninfected control group, while seric ADA activity decreased. Based on this evidence, our findings suggest that regulation of adenine nucleotide hydrolysis occurs in an attempt to restrict the inflammatory process and improve the immune system by hydrolyzing excess extracellular ATP. On the other hand, downregulation of seric ADA activity may be an attempt to augment extracellular adenosine (a molecule with anti-inflammatory effects) levels. In summary, the purinergic system is capable of modulating the immune and inflammatory responses during fish streptococcosis.

It has been recognized that the cholinergic and adenosinergic systems, through the enzymes acetylcholinesterase (AChE) and adenosine deaminase (ADA), exert an important role in the immune and inflammatory responses during bacterial fish diseases. The immune response against Aeromonas caviae remains poorly understood, and the involvement of these systems, through the anti-inflammatory molecules acetylcholine (ACh) and adenosine (Ado), has not been studied. Thus, the aim of this study was to evaluate the involvement of cholinergic and adenosinergic systems on the inflammatory and immune responses in peripheric and splenic lymphocytes of fish experimentally infected with A . caviae . AChE and ADA activities in peripheric and splenic lymphocytes increased in infected animals on day 4 post-infection compared to uninfected animals, while the ACh and Ado levels decreased. Moreover, spleen histopathology revealed an increase in the number of melano-macrophage centers, as well as lipid inclusions and cellular debris in the ellipsoids. This evidence indicates that infection by A . caviae alters the cholinergic and adenosinergic systems, suggesting the involvement of AChE and ADA activities in the impairment of the immune system, since infection leads to a reduction in ACh and Ado levels, respectively. In summary, the upregulation of AChE and ADA activities in peripheric and splenic lymphocytes exerts a pro-inflammatory profile, contributing to systemic and tissue inflammatory damage, and consequently to disease pathogenesis.

Good vaccines should confer protection against specific pathogens in experimental and field conditions. However, some commercial vaccines are not capable to confer protection to animals, being inefficient in a bovine vaccine program. In this sense, the aim of this study was to evaluate the antibody levels involved in the immune response in vaccinated cows against leptospirosis, as well as acute phase protein and the immunological markers in a vaccine program in beef cattle. Twenty non-lactating cows, negative for leptospirosis and without vaccination against this disease were evaluated during five months. The herd was divided into two groups named as A (the control group) and B (the vaccinated group). Ten cows from the group B received an initial dose (5 mL) of vaccine on day 0 and one booster dose (5 mL) on day 29. In order to evaluate humoral response (MAT – titration 1:25), cytokine levels (tumor necrosis factor (TNF) and interleukin-10 (IL-10)), and C-reactive protein levels (an acute phase protein), blood samples were evaluated on days 0, 29, 40, 83 and 144 after vaccination. In none of the evaluated periods it was observed specific antibodies to any of the six serovars presents in the vaccine, as well as no difference between groups regarding cytokine and C-reactive protein levels. Therefore, the vaccine used did not stimulate the immune response of cattle, inferring the absence of protection against infections by L. interrogans.

In the present study, we evaluated diets supplemented with Melaleuca alternifolia essential oil (tea tree oil - TTO) as a growth promoter and its possible hepatoprotective effects in Rhamdia quelen exposed to the insecticide amitraz. Six groups (8 per group, in triplicate) were tested: control A (basal diet), B (basal diet + TTO 1.0 mL/kg), C (basal diet +0.84 mL/kg amitraz), D (basal diet +1.19 mL/kg amitraz), E (basal diet +1.0 mL/kg TTO + 0.84 mL/kg amitraz) and F (basal diet + TTO 1.0 mL/kg + 1.19 mL/kg amitraz). Initially R. quelen received diets according to each group. After 14 days, four groups were exposed to two levels of amitraz for a period of 7 days, and were later transferred to amitraz-free water for recovery. We measured levels of reactive oxygen species (ROS) and lipoperoxidation (LOOH) in liver tissue, and activities of enzymes involved in energy metabolism, adenylate kinase (AK) and pyruvate kinase (PK), in addition to zootechnical indices such as length, weight body and fish weight gain. ROS and LOOH levels increased significantly (p

Improving the health and immunity of pets is a concern of the guardians, while maintaining the health of the animals directly impacts the owners' health and public health. The objective of this study was to produce a dog feed containing a microencapsulated phytogenic blend, as well as determine the impact of the additive on animal health and its intestinal microbiota. The composition included microencapsulated thymol, carvacrol, and cinnamaldehyde, at 300 mg/kg of feed. Ten male beagle dogs were divided into two groups, identified as follows: the control group (C; ingested the feed without the additive) and the treated group (T; consumed feed containing the phytogenic blend). The dogs received 300 g of feed/day divided into two meals. Greater neutrophil counts in group T and lymphocyte counts were observed at the end of the experiment, as well as levels of α2-globulins and γ-globulin, while β1 and β2-globulins levels were lower in group T. Serum nitrogen oxide levels were higher in group T. Levels of reactive oxygen species were lower in group T at days 30 and 45, unlike activity of glutathione peroxidase that was higher. We found less bacterial contamination in the feces of dogs in group T, i.e., total bacterial count, total coliform counts, and counts of Salmonella and Escherichia coli were lower on days 30 and 45. Phytogenic blend intake reduces bacterial counts in stool and improves antioxidant/oxidative status and immune responses.

In early December 2019, an outbreak of coronavirus disease 2019 caused by a new strain of coronavirus (SARS-CoV-2), occurred in the city of Wuhan, Hubei Province, China. On January 30, 2020, the World Health Organization (WHO) declared the outbreak a public health emergency of international concern. Since then, frontline healthcare professionals have been experiencing extremely stressful situations and damage to their physical and mental health. These adverse conditions cause stress and biochemical, hematological, and inflammatory changes, as well as oxidative damage, and could be potentially detrimental to the health of the individual. The study population consisted of frontline health professionals working in BHU in a city in southern Brazil. Among the 45 participants, two were infected with the SARS-CoV-2 virus and were diagnosed using immunochromatographic tests such as salivary RT-LAMP and qRT-PCR. We also evaluated biochemical, hematological, inflammatory, and oxidative stress markers in the participants. The infected professionals (CoV-2-Prof) showed a significant increase in the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), cholesterol, lactic dehydrogenase, lymphocytes, and monocytes. In this group, the levels of uric acid, triglycerides, leukocytes, neutrophils, hemoglobin, hematocrit, and platelets decreased. In the group of uninfected professionals (NoCoV-2-Prof), significant increase in HDL levels and the percentages of eosinophils and monocytes, was observed. Further, in this group, uric acid, LDH, triglyceride, and cholesterol levels, and the hematocrit count and mean corpuscular volume were significantly reduced. Both groups showed significant inflammatory activity with changes in the levels of C-reactive protein and mucoprotein. The NoCoV-2-Prof group showed significantly elevated plasma cortisol levels. To our kowledge, this study is the first to report the use of the RT-LAMP method with the saliva samples of health professionals, to evalute of SARS-CoV-2.

Its integrated energetic and metabolic signaling roles place the phosphoryl transfer network, through the enzymes creatine kinase (CK), adenylate kinase (AK), and pyruvate kinase (PK), as a regulatory system coordinating components of the cellular bioenergetics network. Analysis of these enzymes provides new information and perspectives with which to understand disturbances in energetic metabolism between sites of adenosine triphosphate (ATP) generation and utilization. Thus, the aim of this study was to evaluate the involvement of the phosphoryl transfer network in splenic tissue linked with the pathogenesis of silver catfish naturally infected with Ichthyophthirius multifiliis. Splenic cytosolic and mitochondrial CK activities decreased in infected animals compared to uninfected animals, as was also observed for splenic PK activity and splenic ATP levels. In contrast, splenic AK activity increased in infected animals compared to uninfected animals. Based on this evidence, the inhibition and absence of efficient communication between CK isoenzymes cause the impairment of splenic bioenergetics, which is in turn compensated by the augmentation of splenic AK activity in an attempt to restore energy homeostasis. The inhibition of splenic PK activity impairs communication between sites of ATP generation and ATP utilization, as corroborated by splenic ATP depletion. In summary, these alterations contribute to disease pathogenesis linked to spleen tissue in animals infected with white spot disease.

Several studies have been demonstrated that phosphotransfer network, through the adenylate kinase (AK) and pyruvate kinase (PK) activities, allows for new perspectives leading to understanding of disease conditions associated with disturbances in energy metabolism, metabolic monitoring and signalling. In this sense, the aim of this study was to evaluate whether experimental infection by Aeromonas caviae alters hepatic AK and PK activities of silver catfish Rhamdia quelen. Hepatic AK and PK activities decreased in infected animals compared to uninfected animals, as well as the hepatic adenosine triphosphate (ATP) levels. Also, a severe hepatic damage was observed in the infected animals due to the presence of dilation and congestion of vessels, degeneration of hepatocytes and loss of liver parenchyma architecture and sinusoidal structure. Therefore, we have demonstrated, for the first time, that experimental infection by A. caviae inhibits key enzymes linked to the communication between sites of ATP generation and ATP utilization. Moreover, the absence of a reciprocal compensatory mechanism between these enzymes contributes directly to hepatic damage and for a severe energetic imbalance, which may contribute to disease pathophysiology.

Oxidative stress has been linked to a pathological mechanism that contributes to the initiation and progression of hepatic injury during Ichthyophthirius multifiliis infection. Thus, natural compounds with antioxidant and free radical scavenger properties, such as the Melaleuca alternifolia essential oil (TTO), might help to prevent or reduce hepatic damage. Thus, the aim of this study was to investigate whether TTO is capable of preventing or reducing hepatic oxidative damage in silver catfish naturally infected with I. multifiliis. After a TTO bath treatment of 1 h/day for 4 days, the number of trophonts on the skin of catfish was reduced by 94.87% compared to the control group. Hepatic samples from fish infected by I. multifiliis showed increased thiobarbituric acid reactive substances (TBARS) and protein carbonylation levels, while catalase (CAT) activity decreased compared to uninfected and untreated animals. Moreover, the histopathology analyses demonstrated the presence of necrosis, nuclear lateralization and cariorrexis, as well as swelling and vacuolization of cytoplasm. Treatment with TTO reduced hepatic TBARS and protein carbonylation levels and ameliorated the antioxidant system of infected fish, as well as preserve the hepatocytes morphology, but not prevented the occurrence of necrosis. Based on our findings, we propose that TTO is an alternative therapeutic option for silver catfish infected with I. multifiliis. Moreover, TTO treatment is a useful approach for avoiding or minimizing the hepatic oxidative stress caused by I. multifiliis, thus improving the hepatic antioxidant system.

This study aimed to evaluate for the first time the insecticidal effects of essential oils of bergamot (Citrus bergamia), palmarosa grass (Cymbopogon martini), vetiver grass (Vetiveria zizanioides), and red cedar (Juniperus virginiana) against the house fly (Musca domestica). The in vitro study was performed in captured adult flies, which were separated on testing cages (n = 20). Subsequently, the essential oils cited above were used in the concentrations of 1, 5, and 10%, and a control group was maintained for test validation. All flies were monitored for 8 h after treatment. All four oils showed insecticidal effect against the fly species studied in vitro and after 8 h of treatment, an efficacy of 73% was observed for the essential oil of bergamot, 55% for palmarosa grass, 75% for vetiver grass, and 89% for red cedar. We conclude that the essential oils tested showed insecticidal effect against house fly, acting as an environmentally sustainable alternative to be applied in human habitats, especially against flies’ resistant to chemical insecticides. In addition, the use of such oils may decrease the doses of synthetic drugs routinely used.

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi and causes severe cardiac and brain damage, leading to behavioral alterations in humans and animals. However, the mechanisms involved in memory impairment during T. cruzi infection remain unknown. It has long been recognized that the enzymatic activities of acetylcholinesterase (AChE) and Na+, K+-ATPase are linked with memory dysfunction during other trypanosomiasis. Thus, the aim of this study was to evaluate the involvement of cerebral AChE and Na+, K+-ATPase activities in the memory impairment during T. cruzi (Colombian strain) infection. A significant decrease on latency time during the inhibitory avoidance task was observed in animals infected by T. cruzi compared to uninfected animals, findings compatible to memory dysfunction. Moreover, the cerebral AChE activity increased, while the Na+, K+-ATPase decreased in T. cruzi infected compared to uninfected animals. Histopathology revealed mild to moderate multifocal gliosis in the cerebral cortex and light focal meningeal lymphoplasmacytic infiltrate, which may have contributed to memory loss. Based on these evidences, we can conclude that T. cruzi (Colombian strain) causes memory impairment in mice experimentally infected. Moreover, the changes in AChE and Na+, K+-ATPase activities may be considered a mechanism involved in disease pathogenesis.

The aim of this study was to evaluate the enzymatic activity of the purinergic system in sera samples from alloxan-induced diabetic mice treated with tucuma oil (Astrocaryum vulgare). For this, the mice were divided into four groups (n = 6): control/water (the group CW); control/tucuma oil (the group CT); diabetic/water (the group DW), and diabetic/tucuma oil (the group DT) treated for 14 days with 5.0 mL kg−1 via oral gavage. On day 14 post-treatment, mice were submitted to euthanasia and blood samples were collected by cardiac puncture. Tucuma oil treatment significantly decreased (p

Cytosolic and mitochondrial creatine kinases (CK), through the creatine kinase-phosphocreatine (CK/PCr) system, provide a temporal and spatial energy buffer to maintain cellular energy homeostasis. However, the effects of bacterial infections on the kidney remain poorly understood and are limited only to histopathological analyses. Thus, the aim of this study was to investigate the involvement of cytosolic and mitochondrial CK activities in renal energetic homeostasis in silver catfish experimentally infected with Aeromonas caviae. Cytosolic CK activity decreased in infected animals, while mitochondrial CK activity increased compared to uninfected animals. Moreover, the activity of the sodium-potassium pump (Na+, K+-ATPase) decreased in infected animals compared to uninfected animals. Based on this evidence, it can be concluded that the inhibition of cytosolic CK activity by A. caviae causes an impairment on renal energy homeostasis through the depletion of adenosine triphosphate (ATP) levels. This contributes to the inhibition of Na+, K+-ATPase activity, although the mitochondrial CK activity acted in an attempt to restore the cytosolic ATP levels through a feedback mechanism. In summary, A. caviae infection causes a severe energetic imbalance in infected silver catfish, which may contribute to disease pathogenesis.

Some studies have demonstrated that xanthine oxidase activity, through the regulation of uric acid levels, exerts a pro-inflammatory profile during infectious diseases. It has been recognized that uric acid induces the release of pro-inflammatory mediators, such as reactive oxygen species (ROS) and nitric oxide (NO), which contribute to inflammatory processes. Considering this, the aim of this study was to evaluate whether upregulation of branchial xanthine oxidase activity may be considered a pathway involved in ROS and nitric oxide (NOx) metabolites production in experimentally infected Rhamdia quelen (silver catfish) with Streptococcus agalactiae. Xanthine oxidase activity, and uric acid, ROS and NOx levels increased in gills of infected animals compared to uninfected animals. Moreover, a positive Pearson correlation was observed between uric acid and ROS levels, and between uric acid and NOx levels. Histopathology revealed the presence of necrosis, hyperplasia and vein congestion in gills of animals infected with S. agalactiae. Based on this evidence, the upregulation of xanthine oxidase activity induces a pro-inflammatory and oxidative profile in the gills of fish infected with S. agalactiae. The excessive uric acid levels induce the release of pro-inflammatory mediators, such as ROS and NOx, which contribute to disease pathogenesis. In summary, the upregulation of xanthine oxidase activity may be considered a pathway involved in ROS and NOx production.

It has been recognized that the cholinergic and adenosinergic systems have an essential role in immune and inflammatory responses during bacterial fish pathogens, such as the enzymes acetylcholinesterase (AChE) and adenosine deaminase (ADA), which are responsible for catalysis of the anti-inflammatory molecules acetylcholine (ACh) and adenosine (Ado) respectively. Thus, the aim of this study was to investigate the involvement of the cholinergic and adenosinergic systems on the immune response and inflammatory process in gills of experimentally infected Rhamdia quelen with Streptococcus agalactiae. Acetylcholinesterase activity decreased, while ACh levels increased in gills of infected animals compared to uninfected animals. On the other hand, a significant increase in ADA activity with a concomitant decrease in Ado levels was observed in infected animals compared to uninfected animals. Based on this evidence, we concluded that infection by S. agalactiae in silver catfish alters the cholinergic and adenosinergic systems, suggesting the involvement of AChE and ADA activities on immune and inflammatory responses, regulating the ACh and Ado levels. In summary, the downregulation of AChE activity exerts an anti-inflammatory profile in an attempt to reduce or prevent the tissue damage, while the upregulation of ADA activity exerts a pro-inflammatory profile, contributing to disease pathophysiology.

The aim of this study was to investigate the occurrence of toxic effects in liver tissue of rats treated with α-terpinene. All treatments were intraperitoneally administered at doses of 0.5, 0.75 and 1.0 ml kg−1 during 10 days. Liver samples were collected and assessed by histopathological analysis, caspases -1, -3, -8 assay, biomarkers of hepatic damage and determination of oxidant/antioxidant status (thiobarbituric acid-reactive substances (TBARS), catalase (CAT), superoxide dismutase (SOD), reactive oxygen species (ROS), glutathione S-transferase (GST) and glutathione peroxidase (GPx)). Additionally, the cytotoxic and genotoxic effects were evaluated by comet assay. An increase was observed on TBARS levels and GPx activity on the hepatic tissue. Instead, CAT and SOD activities decreased in rats treated with a dose of 1.0 ml kg−1 of α-terpinene. Concomitantly, ROS levels increased and GST levels decreased in rats treated with α-terpinene at doses of 0.5, 0.75 and 1.0 ml kg−1. Also, there was an increase in frequency of damage, damage index and caspases, while cell viability decreased in rats treated with α-terpinene. Alanine aminotransferase and aspartate aminotransferase increased in rats treated with 1.0 ml kg−1 of α-terpinene. Therefore, α-terpinene induces oxidative stress, cytotoxic and genotoxic effects in liver tissue involving the caspases activation.

Trypanosoma cruzi is a flagellated protozoan belonging to the Trypanosomatidae family, the etiologic agent of Chagas disease. Currently, there is neither a licensed vaccine nor effective treatment, characterizing an unmet clinical need. The IgY refers to the egg yolk immunoglobulin (Y = yolk) and its production and use are subjects of many studies due to the diversity of its diagnostic and therapeutic applications. Several researchers have shown that the use of specific IgY may prevent and/or control infectious and parasitic diseases. Based on these evidences, the aim of this study was to immunize chickens with trypomastigotes of T. cruzi in order to produce highly effective and pure antibodies (IgY), as well as extract, characterize, quantify, and verify cytotoxic effects of IgY anti-T. cruzi. After the induction of IgY production by chickens, the eggs were collected and the IgY was extracted by method of precipitation of polyethylene glycol 6000. The IgY anti-T. cruzi characterization was performed using polyacrylamide gel electrophoresis (SDS-PAGE), western-blot and enzyme-linked immunosorbent assay (ELISA). Moreover, the cytotoxic or proliferative effects of IgY anti-T. cruzi was verified by MTT assay. The concentration of IgY in yolk was 8.41 ± 1.47 mg/mL. The characterization of IgY reveled bands of stained peptides with molecular weight between 75 and 50 kDa and 37 and 25 kDa. In the ELISA test was observed that there was antigen-antibody reaction throughout the sample period. The concentrations of 1, 5 and 10 mg/mL of IgY anti-T. cruzi presented no cytotoxic of proliferative effects in mononuclear and VERO cells in vitro. The results indicated that T. cruzi is able to generate a high production of specific immunoglobulins in chickens, it did not cause damage to the cell membrane and no proliferative effect.

Oxidative stress has been recognized as a conjoint pathological mechanism that contributes to initiation and progression of liver injury, such as that caused by bacterial diseases. Natural antioxidants are considered a rational curative strategy to prevent and cure hepatic diseases involved with oxidative stress. Thus, the aim of this study was to evaluate, for the first time, whether treatment with bactericidal Melaleuca alternifolia essential oil (TTO) nanoparticles prevents or reduces the hepatic damage in silver catfish (Rhamdia quelen) experimentally infected with Pseudomonas aeruginosa (PAO1). Liver samples from fish infected with P. aeruginosa showed increased thiobarbituric acid reactive substances (TBARS), protein carbonylation and advanced oxidation protein product (AOPP) levels, while catalase (CAT) activity was reduced compared to uninfected animals. The prophylactic treatment with nanoencapsulated TTO prevented these alterations. Based on this evidence, we concluded that P. aeruginosa infection causes hepatic damage, evidenced by increased TBARS, protein carbonylation and AOPP levels, which inhibits the antioxidant defense system, contributing to disease pathophysiology. Thus, this treatment may be considered an important approach for the prevention of hepatic oxidative damage caused by P. aeruginosa infection in fish.

Studies have demonstrated that fish are able to mount protective immune responses against various parasites, including Ichthyophthirius multifiliis, an economically important protozoosis in freshwater aquaculture. Although the immune response against this parasite have been partly elucidated in the literature, the involvement of the cholinergic and adenosinergic systems, through the anti-inflammatory molecules acetylcholine (ACh) and adenosine (Ado), has not been studied. Thus, the aim of this study was to evaluate the involvement of the cholinergic and adenosinergic systems in the immune and inflammatory responses in the immune lymphatic organs of silver catfish, Rhamdia quelen, naturally infected with I. multifiliis. Acetylcholinesterase (AChE) activity increased, while adenosine deaminase (ADA) activity decreased in the head kidney and spleen of silver catfish naturally infected with I. multifiliis compared to the uninfected control group. Moreover, the levels of ACh in the head kidney and spleen decreased in infected animals, while the Ado levels increased compared to the uninfected control group. A negative and significant Pearson correlation was observed between AChE activity and ACh levels, as well as between ADA activity and Ado levels. Therefore, the cholinergic system exerts a pro-inflammatory profile due to upregulation of AChE activity and a consequent reduction in ACh levels, which contributes to inflammatory damage. Conversely, the adenosinergic system plays an anti-inflammatory profile via downregulation of ADA activity and consequent augmentation of Ado levels, which may contribute to restricting the inflammatory process and improving the immune response during ichthyophthiriasis.

SUMMARYDespite significant advances in therapies against Trypanosoma evansi, its effective elimination from the central nervous system (CNS) remains a difficult task. The incapacity of trypanocidal drugs to cross the blood–brain barrier (BBB) after systemic administrations makes the brain the main refuge area for T. evansi. Nanotechnology is showing great potential to improve drug efficacy, such as nerolidol-loaded nanospheres (N-NS). Thus, the aim of this study was to investigate whether the treatment with N-NS was able to cross the BBB and to eliminate T. evansi from the CNS. High-performance liquid chromatography revealed that N-NS can cross the BBB of T. evansi-infected mice, while free nerolidol (F-N) neither the trypanocidal drug diminazene aceturate (D.A.) were not detected in the brain tissue. Polymerase chain reaction revealed that 100% of the animals treated with N-NS were negatives for T. evansi in the brain tissue, while all infected animals treated with F-N or D.A. were positives. Thus, we concluded that nanotechnology improves the therapeutic efficacy of nerolidol, and enables the transport of its active principle through the BBB. In summary, N-NS treatment can eliminate the parasite from the CNS, and possesses potential to treat infected animals.

The aim of this study was to investigate the effects of tucuma oil (Astrocaryum vulgare) on memory, enzymatic activities of sodium–potassium pump (Na+, K+-ATPase) and acetylcholinesterase (AChE) in the brain of alloxan-induced diabetic mice. The animals were divided into four groups (n = 6 each): the group A (non-diabetic/water), the group B (non-diabetic/tucuma oil), the group C (diabetic/water), and the group D (diabetic/tucuma oil) treated 14 days with 5.0 mL kg−1 via oral gavage. Untreated diabetic mice (the group C) showed memory deficit, increased levels of thiobarbituric acid reactive species (TBARS) and protein carbonylation (PC), and decreased (p

It has long been recognized that there are several infectious diseases linked to the impairment of enzymatic complexes of the mitochondrial respiratory chain, with consequent production of reactive oxygen species (ROS), that contribute to disease pathogenesis. In this study, we determined whether the inhibition on mitochondrial respiratory chain might be considered a pathway involved in the production of ROS in gills of Rhamdia quelen experimentally infected by P. aeruginosa. The animals were divided into two groups with six fish each: uninfected (the negative control group) and infected (the positive control group). On day 7 post-infection (PI), animals were euthanized and the gills were collected to assess the activities of complexes I-III, II and IV of the respiratory chain, as well as ROS levels. The activities of complexes I-III, II and IV of the respiratory chain in gills decreased, while the ROS levels increased in infected compared to uninfected animals. Moreover, a significant negative correlation was found between enzymatic activity of the complexes I-III and IV related to ROS levels in P. aeruginosa infected animals, corroborating to our hypothesis that inhibition on complexes of respiratory chain leads to ROS formation. Also, microscopic severe gill damage and destruction of primary and secondary lamellae were observed in infected animals, with the presence of hyperplasia, leukocytic infiltration and telangiectasia. In summary, we have demonstrated, for the first time, that experimental infection by P. aeruginosa inhibits the activities of mitochondrial complexes of respiratory chain and, consequently, impairs the cellular energy homeostasis. Moreover, the inhibition on mitochondrial complexes I-III and IV are linked to the ROS production, contributing to disease pathogenesis.

The aim of this study was to evaluate whether oxidative stress occurs in rats experimentally infected by Sporothrix schenckii, and its possible effect on disease pathogenesis. Thirty rats were divided into two groups: the group A (uninfected, n = 18) and the group B (infected by S. schenckii, n=21). Blood samples were collected on days 15, 30 and 40 post-infection (PI). At each sampling time, six rats of the group A, and seven of the group B were bled. TBARS (thiobarbituric acid reactive substances) levels in serum samples were measured to evaluate lipid peroxidation. In addition, catalase (CAT) and superoxide dismutase (SOD) activities, known as biomarkers of antioxidants levels, were verified in whole blood. Seric pro-inflammatory cytokine levels were measured (IFN-γ, TNF-α, and IL-6), which showed that these inflammatory mediators were at higher levels in the infected rats (P

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.

Sheep breeding represents an important economic source in many countries; however, anthelmintic resistance is an important limiting factor for sheep breeding development, due to its effects in animal performance. Monepantel is an active principle derived from an amino-acetonitrile class, with proven efficacy in the control of gastrointestinal parasites. However, the side effects associated to this treatment remain unknown. Thus, the aim of this study was to evaluate the effect of anthelmintic treatment with monepantel as well as evaluate the hepatic function, proteic and lipid metabolism, and antioxidant/oxidant levels in serum of naturally infected sheep with helminths. Sixteen naturally infected animals were used; all subjects had similar parasitic degree (determined by McMaster technique) on day 0. The animals were divided in two groups (A and B) with eight animals each. Group A did not receive any treatment (control group), while group B received a single dose of monepantel (2.5 mg/kg) on day 0 of the experiment. Fecal exams performed on days 4 and 8 post-treatment (PT) revealed a significant reduction (p

The aim of this study was to evaluate nucleoside triphosphate diphosphohydrolase, 5′-nucleotidase, and adenosine deaminase activities in cattle fed on cuttings from pastures fertilized with urea compared to animals fed on cuttings from organically fertilized or from non-fertilized pastures. Blood samples were collected up to 9 h after feeding, and nitrite and enzyme activities were evaluated. The animals feeding on urea-fertilized pasture suffered subclinical intoxication. Serum nitrite levels increased by about 50% and adenosine deaminase activity increased almost sixfold 4 and 6 h after feeding on urea-fertilized pasture, and adenosine deaminase in platelets almost doubled 6 and 9 h after feeding. In platelets, nucleoside triphosphate diphosphohydrolase activity with adenosine triphosphate as substrate increased 2, 4, 6 and 9 h after feeding while nucleoside triphosphate diphosphohydrolase with adenosine diphosphate as substrate and 5′-nucleotidase activities increased only 9 h after feeding. In...

The aim of the study was to investigate the effect of the oral administration of tucuma oil (Astrocaryum vulgare) on glucose and insulin levels, oxidative status, and pancreatic genotoxic parameters of alloxan-induced diabetic mice. The animals were divided into four groups (n = 6 each): control/water; control/tucuma oil; diabetic/water; diabetic/tucuma oil treated for 14 days with 5.0 mL kg−1 via oral gavage. Gas chromatograph characterization demonstrated that oleic/elaidic fatty acid is the most abundant component present in this oil, followed by palmitic and stearic fatty acids. Our results demonstrated an increase (p

Purinergic system has been proven to play a critical role in the inflammatory process and to represent an important therapeutic target to improve the immune response during hypercholesterolemia. β-caryophyllene, a phytocannabinoid compound, has a powerful hypolipidemic and anti-inflammatory actions. However, the effects of β-caryophyllene on seric enzymes of purinergic system have not been evaluated. The purpose of this study was to investigate whether β-caryophyllene is able to ameliorate the seric activities of NTPDase and adenosine deaminase (ADA) in a model of hypercholesterolemia induced by Triton WR-1339. The activities of NTPDase and ADA were evaluated enzymatically, and the seric levels of β-caryophyllene were evaluated by high-performance liquid chromatography. We found that treatment with β-caryophyllene ameliorates the enzymatic activities of NTPDase and ADA in serum of hypercholesterolemic rats, in a concentration-dependent manner. These results indicated that β-caryophyllene treatment could improve the immune response during hypercholesterolemia through purinergic pathway.

The aim of this study was to evaluate whether infection by Pseudomonas aeruginosa, an important opportunistic Gram-negative bacterium, causes behavioral alterations in Rhamdia quelen, as well as to investigate the involvement of markers of stress response and brain neurotransmitters in experimentally infected fish. For this, twelve animals were divided in two groups: uninfected (negative control) and experimentally infected animals with P. aeruginosa (positive control), in order to assess the behavioral parameters, plasma cortisol levels, as well as the Na+, K+-ATPase and acetylcholinesterase (AChE) activities. Animals infected with P. aeruginosa presented a behavioral impairment linked with hyperlocomotion. Also, the plasma cortisol and reactive oxygen species (ROS) levels increased in infected fish compared to uninfected ones. Cerebral Na+, K+-ATPase activity decreased in infected animals, while cerebral AChE activity increased compared to uninfected animals. In summary, fish experimentally infected with P. aeruginosa presented behavioral impairments, which are associated with stress and hyperlocomotion. Moreover, the impairment of the cerebral Na+, K+-ATPase pump and cholinergic system may directly contribute to this behavior, since dysfunction in the synapse is promoted, and levels of ACh, an important neurotransmitter involved in several behavioral functions, is decreased.

Oxidative stress has been considered as a pathological mechanism that contributes to initiation and progression of cardiac injury during the Trypanosoma evansi infection. In this sense, the natural compounds with antioxidant and free radical scavenger abilities, such the Achyrocline satureioides essential oil loaded in nanocapsules (AS-NC), may be considered important approach to minimize the cardiac damage. Thus, the aim of this study was to investigate whether AS-NC treatment is able to prevents or reduce the cardiac oxidative damage in infected rats with T. evansi. Heart samples from rats infected by T. evansi showed increased reactive oxygen species (ROS), thiobarbituric reactive-acid substances (TBARS) and glutathione reduced (GSH) levels, while catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities decreased compared with uninfected and untreated animals. Also, the seric biomarkers of cardiac function increased in the infected animals compared with uninfected animals. AS-NC treatment reduced ROS and TBARS levels, ameliorate cardiac CAT and SOD activities of infected rats, and reduced seric biomarkers of cardiac function. AS-NC treatment protected the heart from oxidative stress caused by T. evansi, which might be due to its antioxidant properties. AS-NC might be considered a promising therapeutic agent against oxidative stress, when associated with nanotechnology.

The aim of this study was to evaluate the influence of dictyocaulosis (mild or severe) on enzymes of NTPDase, 5'-nucleotidase, and adenosine deaminase (ADA) of dairy cows naturally infected by Dictyocaulus viviparus. Blood and faeces were collected from 22 dairy cows of the same farm to evaluate NTPDase (ATP and ADP substrate), 5'-nucleotidase, and ADA activities on days 0 (pre-treatment) and 10 (post-treatment). Seric activities of NTPDase (ATP substrate), 5'-nucleotidase, and ADA were lower (P0.05) in D. viviparus infected animals compared to uninfected cows. The number of D. viviparus larvae per gram of faeces varied among the animals, and they showed different degrees of severity according to respiratory clinical signs of the disease (cough and nasal discharge). Later, these cows were divided into two groups: those with mild (n=10) and severe (n=12) disease. Cows with severe disease showed higher NTPDase activity (ATP substrate) than those with mild disease (P≤0.05). The opposite occurred with NTPDase (ADP substrate), 5'-nucleotidase, and ADA in cows with severe disease, that is, the enzymatic activity of these seric enzymes significantly decreased (P≤0.05) compared to animals with mild disease. Infected animals showed reduced NTPDase activity (ATP and ADP substrate) after treatment. No enzymatic changes were observed for 5'-nucleotidase, and ADA pre- and post-treatment (P0.05). Based on these results, we conclude that dictyocaulosis alters NTPDase, 5'-nucleotidase, and ADA activities of cow naturally infected by the parasite, in consequence the enzymes act as inflammatory markers.

Appropriate control of immune responses is a critical determinant of fish health. The cholinergic and adenosinergic systems have important roles in the immune response, since acetylcholine (ACh) and adenosine (Ado) possess important anti-inflammatory properties and modulate the immune response during infectious diseases. Thus, the aim of this study was to evaluate whether splenic and lymphocytic adenosinergic and cholinergic systems are able to modulate the immune response during Pseudomonas aeruginosa infection. Acetylcholinesterase (AChE) and adenosine deaminase (ADA) activities in spleen tissue and splenic lymphocytes increased in infected animals compared to uninfected animals. Moreover, plasmatic and splenic metabolites of nitric oxide (NOx) increased in infected animals compared to uninfected animals. Therefore, our results support the hypothesis that the cholinergic and adenosinergic systems are not able to modulate the immune response against P. aeruginosa. In summary, increased AChE and ADA activities exert a pro-inflammatory profile, impairing the immune system and contributing to inflammatory damage.

Integration of mitochondria with cytosolic ATP-consuming/ATP-sensing and substrate supply processes is critical for gills bioenergetics, since this tissue plays an important role in the respiratory energy metabolism. The effects of bacterial infection on gills remain poorly understood, limited only to histopathological analyses. Thus, the aim of this study was to investigate whether experimental infection by Pseudomonas aeruginosa strain PA01 alters the enzymes of the phosphoryltransfer network (adenylate kinase (AK), pyruvate kinase (PK) and cytosolic and mitochondrial creatine kinase (CK)) in gills of silver catfish (Rhamdia quelen). The animals were divided into two groups with six fish each: uninfected (negative control) and infected (positive control). On day 7 post-infection (PI), animals were euthanized and the gills collected. AK, PK, and cytosolic and mitochondrial CK activities in gills decreased in infected compared to uninfected animals. Also, severe gill damage and destruction in the primary and secondary lamellae was observed in the infected animals. Therefore, we have demonstrated, for the first time, that experimental infection by P. aeruginosa inhibits key enzymes linked to the production and utilization of metabolic energy in silver catfish, and consequently, impairs cellular energy homeostasis, which may contribute to disease pathogenesis.

A description of physiological and biochemical parameters in suckling piglets is important for identifying suitable management methods according to current realities of commercial swine management. Therefore, the aim of this study was to measure plasma glucose and urea levels in suckling piglets on the first days of life. To accomplish this, 30 male newborn piglets born to 10 sows were used as the experimental model. The animals were weighed on days of life 1 (newborn), 7, 14, and 21, and blood samples were collected to measure plasma levels of glucose and urea. Plasma glucose levels increased over time, while plasma urea levels decreased over time. During the first days of life, suckling piglets use amino acids as sources of energy, increasing plasma urea levels. However, glucose levels at birth depend on biochemical conditions of the mother as well as transfer of nutrients during gestation.

The trend toward using plant-based ingredients in aquafeeds has raised important concerns for aquaculture owing to the negative impacts of mycotoxins on fish health; with emphasis for contamination by fumonisin B

The aim of this study was to evaluate the toxicity of tucumã oil nanocapsules from the Amazon region in silver catfish, Rhamdia quelen. Fish were exposed to water treated with different concentrations of tucumã nanocapsules, white, solubilized oil and surfactant vehicles. After three days of exposure, fish were euthanized and liver, gills and brain removed for analysis of the dichlorofluorescein, nitric oxide and PicoGreen® assays. Plasma was collected for assay of hepatic transaminases. The nanocapsules had a diameter of 221 ± 1.27 nm, confirmed by atomic force microscopy. The oil nanocapsules were not toxic to this species of fish, but white nanocapsules and surfactant increased the levels of reactive oxygen species. Thus, nanocapsules are promising for the transport of tucumã oil. In view of the anti-inflammatory properties of this oil, it is possible to envisage its application in skin diseases for example, since they present essentially inflammatory conditions.HighlightsThe most abundant carotenoid in tucumã oil was all-trans-beta-carotene.Nanocapsules are good carriers for tucumã oil.Tucumã oil nanocapsules does nothas toxicity effect in catfish. The most abundant carotenoid in tucumã oil was all-trans-beta-carotene. Nanocapsules are good carriers for tucumã oil. Tucumã oil nanocapsules does nothas toxicity effect in catfish.

Amazon fish are vulnerable to climate change. Several lines of evidence suggest that the temperature of Amazonian rivers will increase in the coming years. Elevated temperature disturbs homeostasis and subjects fish to physiological stress; however, the effects of temperature on immunity remain poorly understood, particularly those effects involving purinergic signaling. This system fine-tunes the inflammatory and immune responses triggered by stress. Therefore, the aims of this study were to determine whether acute heat stress induces the release of nucleotides into extracellular compartment and to determine whether purinergic enzymes modulate the proinflammatory effects of adenosine triphosphate (ATP) in plasma and spleen of matrinxa (Brycon amazonicus) exposed to acute heat stress. We exposed juvenile matrinxa to four temperature regimes (28 °C as control, 30, 32 and 34 °C) for 72 h and observed the effects on purinergic signaling. Plasma cortisol levels were significantly higher in fish exposed to 34 °C than in the control group, while spleen ATP, adenosine diphosphate (ADP) and adenosine monophosphate (AMP) levels were significantly higher in this group than in controls. Activities of spleen nucleoside triphosphate diphosphohydrolase (NTPDase) and 5′-nucleotidase were significantly higher in fish exposed to 34 °C than those of the control group, while spleen interleukin-1 (IL-1) and interleukin-6 (IL-6) levels were higher in this same group than in the control group. No significant differences were observed between the groups regarding plasma parameters. Based on these data, we concluded that acute heat stress at 34 °C caused physiological stress in matrinxa, manifesting as elevated plasma cortisol levels. The most important finding is that purinergic enzymes were modulated, though not efficiently, in response to the excessive release of nucleotides into the extracellular space. In summary, the purinergic signaling pathway may be involved in the impairment of immune and inflammatory responses in matrinxa exposed acutely to 34 °C.

The aim of this study was to evaluate whether the use phytogenic as feed additive of Holstein calves could exert beneficial effects on animal health and performance. Thirty newborn calves were randomly divided into two groups (control and treated), and the treated consisted of 10 g of the phytogenic product diluted in milk once a day for 30 days. Blood and fecal samples were collected, and fecal score was performed daily in order to determine the occurrence of diarrhea. Treated calves showed higher hematocrit on days 45 and 60 of life. Serum levels of urea, total proteins, globulins and glucose were lower in the treated group on day 60 of life, while triglycerides were lower on days 15 and 60 of life. Serum glutathione S-transferase activity was higher in treated animals on day 60 of life. Fecal bacterial count was lower in treated animals on days 30 and 60 of life. The weight gain was higher in treated animals on days 60 and 210 of life. Based on these results, it is possible to conclude that the addition of phytogenic as feed additive for calves was able to minimize fecal bacterial infections and to increase body weight gain.

The head kidney is a lymphoid immune organ that plays a key role in the immune and inflammatory responses of teleost fish. It is associated with immunoglobulin G production and differentiation of B cells. The presence of a multi-enzymatic complex found anchored in the plasma membrane makes the head kidney an important purinergic-dependent tissue. Purinergic signaling has been associated with these responses under pathological conditions via regulation of extracellular adenosine triphosphate (ATP), the main damage molecular associated pattern agent released during bacterial infections. The aim of this study was to determine whether purinergic signaling is a pathway associated with impairment of immune responses in silver catfish (Rhamdia quelen) experimentally infected by Flavobacterium columnare, as well as to evaluate the role of P2 purine receptors in this response. Triphosphate diphosphohydrolase (NTPDase) activity in the head kidney was significantly lower in silver catfish experimentally-infected F. columnare 72 h post-infection (hpi) than in the control group, while no significant difference was observed with respect NTPDase activity on adenosine diphosphate, as well as on 5′-nucleotidase and adenosine deaminase activities. Extracellular ATP levels were significantly higher in the head kidney of experimentally-infected fish than in the control group at 72 hpi. Finally, p2ry11 and p2rx3 purine receptor levels were significantly higher in experimentally-infected fish than in the control group at 72 hpi. We conclude that purinergic signaling in the head kidney of silver catfish infected by F. columnare creates a pro-inflammatory profile that may contribute to impairment of immune and inflammatory responses via reduction of ATP hydrolysis and its accumulation in the extracellular milieu, accompanied by upregulation of p2ry11 and p2rx3 purine receptors, leading to pro-inflammatory status.

Mercury (Hg) induces neurobehavioral disorders through reactive oxygen species (ROS) elevation and impairment of brain key enzyme activities. Nevertheless, the therapeutic and toxic selenium concentrations for fish are very close; diphenyl diselenide (Ph2Se2), an organoselenium compound with neuroprotective effects, may be an alternative to elemental Se. Therefore, the aim of this study was to determine whether dietary supplementation with Ph2Se2 prevented or reduced the neurobehavioral alterations and oxidative damage elicited by CH3HgCl in grass carp Ctenopharyngodon idella. Fish exposed to CH3HgCl exhibited significantly reduced distance travelled and swimming speed compared to the control group, as well as augmented cortisol and ROS levels and xanthine oxidase (XO) activities. CH3HgCl exposure significantly increased lipid peroxidation (LOOH) and protein carbonylation (PC) levels compared to those of the control group, while acetylcholinesterase (AChE) and sodium-potassium pump (Na+, K+-ATPase) activities were inhibited. Dietary supplementation with 3 mg/kg Ph2Se2 ameliorated locomotor activity impairment and prevented the augmented brain cortisol and ROS levels as well as XO activity. The supplement reduced lipid and protein damage elicited by CH3HgCl and exerted protective effects on brain AChE and Na+, K+-ATPase activities. Exposure to an environmental concentration of CH3HgCl elicited neurobehavioral alterations linked to reduced locomotor activity, a finding that can be explained by oxidative damage and reduced activity of AChE and Na+, K+-ATPase in telencephalon and mesencephalon structures. Dietary supplementation with Ph2Se2 prevented CH3HgCl-induced locomotor impairment. This effect appeared to be mediated by antioxidant action. Ph2Se2 may be a viable approach to prevention or reduction CH3HgCl-mediated neurotoxic effects.

Neospora caninum is a protozoan that has tropism for the central nervous system. The aim of this study was to determine whether experimental infection of gerbils would interfere with activity of enzymes associated with energy metabolism. We randomized 20 gerbils into two groups (ten animals per group): the control group (healthy animals; uninfected) and the infected group (experimentally infected with dose 7.8 × 102 tachyzoites of N. caninum per gerbil). On day six and twelve post-infection (PI), brain and spleen tissues were collected for biochemical and histopathological analyses. No histopathological lesions were observed in the brains of infected animals; however, inflammatory infiltrates were found in the spleen. Significantly greater levels of reactive oxygen species (ROS) were observed in the brain and spleen of infected gerbils than in the control group at 12 days PI. Cytosolic creatine kinase (CK-CYT), mitochondrial creatine kinase (CK-MIT), and pyruvate kinase (PK) activities were lower in the brains of infected gerbils than in those of the control group on day 12 PI. There was significantly less CK-CYT activity in the spleens of infected gerbils on day 6 and 12 PI. Finally, there was significantly less sodium-potassium ion pump (Na+/K+ ATPase) activity in the brains and spleens of infected gerbils on day 12 PI. These data suggest that experimental infection with N. caninum interfered with energy metabolism associated with ATP homeostasis in the brain and spleen, directly or indirectly, apparently mediated by ROS overproduction, contributing to inhibition of Na+/K+ ATPase activity.

The aim of this study was to evaluate whether the supplementation with açaí flour in the feed of laying hens at the end of the production cycle has beneficial effects on the health and performance of the birds and on the quality of the eggs. Groups received basal diets supplemented with 0%, 0.25%, 0.5%, 1.0%, and 2.0% açaí lump flour. We observed better productivity linked to oviposition and egg mass in a dose-dependent manner. We also observed higher shell resistance in stored eggs and higher % albumen and peel in fresh eggs. Lower levels of lipoperoxidation were observed in fresh eggs (2.0%). In stored eggs, lipoperoxidation levels were lower in all supplemented groups. The antioxidant capacity levels in fresh or stored eggs was higher (2.0%). We also observed a higher content of monounsaturated fatty acids in the supplemented groups, whereas saturated fatty acids were lower in the egg yolks. PRACTICAL APPLICATIONS: Based on a regression analysis, we verified that 1.47% of açaí flour is ideal in terms of productive efficiency. Dietary supplementation with açaí flour improved performance, egg quality, and had positive effects on the health of hens. Supplementation with açaí flour increased egg shelf life, reducing lipid peroxidation, biochemical reaction responsible for egg putrefaction.

Some evidence suggests the involvement of phosphotransfer network in the pathogenesis of fish bacterial diseases, catalyzed by creatine kinase (CK), pyruvate kinase (PK) and adenylate kinase (AK); nevertheless, the effects on fish affected by Aeromonas hydrophila remain unknown. Recent evidence suggested a potent protective effect of caffeine on the branchial phosphotransfer network of fish subjected to challenge conditions. Therefore, the aim of this study was to evaluate whether A. hydrophila infection impaired branchial bioenergetics. We also determined whether dietary supplementation with caffeine protected against A. hydrophila-induced gill bioenergetic imbalance. We found that branchial cytosolic CK and AK activities were significant lower in fish experimentally infected with A. hydrophila than in uninfected fish, while mitochondrial CK activity was significant higher. Branchial lactate dehydrogenase (LDH) activity and lactate levels were significant higher in fish experimentally infected by A. hydrophila than in uninfected fish, while sodium-potassium ion pump (Na+, K+-ATPase) activity and adenosine triphosphate (ATP) levels were significant lower. No significant difference was observed between groups with respect to branchial PK activity. The dietary supplementation with 8% caffeine improved the branchial CK (cytosolic and mitochondrial), AK, and LDH activities, as well as ATP levels, but did not prevent increases in branchial lactate levels or the inhibition of Na+, K+-ATPase activity elicited by aeromonosis. Based on this evidence, we believe that reduction of CK (cytosolic) and AK activities contributes to impairment of bioenergetic homeostasis, while augmentation of mitochondrial CK activity can be considered an attempt to prevent or reduce the energetic imbalance during aeromonosis caused by A. hydrophila. The use of 8% caffeine dietary supplementation improved the energetic metabolism via protective effects on CK and AK activities, avoiding the necessity of using anaerobic metabolism. In summary, 8% dietary caffeine can be used to improve branchial energetic homeostasis during aeromonosis caused by A. hydrophila.

Aflatoxin B1 (AFB1) is one of the most important mycotoxins due to its hepatotoxic and carcinogenic effects on animals. The effect of dietary supplementation with vegetable choline (VC) at 400, 800, and 1200 mg/kg against the deleterious effects of AFB1 (2 ppm/kg diet) in the liver of Nile tilapia (Oreochromis niloticus) was studied. The experimental period was 81 days, and the diet with VC was offered to the fish for 60 days prior to challenge with AFB1. Diets with AFB1 were tested in three replications and animals were analyzed at days 14 and 21 of dietary intake. The addition of VC to tilapia diet increased body weight (days 30 and 60 pre-challenge and day 21 post-challenge). The group fed aflatoxin-contaminated diet presented significantly reduced antioxidant enzymes and increased reactive oxygen species (ROS) levels, thiobarbituric acid reactive species (TBARS) levels, and protein carbonyl (PC) content in the liver. Dietary supplementation with VC at 800 and 1200 mg/kg demonstrated a significant protective effect, avoiding the increase of ROS, TBARS, and PC levels in the liver of tilapia from the aflatoxin contaminated groups. Thus, dietary VC supplementation may be used in tilapia to increase antioxidant status and reduce the negative effects caused by AFB1 toxicity. Based on the findings, it is recommended to use VC as a food supplement for Nile tilapia in order to avoid AFB1 toxication. In addition, decreased aflatoxin toxicity can be attributed to the VC antioxidant property.

Extracellular adenosine triphosphate (ATP) is as key mediator of immune and inflammatory responses. ATP is normally sequestered in the intracellular milieu and released by apoptotic and necrotic cells, where it acts as a pro-inflammatory mediator in the extracellular milieu. A limited number of studies have explored the involvement of purinergic signaling in oomycete infections, including Saprolegnia parasitica; this is a most destructive oomycete pathogen, associated with high mortality and severe economic losses for fish producers. The aim of this study was to determine whether purinergic signaling exerts anti- or pro-inflammatory effects in spleens of grass carp (Ctenopharyngodon idella) naturally infected by S. parasitica. Animals naturally infected with S. parasitica showed typical gross lesions characterized by cotton-wool tufts on the tail and fins, as well as severe histopathological lesions such as necrosis. Spleen ATP and metabolites of nitric oxide (NOx) levels were higher in fish naturally infected by S. parasitica compared to control on day 7 post-infection (PI). Spleen nucleoside triphosphate diphosphohydrolase (NTPDase) activity (ATP as substrate) was greater in fish naturally infected by S. parasitica than in uninfected on day 7 PI, while no significant differences were observed between groups with respect to NTPDase (adenosine diphosphate as substrate) and 5'-nucleotidase activities. Finally, adenosine deaminase (ADA) activity was lower in fish naturally infected by S. parasitica than in uninfected fish on day 7 PI. In summary, spleen tissue necrosis in the context of saprolegniosis provokes an intense release of ATP into the extracellular milieu, where it interacts with the P2X7 purine receptor and leads to a self-sustained pro-inflammatory deleterious cycle, contributing to an intense inflammatory process. In response to excessive ATP levels in the extracellular milieu, ATP and adenosine hydrolysis were modulated in an attempt to restrict the inflammatory process via upregulation of NTPDase and downregulation of ADA activities. We conclude that the purinergic signaling pathway modulates immune and inflammatory responses during natural infection with S. parasitica.

The aim of this study was to investigate whether microalgae in Japanese quail feed alters performance, fatty acid profiles in the eggs and egg quality. One hundred quails were distributed in four groups and five replicates of five birds per experimental group. The treatments consisted of four levels of Spirulina platensis microalgae (0%, 5%, 10%, and 15%) in the diets. We evaluated the productive performance and chemical-physical characteristics of eggs, the oxidant/antioxidant status in egg yolks, and the fatty acid profile in the diet and egg yolks. Microalgae in the diet did not influence egg production; however, it increased the yolk index as well as the color intensity of the yolk. Saturated and polyunsaturated fatty acid levels decreased in egg yolks, and monounsaturated fatty acid levels increased in the yolks. Lipid peroxidation levels were lower and total antioxidant capacity was higher in egg yolks of quails receiving microalgae in the diet. PRACTICAL APPLICATIONS: Microalgae in quail diets improves egg quality and provides benefits to consumer health, acting as an antioxidant and immune-stimulant. Microalgae in quail diets had positive effects on egg quality. This is because it reduced levels of saturated fatty acids that are undesirable, and increased monounsaturated fatty acid levels that are beneficial to the health of consumers. Finally, antioxidants increased in egg yolks, consequently reducing lipid peroxidation.

Bacterial infections require special care since the indiscriminate use of antibiotics to treat them has been linked to the emergence of resistant strains. In this sense, phytoterapeutic alternatives such as curcumin and its nanocapsules have emerged as a promising supplement in optimizing availability of bioactives and reducing the development of antimicrobial resistance. Thus, the aim of this study was to verify the effects of pure and nanoencapsulated curcumin in the treatment of experimental listeriosis in gerbils regarding many aspects including antibacterial effect, antioxidant mechanisms involved and the energetic metabolism. Four groups were used containing 6 animals each: T0 (control), T1 (infected), T2 (infected and treated with free curcumin - dose of 30 mg/kg/day) and T3 (infected and treated with nanocapsules containing curcumin - a dose of 3 mg/kg/day). Treated animals received curcumin for 6 consecutive days starting 24 h after Listeria monocytogenes infection. All animals were euthanized on the 12th day after L. monocytogenes infection. Quantitative polymerase chain reaction (qPCR) identified L. monocytogenes DNA in the spleens of all animals of the T1 group, as well as T2 (2 out of 6) and T3 (5 out of 6). The weight of the spleens confirmed the infection, since it was larger in the T1 group, differing statistically from T0, and similarly to T2 and T3. Hepatic histopathological examination showed mild infiltration of neutrophils and macrophages, except for the T3 group (only 1/6). In the liver, the pyruvate kinase activity was higher in T1 and T2 compared to T0 and T3. The adenylate kinase activity did not differ between groups. The Na+/K+ATPase activity was lower in T1 group compared to T0 and T3. Lipoperoxidation was lower in the T3 group compared to groups T0, T1 and T2. The antioxidant capacity against peroxyl radicals was higher in T1, T2 and T3 groups compared to T0. In conclusion, free curcumin showed potent antibacterial effects; however, the nanoencapsulated form was able to minimize the effects caused by L. monocytogenes regarding tissue injury, changes on enzymes of the energetic metabolism, in addition to an antioxidant effect against lipoperoxidation.

The objective of this study was to determine whether supplementing the diets of laying hens with selenomethionine (SM, 1% selenium) improves performance and egg quality. We supplemented diets with SM as follows: T0 control (without SM); T5, T10, T15, and T20 were supplemented with 5, 10, 15, and 20 mg of SM/kg of feed, respectively (equal to 0.05, 0.10, 0.15, and 0.20 mg selenium/kg of feed). T5 and T10 hens showed better feed conversion per kg of egg, percentage of laying, higher daily feed intake, and higher average egg weight. The eggs of hens supplemented with SM had lower levels of lipoperoxidation (LPO) in fresh (T15 and T20) and stored eggs (T20). Glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities, as well as total antioxidant capacity were greater in egg yolks after storage (T10; T15; T20 compared to T0). Hens supplemented with SM had elevated GPx and SOD activities and decreased oxidative reactions. PRACTICAL APPLICATIONS: Selenium has several nutraceutical properties, with beneficial effects on the health of the animal and the food produced from them (eggs, in this case). Selenomethionine supplementation in the diet of laying hens improves productive efficiency, stimulates the antioxidant system and reduces lipid peroxidation in the egg yolk. Egg-laying hens that received selenomethionine showed minimized lipid peroxidation in stored eggs, possibly improving shelf life of the eggs.