ABSTRACT
This study aimed to evaluate the effects of Protium heptaphyllum fruit essential oil (PHEO) on the physiology of silver catfish (Rhamdia quelen) during anesthesia and recovery, through studying echocardiograms, oxidative status, and metabolic parameters. Three experiments were performed: (1) 50 silver catfish juveniles were submitted to anesthesia and recovery tests with 300, 400, 500, 600, and 700 mg L-1 of PHEO. (2) Echocardiogram analysis was performed in anesthetized and non-anesthetized fish. (3) Biochemical parameters were evaluated at 0, 30, 60, and 120 min of recovery after being anesthetized for 3 min with 600 mg L-1 PHEO. Times to sedation and deep anesthesia were reduced with PHEO increasing concentrations. The echocardiogram showed a higher cardiac rate in anesthetized fish. Plasma glucose levels increased in control fish through recovery time, but anesthetized fish showed lower levels than controls at 120 min of recovery. Metabolic parameters such as plasma and hepatic glucose did not show changes considering the recovery time of up to 120 min. Hepatic glycogen, lactate, and triglycerides reduced their levels over recovery times. Fish anesthetized enhanced superoxide dismutase activity and thiobarbituric acid reactive substances levels but decreased reduced glutathione (GSH) levels at 30 min compared to controls. After 60 min, GSH values were significantly higher in anesthetized fish than in controls. These results suggest that PHEO at 600 mg L-1 is an effective anesthetic for the rapid handling of silver catfish, providing stable metabolic parameters and enhanced antioxidant responses during recovery. Echocardiogram analysis confirms the anesthetic effect, supporting PHEO as a viable and efficient option for fish anesthesia in aquaculture. The use of PHEO in aquaculture can enhance fish welfare by reducing stress during handling and transportation, potentially leading to improved growth, health, and survival rates.
ABSTRACT
This study evaluated the use of essential oil of Ocimum gratissimum (EOOG) for anesthesia and in transport of Colossoma macropomum. Experiment 1, Test 1, anesthesia induction and recovery times were determined using different EOOG concentrations (0, 20, 50, 100, 200, 300 mg L-1), with two size classes: Juveniles I (0.86 g) and Juveniles II (11.46 g) (independent tests in a completely randomized design). Based on the results of Test 1, in Test 2 Juveniles II were exposed to EOOG concentrations: 0, 20, 100 mg L-1. Tissue samples were collected immediately after induction and 1 h post-recovery, to assess oxidative status variables. Experiment 2, Juveniles I (0.91 g) and Juveniles II (14.76 g) were submitted to transport in water with different concentrations of EOOG (0, 5, 10 mg L-1) (independent tests in a completely randomized design). The effects on oxidative status variables were evaluated. Concentrations between 50 and 200 mg L-1 EOOG can be indicated for Juveniles I, while concentrations between 50 and 100 mg L-1 EOOG for Juveniles II. The concentration of 100 mg L-1 EOOG was able to prevent oxidative damage in the liver. In Experiment 2, the concentrations of 5 and 10 mg L-1 EOOG added to the transport water caused sedation for both studied size classes of juveniles and did not cause oscillations in water quality variables nor any mortality. The concentration of 10 mg L-1 EOOG improved the oxidative status. It can be concluded that EOOG can be used for anesthesia and transport of C. macropomum.
Subject(s)
Ocimum , Oils, Volatile , Animals , Oils, Volatile/pharmacology , Ocimum/chemistry , Oxidative Stress/drug effects , Characiformes , Anesthesia/veterinary , Liver/metabolism , Liver/drug effectsABSTRACT
The growing increase in the fish farming sector has favored the establishment of bacterial outbreaks caused by Aeromonas hydrophila in several species. The hexane extract of Hesperozygis ringens (HEHR) (Lamiaceae) leaves increased the survival rate of silver catfish (Rhamdia quelen) experimentally infected by A. hydrophila. However, it is noteworthy that no reports have been found on the possible mechanisms of action of this extract in infected fish. This study aimed to evaluate the effect of the HEHR, administered through single immersion bath, on lipid peroxidation and antioxidant defenses in muscle and liver tissue of silver catfish challenged with A. hydrophila. The results showed that the oxidative status of silver catfish was altered, although oxidative stress was not triggered during the experiment. HEHR at 30 mg/L (HEHR30) was not characterized as a pro-oxidant agent in the presence of infection, unlike florfenicol and HEHR at 15 mg/L treatments in some cases. In short, HEHR30 provided an important increase in hepatic catalase activity, characterizing one of the possible mechanisms involved in the greater survival of fish experimentally infected by A. hydrophila. Additionally, HEHR30 did not induce lipid peroxidation, nor reduced antioxidant defenses of silver catfish infected or not by A. hydrophila.
Subject(s)
Catfishes , Fish Diseases , Gram-Negative Bacterial Infections , Lamiaceae , Animals , Aeromonas hydrophila , Antioxidants/pharmacology , Hexanes , Immersion , Oxidation-Reduction , Fish Diseases/drug therapy , Fish Diseases/microbiology , Gram-Negative Bacterial Infections/drug therapy , Gram-Negative Bacterial Infections/veterinary , Gram-Negative Bacterial Infections/microbiologyABSTRACT
Climatic events are affecting the Amazon basin and according to projections it is predicted the intensification of climate changes through increases in temperature and carbon dioxide (CO2). Recent evidence has revealed that exposure to an extreme climate scenario elicits oxidative damage in some fish species, impairing their metabolism and physiology, contributing to their susceptibility. Thus, the comprehension of physiological alterations in Arapaima gigas (pirarucu) to the climatic changes forecasted for the next 100 years is important to evaluate its capability to deal with oxidative stress. The objective of this work was to determine whether antioxidant defense system is able to prevent muscle oxidative damage of pirarucu exposed 96 h to extreme climate scenario, as well as the effects of this exposition on muscle fatty acid levels. Lipid peroxidation and reactive oxygen species significantly increase in the muscle of pirarucus exposed to an extreme climate scenario compared to control, while muscle superoxide dismutase, catalase, and glutathione peroxidase were significantly lower. Total amount of saturated fatty acids (SFAs) was significantly higher in pirarucu exposed to an extreme climate scenario compared to control, while total content of monounsaturated (MUFAs) and polyunsaturated fatty acids (PUFAs) was significantly lower. Exposure to an extreme climate scenario causes muscular oxidative stress and that the antioxidant systems are inefficient to avoid oxidative damage. In addition, the increase of total SFAs and the decrease of MUFAs and PUFAs probably intend to maintain membrane fluidity while facing high temperature and CO2 levels.
Subject(s)
Antioxidants , Fatty Acids , Animals , Antioxidants/metabolism , Temperature , Carbon Dioxide/pharmacology , Oxidative Stress , Fishes/metabolism , Fatty Acids, UnsaturatedABSTRACT
This study aimed to identify the regions of the body surface of silver catfish (Rhamdia quelen) with a higher population of mucous cells in the skin. Additionally, the effects of stressful conditions, such as different stocking densities and food deprivation, on the proliferative response of mucous cells in the skin and gill epithelium and their impact on cutaneous mucous lysozyme activity were investigated. Silver catfish were divided into four experimental groups: high stocking density (32 kg/m3) and fed (HSD-F), high stocking density and fasted (HSD-FS), low stocking density (2.5 kg/m3) and fed (LSD-F), and low stocking density and fasted (LSD-FS). Fish in the fed groups received commercial feed twice a day, amounting to 1% of the tank biomass. After a 14-day experimental period, the fish were anesthetized and euthanized. Samples of cutaneous mucous and skin fragments from seven different points and the second left branchial arch were collected. Histological slides of the skin and gills were stained with PAS + Alcian Blue at pH 2.5, and the epidermal mucous lysozyme activity was assessed using the turbidimetric method. The ventral point in front of the ventral fin was found to be the optimal location for collecting cutaneous epithelia due to its higher density of mucous cells. The population of mucous cells in both the skin and gills varied based on the collection point and treatment applied. The highest lysozyme activity in the epidermal mucous was observed in fish from the HSD-F group. Overall, these findings suggest that stocking density and food deprivation create stressful conditions for silver catfish, which modulate their mucosal response to each situation.
ABSTRACT
R-(+)-limonene is a monoterpene from plants of the genus Citrus with diverse biological properties. This research evaluated the effects of dietary supplementation with R-(+)-limonene on growth, metabolic parameters in plasma and liver, and the antioxidant and stress responses in silver catfish, Rhamdia quelen, challenged or not with Aeromonas hydrophila. Fish were fed for 67 days with different doses of R-(+)-limonene in the diet (control 0.0, L0.5, L1.0, and L2.0 mL/kg of diet). On the 60th day, a challenge with A. hydrophila was performed. R-(+)-limonene in the diet potentiated the productive performance of the fish. The metabolic and antioxidant responses indicate that R-(+)-limonene did not harm the health of the animals and made them more resistant to the bacterial challenge. Histological findings showed the hepatoprotective effect of dietary R-(+)-limonene against A. hydrophila. Igf1 mRNA levels were upregulated in the liver of fish fed with an L2.0 diet but downregulated with bacterial challenge. The expression levels of crh mRNA were higher in the brains of fish fed with the L2.0 diet. However, the L2.0 diet downregulated crh and hspa12a mRNA expression in the brains of infected fish. In conclusion, the results indicated that R-(+)-limonene can be considered a good dietary supplement for silver catfish.
ABSTRACT
The aim of this study was to determine the biological effects of dietary supplementation with 0.05% and 0.1% cinnamon essential oil extracted from Cinnamomum cassia on silver catfish (Rhamdia quelen). The final body weight, weight gain, and specific growth rate were significantly higher in fish supplemented with 0.05% cinnamon essential oil than in the control(untreated) group. Muscle reactive oxygen species and lipid peroxidation levels were significantly lower in fish supplemented with 0.05% cinnamon essential oil but higher at the 0.1% concentration. Muscle antioxidant capacity against peroxyl radicals (ACAP) and superoxide dismutase activity were significantly higher in fish supplemented with 0.05% cinnamon essential oil, while ACAP levels were lower in fish supplemented with 0.1%. The total saturated fatty acid content was significantly higher in the muscle of supplemented fish than in controls, while the total monounsaturated fatty acid content was significantly higher only in fish fed 0.1% cinnamon essential oil. Finally, the total content of polyunsaturated fatty acids was significantly lower in fish fed 0.1% essential oil. Thus, data demonstrated that 0.05% C. cassia essential oil improves fish health by improving performance and muscle oxidant/antioxidant status. Higher doses of cinnamon essential oil produced oxidative stress in muscle, suggesting toxicity at the 0.1% level. Although this cinnamon essential oil diet exerted positive health effects, this diet impaired the muscle fatty acid profile, suggesting adverse impacts on human health.
Subject(s)
Catfishes , Cinnamomum aromaticum , Oils, Volatile , Animals , Humans , Antioxidants , Fatty Acids , Dietary Supplements , Muscles , Oils, Volatile/toxicityABSTRACT
This study aimed to verify the effect of different feeding and stocking conditions during 14 days on the gene expression of several hormones and enzymes related to the stress cascade and metabolic parameters in silver catfish Rhamdia quelen under the following experimental conditions: 1) fed at low stocking density (2.5 kg m-3, LSD-F); 2) fed at high stocking density (32 kg m-3, HSD-F); 3) food-deprived at LSD (LSD-FD); and 4) food-deprived at HSD (HSD-FD). Fish from LSD-F and HSD-F groups were fed daily (1 % of their body mass), while fish from food-deprived groups (LSD-FD and HSD-FD) were not fed during the experimental time. Plasma metabolic parameters (glucose, lactate, triglycerides, and proteins) and hepatosomatic index (HSI) were evaluated. In addition, mRNA expression of genes related to the stress axis (crh, pomca, pomcb, nr3c2, star, hsd11b2 and hsd20b), heat shock protein family (hsp90 and hspa12a), sodium-dependent noradrenaline transporter (slc6a2), and growth axis (gh and igf1) were also assessed. Specific growth rate and HSI decreased in food-deprived fish regardless of stocking density. The HSD-FD group showed weight loss compared to the HSD-F, LSD-F, and LSD-FD groups. Plasma glucose and triglycerides were reduced in food-deprived groups, while lactate and protein levels did not change. The expression of key players of the stress response (crh, pomca, pomcb, hsd11b2, nr3c2, and hsp90b) and growth (gh and igf1) pathways were differently regulated depending on the experimental condition, whereas no statistical difference between treatments was found for hsd20b, scl6a2, hspa12a, and star mRNAs expression. This study suggests that LSD acts as a stressor affecting negatively the physiological status of fed fish, as demonstrated by the reduction in growth rates, altered metabolic orchestration, and a higher crh mRNA expression. In addition, food deprivation also increased mRNA expression of other assessed genes (nr3c2, hsp90b, pomca, and pomcb) in fish from the HSD group, indicating higher responsiveness to stress in this stocking density when combined with food deprivation.
Subject(s)
Catfishes , Animals , Heat-Shock Proteins , HSP90 Heat-Shock Proteins , Lactates , RNA, MessengerABSTRACT
This study aimed to evaluate different concentrations of the essential oil of Hesperozygis ringens (EOHR) and its effects on anesthesia and transport of Oreochromis niloticus. Experiment I evaluated the concentrations of 0, 150, 300, 450, and 600 µL L-1 EOHR for times of induction and recovery from anesthesia and ventilatory frequency (VF) of O. niloticus (26 g), with 10 repetitions each in a completely randomized design. Based on the results of Experiment I, Experiment II submitted fish (25 g) to three treatments-control (clean water), ethanol (5 mL ethyl alcohol), and 600 µL L-1 EOHR-and then handling for biometry. Blood was collected 1 and 24 h after exposure and handling to analyze hematological and biochemical parameters in a completely randomized design in a factorial arrangement (3 × 2). Experiment III submitted fish (35 g) to simulated transport (4.5 h) with 0, 10, or 20 µL L-1 EOHR and determined the effects on blood variables. Concentrations of 450 and 600 µL L-1 EOHR provoked deep anesthesia in juvenile O. niloticus and provided induction and recovery times within the limits considered ideal for fish. However, this essential oil was not able to attenuate the effects of stress caused by biometric handling. EOHR was able to attenuate the effects of stress from simulated transport, with 10 µL L-1 EOHR being responsible for causing a decrease in protein, triglycerides, and cholesterol values immediately after transport of O. niloticus.
Subject(s)
Anesthetics , Cichlids , Oils, Volatile , Animals , Oils, Volatile/pharmacology , Hypnotics and Sedatives , Anesthetics/pharmacology , Biometry , Ethanol , Triglycerides , WaterABSTRACT
The physiological and behavioral responses of Pomacea canaliculata exposed to different pH values (4, 5, 6, 7, 8, 9, and 10) were evaluated. Survival, behavior (avoidance), metabolites (mantle), net ion fluxes (Na+ and K+), and ATPase activity (gills) were the parameters analyzed. The final survival rates were 100% (pH 4-9) and 90% (pH 10), and the groups did not differ significantly. Avoidance behavior was not identified in animals exposed to an extreme pH compared to pH 7. The main changes observed in the metabolites were in those exposed to an alkaline pH. Glucose (pH 9) and total protein (pH 9 and 10) levels increased, and lactate decreased (pH 9 and 10) compared to a neutral pH. There was an increase in Na+ efflux at pH 4, 5, and 8 and an influx at pH 9 and 10. Extreme pH values (4 and 10) also caused an increase in K+ efflux. At pH values outside the neutrality range (pH 7), there was a significant decrease in the activities of Na+/K+-ATPase (4, 5, 6, 9, and 10) and H+-ATPase (pH 4, 5, 9, and 10). Variations in environmental pH did not cause statistically significant mortality or avoidance behavior in P. canaliculata at the analyzed times. However, due to changes in energy metabolism (glucose and lactate, mainly) and ionoregulation, these can be considered sensitive biomarkers of stress in this species.
Subject(s)
Gills , Snails , Animals , Hydrogen-Ion ConcentrationABSTRACT
OBJECTIVE: To verify the efficacy of citral in inducing sedation and anesthesia in silver catfish (Rhamdia quelen) and grass carp (Ctenopharyngodon idella) and to assess the safety of essential oil (EO) of Aloysia citriodora and citral in inducing and maintaining anesthesia in silver catfish. STUDY DESIGN: Clinical study, randomized, parallel, multi-arm with control group in target species. ANIMALS: A total of 96 juvenile and 72 adult silver catfish and 80 juvenile grass carp were used. METHODS: Silver catfish and grass carp were exposed to different concentrations of citral, 15-675 and 15-600 µL L-1, respectively, during the maximum period of 30 minutes to verify sedation and anesthesia induction and recovery times. In addition, for anesthetic induction, silver catfish were exposed to the EO of A. citriodora and citral at 225 µL L-1 for 3.5 minutes. Then, fish were transferred to an anesthesia maintenance solution at 50 µL L-1 for 10 minutes to assess hematologic and biochemical variables at 60 minutes, 2 and 6 days after treatment. RESULTS: Citral only induced sedation from 15, 25 and 40 µLL-1 in both species. Anesthesia without mortality was induced in silver catfish at 50-600 µL L-1 and grass carp at 75-450 µL L-1. At 675 and 600 µL L-1, mortality was recorded in silver catfish and grass carp, respectively. The EO of A. citriodora and citral were safe in inducing and maintaining anesthesia in silver catfish, with mean corpuscular hemoglobin concentration being the only variable that varied in relation to time and treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Citral was effective in inducing sedation and anesthesia in both species. In addition, A. citriodora EO and citral were safe in inducing and maintaining anesthesia in silver catfish. Both agents are promising substances for the development of new drugs for fish.
Subject(s)
Anesthetics , Carps , Catfishes , Oils, Volatile , Acyclic Monoterpenes , Anesthetics/pharmacology , Animals , Hypnotics and Sedatives/pharmacology , Palau , VerbenaceaeABSTRACT
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.
Subject(s)
Catfishes , Nanocapsules , Animals , Gills , Liver , Models, TheoreticalABSTRACT
This study assessed the potential of eugenol and the essential oil of Lippia alba (EOLA) in providing suitable anesthetic induction and recovery times, and their consequent effects on the blood and respiratory physiology, as well as the gill architecture of an Amazonian freshwater stingray, Potamotrygon wallacei, shortly after reaching the recovery and 48 h later. Juveniles of P. wallacei were exposed to increasing concentrations of eugenol (75, 100, 125, and 150 µL L-1) and EOLA (150, 175, 200, and 225 µL L-1) in an immersion bath. Anesthetic induction was found to be faster with the use of eugenol compared to EOLA. On the other hand, the stingrays anesthetized with eugenol displayed a longer recovery time than those exposed to EOLA. The highest concentrations of eugenol caused moderate to severe histological changes in the gills. No significant changes were found for hematocrit and plasma energy metabolites in the stingrays anesthetized with all concentrations of both eugenol and EOLA shortly after reaching the recovery from the ansthesia, when compared to those recovered after 48 h. Investigations regarding the potential use of these natural anesthetics are unprecedented for freshwater stingray species, and 200 µL L-1 EOLA is recommended as the most suitable anesthetic for use in juveniles of P. wallacei.
Subject(s)
Anesthetics , Eugenol , Lippia , Oils, Volatile , Skates, Fish , Anesthetics/pharmacology , Animals , Eugenol/pharmacology , Fresh Water , Lippia/chemistry , Oils, Volatile/pharmacologyABSTRACT
The objective of this study was to evaluate the possible relaxing effect of essential oils (EOs) (Aloysia triphylla and Lippia alba) and phytochemicals (citral and linalool) in the gastropod Pomacea canaliculata. Animals were exposed to compounds at the concentrations range of 25-750 µL L-1. Magnesium chloride (MgCl2, 10-50 g L-1) and control group (ethanol 6.75 mL L-1, highest concentration used for treatment dilution) were also tested. The EOs, citral and MgCl2 had no relaxing effect at the concentrations range tested, and citral caused aversive behavior (closure of the operculum) from 90 µL L-1. Exposure to linalool at 25, 50, 100, 200 and 400 µL L-1 relaxed 28, 76, 88, 96 and 100% of the animals, respectively. The concentrations of 25, 50 and 400 µL L-1 differed statistically from each other, while 100 and 200 µL L-1 were equal to 50 and 400 µL L-1. All animals recovered up to 40 min, except at of 400 µL L-1. Linalool is effective for relaxing P. canaliculata and can be useful in management techniques that require relaxation. However, further studies are needed to certify whether linalool is appropriate for maintaining animal welfare in invasive procedures that require total insensitivity.
Subject(s)
Acyclic Monoterpenes/pharmacology , Lippia , Snails/drug effects , Verbenaceae , AnimalsABSTRACT
Lactococcosis, particularly that caused by Lactococcus garvieae, is a major re-emerging bacterial disease seriously affecting the sustainability of aquaculture industry. Medicinal herbs and plants do not have very much in vitro antagonism and in vivo disease resistance towards lactococcosis agents in aquaculture. Most in vitro studies with herbal extractives were performed against L. garvieae with no strong antibacterial activity, but essential oils, especially those that contain thymol or carvacrol, are more effective. The differences exhibited by the bacteriostatic and bactericidal functions for a specific extractive in different studies could be due to different bacterial strains or parts of chemotypes of the same plant. Despite essential oils being shown to have the best anti-L. garvieae activity in in vitro assays, the in vivo bioassays required further study. The extracts tested under in vivo conditions presented moderate efficacy, causing a decrease in mortality in infected animals, probably because they improved immune parameters before challenging tests. This review addressed the efficacy of medicinal herbs to lactococcosis and discussed the presented gaps.
ABSTRACT
An increase in water temperature in the Amazon River has elicited concerns about commercially important fish species associated with food security, such as matrinxã (Brycon amazonicus). Studies have demonstrated the positive effects of diets supplemented with plant-based products that combat heat stress-induced oxidative damage. The aim of this study was to determine whether dietary supplementation with nerolidol prevents or reduces muscle oxidative damage and impairment of the fillet fatty acid profile of matrinxã exposed to heat stress. Plasma and muscle reactive oxygen species (ROS) and lipid peroxidation (LPO) levels were significantly higher in fish exposed to heat stress compared to fish not exposed to heat stress, while plasma superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity was significantly lower. The total content of saturated fatty acids (SFA) in fillets was significantly higher in fish exposed to heat stress compared to fish not exposed to heat stress, while he total content of polyunsaturated fatty acids (PUFA) was significantly lower. Nerolidol prevented the increase of muscle LPO and plasma ROS and LPO levels in fish exposed to heat stress, and partially prevented the increase in muscle ROS levels. Diets containing nerolidol prevented the inhibition of muscle GPx activity in fish exposed to heat stress, and partially prevented the decrease of plasma GPx activity. The nerolidol-supplemented diet prevented the increase of fillet SFA in fish exposed to heat stress, while partially preventing the decrease of PUFA. We conclude that acute heat stress at 34 °C for 72 h causes plasma and muscular oxidative damage, and that homeoviscous adaptation to maintain membrane fluidity can represent a negative impact for fish consumers. A nerolidol diet can be considered a strategy to prevent heat stress-induced oxidative damage and impairment of muscle fatty acid profiles.
Subject(s)
Antioxidants/metabolism , Characidae/metabolism , Fatty Acids/metabolism , Heat-Shock Response , Muscles/metabolism , Sesquiterpenes/administration & dosage , Animals , Dietary Supplements , Lipid Peroxidation , Reactive Oxygen SpeciesABSTRACT
The aim of the current study is to investigate whether silver catfish (Rhamdia quelen) individuals exposed to commercial formulation of the chlorantraniliprole insecticide used in rice crops present changes in biochemical parameters. Fifty-four (54) silver catfish individuals were distributed in six units per tank (n = 6/repetition; triplicate/treatment) and subjected to the following treatments: T1-control, without insecticide; T2 (0.02 µg/L of insecticide) and T3 (0.20 µg/L of insecticide). Exposure time lasted 24 or 96 h, and it was followed by 96 h recovery in pesticide-free water. Results have indicated biochemical changes in cortisol, glucose, lactate and plasma protein levels, as well as few ionic changes in animals' gills during the exposure and recovery periods. Chlorantraniliprole incidence in water resulted in some biochemical changes in silver catfish specimens' plasma and gills throughout the acute exposure protocol (sub-lethal dose). Thus, chlorantraniliprole insecticide has caused osmoregulatory and/or biochemical imbalance in the investigated species under the herein adopted laboratory conditions; these changes did not get back to normal levels even after specimens were left to recover for 96 h in clean water.
Subject(s)
Catfishes , Insecticides , Animals , Gills , Humans , Insecticides/toxicity , ortho-Aminobenzoates/toxicityABSTRACT
This study points to evaluate the effects of pre-treatment with standardized dry extract of Curcuma longa (Motore™) added to the diet (0; 250; 500; and 750 mg/kg) on oxidative stress parameters, longevity, and therapeutic success in Rhamdia quelen experimentally infected with Aeromonas hydrophila (MF 372510). After treatment, the liver and kidney were collected to determine non-enzymatic oxidative parameters such as the formation of thiobarbituric acid reactive substances (TBARS), non-protein thiols (NPSH), and quantification of reactive oxygen species (ROS) levels. Also, two enzymatic antioxidant parameters were evaluated: superoxide dismutase (SOD) and catalase (CAT) activities. The results showed an increase of ROS and TBARS levels, a depletion in NPSH, and a decrease of SOD and CAT activities in infected fish compared to control. The highest Motore™ dose minimized the deleterious effect of A. hydrophila infection improving longevity, oxidative status, and survival rate. The addition of 750 mg Motore™/kg feed is recommended for silver catfish in fish farming. Serious economic losses in Rhamdia quelen culture caused by Aeromonas hydrophila infections can be prevented by the addition of Motore™ to the diet.
Subject(s)
Catfishes , Fish Diseases , Gram-Negative Bacterial Infections , Aeromonas hydrophila , Animals , Antioxidants , Dietary Supplements , Gram-Negative Bacterial Infections/drug therapy , Gram-Negative Bacterial Infections/veterinary , Oxidative StressABSTRACT
The Amazonian aquatic ecosystem undergoes seasonal variations and daily changes that directly affect the availability of oxygen. During the day the levels of oxygen can reach supersaturation, and at night can drop to zero. In this way, aquatic organisms are exposed daily to physiological challenges regarding the availability of oxygen. The present study revealed significant differences in the physiology and performance of two cichlids: Geophagus proximus (black water cichlid - from Negro River) and Chaetobranchopsis orbicularis (white water cichlid - from Amazon River), exposed to hypoxia. The white water cichlid showed lower value (1.99 ± 0.79 pKa) of critical pressure of oxygen (Pcrit) and a longer time (68.00 ± 14.11 min) for total loss of balance (LOE); however, this species showed 50% mortality during exposure to hypoxia, while the black water cichlid did not show mortality. Both cichlids presented a decrease in O2 consumption rate (OCR) during hypoxia.. In this sense, it was observed that the black water cichlid presented several physiological strategies during hypoxia, such as, a significant increase in plasma cortisol levels, nucleoside triphosphate diphosphohydrolase activity (for adenosine diphosphate (ADP) as a substrate) in the gills, and the activity of adenosine deaminase (ADA) in gills and liver, in addition to a significant increase in the activity of complexes (II-III) in the transporter chain of electrons in both analyzed tissues and succinate dehydrogenase activity of gills' mitochondria. On the other hand, the only physiological change observed in the white water cichlid was a significant reduction in the activity of complexes II-III in gills and liver. Based on our findings, we can hypothesize that the white water cichlid specie has less tolerant to hypoxia when compared to the black water cichlid.
Subject(s)
Cichlids/metabolism , Hypoxia/metabolism , Receptors, Purinergic/metabolism , Animals , Electron Transport , Fresh Water , Hydrocortisone/blood , Mitochondria, Liver/metabolism , South America , Species SpecificityABSTRACT
Evidence suggests the involvement of purinergic signaling, a mechanism mediated by extracellular nucleotides and nucleosides, with the impairment of immune and inflammatory responses in silver catfish (Rhamdia quelen) exposed to trichlorfon. Plant-derived substances have been considered potent anti-inflammatory agents due to effects on the purinergic system, such as the use of the flavonoid rutin. The aim of this study was to determine whether a diet containing rutin is able to prevent or reduce trichlorfon-induced impairment of immune responses through alteration of the purinergic pathway. Spleen adenosine triphosphate (ATP) levels were significantly higher in silver catfish exposed to 11 mg/L trichlorfon for 48 h compared to the control group, while adenosine (Ado) levels were significantly lower. Spleen ectonucleoside triphosphate diphosphohydrolase (NTPDase) activity was significantly lower in silver catfish exposed to trichlorfon compared to control group, while adenosine deaminase activity was significantly higher. Spleen metabolites of nitric oxide, interleukin-1, and IL-6 were significantly higher in silver catfish exposed to trichlorfon compared to control group. Diet with 3 mg rutin/kg diet was able to prevent all the alterations elicited by trichlorfon, except restoring spleen ATP levels. The purinergic exposure signaling is involved in impairment of immune and inflammatory responses in fish exposed to trichlorfon due to reduction in ATP hydrolyses and by an increase in Ado deamination, leading to release of pro-inflammatory mediators. Use of rutin-added diet exerted an essential role in protecting the silver catfish spleen from trichlorfon-induced impairment on immune and inflammatory responses, preventing all alterations on splenic purinergic signaling.