Assessment of Detoxifying Markers for Florfenicol in Rainbow Trout Liver

Impacts of florfenicol on immunity, antioxidant activity, and histopathology of Oreochromis niloticus: a potential protective effect of dietary spirulina platensis

The misuse of antibiotics enhances the development of resistant microorganisms and decreases the efficacy of treatments. Florfenicol (FF) is one of the antibiotics approved for use in aquaculture in Egypt. Because of its extensive usage, potential negative impacts on aquatic creatures are a major concern. This motivates us to search for an appropriate neoadjuvant to work synergistically with FF and reduce adverse effects. Results from this study will contribute towards improving the understanding of the impacts of FF on Oreochromis niloticus and the possible amelioratory effects of Spirulina platensis algae (SP). O. niloticus (n = 240; 40 ± 2.5 g) were fed on two diets supplemented with or without SP for 4 weeks, then divided into four treatments each in three replicates (n = 60/treatment). G1; was fed a control diet, and the other groups were fed diets supplemented with FF (10 mg /kg of BW, G2), SP (2 g/kg of diet, G3), or FF + SP (G4) for 10 days. Among the four groups, the SP group (G3) had the best immunostimulatory effects as observed by a significant (p < 0.05) elevation in phagocytic activity, phagocytic index, IL6, and TNF-α. The treatment with FF had significantly impacted hepatic and renal tissues, as the values of liver enzymes and creatinine demonstrated tissue deterioration and also resulted in oxidative stress, which was expressed by an increase of GPx, CAT, and SOD in (G2). Additionally, the combined FF + SP improved the hematological parameters and decreased the oxidative damage induced by FF (G4). Thus, it was clear that FF has harmful effects on O. niloticus and that SP can modulate such impacts. These data recommend the use of SP as an effective immunostimulant and a probable adjuvant to FF in O. niloticus diets to attain maximum disease resistance.

Impacts of Oral Florfenicol Medication and Residues on the Kidney and Liver of Nile Tilapia Oreochromis niloticus (L.)

Florfenicol (FFC), an approved aquaculture antibiotic, is administered in feed at doses of 10-15 mg kg biomass^-1 day^-1 for 10 successive days. In this study, healthy Oreochromis niloticus were fed with 0-10 times the therapeutic dose of 15 mg kg biomass^-1 day^-1 for 10 days and tracked for 43 days post dosing. Assessments of residue accrual and depletion, oxidative stress, serum biochemistry, histopathology and extent of kidney and liver damages were made. FFC dosing reduced the feed intake significantly. The therapeutic dose produced no mortalities on day 10. Dose-dependent alterations in serum biochemistry were noted upon dosing. Several histopathological alterations were observed in the kidney and liver, which vindicated the toxic potentials of FFC. The residual FFC and florfenicol amine (FFA) accrual, depletion and oxidative stress responses, such as increased malondialdehyde, total nitric oxide, ferric reducing antioxidant power and reduced glutathione S-transferase activity, were documented. The dietary FFC persuaded the physiological state of O. niloticus, the effects of which normalized sparsely with time upon cessation of dosing at the higher doses. The study provided a brief outlook on the physiological responses upon oral FFC administration, which should be kept in mind during its application for fish health safety purposes.

Biological Responses of Nile tilapia Oreochromis niloticus as Influenced by Dietary Florfenicol

Antibiotics are used in the treatment of bacterial diseases in commercial aquaculture. In this study, we the biological responses of Oreochromis niloticus juveniles upon dietary florfenicol (FFC) administration at 15 mg (1×) and 45 mg kg biomass^-1 day^-1 (3×) for 10 days in terms of feed intake, survival, biomass, hematological, erythro-morphological, serum biochemical, and histopathological aberrations as compared with controls. FFC caused a dose-dependent reduction in feed intake, survival, and biomass, with marked variations in hematology, hematological indices, and erythrocytic cellular and nuclear abnormalities, suggesting its apparent cytotoxic and nucleotoxic effects. The serum biomarkers increased significantly in a dose-dependent manner, except for calcium and chloride, which decreased significantly. The therapeutic dose (1×) group exhibited marked histopathological aberrations, such as renal tubular epithelial degeneration and a widened lumen in the kidney, as well as glycogen-type vacuolation and cytoplasmic degeneration in the liver during the dosing period. The extent of kidney and liver tissue damage was more prominent in the 3× group. The 1× serum biomarker levels became normal, with the exception of alkaline phosphatase, within 3 weeks of suspension of dosing. The recovery of the measured parameters and histopathological and erythro-morphological changes suggested that the therapeutic dietary biological responses induced by FFC are reversible and safe for O. niloticus.

Proteome and transcriptome explore the mechanism of Salvia miltiorrhiza polysaccharides to relieve florfenicol-induced kidney injury in broilers

This experiment explored the mechanism of Salvia miltiorrhiza polysaccharides (SMPs) on florfenicol (FFC)-induced kidney injury in broilers. Ninety healthy 1-day-old Arbor Acres broilers were randomly divided into 3 groups with 6 replicates in each group and 5 chickens in each replicate. The three groups included control group, model group (0.15 g/L FFC), and SMPs group (0.15 g/L FFC + 5.00 g/L SMPs). After 5 days of experimental period, blood was collected, and kidney tissues were extracted. Renal injury was evaluated by serum biochemical indicators and pathological sections. Renal oxidative stress indexes were detected; transcriptomics and proteomics were used to comprehensively analyze the effects of SMPs on broiler kidney injury. The results showed that the model group inhibited average day gain (P < 0.01) and significantly adjusted blood urea nitrogen (BUN), uric acid (UA), and creatinine (Cr) (P < 0.01 or P < 0.05). The histological observation of the kidneys in the model group showed abnormal morphology, and the oxidative stress parameters showed that FFC induced oxidative stress in the kidneys. Comprehensive transcriptome proteomic analysis data showed phosphoribose pyrophosphate synthase 2 (PRPS2), cytochrome 2AC1 (CYP2AC1), cytochrome 2D6 (CYP2D6), glutathione transferase (GST), and sulfotransferase 1B (SULT1B) expression levels changed. It is worth noting that our data showed that supplementation of 5.00 g/L SMPs in drinking water reversed the changes in BUN, Cr, and daily weight gain (P < 0.05) and relieved the abnormal kidney morphology caused by FFC. After SMPs processing, it improved the detoxification process of drug-metabolizing enzymes and improved the oxidative stress state induced by FFC. Therefore, SMPs reduced the nephrotoxicity caused by FFC by promoting drug-metabolizing enzymes and alleviating oxidative stress in the kidneys.

The effects of extended feeding of florfenicol coated medicated diets on the safety, serum biomarkers and blood cells morphology of Nile tilapia Oreochromis niloticus (L.)

Tilapia is one of the most consumed farmed fish, which requires the use of antibiotics in certain phases of its production. This study assessed the safety of 30 days of oral florfenicol (FFC) dosing at 0-10 times the therapeutic dose (1 × : 10 mg/kg biomass/day) in Oreochromis niloticus juveniles. Behavioural changes, feed consumption, mortality and biomass were evaluated. Besides, the levels of serum glucose, calcium, chloride, creatinine, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and blood cell morphology were determined at scheduled intervals. The 30 days of oral FFC dosing caused 3.33% (1 ×) to 18.33% (10 ×) mortalities, reduced feed intake and biomass in a dose-dependent manner. The fish fed the therapeutic dose recorded 1.25-fold increase in biomass, while the control group recorded 1.45-fold increase in 30 days. No significant erythrocyte morphological alterations were observed in the 1 × group compared to the control. However, marked morphological alterations like tear-shaped, spindle-shaped and degenerative erythrocytes in higher dosing groups indicated FFC cytotoxicity. All the serum biomarkers of O. niloticus increased significantly on day 10 and day 30 FFC dosing in a dose-dependent manner, except for calcium and chloride, which reduced significantly during the dosing period. Within 2 weeks of suspension of FFC dosing, the serum biomarker levels became normal except for alkaline phosphatase and creatinine. The recovery of biomass, feed intake, serum biomarker levels and erythrocyte morphological changes suggested that the FFC-induced changes are reversible. This study has, thus, proclaimed the safety of FFC at the therapeutic dose in O. niloticus.

Toxicity evaluation and oxidative stress response of fumaronitrile, a persistent organic pollutant (POP) of industrial waste water on tilapia fish (Oreochromis mossambicus)

The study was designed to determine the impact of acute toxicity of fumaronitrile exposure through tissue damaging, oxidative stress enzymes and histopathological studies in gills, liver and muscle cells of freshwater tilapia fish (Oreochromis mossambicus). In gill, liver, and muscle cells, biochemical indicators such as tissue damage enzymes (Acid Phosphatase (ACP), Alkaline Phosphatase (ALP), and Lactate Dehydrogenase (LDH)) and antioxidative enzymes (Superoxide Dismutase (SOD); Catalase (CAT); Glutathione-S-transferase (GST); Reduced Glutathione (GSH); Glutamate oxaloacetate transaminase (GOT) and Glutamate pyruvate transaminase (GPT) were quantified in the time interval of 30, 60 and 90 days exposure to the fumaronitrile. After 90 days, under 6 ppb exposure conditions, the acid phosphatase (ACP) levels of fish increased significantly in the gills (3.439 μmol/mg protein/min), liver (1.743 μmol/mg protein/min), and muscles (2.158 μmol/mg protein/min). After 90 days of exposure to the same concentration and days, ALP activity increased significantly in gills (4.354 μmol/mg protein/min) and liver (1.754 μmol/mg protein/min), but muscle cells had a little decrease in ALP activity (2.158 μmol/mg protein/min). The LDH concentration in gills following treatment with fumaronitrile over a period of 0-90 days was 3.573 > 3.521 > 2.245 μmol/mg protein/min over 30 > 60 > 90 days. However, at the same dose and treatment duration, a greater LDH level of 0.499 μmol/mg protein/min was found in liver and muscle cells. Histopathological abnormalities in the gills, liver, and muscle cells of treated fish were also examined, indicating that fumaronitrile treatment generated the most severe histological changes. The current study reveals that fumaronitrile exposure has an effect on Oreochromis mossambicus survival, explaining and emphasising the risk associated with this POP exposure to ecosystems and human populations.

Modulation of Antioxidant Defense in Farmed Rainbow Trout (Oncorhynchus mykiss) Fed with a Diet Supplemented by the Waste Derived from the Supercritical Fluid Extraction of Basil (Ocimum basilicum)

Phytotherapy is based on the use of plants to prevent or treat human and animal diseases. Recently, the use of essential oils and polyphenol-enriched extracts is also rapidly increasing in the aquaculture sector as a means of greater industrial and environmental sustainability. Previous studies assessed the antibacterial and antiparasitic effects of these bioactive compounds on fish. However, studies on the modulation of oxidative stress biomarkers are still scant to date. Thus, in this study, the modulation of antioxidant defense against oxidative stress exerted by fish diets supplemented with a basil supercritical extract (F1-BEO) was assessed in rainbow trout Oncorhynchus mykiss. The F1-BEO extracted with supercritical fluid extraction was added to the commercial feed flour (0.5, 1, 2, 3% w/w) and mixed with fish oil to obtain a suitable compound for pellet preparation. Fish were fed for 30 days. The levels of stress biomarkers such as superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, glutathione reductase, glyoxalase I, glyoxalase II, lactate dehydrogenase, glutathione and malondialdehyde showed a boost in the antioxidant pathway in fish fed with a 0.5% F1-BEO-supplemented diet. Higher F1-BEO supplementation led to a failure of activity of several enzymes and the depletion of glutathione levels. Malondialdehyde concentration suggests a sufficient oxidative stress defense against lipid peroxidation in all experimental groups, except for a 3% F1-BEO-supplemented diet (liver 168.87 ± 38.79 nmol/mg prot; kidney 146.86 ± 23.28 nmol/mg prot), compared to control (liver 127.76 ± 18.15 nmol/mg prot; kidney 98.68 ± 15.65 nmol/mg prot). Our results suggest supplementing F1-BEO in fish diets up to 0.5% to avoid potential oxidative pressure in farmed trout.

Environmentally Relevant Concentrations of Triclosan Induce Cyto-Genotoxicity and Biochemical Alterations in the Hatchlings of Labeo rohita

Xenobiotic Triclosan (TCS) is of great concern because of its existence in a variety of personal, household and healthcare products and continuous discharge in water worldwide. Excessive use of TCS-containing sanitizers and antiseptic products during the COVID-19 pandemic further increased its content in aquatic ecosystems. The present study deals with the cyto-genotoxic effects and biochemical alterations in the hatchlings of Labeo rohita on exposure to environmentally relevant concentrations of TCS. Three-days-old hatchlings were exposed to tap water, acetone (solvent control) and 4 environmentally relevant concentrations (6.3, 12.6, 25.2 and 60 µg/L) of TCS for 14 days and kept for a recovery period of 10 days. The significant concentration-dependent decline in cell viability but increase in micronucleated cells, nucleo-cellular abnormalities (NCAs) and DNA damage parameters like tail length, tail moment, olive tail moment and percent of tail DNA after exposure persisted till the end of recovery period. Glucose, triglycerides, cholesterol, total protein, albumin, total bilirubin, uric acid and urea (except for an increase at 60 µg/L) showed significant (p ≤ 0.05) concentration-dependent decrease after 14 days of exposure. The same trend (except for triglycerides, albumin and total bilirubin) continued till 10 days post exposure. In comparison to control, transaminases (alanine and aspartate aminotransferases) increased (p ≤ 0.05) after exposure as well as the recovery period, while a decline in alkaline phosphatase after exposure was followed by a significant increase during the recovery period. The results show that the environmentally relevant concentrations of TCS cause deleterious effects on the hatchlings of L. rohita.

Updating the use of biochemical biomarkers in fish for the evaluation of alterations produced by pharmaceutical products

The evaluation of toxic effects in stressful environmental conditions can be determined through the imbalance between exogenous factors (environmental contaminants) and enzymatic and non-enzymatic defenses in biological systems. The use of fish for the identification of alterations in biochemical biomarkers provides a comprehensive vision of the effects that pharmaceutical products cause in the aquatic ecosystem, as they are organisms with high sensitivity to contaminants, filtering capacity, and potential for environmental toxicology studies. A wide range of pharmaceuticals can stimulate or alter a variety of biochemical mechanisms, such as oxidative damage to membrane lipids, proteins, and changes in antioxidant enzymes. This review includes a summary of knowledge of the last 20 years, in the understanding of the different biochemical biomarkers generated by exposure to pharmaceuticals in fish, which include different categories of pharmaceutical products: NSAIDs, analgesics, antibiotics, anticonvulsants, antidepressants, hormones, lipid regulators and mixtures. This review serves as a tool in the design of studies for the evaluation of the effects of pharmaceutical products, taking into account the most useful biomarkers, type of matrix, enzyme alterations, all taking the pharmaceutical group of interest.

Enzymatic activity changes in striped catfish Pseudoplatystoma magdaleniatum, induced by exposure to different concentrations of ibuprofen and triclosan

The present study aimed to evaluate the effects of exposure for four months, with ibuprofen and triclosan at 25 and 50 μg/L in Striped catfish Pseudoplatystoma magdaleniatum, evaluated between sexes and exposure times. Biochemical biomarkers such as lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyltransferase, acetylcholinesterase, creatine kinase, lipid peroxidation, albumin, globulins, creatinine, and urea were evaluated. The results of this study suggest that both ibuprofen and triclosan at concentrations of 25 and 50 μg/L can cause alterations to P. magdaleniatum, interfering with the activity of certain enzymes associated with energy production, immune response, architecture, and cellular physiology. Also, we determined the current state of contamination in fish, the concentration of ibuprofen and triclosan in P. magdaleniatum muscle samples from the different places markets located on the banks of the main rivers of Colombia was quantified by UHPLC-QqQ-MS/MS, in three climatic periods; finding triclosan levels in the dry season in some of the sampling points compatible with enzyme-level alterations in this species.

Evaluation of health and environmental risks for juvenile tilapia (Oreochromis niloticus) exposed to florfenicol

Intensive fish cultivation has a high incidence of infection, which is often controlled by administering antibiotics. Florfenicol (FF) is one of the two antimicrobial drugs permitted for aquaculture in Brazil. Due to their intensive use, potentially harmful effects on aquatic organisms are of great concern. In this sense, we investigated whether the presence of FF in cultivation water could change the health parameters of Nile tilapia. For this, we evaluated hemoglobin, hematocrit, mean corpuscular hemoglobin (MCHC) concentration, mean corpuscular volume (MCV), total plasma protein (TPP), number of circulating red blood cells and leukocytes, as lipid peroxidation levels, catalase activity and glutathione S-transferase activity of fish exposed to 11.72 mg L⁻¹ of FF in water for 48 h. The fish were divided into two groups: Nile tilapia in water with FF or without FF (control). Exposure to FF in cultivation water for a short period didn't change the hematological variables analyzed, but caused changes in liver ROS (Reactive oxygen species) markers of the Nile tilapia, which was revealed by lipid peroxidation levels, catalase activity, and glutathione S-transferase. The 48h exposure period was enough to induce oxidative stress in hepatocytes, causing cellular oxidative damage. Therefore, the antibiotic florfenicol may cause toxicity to organisms and aquatic ecosystems, even at a sublethal concentrations near 1/100 LC50-48h for fish species.

Effects of dietary caffeic acid supplement on antioxidant, immunological and liver gene expression responses, and resistance of Nile tilapia, Oreochromis niloticus to Aeromonas veronii

The present study investigated the effects of dietary caffeic acid on haematological, serum biochemical, non-specific immune and liver gene expression responses of Nile tilapia, Oreochromis niloticus. Five experimental groups of fish with mean weights of 89.85 ± 2.5 g were used in the study; three of them were fed with caffeic acid incorporated diets (1 g kg^-1-Caf1, 5 g kg^-1-Caf5, 10 g kg^-1-Caf10), whereas an additive free basal diet served as the control. Additionally, the fifth group was an antibiotic medicated diet (0.02 g kg^-1-AMF), prepared with the florfenicol. Dietary caffeic acid especially at 5 g kg^-1 significantly increased phagocytic index, potential killing activity, respiratory burst activity, serum myeloperoxidase activity and serum catalase activity. Furthermore, increased levels of immune expression [heat shock protein 70 (HSP70), interleukin 1, beta (IL-1β), tumor necrosis factor (TNF-α), CC-chemokine (CC1), interleukin 8 (IL-8), toll-like receptor 7 (tlr-7), interferon gamma (IFN-γ) and immunoglobulin M (IgM)] and antioxidant related genes [superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)] in the liver of fish fed with 5 g kg^-1 caffeic acid. At the end of the 20-day challenge period the survival rates were significantly higher in the Caf5 and AMF groups compared to all other treatment groups. As a result, feeding Nile tilapia with a diet containing 5 g kg^-1 caffeic acid over a period of 60 days might be adequate to improve fish immune parameters, antioxidant status, as well as survival rate against A. veronii, similar to antibiotic treatment. Thus caffeic acid can be suggested as a dietary substitute for antibiotic to prevent A. veronii in tilapia.

Subacute Toxicity Effects of Deltamethrin on Oxidative Stress Markers in Rainbow Trout

Deltamethrin is a pyrethroid insecticide that is considered extremely toxic to aquatic organisms. We evaluated the effect of subacute doses (0.033, 0.1, or 0.3 mg/kg) of deltamethrin on micronucleus frequency and oxidative stress markers in Rainbow Trout Oncorhynchus mykiss at 1, 2, 3, 4, and 8 d after intracoelomic injection. No genotoxic damage was recorded, as no specimen showed a micronucleus number above the physiological range. Deltamethrin exposure elicited a transient reduction in the levels of superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase and a persistent decrease in glutathione reductase activity. Overall, the lower antioxidant enzyme activity in the deltamethrin-treated fish was mainly dose-dependent. Received May 27, 2016 accepted June 18, 2017.

Oxidative stress and related biomarkers in cupric and cuprous chloride-treated rainbow trout

We examined the time-course stress responses in the liver of rainbow trout exposed to cuprous chloride (CuCl) and cupric chloride (CuCl₂). The treatment groups received a single intraperitoneal injection of CuCl or CuCl₂ (both at a dose of 0.01 and 0.05 mg/kg); the control group received only the physiologic solution vehicle. Liver tissue samples were analyzed for total copper, superoxide dismutase, catalase, glutathione peroxidases, glutathione reductase, glutathione S-transferase, glyoxalases, and lactate dehydrogenase at 3, 6, and 9 days post-injection. Total glutathione, metallothionein, and malondialdehyde levels were also measured. The time course of metal accumulation differed between the groups; no dose-response relationship for metal load was found. Both copper species elicited significant changes in oxidative stress markers and in metal trapping. Copper underwent adaptive shifts in glutathione and metallothionein concentrations. The defense strategy primarily versus CuCl₂ first involved glutathione, with a peak in metallothionein levels at day 6 for CuCl₂ (at both doses) and for CuCl (0.05 mg/kg). Early stimulation of lipid peroxidation was noted after treatment with the higher copper dose and at day 9 after treatment with the lower dose of both CuCl and CuCl₂. Antioxidant enzyme activity was impaired due to a more or a less severe oxidative stress condition in relation to the copper species and exposure time. Copper dynamics, in terms of metal accumulation and homeostatic regulation, is noticeably complex. The present findings may advance our understanding of the effects of both copper species on the antioxidant response of rainbow trout.