The effect of lycopene on oxytetracycline-induced oxidative stress and immunosuppression in rainbow trout (Oncorhynchus mykiss, W.)

Influence of Long-Term Feeding Antibiotics on the Gut Health of Zebrafish

The use of antibiotics for anti-infection and growth promotion has caused the overuse of antibiotics in aquaculture. However, the benefit or risk of the long-term use of antibiotics on fish growth or health has not been fully addressed. In the present study, zebrafish were fed with sulfamethoxazole (SMX) or oxytetracycline (OTC) at the therapeutic concentrations (100 and 80 mg/kg body weight per day, respectively) for 6 weeks to mimic the long-term use of antibiotics. The digestive enzyme activities were higher in both antibiotic treatments, and higher oxygen consumption rate was found in OTC treated group. As a result, SMX increased the weight gain of zebrafish, and OTC treatment did not show significant prompting effect on growth. The mortality was higher in SMX or OTC treated group on 2nd-4th day after exposure to Aeromonas hydrophila. Lower alkaline phosphatase (AKP) and acid phosphatase (ACP) activities were found in OTC treated group, while higher malondialdehyde (MDA) content was found in the intestine of both SMX and OTC treated zebrafish. Furthermore, feeding OTC decreased the intestinal microbial richness. This study revealed that long-term use of legal aquaculture concentrations of antibiotics caused systemic adverse effects on fish gut health; stringent policy for use of antibiotics in fish is urgent.

Effect of excessive doses of oxytetracycline on stress-related biomarker expression in coho salmon

Fish are exposed to a wide variety of environmental stressors, such as chemicals and acute changes in temperature. Oxytetracycline (OTC) has been used as an antibiotic for many kinds of bacterial diseases in cultured fish, but excessive doses of OTC are known to cause side effects in fish and can have negative effects on their environment. In the present study, we examined stress-related biomarker expression in response to excessive doses of dietary OTC in coho salmon (Oncorhynchus kisutch). Fish received OTC (100 mg/kg body weight/day) orally for 2 weeks. The percentage of liver to body weight (hepatosomatic index; HSI) and plasma biochemical parameter, alanine aminotransferase (ALT) activity, of the group fed a diet containing OTC were observed to be significantly higher than those of the control group. The total glutathione (tGSH) levels in the liver of OTC-fed fish were four fold higher than those in control fish and double the control levels in muscle and stomach. Plasma tGSH levels in OTC-fed fish were also higher than those in control fish. Expression levels of heat shock protein 70 in the liver, muscle, and stomach decreased by OTC administration. Accordingly, OTC-induced stress might increase the metabolic turnover of GSH due to consumption by scavenging oxidants generated by stress. These results concerning the changing patterns of stress-related biomarkers indicate that excessive doses of OTC fed to coho salmon induce oxidative stress, which might enhance oxidation in the body and result in damage to tissues, especially in the liver. The present results also suggest that tissue-specific damage caused by OTC might already exist in fish.

UVB induces apoptosis via downregulation of CALML3-dependent JNK1/2 and ERK1/2 pathways in cataract

The aim of the current study was to understand the mechanisms of apoptosis occurring in cultured human lens epithelial cells (HLECs) following ultraviolet B (UVB) irradiation. The investigations intended to confirm the presence of apoptosis and to reveal the roles of oxidative stress, calcium (Ca2+), c‑Jun NH2‑terminal kinase (JNK)1/2, and extracellular signal‑regulated kinase (ERK)1/2 signaling pathway in these progresses. Cell apoptosis, ROS generation and intracellular Ca2+ concentration was measured by flow cytometry. The expression of CALML3, caspase-3, Bax, Bcl-2, p-JNK1/2, JNK1/2, p-ERK1/2 and ERK1/2 was measured by RT-qPCR and western blot analysis. Annexin V‑fluorescein isothiocyanate/propidium iodide staining demonstrated that UVB irradiation increased the apoptotic rate, reactive oxygen species (ROS) production and intracellular Ca2+ concentration of HLECs in dose‑ and time‑dependent manners. Overexpression of calmodulin like 3 (CALML3) reversed the effects of UVB irradiation on apoptosis, ROS production and Ca2+ concentration of HLECs, and decreased expressions of caspase‑3 and Bax, with increased expressions of Bcl‑2. Notably, silencing of CALML3 had similar effects to UVB irradiation and inhibited the activation JNK1/2 and ERK1/2 pathways. Nimodipine, a Ca2+‑channel antagonist, significantly attenuated the damages induced by CALML3 downregulation. In conclusion, UVB irradiation induced increase in apoptosis, ROS production and Ca2+ concentration of HLECs, in part, by downregulating the expression of CALML3 and involved oxidative stress, Ca2+, JNK1/2 and ERK1/2 signaling pathways, suggesting that investigating CALML3 may useful for developing cataract treatment.

The oxidative stress response of oxytetracycline in the ciliate Pseudocohnilembus persalinus

Oxytetracycline (OTC) is commonly employed in fish farms to prevent bacterial infections in China, and because of their widely and intensive use, the potential harmful effects on organisms in aquatic environment are of great concern. Ciliates play an important role in aquatic food webs as secondary producers, and Pseudocohnilembus persalinus, is one kind of them which are easily found in fish farms, surviving in polluted water. Therefore, using P. persalinus as experimental models, this study investigated the effects of oxytetracycline (OTC) on the growth, antioxidant system and morphological damage in pollution-resistant ciliates species. Our results showed that the 96-h EC₅₀ values for OTC of P. persalinus was 21.38mgL^-1. The increased level of SOD and GSH during 96h OTC stress was related to an adaptive response under oxidative stress induced in ciliates. Additionally, sod1, sod2 and sod3 exhibited a significant increased expression level compared to control group at 24h treatment, indicating a promoting of dense system in ciliates at this exposure time. However, only sod1 and sod2 showed raised expression level at 48h stress, showing the different sensitive of gene isoforms to some extent. With OTC treatment, damage of regular wrinkles, shrunk, twisted on the cell surface, even forming cyst of scuticociliatid ciliate cells were firstly observed by SEM (scanning electron microscope) in this study. Overall, physiological, molecular and morphological information on the toxicological studies of ciliates and more information on possibility of ciliates as indicators of contamination were provided in this study.

Modulatory effect of lycopene against carbofuran toxicity in African catfish, Clarias gariepinus

In the current study, African catfish, Clarias gariepinus, was exposed to a sublethal concentration of carbofuran (CF) to investigate its negative effects on biochemical and oxidative stress biomarkers. Also, the putative role of lycopene (LYC) administration in alleviating these negative effects was evaluated. Fish were divided into six groups in triplicates as follows: group I was without treatment, group II was orally administered corn oil, group III was orally administered 18 mg LYC/kg body weight, group IV was exposed to 0.121 mg CF/L, group V was orally administered 9 mg LYC/kg body weight and exposed to 0.121 mg CF/L, and group VI was orally administered 18 mg LYC/kg body weight and exposed to 0.121 mg CF/L for 4 weeks. At the end of this period, blood and tissue (liver and kidney) samples were collected and biochemical and oxidative stress biomarkers were analysed. Also, histopathological changes were determined. Carbofuran caused significant increments of glucose, cortisol, aspartic amino transferase, alanine amino transferase, cholesterol, urea, and creatinine; meanwhile, serum acetylcholinesterase, total protein, albumin, and total lipids were significantly reduced. Significant increments in hepatic and renal malondialdehyde (MDA) and superoxide dismutase (SOD) levels and marked reduction in hepatic and renal catalase (CAT), glutathione (GSH), and total antioxidant capacity (TAC) levels were observed in CF-exposed fish comparing to the control group. Treatment with LYC attenuated the CF-induced oxidative stress, and this improvement was more pronounced in fish received the high LYC dose (18 mg/kg body weight). Further, congestion of the central vein with infiltration of mononuclear inflammatory cells, vacuolar necrosis, and haemorrhage was observed in the livers of CF-exposed fish. Oral administration of LYC reduced behavioural changes and histopathological alterations. All the altered biochemical parameters and antioxidant biomarkers were also restored to be near the normal levels. The obtained results evoked that LYC administration alleviated the destructive effects of carbofuran and reduced its toxicity effect on African catfish.

Histological alterations in gills and liver of rainbow trout (Oncorhynchus mykiss) after exposure to the antibiotic oxytetracycline

The aim of this study was to investigate the histopathological effects of oxytetracycline (OTC) on the gill and liver tissues of rainbow trouts (Oncorhynchus mykiss) following acute (96h: 0.005-50mg/L) and chronic (28days: 0.3125-5μg/L) exposures. Results suggest the existence of a cause-and-effect relationship between the exposure to OTC and tissue damage. Most predominant disorders observed in gills were progressive (e.g. hypertrophy of mucous cells and hyperplasia of epithelial cells) in acute exposure and regressive (e.g. lamellar fusion, epithelial lifting of lamellae and some changes in tissue architecture) in chronic exposure. However, only the acute exposure was responsible for a significant increase of the total gill pathological index. PAGE index, reflecting the extent of gill tissue available for gas exchanges in fish, remained unchanged for both exposures. In liver, circulatory (e.g. hemorrhage and increase of sinusoidal space), regressive (e.g. pyknotic nucleus, vacuolization and hepatocellular degenerations) and progressive (e.g. hypertrophy of hepatocytes) changes were observed, but just after acute exposure. After chronic exposure, only inflammatory changes (e.g. leucocytes infiltration) were observed. Following both exposures, a significant increase of the total liver pathological index was recorded. Despite the increase of the histological damage in individuals exposed to OTC, lesions observed were of minimal or moderate pathological importance, non-specific and reversible. The data gathered following acute and chronic exposures also suggest the onset of adaptive mechanisms of fish, namely for longer exposure periods. Furthermore the observed histological alterations appear to be result of several physio-metabolic disorders consequence of the biochemical and molecular modes of action of OTC.

Biochemical parameters of silver catfish (Rhamdia quelen) after transport with eugenol or essential oil of Lippia alba added to the water

The transport of live fish is a routine practice in aquaculture and constitutes a considerable source of stress to the animals. The addition of anesthetic to the water used for fish transport can prevent or mitigate the deleterious effects of transport stress. This study investigated the effects of the addition of eugenol (EUG) (1.5 or 3.0 µL L-1) and essential oil of Lippia alba (EOL) (10 or 20 µL L-1) on metabolic parameters (glycogen, lactate and total protein levels) in liver and muscle, acetylcholinesterase activity (AChE) in muscle and brain, and the levels of protein carbonyl (PC), thiobarbituric acid reactive substances (TBARS) and nonprotein thiol groups (NPSH) and activity of glutathione-S-transferase in the liver of silver catfish (Rhamdia quelen; Quoy and Gaimard, 1824) transported for four hours in plastic bags (loading density of 169.2 g L-1). The addition of various concentrations of EUG (1.5 or 3.0 µL L-1) and EOL (10 or 20 µL L-1) to the transport water is advisable for the transportation of silver catfish, since both concentrations of these substances increased the levels of NPSH antioxidant and decreased the TBARS levels in the liver. In addition, the lower liver levels of glycogen and lactate in these groups and lower AChE activity in the brain (EOL 10 or 20 µL L-1) compared to the control group indicate that the energetic metabolism and neurotransmission were lower after administration of anesthetics, contributing to the maintenance of homeostasis and sedation status.

Toxic responses of swimming crab (Portunus trituberculatus) larvae exposed to environmentally realistic concentrations of oxytetracycline

Oxytetracycline (OTC) is the most commonly used antibiotics for bacterial treatment in crustacean farming in China, and because of their intensive use, the potential harmful effects on aquatic organisms are of great concern. The aim of this study was to investigate the effects of oxytetracycline (OTC) on the antioxidant system, detoxification progress, and biomolecule damage in Portunus trituberculatus larvae. In this study, larvae that belonged to four zoeal stages were exposed to four different concentrations of OTC (0, 0.3, 3, and 30 μg/L) for 3 days. The results showed that the exposure to OTC significantly suppressed the antioxidant system of, especially, zoea I (Z1) and zoea II (Z2) larvae. OTC inhibited the transcriptional expression of phase I (CYP2 and CYP3) and phase II detoxification genes (GST) in a dose-dependent manner and altered the expressions of their corresponding enzymes, namely, aminopyrine N-demethylase, erythromycin N-demethylase, and glutathione S-transferase. Moreover, 0.3 μg/L OTC activated the transcription of ATP-binding cassette (ABC) transporter subfamily B (ABCB) and subfamily G (ABCG) in the Z1 and Z2 larvae, while 3 and 30 μg/L OTC suppressed all of them. Additionally, malondialdehyde content exhibited a dose- and zoea-effect relationship to some extent, but no significant differences were observed in the F values of the Z3 and Z4 larvae, except for the 30 μg/L OTC treatment. Thus, the Z3 and Z4 larvae were less sensitive to OTC exposure than the Z1 and Z2 larvae.

Rainbow trout (Oncorhynchus mykiss) pro-oxidant and genotoxic responses following acute and chronic exposure to the antibiotic oxytetracycline

Oxytetracycline (OTC), an antibacterial agent, is extensively used in aquaculture practices all over the world, but also in human and veterinary medicines. Because of its intensive use, low rates of absorption by treated animals, inadequate disposal, and low efficiency of removal in wastewater treatment plants, the potential harmful effects on aquatic organisms are of great concern. This work aimed to assess the effects of this antibiotic in rainbow trout, following both acute and chronic exposures. Catalase (CAT), total glutathione peroxidase (GPx), glutathione reductase (GRed) activities and lipid peroxidation (TBARS levels) were quantified as oxidative stress biomarkers, in gills and liver. Genotoxic endpoints, reflecting different types of genetic damage in blood cells, were also determined, by analysis of genetic damage (determination of the genetic damage index, GDI, measured by comet assay) and erythrocytic nuclear abnormalities (ENAs). The obtained results showed a mild pattern of antioxidant response, with modifications in CAT and GPx activities in gills, and lipid peroxidation in liver. These results suggest that despite the occurrence of oxidative effects, a full scenario of oxidative stress is not likely. However, exposure to OTC resulted in the establishment of genotoxic alterations with the induction of DNA strand breaks in blood cells (increase of GDI), and of chromosome breakage and/or segregational abnormalities (increase of ENAs). Considering that the oxidative response was not totally devisable, other mechanisms may be involved in the genotoxic effects reported.

Assessment of the individual and mixture toxicity of cadmium, copper and oxytetracycline, on the embryo-larval development of the sea urchin Paracentrotus lividus

Multiple pollutions by trace metals and pharmaceuticals have become one of the most important problems in marine coastal areas because of its excessive toxicity on organisms living in this area. This study aimed to assess the individual and mixture toxicity of Cu, Cd, and oxytetracycline frequently existing in the contaminated marine areas and the embryo-larval development of the sea urchin Paracentrotus lividus. The individual contamination of the spermatozoid for 1 h with the increasing concentrations of Cd, Cu, and OTC decreases the fertility rate and increases larvae anomalies in the order Cu > Cd > OTC. Moreover, the normal larva frequency and the length of spicules were more sensitive than the fertilization rate and normal gastrula frequency endpoints. The mixture toxicity assessed by multiple experimental designs showed clearly that concentrations of Cd, Cu, and OTC superior to 338 μg/L, 0.56 μg/L, and 0.83 mg/L, respectively, cause significant larva malformations.

Antioxidant defenses at transcriptional and enzymatic levels and gene expression of Nrf2-Keap1 signaling molecules in response to acute zinc exposure in the spleen of the large yellow croaker Pseudosciaena crocea

We evaluated the effects of acute Zn exposure (4 and 8 mg L(-1) Zn) on lipid peroxidation, and activities and mRNA levels of antioxidant enzyme genes (Cu/Zn-SOD, CAT, GPx, and GR), and gene expression of the Nrf2-Keap1 signaling molecule at different exposure times (0, 6, 12, 24, 48, and 96 h) in the spleen of large yellow croaker. Lipid peroxidation remained relatively constant during 6-48 h and 6-24 h and sharply increased at 96 h and during 48-96 h in fish exposed to 4 and 8 mg L(-1) Zn, respectively. Activities of all tested enzymes increased during the early stage of exposure and decreased towards the end of the exposure in both groups. However, mRNA levels of antioxidant enzyme genes were dramatically up-regulated by 4 and 8 mg L(-1) Zn during the late stage of exposure. During the early stage of exposure for 6 h, the 8 mg L(-1) Zn exposure sharply increased mRNA levels of Cu/Zn-SOD, CAT, GPx1b, Nrf2, and Keap1, whereas, the 4 mg L(-1) Zn exposure did not significantly affect the expression of these genes. Our data also showed positive relationships between Nrf2 expression and mRNA levels of its target genes, suggesting that Nrf2 was required for the protracted induction of these genes. Furthermore, a sharp increase in Keap1 expression levels was observed in fish exposed to 4 mg L(-1) at 96 h, and 8 mg L(-1) at 6, 48, and 96 h. In conclusion, the present study demonstrated that Zn-induced antioxidant defenses were involved in modifications at enzymatic and transcriptional levels and the transcriptional regulation of the Nrf2-Keap1 signaling molecule; these results may contribute to the understanding of mechanisms that maintain the correct redox balance in the immune organ of the large yellow croaker.

Effect of dietary glutamine on growth performance, non-specific immunity, expression of cytokine genes, phosphorylation of target of rapamycin (TOR), and anti-oxidative system in spleen and head kidney of Jian carp (Cyprinus carpio var. Jian)

This study was designed to investigate the effects of dietary glutamine on the growth performance, cytokines, target of rapamycin (TOR), and antioxidant-related parameters in the spleen and head kidney of juvenile Jian carp (Cyprinus carpio var. Jian). Fish were fed the basal (control) and glutamine-supplemented (12.0 g glutamine kg(-1) diet) diets for 6 weeks. Results indicated that the dietary glutamine supplementation improved the growth performance, spleen protein content, serum complement 3 content, and lysozyme activity in fish. In the spleen, glutamine down-regulated the expression of the interleukin 1 and interleukin 10 genes, and increased the level of phosphorylation of TOR protein. In the head kidney, glutamine down-regulated the tumor necrosis factor α and interleukin 10 gene expressions, phosphorylated and total TOR protein levels, while up-regulated the transforming growth factor β2 gene expression. Furthermore, the protein carbonyl content was decreased in the spleen of fish fed glutamine-supplemented diet; conversely, the anti-hydroxyl radical capacity and glutathione content in the spleen were increased by glutamine. However, diet supplemented with glutamine did not affect the lipid peroxidation, anti-superoxide anion capacity, and antioxidant enzyme activities in the spleen. Moreover, all of these antioxidant parameters in the head kidney were not affected by glutamine. Results from the present experiment showed the importance of dietary supplementation of glutamine in benefaction of the growth performance and several components of the innate immune system, and the deferential role in cytokine gene expression, TOR kinase activity, and antioxidant status between the spleen and head kidney of juvenile Jian carp.

Acute effects of tetracycline exposure in the freshwater fish Gambusia holbrooki: antioxidant effects, neurotoxicity and histological alterations

A large body of evidence was compiled in the recent decades showing a noteworthy increase in the detection of pharmaceutical drugs in aquatic ecosystems. Due to its ubiquitous presence, chemical nature, and practical purpose, this type of contaminant can exert toxic effects in nontarget organisms. Exposure to pharmaceutical drugs can result in adaptive alterations, such as changes in tissues, or in key homeostatic mechanisms, such as antioxidant mechanisms, biochemical/physiological pathways, and cellular damage. These alterations can be monitored to determine the impact of these compounds on exposed aquatic organisms. Among pharmaceutical drugs in the environment, antibiotics are particularly important because they include a variety of substances widely used in medical and veterinary practice, livestock production, and aquaculture. This wide use constitutes a decisive factor contributing for their frequent detection in the aquatic environment. Tetracyclines are the individual antibiotic subclass with the second highest frequency of detection in environmental matrices. The characterization of the potential ecotoxicological effects of tetracycline is a much-required task; to attain this objective, the present study assessed the acute toxic effects of tetracycline in the freshwater fish species Gambusia holbrooki by the determination of histological changes in the gills and liver, changes in antioxidant defense [glutathione S-transferase (GST), catalase (CAT), and lipoperoxidative damage] as well as potential neurotoxicity (acetylcholinesterase activity). The obtained results suggest the existence of a cause-and-effect relationship between the exposure to tetracycline and histological alterations (more specifically in gills) and enzymatic activity (particularly the enzyme CAT in liver and GST in gills) indicating that this compound can exert a pro-oxidative activity.

Development and application of a multiroute physiologically based pharmacokinetic model for oxytetracycline in dogs and humans

Oxytetracycline (OTC) is a commonly used tetracycline antibiotic in veterinary and human medicine. To establish a quantitative model for predicting OTC plasma and tissue exposure, a permeability-limited multiroute physiologically based pharmacokinetic model was developed in dogs. The model was calibrated with plasma pharmacokinetic data in beagle dogs following single intravenous (5 mg/kg), oral (100 mg/kg), and intramuscular (20 mg/kg) administrations. The model predicted other available dog data well, including drug concentrations in the liver, kidney, and muscle after repeated exposure, and data in the mixed-breed dog. The model was extrapolated to humans and the human model adequately simulated measured plasma OTC concentrations after intravenous (7.14 mg/kg) and oral exposures (6.67 mg/kg). The dog model was applied to predict 24-h OTC area-under-the-curve after three therapeutic treatments. Results were 27.75, 51.76, and 64.17 μg/mL*h in the plasma, and 120.93, 225.64, and 279.67 μg/mL*h in the kidney for oral (100 mg/kg), intravenous (10 mg/kg), and intramuscular (20 mg/kg) administrations, respectively. This model can be used to predict plasma and tissue concentrations to aid in designing optimal therapeutic regimens with OTC in veterinary, and potentially, human medicine; and as a foundation for scaling to other tetracycline antibiotics and to other animal species. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:233-243, 2015.

Tomato juice consumption improves blood antioxidative biomarkers in overweight and obese females

BACKGROUND & AIMS

A few studies reported the beneficial effects of tomato juice on oxidative stress status. However, supporting data in obese subjects is scarce. This study aimed to determine the effects of tomato juice consumption on erythrocyte antioxidant enzymes, namely, superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT), plasma total antioxidant capacity (TAC), and serum malondialdehyde (MDA) in overweight and obese females.

METHODS

A randomized controlled clinical trial was conducted on 64 overweight or obese (BMI = 25 kg/m(2) or higher) female students of Shiraz University of Medical Sciences. Subjects randomly received tomato juice (n = 32, 330 ml/d) or water (n = 28) for 20 days. Daily dietary intake, anthropometric measures and blood antioxidant parameters were determined at the beginning and after 20 days intervention period.

RESULTS

Plasma TAC and erythrocyte antioxidant enzymes increased and serum MDA decreased in the intervention group compared with baseline and with the control group (p < 0.05). In the intervention group, similar results were found in overweight, but not in obese, subjects.

CONCLUSION

Our results suggest that tomato juice reduces oxidative stress in overweight (and possibly obese) females and, therefore, may prevent from obesity related diseases and promote health.

Protective effect of shrimp carotenoids against ammonia stress in common carp, Cyprinus carpio

This study is aimed at evaluating the protective effect of shrimp carotenoids on ammonia stress in common carp. Crude carotenoid extract from shrimp exoskeleton, astaxanthin and astaxanthin ester fractionated from crude extract was fed to the common carp fingerlings at 100 and 200ppm concentration by incorporating carotenoids into feed. Experimental and control fish were then exposed to sublethal dose of ammonia. Serum total antioxidant status (TAS), activities of superoxide dismutase (SOD) and catalase were measured to determine the effect of dietary carotenoid on defense status of fish. Activities of aspartate transaminase (AST) and alanine transaminase (ALT) were measured to determine the protective effect of carotenoids against tissue damage caused by the ammonia stress. TAS, catalase and SOD activity was higher in tissues from fish fed with the diet containing astaxanthin rich and astaxanthin ester rich extract compared to fish fed with control diet. TAS reduced in the tissues considerably after exposure to ammonia. However, TAS was still higher in tissues from fish fed with carotenoid containing diet than in tissues from fish fed with control diet. Eventhough there was an increase in the activities of ALT and AST due to stress by ammonia toxicity in all groups, fish fed with astaxanthin extract had lower activities and also prevented lipid peroxidation in the tissues. In conclusion, shrimp carotenoid increased the resistance of common carp fingerlings to ammonia induced stress.

Transferability of oxytetracycline (OTC) from feed to carp muscle and evaluation of the antibiotic effects on antioxidant systems in liver and kidney

Oxytetracycline (OTC) is employed in fish farms to contest or prevent bacterial infections. We simulated an OTC treatment at therapeutic level (75 mg kg(-1)) and at higher doses (150, 300 mg kg(-1)) for 10 days. A withdrawal period of 10 days was considered for treated carp, carrying out the same chemical and biochemical analyses (total glutathione, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione S-transferase and malondialdehyde). The aim was to obtain data related to the carryover in muscle and on variations in the antioxidant indicators in liver and kidney. The OTC residual levels in muscle showed a dose-response relationship. After 10 days of treatment at the recommended dose (75 mg kg(-1)), the mean value in muscle was 295 μg kg(-1). After 10 withdrawal days, residues in all treated groups were not entirely eliminated by fish. Residues of recommended 75 mg kg(-1) OTC dose were lower than the maximum permitted by EEC regulation: 100 μg kg(-1). Disturbance in the antioxidant systems in liver and kidney was recorded in (150, 300 mg kg(-1)) carp, as well as during the withdrawal period. A lowered superoxide dismutase activity and higher levels of catalase, glutathione peroxidase, glutathione reductase and glutathione were evaluated in liver, while in kidney only higher malondialdehyde and glutathione S-transferase concentrations were recorded for 300 mg kg(-1) dose. The therapeutic OTC dose exerted lower effects, and only in liver, enhancement of GPx and GR activities was recorded. After the withdrawal period, altered antioxidant responses in tissues were restored for all three OTC doses.

Protective effect of aquacultured flounder fish-derived peptide against oxidative stress in zebrafish

This study investigates the protective effect of aquacultured flounder fish-derived peptide (AFFP) against 2,2-azobis-(2-amidinopropane) hydrochloride (AAPH)-induced oxidative damage in a zebrafish model. Zebrafish embryos were evaluated for the protective effect by heartbeat rate, survival rate, ROS generation, lipid peroxidation, and cell death. In the results, the AAPH group showed a low survival rate, whereas the AFFP and AAPH co-treated group increased a survival rate. Also, AFFP dose-dependently reduced AAPH-induced intracellular ROS and lipid peroxidation, and decreased cell death in AAPH-induced zebrafish. These results revealed that AFFP could be used as a natural antioxidant, and that the zebrafish provides an alternative in vivo model to efficiently evaluate the antioxidative effects of peptides on fishes.

The effect of oyster mushroom β-1.3/1.6-D-glucan and oxytetracycline antibiotic on biometrical, haematological, biochemical, and immunological indices, and histopathological changes in common carp (Cyprinus carpio L.)

The aim of the study was to evaluate the effect of micronized β-1.3/1.6-D-glucan (BG) derived from the oyster mushroom Pleurotus ostreatus Hiratake and tetracycline antibiotic oxytetracycline (OTC) on biometrical, haematological, biochemical, and immunological indices, and histopathological changes in tissues of one- to two-year-old common carp (Cyprinus carpio L.). The fish tested were divided into five experimental groups and one control. Carp in the control group were fed commercial carp feed pellets. Fish in the five experimental groups were fed the same pellets supplemented with either OTC, a combination of OTC and BG, or BG as follows: 75 mg oxytetracycline kg(-1) bw (OTC group), 75 mg oxytetracycline kg(-1) bw and 0.5% β-glucan (OTC + 0.5% BG group), 75 mg oxytetracycline kg(-1) bw and 2.0% β-glucan (OTC + 2.0% BG group), 0.5% β-glucan (0.5% BG group), and 2.0% β-glucan (2.0% BG group). OTC- and BG-supplemented diets and the control diet were administered to experimental and control carp for 50 days (i.e. samplings 1-3, the exposure period); for the following 14 days, fish were fed only control feed pellets with no OTC or BG supplementation (i.e. sampling 4, the recovery period). Blood and tissue samples were collected both during, and at the end of the study. No significant changes in biometrical indices (i.e. total length, standard length, total weight, hepatosomatic and spleen somatic index, and Fulton's condition factor) were found in experimental carp compared to control in any sampling. In haematological indices, significant changes were found only in sampling 2, in which shifts in PCV (P < 0.01), Hb (P < 0.01), and WBC (P < 0.01), and in the counts of lymphocytes (P < 0.01), monocytes (P < 0.01), and neutrophil granulocytes-segments (P < 0.05) were revealed. As for biochemical profiling, plasma concentrations of glucose, albumins, cholesterol, natrium, and chlorides (all P < 0.01), and total proteins, lactate, phosphorus, and potassium (all P < 0.05) as well as the catalytic activity of ALP (P < 0.05) were altered in common carp. A significant change in induced (opsonizedzymosan particles, OZP) chemiluminescence (P < 0.05) in sampling 3 and no shifts in serum immunoglobulins concentration were found in the immunological analysis. Histopathological examination of skin, gills, liver, spleen, and cranial and caudal kidneys revealed no obvious specific changes in any tissue analysed. The use of β-glucans in clinically healthy aquaculture remains an issue. Nevertheless, their use in breeding endangered by stress stimuli, infectious disease, or adverse environmental factors is defensible.

Toxic effects of malathion in carp, Cyprinus carpio carpio: protective role of lycopene

The present study was carried out in order to investigate the potential protective effects of lycopene against malathion-induced toxicity in carp. The fish were exposed to sublethal concentrations of malathion (0.5 and 1mgL(-1)) for 14 days, and lycopene (10mgkg(-1) of fish weight) was simultaneously administered. Samples of the blood and tissue (liver, kidneys, and gills) were collected at the end of the experimental period and their haematological profiles [red blood cell (RBC) counts, haemoglobin (Hb) concentrations, haematocrit (Ht) levels, and erythrocyte indices, including the mean corpuscular volume (MCV), the mean corpuscular haemoglobin (MCH) and the mean corpuscular haemoglobin concentration (MCHC)], immune responses [white blood cell (WBC) counts, oxidative radical production (nitroblue tetrazolium (NBT) activity), total plasma protein (TP) and total immunoglobulin (TI) levels and phagocytic activities (PA)] and oxidant/antioxidant statuses [malondialdehyde (MDA) levels, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities, and reduced glutathione (GSH) concentrations] were analysed. The findings of the present study demonstrated that the exposure of carp to malathion resulted in alterations in the haematological profiles and immune responses, and lead to increased reactive oxygen species formation, resulting in oxidative damage and inhibition of the antioxidant capacities. However, the administration of lycopene prevented malathion-induced toxic effects.

Effects of praziquantel and sanguinarine on expression of immune genes and susceptibility to Aeromonas hydrophila in goldfish (Carassius auratus) infected with Dactylogyrus intermedius

Praziquantel and sanguinarine have been demonstrated positive therapeutic effects on monogenean Dactylogyrus intermedius; however, few studies have considered the post impacts of these antiparasitic chemicals on host after repelling the parasites. The changes of expression of selected immune genes (CCL-1, CXCL-8, IL-1β-1, IL-1β-2, TNFα-1, TNFα-2 and TGF-β) in gill, kidney and spleen and bacterial loads of Aeromonas hydrophila in gill, kidney, spleen and liver following bath administration of these antiparasitic chemicals were evaluated. The results showed that praziquantel and sanguinarine up-regulated to varying degrees of CXCL-8, IL-1β-1, IL-1β-2, TNFα-1 and TNFα-2 in gill, kidney and spleen. They both decreased the CCL-1 expression in gill while increased it in kidney and spleen. However, in all the tested tissues, the expression of TGF-β decreased in praziquantel treated goldfish whereas that increased in sanguinarine treated goldfish. The A. hydrophila challenge test showed that the praziquantel treatment enhanced the susceptibility to A. hydrophila while sanguinarine treatment decreased the susceptibility, as compared with the non-treated group. Overall, the results indicate that bath administration of praziquantel and sanguinarine modulates the immune related genes in goldfish and these may, to some extent, affect their ability to resist bacterial pathogens.

Chlorpyrifos-induced changes in oxidant/antioxidant status and haematological parameters of Cyprinus carpio carpio: ameliorative effect of lycopene

The present study was carried out to investigate the potential ameliorative effects of lycopene against chlorpyrifos (CPF) toxicity in carp. The fish were divided into 7 different experimental groups and received the following treatments: Group 1, control; Group 2, orally administered corn oil; Group 3, oral lycopene (10 mg kg(-1) body weight); Group 4, exposure to 0.040 mg L(-1) CPF; Group 5, exposure to 0.040 mg L(-1) CPF plus oral administration of 10 mg kg(-1) lycopene; Group 6, exposure to 0.080 mg L(-1) CPF; and Group 7, exposure to 0.040 mg L(-1) CPF plus oral administration of 10 mg kg(-1) lycopene. Treatment was continued for 14 d and samples of the blood and tissue (liver, kidney, and gill) were collected at the end of the experiment and analysed for their oxidant-antioxidant status, including the malondialdehyde (MDA) levels, and the superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activity. The samples were also measured for changes in the haematological parameters, such as the red blood cell (RBC) and white blood cell (WBC) counts, the haemoglobin concentration (Hb), the haematocrit (Ht) level, and the erythrocyte indices: the mean corpuscular volume (MCV), the mean corpuscular haemoglobin (MCH) and the mean corpuscular haemoglobin concentration (MCHC). The findings of this study demonstrated that CPF had a negative effect on the haematological parameters and the antioxidant enzyme activities of the fish; this toxic effect was neutralised by the administration of lycopene. The present results suggest that lycopene (10 mg kg(-1)) can be effective in the protection of CPF-induced toxicity in fish.