The Experts below are selected from a list of 88155 Experts worldwide ranked by ideXlab platform
Elham Awad - One of the best experts on this subject based on the ideXlab platform.
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possible effect of hala extract pandanus tectorius on Immune Status anti tumour and resistance to yersinia ruckeri infection in rainbow trout oncorhynchus mykiss
Fish & Shellfish Immunology, 2019Co-Authors: Elham Awad, D A Austin, Alastair Robert Lyndon, Amani S AwaadAbstract:The possible effect of dietary administration of hala extract (Pandanus tectorius) on rainbow trout (Oncorhynchus mykiss) Immune Status as well as its effect as an anti-tumour agent was studied. Fish were divided into 4 groups before feeding with commercial diet (0%, control; 0.5%, 1% and 2% of hala extract) for 2 weeks. The effect of diet on the humoral Immune parameters, ie total protein, myeloperoxidase content, antiproteases, lysozyme and bactericidal activities were studied. Also, the effect of the diets on the expression of some Immune-related genes in rainbow trout head-kidney (TNF, LYZ2, IL-8 and CD-4) as well as tumour suppressor gene (WT-1a) was investigated. At the end of the feeding trial fish groups were challenged with Yersinia ruckeri. The results demonstrated enhancement in all the Immune parameters in fish fed hala extract diets compared to control fish especially with the highest dose (2%) which recorded the highest significant increase (p < 0.05) in some parameters (total protein, myeloperoxidase content, antiproteases, and bactericidal activities) compared to the control. The results obtained from challenge with Y. ruckeri revealed reduction in the mortalities in fish groups fed with 1% and 2% doses of hala extract. Feeding with hala extract provoked upregulation in all Immune- related genes. Again, the highest dose of hala extract showed a significant upregulation in WT1a expression (p < 0.05). The current study suggest that the hala extract, especially the highest dose, could be considered a good food additive to improve the Immune Status, resist tumour formation and to resist or control infectious diseases of rainbow trout.
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role of medicinal plants on growth performance and Immune Status in fish
Fish & Shellfish Immunology, 2017Co-Authors: Elham Awad, Amani S AwaadAbstract:Disease outbreaks increase proportionally with increases in intensive aquaculture. Natural products including medicinal plants have been known from thousands of years for treating some human diseases. It is well known that many active compounds are responsible for potential bio-activities. For that reason, there has been considerable interest in the use of medicinal plants in aquaculture with a view to providing safe and eco-friendly compounds for replacing antibiotics and chemical compounds as well as to enhance Immune Status and control fish diseases. This article describes a wide range of medicinal plants such as herbs, seeds, and spices with different forms such as crude, extracts, mixed and active compounds, used as immunostimulants and resulting in a marked enhancement in the Immune system of fish to prevent and control microbial diseases. Moreover, different activity was recorded from plant parts like seeds, roots, flowers and leaves. The mode of action of medicinal plants was stimulation of the cellular and humoral Immune response which was monitored through elevation in Immune parameters. Various levels of Immune stimulation have been shown by medicinal plants at different concentrations through injection or immersion or oral administration. However, it is critically important to determine the optimal dose to enhance the Immune system of fish and avoid the risk of immunosuppression. Some medicinal plants have been used to replace the protein in fishmeal as a cheap source of protein and proved to be efficient in this respect. Medicinal plants can act as a growth promoter and immunomodulator at the same time. Further investigations should be carried out to examine the influence of those plants on fish health (including physiological and histological parameters) as a preliminary step for use in large scale in aquaculture. The current review describes the role of medicinal plants and their derivatives on innate and adaptive Immune Status as well as growth performance in fish.
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effects of fenugreek trigonella foenum graecum on gilthead seabream sparus aurata l Immune Status and growth performance
Fish & Shellfish Immunology, 2015Co-Authors: Elham Awad, Rebeca Cerezuela, Angeles M EstebanAbstract:The possible effect of dietary administration of fenugreek (Trigonella foenum graecum) on gilthead seabream (Sparus aurata L.) Immune Status and growth performance was studied. Fish were divided into 4 groups before being fed with commercial diet supplemented with 0% (control), 1%, 5% and 10% of fenugreek seeds for 4 weeks. The effects of the diets were analysed on the cellular (respiratory burst activity and leucocyte peroxidase content) and humoral (complement activity, antiprotease, total protein, peroxidase, and IgM level) Immune parameters, as well as growth and haematological parameters (WBC and RBC counts). The results recorded enhancement in all the assayed parameters in fish fed fenugreek diets comparing to control fish. The expression of several Immune-related genes in head-kidney (MHC1, CSF-1R, IL-8, and IgM) and different antioxidant enzyme genes in liver (GR, CAT and SOD) of seabream specimens were also investigated. Again, the highest fenugreek doses tested provoked significant up-regulation in most of Immune-related genes and antioxidant enzyme genes (p < 0.05). No adverse effects were observed on intestine and liver morphology on fish fed fenugreek diets. The present results suggest that the fenugreek seed, specially the highest dosage used in the present work could be considered a good food supplement to improve the Immune Status and increase the production of gilthead seabream.
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effects of dihydroquercetin obtained from deodar cedrus deodara on Immune Status of gilthead seabream sparus aurata l
Fish & Shellfish Immunology, 2015Co-Authors: Elham Awad, Amani S Awaad, Angeles M EstebanAbstract:The use of medicinal plants as prophylactic method in fish is considered safe and a very promising alternative to the use of chemicals in aquaculture practices. The prospective mode of action of dihydroquercetin, fraction of the medical plant deodar (Cedrus deodara), was evaluated on Immune Status of gilthead seabream (Sparus aurata L.). Fish were divided into 4 groups before being fed for 14 days with commercial diets supplemented with 0% (control), 0.1%, 0.5% and 1% of dihydroquercetin. Cellular (phagocytosis and respiratory burst activities) and humoral (seric complement activity, antiprotease, total protein, peroxidase, bactericidal activity and IgM level) Immune parameters were investigated. The results recorded enhancement in all the tested parameters and in all the dihydroquercetin supplemented groups compared to the control. Interestingly, the fish received the lowest dose of dihydroquercetin (0.1%) showed a highly significant difference (p < 0.05) in phagocytosis, respiratory burst, IgM level, total protein, complement, antiprotease and bactericidal activities compared to the control. Direct effect of different doses of dihydroquercetin on head-kidney leucocytes was also studied in a previous in vitro assay. Again, the lowest doses tested provoked the highest Immune cellular activities, where, the highest phagocytic and respiratory bust activities were recorded in leucocytes incubated with 0.025% and 0.0125% doses, respectively. Therefore, the results suggest that low concentrations of dihydroquercetin as food supplements are able to increase the Immune Status of gilthead seabream.
Benjamín Costas - One of the best experts on this subject based on the ideXlab platform.
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Table_1_Dietary Methionine Improves the European Seabass (Dicentrarchus labrax) Immune Status, Inflammatory Response, and Disease Resistance.docx
2018Co-Authors: Marina Machado, Rita Azeredo, Filipa Fontinha, Sergio Fernández-boo, Luis E. C. Conceição, Jorge Dias, Benjamín CostasAbstract:Methionine presents a pivotal role in the regulation of many cellular events with crucial impact on the Immune system, such as in processes involved in the control of inflammation and polyamines synthesis. Accordingly, the present study aimed to assess the modulatory effects of dietary methionine on the European seabass (Dicentrarchus labrax) Immune Status, inflammatory response and disease resistance to Photobacterium damselae subsp. piscicida (Phdp). For this purpose, fish were randomly distributed in three independent groups (three replicates per group) and each was fed the corresponding diet: a control diet (CTRL) formulated to meet the established amino acid requirements for the species; a diet supplemented with methionine at 0.5% of feed weight relative to the CTRL diet (8.2% of methionine concentration above CTRL); and one supplemented with methionine at 1% of feed weight to the CTRL diet (11.8% of methionine concentration above CTRL). To evaluate the Immune Status of fish fed with each of the diets before being submitted to bacterial infection fish were sampled from each group at 2 and 4 weeks after the beginning of feeding. Non-sampled fish were injected intraperitoneally with Phdp (5 × 103 cfu/fish) at 4 weeks after initiation of feeding and the inflammatory response (at 4, 24, and 48 h post-infection) and survival (lasting 21 days post-infection) evaluated. Fish hematological profile, peripheral cell dynamics, plasma humoral Immune parameters, leucocyte migration to the inflammatory focus and head-kidney gene expression were evaluated. Results show that methionine dietary supplementation improves seabass cellular Immune Status without evidence of activation of pro-inflammatory mechanisms. Additionally, the observed enhanced Immune Status provided by methionine supplementation translated into an improved Immune response to infection, as higher cellular differentiation/proliferation and recruitment to the inflammatory focus, improved plasma humoral Immune parameters and modulation of key Immune-related genes was observed. Lastly, after a bacterial challenge, higher survival was observed in fish fed supplemented diets, ultimately corroborating the positive effect of methionine administration for 4 weeks in the cellular Immune Status.
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european sea bass dicentrarchus labrax Immune Status and disease resistance are impaired by arginine dietary supplementation
PLOS ONE, 2015Co-Authors: Rita Azeredo, Jaume Perezsanchez, Ariadna Sitjabobadilla, B Fouz, Lluis Tort, Claudia Aragao, Aires Olivateles, Benjamín CostasAbstract:Infectious diseases and fish feeds management are probably the major expenses in the aquaculture business. Hence, it is a priority to define sustainable strategies which simultaneously avoid therapeutic procedures and reinforce fish immunity. Currently, one preferred approach is the use of immunostimulants which can be supplemented to the fish diets. Arginine is a versatile amino acid with important mechanisms closely related to the Immune response. Aiming at finding out how arginine affects the innate Immune Status or improve disease resistance of European seabass (Dicentrarchus labrax) against vibriosis, fish were fed two arginine-supplemented diets (1% and 2% arginine supplementation). A third diet meeting arginine requirement level for seabass served as control diet. Following 15 or 29 days of feeding, fish were sampled for blood, spleen and gut to assess cell-mediated Immune parameters and Immune-related gene expression. At the same time, fish from each dietary group were challenged against Vibrio anguillarum and survival was monitored. Cell-mediated Immune parameters such as the extracellular superoxide and nitric oxide decreased in fish fed arginine-supplemented diets. Interleukins and Immune-cell marker transcripts were down-regulated by the highest supplementation level. Disease resistance data were in accordance with a generally depressed Immune Status, with increased susceptibility to vibriosis in fish fed arginine supplemented diets. Altogether, these results suggest a general inhibitory effect of arginine on the Immune defences and disease resistance of European seabass. Still, further research will certainly clarify arginine immunomodulation pathways thereby allowing the validation of its potential as a prophylactic strategy.
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dietary tryptophan and methionine as modulators of european seabass dicentrarchus labrax Immune Status and inflammatory response
Fish & Shellfish Immunology, 2015Co-Authors: Marina Machado, Rita Azeredo, Aires Olivateles, Patricia Diazrosales, Antonio Afonso, Helena Peres, Benjamín CostasAbstract:Amino acids regulate key metabolic pathways important to Immune responses and their nutritional supply may increase synthesis of Immune-related proteins. The present study aimed to evaluate the effects of dietary supplementation of tryptophan and methionine on European seabass (Dicentrarchus labrax) cellular and humoral Status. The immunomodulatory effects of tryptophan and methionine during an inflammatory insult was also evaluated after intraperitoneal injection with inactivated Photobacterium damselae subsp. piscicida (Phdp). A practical isonitrogenous (45% crude protein) and isolipidic (16% crude fat) diets was formulated to include fish meal and a blend of plant feedstuffs as protein sources and fish oil as the main lipid source (CRL diet). Two other diets were formulated similar to the control but including L-tryptophan or L-methionine at ×2 the requirement level (diets TRP and MET, respectively). European seabass weighing 275 g were fed the experimental diets for a period of 15 days before being sampled (trial 1). Then, fish were subjected to a peritoneal inflammation by intraperitoneally injecting UV killed Phdp (10(6) colony forming units ml(-1)) and sampled following 4 and 24 h post-injection (trial 2). Fish injected with a saline solution served as control. The haematological profile, peripheral cell dynamics and several plasma Immune parameters were determined in trials 1 and 2, whereas cell migration to the inflammatory focus was also determined in trial 2. MET positively affected European seabass Immune Status by improving the peripheral leucocyte response, complement activity and bactericidal capacity, a stronger cellular recruitment to the inflammatory focus, and higher plasma peroxidase and bactericidal activities. TRP also seemed to improve immunostimulation, as there was a trend to augment both cell-mediated immunity and humoral capacity. However, TRP failed to improve an inflammatory response, verified by a decrease in blood phagocyte numbers and lack of Immune cells recruitment. In summary, it is confirmed that MET has a pronounced influence on the innate Immune response to inflammation, which is more evident than TRP, and raises its potential to incorporate in functional feeds to be used in prophylactic strategies against predictable unfavourable events.
Amani S Awaad - One of the best experts on this subject based on the ideXlab platform.
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possible effect of hala extract pandanus tectorius on Immune Status anti tumour and resistance to yersinia ruckeri infection in rainbow trout oncorhynchus mykiss
Fish & Shellfish Immunology, 2019Co-Authors: Elham Awad, D A Austin, Alastair Robert Lyndon, Amani S AwaadAbstract:The possible effect of dietary administration of hala extract (Pandanus tectorius) on rainbow trout (Oncorhynchus mykiss) Immune Status as well as its effect as an anti-tumour agent was studied. Fish were divided into 4 groups before feeding with commercial diet (0%, control; 0.5%, 1% and 2% of hala extract) for 2 weeks. The effect of diet on the humoral Immune parameters, ie total protein, myeloperoxidase content, antiproteases, lysozyme and bactericidal activities were studied. Also, the effect of the diets on the expression of some Immune-related genes in rainbow trout head-kidney (TNF, LYZ2, IL-8 and CD-4) as well as tumour suppressor gene (WT-1a) was investigated. At the end of the feeding trial fish groups were challenged with Yersinia ruckeri. The results demonstrated enhancement in all the Immune parameters in fish fed hala extract diets compared to control fish especially with the highest dose (2%) which recorded the highest significant increase (p < 0.05) in some parameters (total protein, myeloperoxidase content, antiproteases, and bactericidal activities) compared to the control. The results obtained from challenge with Y. ruckeri revealed reduction in the mortalities in fish groups fed with 1% and 2% doses of hala extract. Feeding with hala extract provoked upregulation in all Immune- related genes. Again, the highest dose of hala extract showed a significant upregulation in WT1a expression (p < 0.05). The current study suggest that the hala extract, especially the highest dose, could be considered a good food additive to improve the Immune Status, resist tumour formation and to resist or control infectious diseases of rainbow trout.
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role of medicinal plants on growth performance and Immune Status in fish
Fish & Shellfish Immunology, 2017Co-Authors: Elham Awad, Amani S AwaadAbstract:Disease outbreaks increase proportionally with increases in intensive aquaculture. Natural products including medicinal plants have been known from thousands of years for treating some human diseases. It is well known that many active compounds are responsible for potential bio-activities. For that reason, there has been considerable interest in the use of medicinal plants in aquaculture with a view to providing safe and eco-friendly compounds for replacing antibiotics and chemical compounds as well as to enhance Immune Status and control fish diseases. This article describes a wide range of medicinal plants such as herbs, seeds, and spices with different forms such as crude, extracts, mixed and active compounds, used as immunostimulants and resulting in a marked enhancement in the Immune system of fish to prevent and control microbial diseases. Moreover, different activity was recorded from plant parts like seeds, roots, flowers and leaves. The mode of action of medicinal plants was stimulation of the cellular and humoral Immune response which was monitored through elevation in Immune parameters. Various levels of Immune stimulation have been shown by medicinal plants at different concentrations through injection or immersion or oral administration. However, it is critically important to determine the optimal dose to enhance the Immune system of fish and avoid the risk of immunosuppression. Some medicinal plants have been used to replace the protein in fishmeal as a cheap source of protein and proved to be efficient in this respect. Medicinal plants can act as a growth promoter and immunomodulator at the same time. Further investigations should be carried out to examine the influence of those plants on fish health (including physiological and histological parameters) as a preliminary step for use in large scale in aquaculture. The current review describes the role of medicinal plants and their derivatives on innate and adaptive Immune Status as well as growth performance in fish.
-
effects of dihydroquercetin obtained from deodar cedrus deodara on Immune Status of gilthead seabream sparus aurata l
Fish & Shellfish Immunology, 2015Co-Authors: Elham Awad, Amani S Awaad, Angeles M EstebanAbstract:The use of medicinal plants as prophylactic method in fish is considered safe and a very promising alternative to the use of chemicals in aquaculture practices. The prospective mode of action of dihydroquercetin, fraction of the medical plant deodar (Cedrus deodara), was evaluated on Immune Status of gilthead seabream (Sparus aurata L.). Fish were divided into 4 groups before being fed for 14 days with commercial diets supplemented with 0% (control), 0.1%, 0.5% and 1% of dihydroquercetin. Cellular (phagocytosis and respiratory burst activities) and humoral (seric complement activity, antiprotease, total protein, peroxidase, bactericidal activity and IgM level) Immune parameters were investigated. The results recorded enhancement in all the tested parameters and in all the dihydroquercetin supplemented groups compared to the control. Interestingly, the fish received the lowest dose of dihydroquercetin (0.1%) showed a highly significant difference (p < 0.05) in phagocytosis, respiratory burst, IgM level, total protein, complement, antiprotease and bactericidal activities compared to the control. Direct effect of different doses of dihydroquercetin on head-kidney leucocytes was also studied in a previous in vitro assay. Again, the lowest doses tested provoked the highest Immune cellular activities, where, the highest phagocytic and respiratory bust activities were recorded in leucocytes incubated with 0.025% and 0.0125% doses, respectively. Therefore, the results suggest that low concentrations of dihydroquercetin as food supplements are able to increase the Immune Status of gilthead seabream.
Angeles M Esteban - One of the best experts on this subject based on the ideXlab platform.
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effects of fenugreek trigonella foenum graecum on gilthead seabream sparus aurata l Immune Status and growth performance
Fish & Shellfish Immunology, 2015Co-Authors: Elham Awad, Rebeca Cerezuela, Angeles M EstebanAbstract:The possible effect of dietary administration of fenugreek (Trigonella foenum graecum) on gilthead seabream (Sparus aurata L.) Immune Status and growth performance was studied. Fish were divided into 4 groups before being fed with commercial diet supplemented with 0% (control), 1%, 5% and 10% of fenugreek seeds for 4 weeks. The effects of the diets were analysed on the cellular (respiratory burst activity and leucocyte peroxidase content) and humoral (complement activity, antiprotease, total protein, peroxidase, and IgM level) Immune parameters, as well as growth and haematological parameters (WBC and RBC counts). The results recorded enhancement in all the assayed parameters in fish fed fenugreek diets comparing to control fish. The expression of several Immune-related genes in head-kidney (MHC1, CSF-1R, IL-8, and IgM) and different antioxidant enzyme genes in liver (GR, CAT and SOD) of seabream specimens were also investigated. Again, the highest fenugreek doses tested provoked significant up-regulation in most of Immune-related genes and antioxidant enzyme genes (p < 0.05). No adverse effects were observed on intestine and liver morphology on fish fed fenugreek diets. The present results suggest that the fenugreek seed, specially the highest dosage used in the present work could be considered a good food supplement to improve the Immune Status and increase the production of gilthead seabream.
-
effects of dihydroquercetin obtained from deodar cedrus deodara on Immune Status of gilthead seabream sparus aurata l
Fish & Shellfish Immunology, 2015Co-Authors: Elham Awad, Amani S Awaad, Angeles M EstebanAbstract:The use of medicinal plants as prophylactic method in fish is considered safe and a very promising alternative to the use of chemicals in aquaculture practices. The prospective mode of action of dihydroquercetin, fraction of the medical plant deodar (Cedrus deodara), was evaluated on Immune Status of gilthead seabream (Sparus aurata L.). Fish were divided into 4 groups before being fed for 14 days with commercial diets supplemented with 0% (control), 0.1%, 0.5% and 1% of dihydroquercetin. Cellular (phagocytosis and respiratory burst activities) and humoral (seric complement activity, antiprotease, total protein, peroxidase, bactericidal activity and IgM level) Immune parameters were investigated. The results recorded enhancement in all the tested parameters and in all the dihydroquercetin supplemented groups compared to the control. Interestingly, the fish received the lowest dose of dihydroquercetin (0.1%) showed a highly significant difference (p < 0.05) in phagocytosis, respiratory burst, IgM level, total protein, complement, antiprotease and bactericidal activities compared to the control. Direct effect of different doses of dihydroquercetin on head-kidney leucocytes was also studied in a previous in vitro assay. Again, the lowest doses tested provoked the highest Immune cellular activities, where, the highest phagocytic and respiratory bust activities were recorded in leucocytes incubated with 0.025% and 0.0125% doses, respectively. Therefore, the results suggest that low concentrations of dihydroquercetin as food supplements are able to increase the Immune Status of gilthead seabream.
Rita Azeredo - One of the best experts on this subject based on the ideXlab platform.
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Dietary Methionine Improves the European Seabass (Dicentrarchus labrax) Immune Status, Inflammatory Response, and Disease Resistance
Frontiers Media S.A., 2018Co-Authors: Marina Machado, Rita Azeredo, Filipa Fontinha, Sergio Fernández-boo, Luis E. C. ConceiçãoAbstract:Methionine presents a pivotal role in the regulation of many cellular events with crucial impact on the Immune system, such as in processes involved in the control of inflammation and polyamines synthesis. Accordingly, the present study aimed to assess the modulatory effects of dietary methionine on the European seabass (Dicentrarchus labrax) Immune Status, inflammatory response and disease resistance to Photobacterium damselae subsp. piscicida (Phdp). For this purpose, fish were randomly distributed in three independent groups (three replicates per group) and each was fed the corresponding diet: a control diet (CTRL) formulated to meet the established amino acid requirements for the species; a diet supplemented with methionine at 0.5% of feed weight relative to the CTRL diet (8.2% of methionine concentration above CTRL); and one supplemented with methionine at 1% of feed weight to the CTRL diet (11.8% of methionine concentration above CTRL). To evaluate the Immune Status of fish fed with each of the diets before being submitted to bacterial infection fish were sampled from each group at 2 and 4 weeks after the beginning of feeding. Non-sampled fish were injected intraperitoneally with Phdp (5 × 103 cfu/fish) at 4 weeks after initiation of feeding and the inflammatory response (at 4, 24, and 48 h post-infection) and survival (lasting 21 days post-infection) evaluated. Fish hematological profile, peripheral cell dynamics, plasma humoral Immune parameters, leucocyte migration to the inflammatory focus and head-kidney gene expression were evaluated. Results show that methionine dietary supplementation improves seabass cellular Immune Status without evidence of activation of pro-inflammatory mechanisms. Additionally, the observed enhanced Immune Status provided by methionine supplementation translated into an improved Immune response to infection, as higher cellular differentiation/proliferation and recruitment to the inflammatory focus, improved plasma humoral Immune parameters and modulation of key Immune-related genes was observed. Lastly, after a bacterial challenge, higher survival was observed in fish fed supplemented diets, ultimately corroborating the positive effect of methionine administration for 4 weeks in the cellular Immune Status
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Table_1_Dietary Methionine Improves the European Seabass (Dicentrarchus labrax) Immune Status, Inflammatory Response, and Disease Resistance.docx
2018Co-Authors: Marina Machado, Rita Azeredo, Filipa Fontinha, Sergio Fernández-boo, Luis E. C. Conceição, Jorge Dias, Benjamín CostasAbstract:Methionine presents a pivotal role in the regulation of many cellular events with crucial impact on the Immune system, such as in processes involved in the control of inflammation and polyamines synthesis. Accordingly, the present study aimed to assess the modulatory effects of dietary methionine on the European seabass (Dicentrarchus labrax) Immune Status, inflammatory response and disease resistance to Photobacterium damselae subsp. piscicida (Phdp). For this purpose, fish were randomly distributed in three independent groups (three replicates per group) and each was fed the corresponding diet: a control diet (CTRL) formulated to meet the established amino acid requirements for the species; a diet supplemented with methionine at 0.5% of feed weight relative to the CTRL diet (8.2% of methionine concentration above CTRL); and one supplemented with methionine at 1% of feed weight to the CTRL diet (11.8% of methionine concentration above CTRL). To evaluate the Immune Status of fish fed with each of the diets before being submitted to bacterial infection fish were sampled from each group at 2 and 4 weeks after the beginning of feeding. Non-sampled fish were injected intraperitoneally with Phdp (5 × 103 cfu/fish) at 4 weeks after initiation of feeding and the inflammatory response (at 4, 24, and 48 h post-infection) and survival (lasting 21 days post-infection) evaluated. Fish hematological profile, peripheral cell dynamics, plasma humoral Immune parameters, leucocyte migration to the inflammatory focus and head-kidney gene expression were evaluated. Results show that methionine dietary supplementation improves seabass cellular Immune Status without evidence of activation of pro-inflammatory mechanisms. Additionally, the observed enhanced Immune Status provided by methionine supplementation translated into an improved Immune response to infection, as higher cellular differentiation/proliferation and recruitment to the inflammatory focus, improved plasma humoral Immune parameters and modulation of key Immune-related genes was observed. Lastly, after a bacterial challenge, higher survival was observed in fish fed supplemented diets, ultimately corroborating the positive effect of methionine administration for 4 weeks in the cellular Immune Status.
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european sea bass dicentrarchus labrax Immune Status and disease resistance are impaired by arginine dietary supplementation
PLOS ONE, 2015Co-Authors: Rita Azeredo, Jaume Perezsanchez, Ariadna Sitjabobadilla, B Fouz, Lluis Tort, Claudia Aragao, Aires Olivateles, Benjamín CostasAbstract:Infectious diseases and fish feeds management are probably the major expenses in the aquaculture business. Hence, it is a priority to define sustainable strategies which simultaneously avoid therapeutic procedures and reinforce fish immunity. Currently, one preferred approach is the use of immunostimulants which can be supplemented to the fish diets. Arginine is a versatile amino acid with important mechanisms closely related to the Immune response. Aiming at finding out how arginine affects the innate Immune Status or improve disease resistance of European seabass (Dicentrarchus labrax) against vibriosis, fish were fed two arginine-supplemented diets (1% and 2% arginine supplementation). A third diet meeting arginine requirement level for seabass served as control diet. Following 15 or 29 days of feeding, fish were sampled for blood, spleen and gut to assess cell-mediated Immune parameters and Immune-related gene expression. At the same time, fish from each dietary group were challenged against Vibrio anguillarum and survival was monitored. Cell-mediated Immune parameters such as the extracellular superoxide and nitric oxide decreased in fish fed arginine-supplemented diets. Interleukins and Immune-cell marker transcripts were down-regulated by the highest supplementation level. Disease resistance data were in accordance with a generally depressed Immune Status, with increased susceptibility to vibriosis in fish fed arginine supplemented diets. Altogether, these results suggest a general inhibitory effect of arginine on the Immune defences and disease resistance of European seabass. Still, further research will certainly clarify arginine immunomodulation pathways thereby allowing the validation of its potential as a prophylactic strategy.
-
dietary tryptophan and methionine as modulators of european seabass dicentrarchus labrax Immune Status and inflammatory response
Fish & Shellfish Immunology, 2015Co-Authors: Marina Machado, Rita Azeredo, Aires Olivateles, Patricia Diazrosales, Antonio Afonso, Helena Peres, Benjamín CostasAbstract:Amino acids regulate key metabolic pathways important to Immune responses and their nutritional supply may increase synthesis of Immune-related proteins. The present study aimed to evaluate the effects of dietary supplementation of tryptophan and methionine on European seabass (Dicentrarchus labrax) cellular and humoral Status. The immunomodulatory effects of tryptophan and methionine during an inflammatory insult was also evaluated after intraperitoneal injection with inactivated Photobacterium damselae subsp. piscicida (Phdp). A practical isonitrogenous (45% crude protein) and isolipidic (16% crude fat) diets was formulated to include fish meal and a blend of plant feedstuffs as protein sources and fish oil as the main lipid source (CRL diet). Two other diets were formulated similar to the control but including L-tryptophan or L-methionine at ×2 the requirement level (diets TRP and MET, respectively). European seabass weighing 275 g were fed the experimental diets for a period of 15 days before being sampled (trial 1). Then, fish were subjected to a peritoneal inflammation by intraperitoneally injecting UV killed Phdp (10(6) colony forming units ml(-1)) and sampled following 4 and 24 h post-injection (trial 2). Fish injected with a saline solution served as control. The haematological profile, peripheral cell dynamics and several plasma Immune parameters were determined in trials 1 and 2, whereas cell migration to the inflammatory focus was also determined in trial 2. MET positively affected European seabass Immune Status by improving the peripheral leucocyte response, complement activity and bactericidal capacity, a stronger cellular recruitment to the inflammatory focus, and higher plasma peroxidase and bactericidal activities. TRP also seemed to improve immunostimulation, as there was a trend to augment both cell-mediated immunity and humoral capacity. However, TRP failed to improve an inflammatory response, verified by a decrease in blood phagocyte numbers and lack of Immune cells recruitment. In summary, it is confirmed that MET has a pronounced influence on the innate Immune response to inflammation, which is more evident than TRP, and raises its potential to incorporate in functional feeds to be used in prophylactic strategies against predictable unfavourable events.
