Dietary Arachidonic Acid Levels Research Articles

Dietary arachidonic acid affects the growth performance, fatty acid profile, immunity and resistance to heat stress in juvenile abalone Haliotis discus hannai Ino

A 93-day feeding trial was performed to evaluate the effects of dietary arachidonic acid (ARA) on the growth performance, antioxidative capacity, immunity and anti-stress capacity of juvenile abalone Haliotis discus hannai Ino with an initial mean body weight of 4.26 ± 0.11 g. Six practical diets with 0.04% (the control), 0.31%, 0.44%, 0.68%, 0.94% and 1.34% of ARA were designed. After the feeding trial, abalones were subjected to a heat stress test. The findings showed that the survival of abalone (91.7–96.7%) after the feeding trial was not significantly influenced by dietary ARA. The 0.31–0.44% of dietary ARA significantly increased the weight gain rate (WGR). The feed conversion ratio (FCR) was decreased by 0.31–0.68% of dietary ARA. The 0.44% of dietary ARA significantly enhanced the activity of trypsin, lipase and α-amylase in the intestine. Besides, dietary ARA supplementation significantly elevated the total antioxidative capacity and activity of superoxide dismutase, catalase and lysozyme in the cell-free hemolymph. Higher levels of dietary ARA (≥0.94%) significantly up-regulated the mRNA levels of nuclear factor κB, inhibitor of κBα and transcription factor AP-1 in the digestive gland. The 0.68% of dietary ARA significantly decreased the falling rate of abalone after heat stress. In conclusion, appropriate dietary ARA levels improved the growth performance and feed utilization of abalone. The optimal dietary ARA content for juvenile abalone was 0.52% based on the quadratic regression analysis of WGR. The 0.44–0.68% of dietary ARA improved the antioxidative capacity, immunity and anti-heat stress of abalone.

Effects of dietary arachidonic acid supplementation in high plant protein diets on growth, feed utilization, and immunity of olive flounder, Paralichthys olivaceus

This study was designed to evaluate the effects of graded levels of arachidonic acid (ARA) in low fish meal diets (30% fish meal, 30% plant protein blends) on growth, feed utilization, and immunity of olive flounder (Paralichthys olivaceus). The control diet was formulated with 3% fish oil and 5.1% soybean oil (ARA0.0). Five other diets were formulated incorporating different levels of ARA into the ARA0.0 diet at the expense of soybean oil; that is, 0.3, 0.6, 0.9, 1.2, and 1.5% ARA (ARA0.3, ARA0.6, ARA0.9, ARA1.2, and ARA1.5), respectively. Three replicate groups of fish (88.24 ± 0.06 g) were placed into 18 polyvinyl circular tanks (215 L), with 24 fish each and fed an experimental diet twice a day for nine weeks. Overall, significantly improved growth performance was observed in the ARA0.6 group. Liver C18:2n-6 was significantly reduced, and liver ARA content was significantly increased with the increase in dietary ARA levels. Nitroblue tetrazolium activity was significantly higher in the ARA0.6 group, and significantly higher superoxide dismutase and myeloperoxidase activities were observed in the ARA0.9 group. Further, immunoglobulin level and lysozyme activity were significantly improved in the ARA0.3 group, antiprotease activity was increased in the ARA0.6 and ARA0.9 groups, and the ARA0.3 group showed lower liver lipid content than the ARA0.0 group. Serum prostaglandin E2 level was significantly increased with 1.5% ARA inclusion. Pro-inflammatory gene expressions of interleukin (IL)-6, IL-8, IL-10, perforin, and tumor necrosis factor in the intestine were significantly downregulated, and anti-inflammatory gene expression of transforming growth factor-β2 gene expression was significantly upregulated with higher dietary ARA supplementation (0.9–1.5%). These results indicate that 0.3–0.9% supplemented ARA may improve the growth, immune, and hematological parameters of olive flounder.

High dietary arachidonic acid produces excess eicosanoids, and induces hepatic inflammatory responses, oxidative stress and apoptosis in juvenile Acanthopagrus schlegelii

As a functional fatty acid, Arachidonic acid (ARA) plays an important role in immunity due to its metabolites in mammals, which have been extensively studied in mammals. However, studies on the function of metabolites produced by dietary ARA in aquatic animals are not comprehensive and in-depth. Hence, an eight-week feeding trial was conducted to evaluated the regulatory effects of dietary ARA and its metabolites-eicosanoids on inflammation, oxidative stress and apoptosis in the liver of Acanthopagrus schlegelii with an initial weight of 0.99 ± 0.10 g. Six isonitrogenous and isolipidic (41% protein, 14% lipid) diets were formulated with gradient levels of ARA: 0% (ARA0.10), 0.5% (ARA0.59), 1.0% (ARA1.04), 1.5% (ARA1.42), 2.0% (ARA1.94), 2.5% (ARA2.42), respectively, and palmitic acid was used to regulate lipid levels. Results showed that the key enzyme contents of ARA metabolic pathway such as phospholipase A2 (PLA2), cyclooxygenase-2 (COX-2), lipoxygenase (LOX) cytochrome P450 (CYP450), prostaglandin E2 (PGE2), leukotriene C4 (LTC4) and 20-hydroxyeicosatetraenoic acid (20-HETE) in the liver were increased with dietary ARA levels increased. High levels of dietary ARA (1.94% and 2.42%) activated the gene expression levels of nuclear factor kappa B (nf-κb), which were confirmed by the results of immunofluorescence assay. Likewise, the expression levels of pro-inflammatory cytokines (tnf-α and il-1β) were up-regulated by ARA1.94 and ARA2.42 groups. Fish fed with excess ARA level has significantly low antioxidant capacity by decreasing the activity of related antioxidant parameters and down-regulating the expression level of related genes. The pro-apoptotic related genes (bax and caspase 7/9) were markedly up-regulated as dietary ARA levels increased from 1.04% to 2.42%. Collectively, excess dietary ARA levels (1.92% and 2.42%) produced excess eicosanoids, triggering inflammation via activating NF-κB expression and promoting its nuclear translocation, resulting in oxidative stress by reducing antioxidant parameters (SOD, GSH and GPX), inducing cell apoptosis through up-regulating pro-apoptotic gene expression levels.

Alteration of Growth Performance, Antioxidant Capacity, Tissue Fatty Acid Profiles, and Lipid Metabolism of Mud Crab (Scylla paramamosain) Juvenile in Response to Different Dietary Arachidonic Acid Levels.

An eight-week feeding trail was carried out to investigate the impacts of different dietary arachidonic acid (ARA) supplementations on growth performance, antioxidant capacity, tissue fatty acid profiles, and lipid metabolism of mud crab (Scylla paramamosain) juvenile. Six isonitrogenous (480 g kg-1 crude protein) and isolipidic (80 g kg-1 crude lipid) diets were formulated to contain 0.40, 2.50, 4.60, 8.90, 12.50, and 15.70 g ARA kg-1 (dry matter), respectively. Each experimental treatment included 24 mud crab juveniles (initial weight 11.29 ± 0.09 g) and was assigned to triplicate groups (n = 3). Crabs fed diets with 2.50, 4.60, and 8.90 g kg-1 ARA presented significantly higher percent weight gain (PWG) and specific growth rate (SGR) than those fed the other diets. Based on two-slope broken-line and quadratic curve regression analysis of PWG against dietary ARA levels, optimal dietary ARA levels were determined to be 5.20 g kg-1 and 6.20 g kg-1, respectively. Crabs fed with 4.60 g kg-1 ARA diet showed the lowest activities of alanine aminotransferase (ALT) as well as aspartate aminotransferase (AST) in hemolymph among all treatments. In hemolymph and hepatopancreas, total antioxidant capacity (T-AOC), the activities of total superoxide dismutase (T-SOD), and glutathione peroxidase (GSH-Px) as well as the contents of reduced glutathione (GSH) rose first and then dropped with the increase of dietary ARA levels, while the concentration of malondialdehyde (MDA) showed an opposite trend. Tissue fatty acid profiles reflected diets fatty acid compositions. The ARA contents in hepatopancreas and muscle significantly increased with the increase of dietary ARA levels. Furthermore, the areas of blasenzellen (B) cells and restzellen (R) cells were significantly downregulated with the increase of dietary ARA levels. Crabs fed with 0.40 g kg-1 ARA diet showed significantly higher gene expression levels of fatty acid synthase (fas) as well as acetyl-CoA carboxylase (acc) among all treatments. Relative gene expression levels of 6-phosphogluconate dehydrogenase (6pgd) as well as glucose-6-phosphate dehydrogenase (g6pd) have been significantly upregulated in 0.40 and 2.50 g kg-1 ARA groups. Relative gene expression level of fatty acid binding protein 1 (fabp1) significantly increased in 4.60, 8.90, 12.50, and 15.70 g kg-1 ARA groups. However, the gene expression levels of fatty acid binding protein 4 (fabp4) as well as scavenger receptor class 2 (srb2) have not been influenced by dietary ARA levels. What is more, crabs fed diets with 4.60, 8.90, 12.50, and 15.70 g kg-1 ARA had a significantly higher expression level of carnitine palmitoyltransferase 1 (cpt1) than those fed diets with 0.40 and 2.50 g kg-1 ARA. In summary, optimum dietary ARA can promote growth, enhance antioxidant capacity, and improve health of mud crab juveniles. It also demonstrated that lipogenesis has been restrained with the increasing dietary ARA levels. These findings could provide theoretical guidance and reference for the lipid nutrition research as well as the development of the commercial diet in mud crab.

Effects of dietary arachidonic acid on the growth performance, feed utilization and fatty acid metabolism of Chinese mitten crab (Eriocheir sinensis)

A 12-week feeding trial was conducted to determine the effect of dietary arachidonic acid (ARA) levels on growth performance, feed utilization, muscle fatty acid composition and body proximate composition for juvenile Chinese mitten crab, Eriocheir sinensis. Six semi-purified diets containing 0.11% (control group, G1), 1.20% (G2), 2.37% (G3), 3.52% (G4), 4.76% (G5) and 7.39% (G6) ARA of total lipid content were formulated to feed six groups of crabs (the initial weight, 1.01 ± 0.12 g), respectively. Crabs in G3 showed the highest final weight, weight gain rate (WGR) and specific growth rate (SGR). The highest feed conversion ratio (FCR) was found in crabs in G1. In addition, the fatty acid composition of muscle was significantly affected by dietary ARA levels. For ARA, 22:2 and 20:5n-3, with the dietary ARA level increased, their contents increased first and then decreased, the highest values were all found in crabs of G4. High dietary ARA significantly affected the fatty acid composition of muscle in E. sinensis by increasing the relative expression of Srebp, while decreasing the relative expression of FAS, FAD 6 and ELOVL 6. Based on the results of the quadratic regression analysis of SGR and FCR, the optimum level of ARA for E. sinensis was suggested to be 4.54% and 3.88% of total lipid content, respectively.

Dietary arachidonic acid affects the innate immunity, antioxidant capacities, intestinal health and microbiota in Chinese mitten crab (Eriocheir sinensis)

Arachidonic acid (ARA) involves in lipid metabolism, biological processes and immune response of animals. The present study aimed to evaluate the effects of ARA on the antioxidant capacity, immune response and intestinal health of Eriocheir sinensis. A 84-day feeding experiment was conducted using six isonitrogenous and isoenergetic semi-purified diets containing 0.11% (control group, G1), 1.20% (G2), 2.37% (G3), 3.52% (G4), 4.76% (G5) and 7.39% (G6) ARA of total fatty acids. Four replicates of crabs (initial body weight, 1.01 ± 0.12 g) were fed one of the experimental diets at satiety level. Dietary ARA level did not affect the THC and phagocytic activity of crabs (P > 0.05), but RBs activity in G4 was significantly higher than that in G6 (P < 0.05). Dietary ARA significantly enhanced the activity of antioxidant enzymes, including SOD, CAT, GST and GPx (P < 0.05). For two antibacterial genes, the highest gene expression of lysozyme was found in G5 (P < 0.05), the highest gene expression of crustin was found in G5 and G6 (P < 0.05), in contrast, the moderate dietary ARA levels (1.20%–3.52% of total fatty acids) significantly inhibited their gene expression (P < 0.05). Higher dietary ARA level significantly decreased the gene expression of IL-1β and TNF-α (P < 0.05), which indicated that ARA might be linked to reduced inflammation. Furthermore, dietary ARA significantly affected the intestinal microbiota composition (P < 0.05), and the opportunistic pathogens, including Shewanella, Vibrio, Citrobacter, Candidatus_Bacilloplasma, Dysgonomonas, were enriched in the intestines of crabs fed with the lowest or highest ARA level. In conclusion, dietary ARA enhanced the antioxidant capacity, immune response and intestinal health of E. sinensis, indicating that moderate ARA supplementation in the diet could be a valuable measure towards establishing the commercial culture of crabs.

The dietary arachidonic acid improved growth and immunity of honey bee (Apis mellifera ligustica).

Honeybees cannot synthesize arachidonic acid (ARA) themselves, only obtain it from food. Most pollen is deficient or contains a small amount of ARA. The necessity of supplementary ARA in bees' diet has not been studied. The objective of this study was to investigate the effects of dietary ARA levels on the growth and immunity of Apis mellifera ligustica. A total of 25 honeybee colonies were randomly assigned to five dietary groups which were fed basic diets supplemented with 0, 2, 4, 6, and 8% of ARA. The diet with 4% ARA improved the body weight of newly emerged worker bees compared with the control group. Supplement of ARA in honeybee diets changed the fatty acid composition of honeybee body. SFA and MUFA contents of bees' body declined, and PUFA content rised in the ARA group. Compared with the control group, the supplement of ARA in honeybee diets increased the contents of ARA, C22:6n-3 (DHA) and C18:3n-6 in bees' body significantly, but decreased the contents of C16:1 and C18:3n-3. The diet supplied with 4% ARA reduced the mortality rate of honeybee infected with Escherichia coli. The activity of immune enzymes (phenoloxidase, antitrypsin, and lysozyme) and the mRNA expression levels of immune genes (defensin-2, toll, myd88, and dorsal) were improved by ARA diets to varying degrees depending on the ARA levels, especially 4% ARA. These results suggested that dietary ARA could improve the growth, survival, and immune functions of honeybees. Supplement of ARA in bees' diet would be valuable for the fitness of honeybees.

Effects of dietary arachidonic acid and docosahexanoic acid at different carbohydrates levels on gilthead sea bream growth performance and intermediary metabolism

A growth trial was performed to assess the interactive effects of high dietary levels of arachidonic acid (ARA) or docosahexaenoic acid (DHA), and carbohydrates on growth performance, feed utilization, proximate composition, plasma metabolites, and intermediary metabolism. Four isoproteic (47% crude protein) and isolipidic (18% crude lipids) diets were formulated for gilthead sea bream juveniles (47.5 g of initial mean body weight) to include low or high gelatinized starch (5 and 20% starch; LS and HS diets, respectively) and different dietary ARA/DHA content (2.3/0.3 and 0/2.6; ARA and DHA diets, respectively). Dietary ARA/DHA content did not affect growth performance or feed utilization. However, dietary starch inclusion increased feed efficiency, protein efficiency ratio, and energy retention (% intake). Dietary ARA/DHA profile did not affect the whole-body composition, but dietary starch increased whole-body dry matter, lipid, and gross energy content and decreased protein content. Low dietary ARA/DHA ratio increased plasma total protein and total lipids, triglycerides, and very-low-density lipoprotein cholesterol (VLDL) and decreased high-density lipoprotein cholesterol (HDL) and low-density lipoprotein cholesterol (LDL), independently of the dietary starch level. On the other hand, in LS diets, total cholesterol levels were lower in fish fed the diet rich in DHA than those fed with ARA. HS diets increased glucose, total protein and lipids, triglycerides, and VLDL plasmatic values, and decreased HDL. HS diets increased the carbohydrates intermediary metabolism and lipogenic enzymes. ARA and HS increased fatty acid desaturase 2 (FADS2) and decreased elongation of very long-chain fatty acid 5 protein (ELOVL5) in the liver, and only HS decreased ELOVL5 in the intestine. The muscle fatty acid content followed the dietary fatty acid profile, but ARA, EPA, and DHA content were increased in LS diets. In conclusion, few interactions between ARA or DHA and dietary digestible carbohydrates were found. The results indicate that at least in the presence of high ARA levels the n-3 LC-PUFA requirements were fulfilled with 0.5% EPA + DHA and gilthead sea bream tolerates well dietary inclusion of 20% starch.

Polychaete consumption increased prostaglandin biosynthesis in female Penaeus monodon.

The polychaete Perinereis nuntia is preferred over commercial feed pellets for boosting ovarian maturation of the female black tiger shrimp Penaeus monodon. High levels of prostaglandins in polychaetes are believed to enhance shrimp ovarian development. However, the impact of polychaete feeding on shrimp prostaglandin biosynthesis and fatty acid regulatory pathways have yet to be investigated. As polychaetes contain higher levels of arachidonic acid (ARA), eicosapentaenoic acid (EPA), prostaglandin E2 (PGE2) and prostaglandin F2α (PGF2α) than feed pellets, we examined the effects of polychaete feeding alone and in combination with eyestalk ablation on shrimp hepatopancreases and ovaries. Shrimp fed with polychaetes contained higher levels of EPA, PGE2 and PGF2α in hepatopancreases than those of pellet-fed shrimp. Similarly, higher levels of ARA and higher transcription levels of cyclooxygenase (COX) and prostaglandin F synthase (PGFS) were detected in ovaries of polychaete-fed shrimp compared to those of pellet-fed shrimp. The combination of polychaete-feeding and eyestalk ablation, commonly practiced to induce ovarian development, increased levels of ARA and EPA and transcription levels of COX in hepatopancreases and ovaries of polychaete-fed shrimp compared to those of pellet-fed shrimp. In ovaries, prostaglandin biosynthesis gene transcripts were induced by polychaete feeding while transcriptional levels of fatty acid regulatory genes were regulated by shrimp feed and eyestalk ablation. Our findings not only elucidate the effects of polychaete consumption on shrimp prostaglandin biosynthesis and fatty acid regulatory pathways during larvae production, but also suggests that high levels of dietary ARA, EPA and prostaglandins are essential during P. monodon ovarian development.

Reproductive performance in virgin pikeperch (Sander lucioperca L.) females fed different dietary levels of arachidonic acid with respect to the duration of spawning induction

Pikeperch (Sander lucioperca) is a species of significant importance for the further development of intensive aquaculture, what makes the total control over species’ reproductive cycle a high priority task. The present study aimed to assess the effect of arachidonic acid (AA) dietary enrichment on the reproductive performance in virgin females (two-years-old; individual weight 1.0 ± 0.2 kg) kept in fully controlled conditions with respect to different time of hormonal application. Two groups of breeders, ARA (fed AA enriched diet) and CTRL (fed control feed), were reared in two separated tanks of the recirculation system over the course of seven months. Five, six, and seven months after the start of trial, batches of five pairs of breeders (in total 15 pairs per each feeding group) from each group were hormonally treated. Ovulations occurred after six and seven months (oocyte diameter range 912−1030 μm), and samples of dry eggs were taken for the analysis of fatty acid profiles. Among the parameters of reproductive success, the embryo survival was significantly affected by the diet, while induction duration affected latency time only. The CTRL group females showed overall higher embryo survival across both reproduction occasions (p = 0.028) than group fed AA enriched diet (35.7 ± 17.1 % and 18.6 ± 13.6 % in CTRL and ARA group, respectively). A significant accumulation of AA was found in ARA group eggs in both reproduction batches. Virgin pikeperch breeders appear to keep at least one month plasticity towards the duration of spawning induction in controlled conditions and optimal oocyte diameter range for artificial reproduction is between 900−1000 μm. Levelling dietary AA with eicosapentaenoic acid during the entire photothermal protocol negatively altered the egg quality.

Arachidonic acid effects on the overall performance, fatty acid profile, hepatopancreas morphology and lipid-relevant genes in Litopenaeus vannamei juveniles

The effect of arachidonic acid (ARA) was evaluated on Litopenaeus vannamei juveniles. Growth performance; hepatopancreas and muscle fatty acid compositions; hepatopancreatic cells morphology; and expression of lipid-relevant genes were estimated after six-week experiment. A basal fat-reduced diet was manufactured and subsequently coated with different fatty acids sources, distinct levels of ARA (0, 0.3, and 0.6%), fish and soybean oil (50:50 Control diet). L. vannamei juveniles (1.10 ± 0.22 g) were randomly divided into twelve tanks with thirty animals each. The animals were fed three times per day, with 8% of the total biomass. The results showed that animals fed with diet containing 0.3% of ARA presented a lower final weight compared to the Control. Different levels of ARA inclusion in the experimental diets directly influenced in the tissues fatty acid profile with lower ARA levels in Control and 0% followed by 0.3% and 0.6%. In muscle and hepatopancreas tissues, a higher accumulation of docosahexaenoic acid (DHA) was revealed in the Control compared to the rest of the experimental treatments. The expression pattern of lipoxygenase (alox5), prostaglandin E synthase (pges2), sterol regulatory element-binding protein-1 (srebp1) and cycloxygenase (cox2) were significantly affected by the ARA inclusion, showing the highest expression in the Control treatment with a decrease according to the increasing levels of dietary ARA. It is concluded that ARA inclusion in shrimp diets result in a negative impact on the overall performance, probably modulated by a differential gene expression related to the eicosanoids synthesis, lipolytic and lipogenic pathways. Besides, the lipid deposition on the hepatopancreatic cells was reduced.

Effects of dietary arachidonic acid in European sea bass (Dicentrarchus labrax) distal intestine lipid classes and gut health.

The use of low fishmeal/fish oil in marine fish diets affects dietary essential fatty acids (EFAs) composition and concentration and, subsequently, may produce a marginal deficiency of those fatty acids with a direct impact on the fish intestinal physiology. Supplementation of essential fatty acids is necessary to cover the requirements of the different EFAs, including the ones belonging to the n-6 series, such as arachidonic acid (ARA). ARA, besides its structural role in the configuration of the lipid classes of the intestine, plays an important role in the functionality of the gut-associated immune tissue (GALT). The present study aimed to test five levels of dietary ARA (ARA0.5 (0.5%), ARA1 (1%), ARA2 (2%), ARA4 (4%), and ARA6 (6%)) for European sea bass (Dicentrarchus labrax) juveniles in order to determine (a) its effect in selected distal intestine (DI) lipid classes composition and (b) how these changes affected gut bacterial translocation rates and selected GALT-related gene expression pre and post challenge. No differences were found between distal intestines of fish fed with the graded ARA levels in total neutral lipids and total polar lipids. However, DI of fish fed with the ARA6 diet presented a higher (P < 0.05) level of phosphatidylethanolamine (PE) and sphingomyelin (SM) than those DI of fish fed with the ARA0.5 diet. In general terms, fatty acid profiles of DI lipid classes mirrored those of the diet dietary. Nevertheless, selective retention of ARA could be observed in glycerophospholipids when dietary levels are low (diet ARA0.5), as reflected in the higher glycerophospholipids-ARA/dietary-ARA ratio for those animals. Increased ARA dietary supplementation was inversely correlated with eicosapentaenoic acid (EPA) content in lipid classes, when data from fish fed with the diets with the same basal composition (diets ARA1 to ARA6). ARA supplementation did not affect intestinal morphometry, goblet cell number, or fish survival, in terms of gut bacterial translocation, along the challenge test. However, after the experimental infection with Vibrio anguillarum, the relative expression of cox-2 and il-1β were upregulated (P < 0.05) in DI of fish fed with the diets ARA0.5 and ARA2 compared with fish fed with the rest of the experimental diets. Although dietary ARA did not affect fish survival, it altered the fatty acid composition of glycerophospholipids and the expression of pro-inflammatory genes after infection when included at the lowest concentration, which could be compromising the physical and the immune functionality of the DI, denoting the importance of ARA supplementation when low FO diets are used for marine fish.

Searching integrated strategies for the evaluation of the physiological status in fish fed functional diets: The example of SDPP in gilthead sea bream (Sparus aurata)

In this study we evaluated the effects of high dietary arachidonic acid (ARA) levels on prostaglandin E2 (PGE2) and E3 (PGE3) production and their effect on two morphogenetic processes occurring during metamorphosis: the establishment of the juvenile pigmentation pattern and eye migration and remodeling of cranial bones. In this sense, Senegalese sole larvae were fed from 2 to 50 days post-hatch (dph) with live prey enriched with an experimental emulsion containing high levels of ARA (ARA-H; 10.2 and 7.1% TFA in enriched rotifer and Artemia, respectively) versus a reference commercial enriching product (Algamac 3050®, AGM; 1.0 and 1.4% TFA in enriched rotifer and Artemia, respectively). High dietary ARA levels did not affect larval growth performance at 50 dph, but significantly induced malpigmentation (81.4 ± 7.5%, versus 0.9 ± 0.3% in larvae fed the AGM diet). This malpigmentation was linked to the higher prostaglandin E2 (PGE2) levels observed in pseudo-albino fish as compared to normally pigmented individuals. The PGE2 levels were higher in normally pigmented specimens fed the ARA-H diet than in those fed the AGM diet. The effects of ARA on normally pigmented fish fed the AGM diet and pseudo-albino specimens fed the ARA-H diet were evaluated by means of the density of melanophores and the texture and image segmentation analyses in the dorsal skin of post-metamorphic fish. The skin of pseudo-albino specimens had a more uniform and homogeneous melanophore pattern than normally pigmented fish. Melanophores in pseudo-albino specimens were less abundant and not so aggregated in patches as they were in normally pigmented ones, whereas their shape differed (round vs. dendritic) suggesting their inability to disperse melanin. In addition, fish fed the ARA-H diet presented a higher percentage of cranial deformities (95.1 ± 1.5%) than those fed the control diet (1.9 ± 1.9%) that was significantly and negatively correlated with the incidence of normally-pigmented animals (R2 = − 0.88, P < 0.001). Cranial deformities in pseudo-albino fish were associated with an impaired migration of the eye from the ocular side (the right eye), whereas the left eye migrated from the blind side into the ocular side almost normally. The effects of high dietary ARA levels in the eye migration and cranial bone remodeling processes in post-metamorphic larvae were evaluated by means of the staining of cranial skeletal elements. Pseudo-albino fish showed higher interocular distance and head height than normally pigmented individuals, a different disposition of the eyes with regard to the vertebral column and mouth axes, and a distinct osteological development of some skeletal structures from the neuro- and splanchnocranium, in relation to high dietary ARA contents and high PGE2 production. These results brought new information about possible nutritional forcing factors and physiological mechanisms of pigmentary disorders and impaired eye migration, which are current major bottlenecks in flatfish aquaculture.

Intestinal homeostasis of juvenile tiger puffer Takifugu rubripes was sensitive to dietary arachidonic acid in terms of mucosal barrier and microbiota

A 74-day feeding trial was conducted to investigate the effects of different levels of dietary arachidonic acid (ARA) on mucosal barrier and microbiota in the intestine of tiger puffer Takifugu rubripes. Three isonitrogenous and isolipidic experimental diets were formulated to contain different ARA levels, i.e., 0.33 (Control), 2.45 (L-ARA), and 23.41 (H-ARA) g kg−1 dry matter. Each diet was fed to triplicate tanks. The results showed that the integrity of intestinal epithelial cells was impaired by increasing ARA levels. The leucocyte infiltration in the lamina propria was also enhanced by dietary ARA supplementation. Compared to the control group, group H-ARA had significantly down-regulated gene expression of intestinal tight junction proteins (claudin-4, claudin-7 and zonula occludens-1), but significantly up-regulated expression of myosin light chain kinase (MLCK). Gene expression of claudin-7 was significantly down-regulated also in group L-ARA. The intestinal lysozyme activity significantly decreased with increasing dietary ARA levels. Compared to the Control, diet H-ARA significantly up-regulated the gene expression of the pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin 8 (IL-8), and down-regulated that of anti-inflammatory cytokines transforming growth factor-β1 (TGF-β1) in the hind intestine. Intestinal gene expression of Toll-like receptor 3 (TLR-3) and nuclear factor kappa B p100 (NF-κB p100) was significantly up-regulated by H-ARA. Sequencing of bacterial 16 s rRNA V4 region showed that Proteobacteria, Tenericutes and Firmicutes were dominant in the intestine of tiger puffer. Fish fed diet H-ARA showed significantly decreased alpha diversity of microbiota and increased relative abundance of Arcobacter, a potential pathogenic genus. These results suggested that dietary ARA tended to induce the dysfunction of intestinal mucosal barrier and modulate the intestinal bacterial community, and MLCK and TLR3/NF-κB signaling were possibly involved in these processes. The ARA content in diets for tiger puffer needs to be carefully managed considering the intestinal sensitivity to dietary ARA of this fish.

Parental high dietary arachidonic acid levels modulated the hepatic transcriptome of adult zebrafish (Danio rerio) progeny.

Disproportionate high intake of n-6 polyunsaturated fatty acids (PUFAs) in the diet is considered as a major human health concern. The present study examines changes in the hepatic gene expression pattern of adult male zebrafish progeny associated with high levels of the n-6 PUFA arachidonic acid (ARA) in the parental diet. The parental generation (F0) was fed a diet which was either low (control) or high in ARA (high ARA). Progenies of both groups (F1) were given the control diet. No differences in body weight were found between the diet groups within adult stages of either F0 or F1 generation. Few differentially expressed genes were observed between the two dietary groups in the F0 in contrast to the F1 generation. Several links were found between the previous metabolic analysis of the parental fish and the gene expression analysis in their adult progeny. Main gene expression differences in the progeny were observed related to lipid and retinoid metabolism by PPARα/RXRα playing a central role in mediating changes to lipid and long-chain fatty acid metabolism. The enrichment of genes involved in β-oxidation observed in the progeny, corresponded to the increase in peroxisomal β-oxidative degradation of long-chain fatty acids in the parental fish metabolomics data. Similar links between the F0 and F1 generation were identified for the methionine cycle and transsulfuration pathway in the high ARA group. In addition, estrogen signalling was found to be affected by parental high dietary ARA levels, where gene expression was opposite directed in F1 compared to F0. This study shows that the dietary n-3/n-6 PUFA ratio can alter gene expression patterns in the adult progeny. Whether the effect is mediated by permanent epigenetic mechanisms regulating gene expression in developing gametes needs to be further investigated.

Moderate levels of dietary arachidonic acid reduced lipid accumulation and tended to inhibit cell cycle progression in the liver of Japanese seabass Lateolabrax japonicus

To investigate the physiological roles of dietary arachidonic acid (ARA) in fish, a feeding trial with Japanese seabass was conducted, followed by a hepatic transcriptome assay. Six experimental diets differing basically in ARA level (0.05%, 0.22%, 0.37%, 0.60%, 1.38% and 2.32% of dry matter) were used in the feeding trial. Liver samples from fish fed diets with 0.05% and 0.37% ARA were subjected to transcriptomic assay, generating a total of 139 differently expressed unigenes, which were primarily enriched in lipid metabolism and cell cycle-related signaling pathways. Then, qRT-PCR validation on lipid metabolism and cell cycle-related genes as well as corresponding enzyme-linked immunosorbent assay of selected proteins were conducted with liver samples from all six groups. Moderated ARA levels reduced lipogenesis and stimulated β-oxidation concurrently, but high ARA levels seemed to affect lipid metabolism in complicated ways. Both gene expression and protein concentration of cell cycle-related proteins were decreased by moderate levels of dietary ARA. The lipid content and fatty acid composition in fish confirmed the transcription and protein concentration results related to lipid metabolism. In conclusion, moderate levels of dietary ARA (0.37% and 0.60%) reduced lipid accumulation and tended to inhibit cell cycle progression in the liver of Japanese seabass.

Effects of dietary arachidonic acid on the growth performance, antioxidant capacity, and fatty acid metabolism of sea cucumber ( Apostichopus japonicus )

PDF HTML阅读 XML下载 导出引用 引用提醒 饲料中花生四烯酸含量对刺参生长性能、抗氧化能力及脂肪酸代谢的影响 DOI: 作者: 作者单位: 1. 山东省海洋资源与环境研究院, 山东省海洋生态修复重点实验室, 山东 烟台 264006;2. 上海海洋大学 水产与生命学院, 上海 201306 作者简介: 王成强(1988-),男,研究实习员,主要从事水产动物营养与饲料研究.E-mail:chengqiangwang@126.com 通讯作者: 中图分类号: S963 基金项目: 山东省科技发展计划项目（2016GSF115005）；山东省现代农业产业技术体系项目（SDAIT-22-06）. Effects of dietary arachidonic acid on the growth performance, antioxidant capacity, and fatty acid metabolism of sea cucumber (Apostichopus japonicus) Author: Affiliation: 1. Shandong Provincial Key Laboratory of Restoration for Marine Ecology, Shandong Marine Resource and Environment Research Institute, Yantai 264006, China;2. College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为探究饲料中添加花生四烯酸（arachidonic acid，ARA）对刺参（）生长性能、抗氧化能力及脂肪酸代谢的影响，选用初始体重为（10.78±0.06）g的刺参为研究对象，以鱼粉和发酵豆粕为主要蛋白质源，小麦粉为主要糖源制作基础饲料，通过在基础饲料中添加不同比例的ARA-纯化油，制成ARA含量分别为0.02%（对照组）、0.17%、0.36%、0.51%、0.59%和0.98%（占饲料干重）的6组等氮等脂的实验饲料，在室内循环水养殖系统进行为期56 d的养殖实验。结果表明，随着饲料中ARA含量的升高，刺参增重率（weight gain rate，WGR）呈先上升后降低的趋势，0.36%和0.51% ARA饲料组刺参WGR显著高于其他处理组（<0.05），刺参的特定生长率（specific growth rate，SGR）和饲料效率（feed efficiency，FE）与WGR具有相同的变化趋势；刺参体壁粗脂肪含量随饲料ARA含量升高呈先降低后升高的趋势，在0.51% ARA饲料组含量最低，且显著低于对照组与0.98% ARA饲料组（< 0.05）；同时，随饲料中ARA含量的提高，刺参体壁中ARA和n-6多不饱和脂肪酸（n-6 polyunsaturated fatty acids，n-6 PUFA）含量呈显著上升趋势，而二十碳五烯酸（eicosapentaenioc acid，EPA）、二十二碳六烯酸（docosahexaenoic acid，DHA）和n-3多不饱和脂肪酸（n-3 polyunsaturated fatty acids，n-3 PUFA）含量显著降低（<0.05）；抗氧化能力方面，0.36%和0.51% ARA饲料组刺参肠道中超氧化物歧化酶（superoxide dismutase，SOD）、过氧化氢酶（catalase，CAT）和总抗氧化能力酶（total antioxidant capacity enzyme，T-AOC）活性均显著高于对照组与0.98% ARA饲料组（<0.05）；刺参肠道中脂肪酸合成酶（fatty acid synthase，FAS）和乙酰辅酶A羧化酶（acetyl-CoA carboxylase，ACC）活性随饲料ARA含量的升高呈显著降低趋势（<0.05）；刺参肠道中肉毒碱棕榈酰转移酶-1（carnitine palmitoyltransferase-1，CPT-1）活性随饲料ARA含量升高呈先升高后降低的趋势（>0.05）。研究表明，在本实验条件下，饲料中添加适量ARA （0.36%~0.51%）能够对刺参生长、抗氧化能力起到一定的促进作用，同时结果显示，饲料ARA含量会对刺参肠道内脂肪酸代谢产生一定的影响。 Abstract:A 56-d feeding experiment in an indoor flowing-through water system was conducted to evaluate the effects of arachidonic acid (ARA) in diets on the growth performance, antioxidant capacity, and body wall fatty acid composition of sea cucumbers () with initial weights of (10.78 ±0.06) g. Six isonitrogenous and isoenergetic diets with varying levels of dietary ARA[0.02% (control group), 0.17%, 0.36%, 0.51%, 0.59%, and 0.98%] were formulated. The ARA content had no significant effect on survival rate (87.50%-94.17%; >0.05). However, both growth rate (WGR) and feed efficiency (FE) increased with increasing ARA content until reaching peak levels at 0.51% dietary ARA, but decreased thereafter (<0.05). Body wall composition analysis indicated that the whole-body lipid content initially decreased but then increased with increasing dietary ARA, whereas the whole-body protein, ash, and moisture contents were unaffected. Superoxide dismutase (SOD), catalase (CAT), and total antioxidant capacity enzyme (T-AOC) activities in the intestinal tract initially increased with increasing ARA content but then decreased (<0.05), whereas the malondialdehyde (MDA) content of the intestinal tract exhibited a contrasting pattern (<0.05). Fatty acid synthase (FAS) and acetyl-COA carboxylase (ACC) activities in the intestinal tract were unaffected when dietary ARA content decreased from 0.02% to 0.59% but decreased significantly when the dietary ARA content increased from 0.59% to 0.98% (<0.05). The ARA and n-6 PUFA contents of the body wall increased with increasing dietary ARA, whereas the EPA and DHA content of the body wall decreased. Therefore, dietary ARA contents of 0.36%-0.51% could be used to promote the growth performance and intestinal antioxidant capacity of sea cucumbers under experimental conditions. The effects of ARA level in diet on the activities of fatty acid synthase, acetyl-CoA carboxylase, and carnitine palmitoyltransferase-1 in the intestinal tract of sea cucumber were also observed in the study. 参考文献 相似文献 引证文献

Estimation of Arachidonic Acid Requirement for Improvement of Pre‐maturation Growth and Egg and Larval Quality in the Female Blue Gourami (Trichopodus trichopterus; Pallas, 1770): A Model for the Anabantidae Family

AbstractThis study investigates the dietary arachidonic acid (ARA) requirement from juvenile to maturation stage in an anabantid model fish, the blue gourami, Trichopodus trichopterus. Specifically we determined the optimum dietary ARA content to maximize juvenile growth and subsequent sexual maturation and to improve the quality of their eggs and offspring. Five experimental diets containing 0.02, 0.53, 1.05, 1.60, and 2.12% ARA (of dry weight) were fed to juveniles over 5 mo. The results showed that whole‐body fatty acid profile of broodstock significantly changed in fish fed diets of different ARA content (ANOVA, P &lt; 0.003). The highest contents of 18:2n‐6 and Σn‐6 were obtained in fish fed 0.53% ARA, and a decreasing trend was observed with elevated dietary ARA levels. Monthly specific growth rate (SGR) measurements revealed significant differences in the juvenile stage, but the SGR of broodstock was unaffected by dietary ARA. Protein and ash content of whole‐body broodstock showed no differences among groups, while lipid content decreased as ARA levels increased. Maximum volume of the oocyte was obtained in the 1.05% ARA group, while the yolk sac size increased as dietary ARA increased. The optimum growth and survival of the larvae produced by broodstock were recorded in the 2.12 and 1.6% ARA groups, respectively. It was concluded that despite the presumed ability of freshwater fish to synthesize and meet their highly unsaturated fatty acid requirements, dietary ARA higher than 1.05% had significant stimulatory effects on growth of juveniles but no obvious influence on the growth of matured fish. Also, higher ARA levels (1.6–2.12%) were found to improve the quality of eggs and offspring.

Effect of dietary arachidonic acid levels on growth performance, fatty acid profiles and lipid metabolism of juvenile yellow catfish (Pelteobagrus fulvidraco)

An 8-week feeding trial was conducted to evaluate the effects of different dietary arachidonic acid (ARA) levels on growth performance, fatty acid composition, hepatic intermediary metabolism and antioxidant responses for juvenile yellow catfish. An ARA-enriched oil was supplemented into the basal diet to formulate six iso-nitrogenous and iso-energetic practical diets containing 0.03% (the control diet), 0.30%, 0.60%, 0.90%, 1.20% and 1.50% of dry weight. Dietary ARA levels were 0.39%, 2.47%, 4.96%, 7.49%, 9.79% and 12.64% total fatty acids, respectively. Triplicate groups of 20 fish (average initial weight is about 1.55±0.01g) were fed to apparent satiation twice daily. The results indicated that fish fed the diets containing 4.96% and 7.49% ARA of total fatty acids have higher final body weight and percent weight gain (PWG) than those fed the other diets. Survival, feed conversion ratio, hepatosomatic index and viscerosomatic index were not significantly influenced by the dietary ARA levels. Fatty acid compositions both in liver and muscle reflected closely those of fatty acid profiles in diets, ARA proportion in liver and muscle significantly increased with dietary ARA levels increasing from 0.39% to 12.64% of total fatty acids, while, EPA proportion in liver significantly decreased with increase of dietary ARA levels. Fish fed the control diet had the highest aspartate aminotransferase (AST) and glucose content in serum among all treatments, and fish fed the 9.79% and 12.64% ARA of total fatty acids had higher malondialdehyde (MDA) content in liver than those fed the other diets. However, the activities of total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-PX) and catalase (CAT) in liver were not significantly influenced by dietary ARA levels. The relative gene expression of accα, g6pd, 6pgd and evovl5 in liver down-regulated significantly with the dietary ARA levels increasing from 0.39% to 12.64% of total fatty acids. The relative gene expression of atgl and hslb in liver down-regulated significantly with the dietary ARA levels increasing from 0.39% to 7.49% of total fatty acids, and then up-regulated as dietary ARA levels increasing from 9.79% to 12.64%. However, relative gene expression of cpt1a and ppara in liver are down-regulated in ARA supplemental groups. These results suggested that dietary moderate ARA levels (4.96% and 7.49% of total fatty acids) could improve growth performance and antioxidant response, and up-regulate or down-regulate relative expression levels of some lipid metabolism-related gene in liver. Two slope broken-line regression analysis of PWG against dietary ARA levels indicated that optimal dietary ARA requirement for juvenile yellow catfish was 6.45% of total fatty acids.

Dietary arachidonic acid promotes growth, improves immunity, and regulates the expression of immune-related signaling molecules in Macrobrachium nipponense (De Haan)

Arachidonic acid (ARA) is involved in the growth and regulation of immunity in fish. Little research has focused on ARA in crustaceans. This study was an 8-week feeding experiment investigating the effects of dietary ARA on growth, antioxidative indices, and immune characteristics of the juvenile oriental river prawn (Macrobrachium nipponense). An ARA-enriched oil was supplemented into the basal diet to formulate six isonitrogenous and isoenergetic diets containing 0.02% (the control group), 0.28%, 0.54%, 0.86%, 1.22%, and 1.54% ARA dry weight. Diets were fed to juvenile prawns (mean weight: 0.104±0.002g) twice daily to apparent satiation in three replicates. Weight gain and specific growth rate of M. nipponense significantly increased with increasing dietary levels of ARA from 0.02% to 0.86% and thereafter declined. Hepatopancreas super oxide dismutase and catalase activities significantly increased with supplementation with ARA, particularly in prawns fed 1.22% and 1.54% ARA. The malondialdehyde level in prawns fed 1.54% ARA also significantly increased, and was higher than that of prawns fed ARA from 0.02% to 0.86%. Serum lysozyme activity was significantly greater in prawns fed 0.86% ARA compared with the other groups. mRNA expression of toll-like receptor signaling pathway-related genes was promoted by a dietary ARA level from 0.54% to 0.86% but inhibited with the higher ARA levels (1.22–1.54%). The mortality percentage increased after challenge with live Aeromonas hydrophila. The mortality percentage of prawns fed 1.54% ARA was significantly higher than that of prawns fed 0.28–1.22% ARA. The results suggest that the optimal dietary ARA requirement for juvenile M. nipponense is 0.82% (dry weight) based on second-order regression analysis of weight gain vs. dietary ARA level, and that 0.86% ARA could significantly enhance non-specific immunity of M. nipponense; however, too high a level of ARA will affect the health status of this prawn.