Dietary Fish Oil Research Articles

Inflammatory stimuli alter bone marrow composition and compromise bone health in the malnourished host.

Inflammation has a role in the pathogenesis of childhood malnutrition. We investigated the effect of malnutrition and inflammatory challenge on bone marrow composition and bone health. We studied an established murine model of moderate acute malnutrition at baseline and after acute inflammatory challenge with bacterial lipopolysaccharide (LPS), a surrogate of Gram-negative bacterial sepsis, or Leishmania donovani, the cause of visceral leishmaniasis. Both of these infections cause significant morbidity and mortality in malnourished children. Of the 2 stimuli, LPS caused more pronounced bone marrow changes that were amplified in malnourished mice. LPS challenge led to increased inflammatory cytokine expression (Il1b, Il6, and Tnf), inflammasome activation, and inflammatory monocyte accumulation in the bone marrow of malnourished mice. Depletion of inflammatory monocytes in Csfr1-LysMcre-DT malnourished mice significantly reduced the inflammasome activation and IL1-ß production after LPS challenge. The inflammatory challenge also led to increased expansion of mesenchymal stem cells (MSCs), bone marrow adiposity, and expression of genes (Pparg, Adipoq, and Srbp1) associated with adipogenesis in malnourished mice. This suggests that inflammatory challenge promotes differentiation of BM MSCs toward the adipocyte lineage rather than toward bone-forming osteoblasts in the malnourished host. Concurrent with this reduced osteoblastic potential there was an increase in bone-resorbing osteoclasts, enhanced osteoclast activity, upregulation of inflammatory genes, and IL-1B involved in osteoclast differentiation and activation. The resulting weakened bone formation and increased bone resorption would contribute to the bone fragility associated with malnutrition. Lastly, we evaluated the effect of replacing lipid rich in omega-6 fatty acids (corn oil) with lipid-rich in omega-3 fatty acids (fish oil) in the nutrient-deficient diet. LPS-challenged malnourished mice that received dietary fish oil showed decreased expression of inflammatory cytokines and Rankl and reduced osteoclast differentiation and activation in the bone marrow. This work demonstrates that the negative effect of inflammatory challenge on bone marrow is amplified in the malnourished host. Increasing dietary intake of omega-3 fatty acids may be a means to reduce inflammation and improve bone health in malnourished children.

Long-term effects of adolescent exposure to olanzapine in C57BL/6J mice and the impact of dietary fish oil supplementation.

Second-generation antipsychotic (SGA) medications can produce abnormal weight gain and metabolic dysfunction in children, but little is known about the post-treatment consequences of adolescent SGA exposure. The objective of this study was to determine the long-term, post-treatment effects of adolescent olanzapine exposure on weight and metabolic function and whether dietary fish oil (FO) modulated any observed effects of olanzapine. Male and female mice were fed a high-fat, high-sugar (HF-HS) diet or an HF-HS diet supplemented with fish oil (HF-HS-FO) and were treated with olanzapine or vehicle for 29days beginning on postnatal day 37. In male mice, adolescent olanzapine treatment suppressed weight gain during and after treatment and improved metabolic function in adulthood; dietary fish oil reduced weight gain, increased expression of fatty acid oxidation genes, and decreased expression of genes associated with fatty acid synthesis and inflammation. In contrast, few effects were observed in female mice. The current results suggest that adolescent olanzapine exposure can produce long-term alterations in weight and metabolic function in male mice and that dietary fish oil can reduce adverse effects of lifelong consumption of an HF-HS diet. Because expected adverse effects of adolescent olanzapine treatment were not observed, the potential beneficial effects of dietary fish oil for SGA-induced weight gain and metabolic dysfunction could not be evaluated.

Diet restriction alone improves glucose tolerance and insulin sensitivity than its coadministration with krill or fish oil in a rabbit model of castration‐induced obesity

This study investigated the effect of 50% diet restriction and its coadministration with krill oil (KO) or fish oil (FO) on glucose tolerance and insulin sensitivity in a rabbit model of obesity. Castrated male rabbits were 50% restricted fed and supplemented with KO or FO (600 mg omega-3 polyunsaturated fatty acids/daily) for 2 months. Simultaneously, two control groups were used: castrated, full-diet-fedand castrated, 50% restricted fed rabbits without additives restricted group(RG). The energy-restricted diet decreased final body weight in castrated male rabbits and improved most insulin sensitivity and β-cell function indexes. Combining the same diet and KO or FO, further reduced fasting blood glucose levels. However, this feed regime significantly accelerated insulin secretion and reduced gene expression of insulin receptor substrate-1, pyruvate kinase and 3-hydroxy-3-methylglutaryl-CoA synthase 2. This was manifested by reduced dynamic insulin sensitivity, assessment homoeostasis-β-cell function indicesand increased glucose elimination rate to levels comparable to or above the obese animals. Aspartate and alanine aminotransferases enzyme activities were raised more than those in the obese group. Surprisingly, KO and FO administration downregulated acetyl-coenzyme A oxidase and carnitine palmitoyltransferase 2 messenger RNA gene expression compared to the RG.In conclusion, we can assume that a better effect on insulin sensitivity and glucose tolerance was observed in the diet restriction alone than in the coadministration of KO or FO when animals are exposed to highly obesity predisposing factors. These effects could be at least in part ascribed to the modified gene expression levels of some critical enzymes and factors involved in liver glucose metabolism and β-oxidation.

Taurine Attenuates Oxidized Fish Oil-Induced Oxidative Stress and Lipid Metabolism Disorder in Mice.

The objective of this study was to determine the effect of dietary taurine on lipid metabolism and liver injury in mice fed a diet high in oxidized fish oil. The ICR mice (six weeks old) were randomly assigned to six groups and fed different diets for 10 weeks: control (CON), normal plus 15% fresh fish oil diet (FFO), normal plus 15% oxidized fish oil diet (OFO), or OFO plus 0.6% (TAU1), 0.9% (TAU2) or 1.2% (TAU3) taurine. Compared to the CON group, OFO mice showed increased liver index, aspartate aminotransferase (AST) and malondialdehyde (MDA) levels in serum (p < 0.05). In addition, OFO mice had increased cholesterol (CHOL)/high-density lipoprotein cholesterol (HDL-C) and decreased HDL-C/low-density lipoprotein cholesterol (LDL-C) and n-6/n-3 polyunsaturated fatty acid (PUFA) ratio in serum (p < 0.05) compared with CON mice. Notably, dietary taurine ameliorated the liver index and AST and MDA levels in serum and liver in a more dose-dependent manner than OFO mice. In addition, compared to OFO mice, decreased levels of CHOL and ratio of CHOL/HDL-C and n-6 PUFA/n-3 PUFA in serum were found in TAU3-fed mice. Supplementation with TAU2 and TAU3 increased the relative mRNA expression levels of peroxisome proliferator-activated receptor α, adipose triglyceride lipase, lipoprotein lipase, hormone-sensitive lipase and carnitine palmitoyl transferase 1 in liver compared with the OFO group (p < 0.05). Moreover, impaired autophagy flux was detected in mice fed with the OFO diet, and this was prevented by taurine. These findings suggested that dietary taurine might provide a potential therapeutic choice against oxidative stress and lipid metabolism disorder.

Nutritional programming of large yellow croaker (Larimichthys crocea) larvae by dietary vegetable oil: effects on growth performance, lipid metabolism and antioxidant capacity.

The nutritional status experienced in the early development of life plays a vital role in the long-term metabolic state of the individual, which is known as nutritional programming. The present study investigated the long-term effects of vegetable oil (VO) nutritional programming during the early life of large yellow croaker. First, larvae were fed either a fish oil (FO) diet or a VO diet for 30 d. Subsequently, under the same conditions, all fish were fed a commercial diet for 90 d and thereafter challenged with an FO or VO diet for 30 d. The results showed that growth performance was significantly lower in larvae fed the VO diet than in those in fed the FO diet in the stimulus phase. Notably, VO nutritional history fish showed lower levels of liver lipids liver total triglycerides and serum nonesterified free fatty acids than the FO nutritional history fish when juveniles were challenged with the VO diet, which was consistent with the expression of lipogenesis-related genes and proteins. Moreover, the VO nutritional history fish showed lower liver damage and higher antioxidant capacity than FO nutritional history fish when challenged with the VO diet. In summary, this study showed that a short VO stimulus during the early life stage of large yellow croaker, had a long-term effect on lipid metabolism and the antioxidant system. Specifically, VO nutritional programming had a positive effect on alleviating abnormal lipid deposition on the liver, liver damage, and the reduction of hepatic antioxidant capacity caused by a VO diet.

Effects of Different Marine-Based Lipid Sources on Growth Performance, Activities of Digestive Enzyme, Antioxidant Responses, and Lipid Metabolism of Large Yellow Croaker (Larimichthys crocea) Larvae

The study of lipid nutrition is an important guarantee for the development of high-efficiency artificial microdiet for fish larvae. Existing studies on lipid nutrition of larvae mainly focus on nutrient requirements and metabolism through a single lipid source. However, there are few reports on the effects of different marine-based lipid sources on fish larvae. In this study, a 30-day feeding experiment was conducted to evaluate the effects of different dietary marine-based lipid sources on survival, growth performance, appetite gene expression, activities of digestive enzyme, antioxidant responses, and lipid metabolism of large yellow croaker (Larimichthys crocea) larvae (initial weight 4.71 ± 0.21 mg ). Four isonitrogenous (520 g/kg crude protein) and isolipidic (190 g/kg crude lipid) diets were formulated to contain fish oil (FO), krill oil (KO), squid viscera oil (SVO), and Schizochytrium sp. oil (SSO), respectively. Results showed that larvae fed with the SSO diet had significantly higher survival rate (SR) than those fed with dietary FO and SVO ( P &lt; 0.05 ). However, larvae fed with the SSO diet had significantly lower final body weight (FBW) and specific growth rate (SGR) than those fed with other diets ( P &lt; 0.05 ). Furthermore, larvae fed with the SSO diet had significantly higher percentage of total n-3 long-chain polyunsaturated fatty acids (LC-PUFA) than those fed with other diets, followed by KO and SVO diets ( P &lt; 0.05 ). Larvae fed with the SSO diet had significantly lower mRNA expression of orexigenic genes (npy and ghrelin) and significantly higher mRNA expression of anorexigenic gene (cart) than those fed with dietary FO ( P &lt; 0.05 ). Meanwhile, larvae fed with the SSO diet had significantly higher activity of alkaline phosphatase (AKP) in intestinal segments (IS) and brush border membrane (BBM) than those fed with dietary FO and SVO ( P &lt; 0.05 ). Larvae fed with the SSO diet had significantly higher activity of total antioxidant capacity (T-AOC) than those fed with dietary FO ( P &lt; 0.05 ). The TG content and mRNA expression of lipogenesis genes (srebp-1c, fas, and scd1) were markedly lower in larvae fed with SSO, KO, and SVO diets than in those fed with dietary FO ( P &lt; 0.05 ). Meanwhile, larvae fed with KO and SSO diets had significantly higher mRNA expression of the lipolysis gene (cpt-1) than those fed with other diets ( P &lt; 0.05 ). In conclusion, results of the present study showed that FO can be completely replaced in large yellow croaker larvae feed with KO and SVO without negative effects. Moreover, the complete replacement of FO by SSO can improve survival, activities of digestive enzyme, antioxidant responses, and lipid metabolism, despite inhibiting the appetite and growth of large yellow croaker larvae.

N-3 PUFA Ameliorates the Gut Microbiota, Bile Acid Profiles, and Neuropsychiatric Behaviours in a Rat Model of Geriatric Depression.

The brain−gut−microbiome (BGM) axis affects host bioinformation. N-3 polyunsaturated fatty acids (PUFAs) alleviate cognitive impairment and depression in older adults. This study investigated altered microbiota−bile acid signalling as a potential mechanism linking fish oil-induced gut changes in microbiota to alleviate psychological symptoms. Sprague Dawley rats were fed a fish oil diet and administered D-galactose combined with chronic unpredictable mild stress (CUMS) to simulate geriatric depression. The cognitive function, psychological symptoms, microbiota compositions, and faecal bile acid profiles of the rats were assessed thereafter. A correlation analysis was conducted to determine whether the fish oil-induced alteration of the rats’ microbiota and bile acid profiles affected the rats’ behaviour. D-galactose and CUMS resulted in lower concentrations of Firmicutes, significantly altered bile acid profiles, and abnormal neurobehaviours. Fish oil intake alleviated the rats’ emotional symptoms and increased the abundance of Bacteroidetes, Prevotellaceae, Marinifilaceae, and Bacteroidesuniformis. It also elevated the concentrations of primary bile acids and taurine-conjugated bile acids in the rats’ faeces. The rats’ taurine-conjugated bile acid levels were significantly correlated with their behavioural outcomes. In short, fish oil intake may alleviate psychological symptoms by altering the microbial metabolites involved in the BGM axis, especially in the conjugation of bile acids.

The Effect of Dietary Restriction and Fish Oil Consumption on Small Intestinal Morphology and Liver Cell Changes in Broilers

The Effect of Dietary Restriction and Fish Oil Consumption on Small Intestinal Morphology and Liver Cell Changes in Broilers

Fatty Acid Composition and mRNA Expression of Fatty Acid Binding Protein Genes (fabp3 and fabp6) in Rainbow Trout Fed Camelina Seed Oil (Camelina sativa)-Based Diets

Vegetable lipids such as camelina oil (Camelina sativa) are used as alternatives oil sources to fish oil in aquafeeds. In this study, we determined fatty acid-binding protein 3 (fabp3) and fatty acid-binding protein 6 (fabp6) gene expression and fatty acid composition in the liver and muscle tissue of rainbow trout fed different amounts of dietary camelina seed oil [100% (CO100), 67% (CO67), and 37% (CO33)]. Palmitic acid and oleic acid were identified as the most abundant saturated and monounsaturated fatty acids, respectively, in both tissues across all experimental groups. The highest levels of n-6 polyunsaturated fatty acid (Σn- 6 PUFA) were found in the first biopsy (15th day) taken from fish fed a diet of CO100, while the highest Σn–3 PUFA level was found in the third biopsy (45th day) taken from the same group. The FO100 (fish oil) diet was found to have the highest Σn-3 / n-6 ratio, as well as the highest levels of eicosapentaenoic acid and docosahexaenoic acid. In general, the fatty acid composition of the fish reflected that of their respective diets. The expression of fabp3 and fabp6 genes in the muscle of fish fed camelina seed oil were not significantly different from control group. However, fabp3 gene expression of liver of FO100 group was found to have significantly higher than CO67 and CO33. A difference in hepatic fabp6 gene expression was also noted in the FO100 group, but was not found to be statistically significant. Growth parameters and survival rate were not affected after the 45 days feeding trial. These results suggest that camelina seed oil can be used as an alternative to fish oil in rainbow trout diet.

Replacement of Fish Oil With Groundnut Oil for Developing Sustainable Feeds for Labeo rohita Fingerling

Groundnut oil (GO) is one of the most widely available vegetable oils (VOs) in India and throughout the world, with a global production of 6.12 million metric tons in the year 2020–2021. GO contains phytochemicals and antioxidants with a longer shelf life. Because of these benefits, GO can produce durable, low-cost, and sustainable aquaculture feeds. To evaluate the nutritional efficacy and possibility of replacing fish oil (FO) with GO, this experiment was carried out to test the effects of partial or total substitution of dietary FO by GO on the growth performance, carcass composition, antioxidant capacity, lysozyme activity, muscle fatty acid composition, and filet nutritional quality in Labeo rohita fingerling. Induced bred healthy rohu fingerlings (4.84 ± 0.13 g) were fed six isonitrogenous (400 g kg−1) and isolipidic (97 g kg−1) casein- and gelatin-containing purified diets, wherein the FO was gradually replaced by 0, 20, 40, 60, 80, and 100% GO. Fishes were stocked randomly in triplicate groups of 30 fish per tank and fed at 08:00, 12:00, and 16:00 h to apparent satiety for 8 weeks. The results showed that FO replacement with GO did not affect the growth but decreased the eicosapentaenoic (EPA), docosahexaenoic acid (DHA) levels, and n-3/n-6 ratio in the muscle of rohu fingerlings. The antioxidant capacity and lysozyme activity improved up to 60% replacement of FO with GO in diet and then declined (P &amp;gt; 0.05) upon further inclusion of GO in diets. Although the atherogenicity, thrombogenicity indices, and hypocholesterolemic/hypercholesterolemic (H/H) ratio did not change significantly among all the muscle samples, the highest filet lipid quality (FLQ) value was found in fish receiving a 100% FO diet. Further inclusion of dietary GO decreased the filet H/H ratio and FLQ value. In summary, replacing FO with GO at a higher level had negative consequences on the filet nutritional quality of rohu fingerlings. Therefore, FO can be replaced by GO in formulated feeds to a level of 60% without hampering the growth, antioxidant capacity, and lysozyme activity and to avoid degrading the nutritional quality of fish filet.

Nrf2 pathway in vegetable oil-induced inflammation of large yellow croaker (Larimichthys crocea)

This study was conducted to investigate the effects and regulation of dietary vegetable oil (VO, enriched with α-linolenic acid [ALA] and linoleic acid [LNA]) on the nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-κB (NF-κB) pathways in large yellow croaker. In vivo study showed that the VO diet significantly decreased the activity of antioxidant enzymes and antioxidant enzyme-related mRNA expression in the liver tissue, in comparison with the fish oil (FO) diet (P < 0.05). The suppression of antioxidant capacity might be due to the decrease of nuclear Nrf2 protein translocation, Nrf2 binding to antioxidant response element (ARE) sequences, and subsequently, antioxidant genes transcription as electrophoretic mobility shift assay (EMSA) and luciferase assay showed. VO-derivated ALA and LNA exerted a lower antioxidant capacity than FO-derivated DHA and EPA, characterized by significantly lower nucleus Nfr2 protein expression but significantly higher ROS production values in primary hepatocytes (P < 0.05). The pro-inflammatory genes (tumor necrosis factor α [TNFα] and interleukin 1β [IL1β]) expression was significantly higher in the liver tissue of fish fed the VO diet which might be due to the activation of the NF-κB pathway (P < 0.05). Knockdown of the Nrf2 gene negatively affected the anti-inflammatory effect of fatty acids by increasing the expression of TNFα and the IL1β gene and nuclear p65 protein (P < 0.05). In general, the results indicated that dietary vegetable oil decreased antioxidant capacity but induced inflammatory responses through the Nrf2/NF-κB pathway.

Abstract 254: Dietary fish oil and aspirin to augment anti-PD-1 immunotherapy in metastatic melanoma

Abstract Introduction: First line anti-PD-1 immune checkpoint inhibition (αPD-1 ICI) induces objective responses in less than 50% of metastatic melanoma patients. Aspirin (ASA) use is associated with improved responsiveness to ICI, with inhibition of myeloid-induced immunosuppression in the tumor microenvironment (TME) a purported mechanism. Cyclooxygenase modulators ASA (pharmacologic inhibitor) and dietary fish oil (FO, substrate) shift myeloid and T cell populations to anti-inflammatory, pro-resolution phenotypes in immunity and cancer. Methods: C57-BL6/J mice were injected with YUMM 1.7 melanoma in the flank. Mice were fed control chow and water (CTL) or omega-3 rich (FO) chow (10% w/w, 30%kcal/kcal), given ASA in drinking water (600 ug/mL), or FO/ASA combined (COMBO) starting 12 days post tumor implantation, the same day as starting intraperitoneal αPD1 or IgG2a vehicle (q3-4 days). An alternative cohort received pre-αPD-1 treatment ASA and FO starting day 7. Tumors were assessed for growth, harvested, and characterized via flow cytometry on day 32. Results: When diets and water were started concurrent with αPD-1/IgG2a, FO decreased tumor volume vs. CTL for both vehicle (28%) and αPD-1 (27%) treatments; ASA and COMBO (p = 0.0501) did not. Compared to CTL, FO and COMBO increased monocytes (CD45+, CD11b+, Ly6C+, Ly6G-) and PD-L1+ monocytes in the TME with no effect on tumor associated macrophages (TAMS); ASA decreased the percent of Arginase 1+, CD206+ TAMs. ASA increased PD1+ CD8 T cells, while COMBO increased CD4 and CD8 T cells including LAG3+ and PD1+ CD8 T cells. When diets and water were started on day 7, FO + αPD-1 decreased tumor volume (21%) vs. αPD-1 controls; ASA and COMBO did not. Compared to CTL, FO and COMBO similarly altered immune populations as above, with FO additionally increasing total CD3+ T-cells, PD-L1+ CD4 T cells, and PD-1+ CD8 T cells; COMBO increased dendritic cells (CD11c+, MHCII+, F4/80-). TAMS were not assessed. Results significant (p&amp;lt; 0.05) by ANOVA or t-test unless specified. Food eaten, water imbibed, and weight did not vary between groups. Conclusions: Dietary fish oil impaired in vivo melanoma tumor growth with and without αPD-1 ICI despite increases in classically deleterious monocyte populations, while aspirin decreased M2-like macrophages in the TME without alterations in tumor growth. Modulation of the cyclooxygenase axis may be a cost-effective method to skew TME immune populations to favor αPD-1 immunotherapy responses in metastatic melanoma. Citation Format: Alexander C. Chacon, Shuyang S. Qin, Alexa D. Melucci, Katherine M. Jackson, Paul R. Burchard, Yatee A. Dave, Rachel Jewell, Brian A. Belt, William Tabayoyong, David C. Linehan, Peter A. Prieto. Dietary fish oil and aspirin to augment anti-PD-1 immunotherapy in metastatic melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 254.

A Paternal Fish Oil Diet Preconception Modulates the Gut Microbiome and Attenuates Necrotizing Enterocolitis in Neonatal Mice.

Epidemiology and animal studies suggest that a paternal history of toxicant exposure contributes to the developmental origins of health and disease. Using a mouse model, our laboratory previously reported that a paternal history of in utero exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increased his offspring’s risk of developing necrotizing enterocolitis (NEC). Additionally, our group and others have found that formula supplementation also increases the risk of NEC in both humans and mice. Our murine studies revealed that intervening with a paternal fish oil diet preconception eliminated the TCDD-associated outcomes that are risk factors for NEC (e.g., intrauterine growth restriction, delayed postnatal growth, and preterm birth). However, the efficacy of a paternal fish oil diet in eliminating the risk of disease development in his offspring was not investigated. Herein, reproductive-age male mice exposed to TCDD in utero were weaned to a standard or fish oil diet for one full cycle of spermatogenesis, then mated to age-matched unexposed females. Their offspring were randomized to a strict maternal milk diet or a supplemental formula diet from postnatal days 7–10. Offspring colon contents and intestines were collected to determine the onset of gut dysbiosis and NEC. We found that a paternal fish oil diet preconception reduced his offspring’s risk of toxicant-driven NEC, which was associated with a decrease in the relative abundance of the Firmicutes phylum, but an increase in the relative abundance of the Negativicutes class.

Molecular Characterization, Tissue Distribution Profile, and Nutritional Regulation of acsl Gene Family in Golden Pompano (Trachinotus ovatus).

Long chain acyl-coA synthase (acsl) family genes activate the conversion of long chain fatty acids into acyl-coA to regulate fatty acid metabolism. However, the evolutionary characteristics, tissue expression and nutritional regulation of the acsl gene family are poorly understood in fish. The present study investigated the molecular characterization, tissue expression and nutritional regulation of the acsl gene family in golden pompano (Trachinotus ovatus). The results showed that the coding regions of acsl1, acsl3, acsl4, acsl5 and acsl6 cDNA were 2091 bp, 2142 bp, 2136 bp, 1977 bp and 2007 bp, encoding 697, 714, 712, 659 and 669 amino acids, respectively. Five acsl isoforms divided into two branches, namely, acsl1, acsl5 and acsl6, as well as acsl3 and acsl4. The tissue expression distribution of acsl genes showed that acsl1 and acsl3 are widely expressed in the detected tissues, while acsl4, acsl5 and acsl6 are mainly expressed in the brain. Compared to the fish fed with lard oil diets, the fish fed with soybean oil exhibited high muscular C18 PUFA contents and acsl1 and acsl3 mRNA levels, as well as low muscular SFA contents and acsl4 mRNA levels. High muscular n-3 LC-PUFA contents, and acsl3, acsl4 and acsl6 mRNA levels were observed in the fish fed with fish oil diets compared with those of fish fed with lard oil or soybean oil diets. High n-3 LC-PUFA levels and DHA contents, as well as the acsl3, acsl4 and acsl6 mRNA levels were exhibited in the muscle of fish fed diets with high dietary n-3 LC-PUFA levels. Additionally, the muscular acsl3, acsl4 and acsl6 mRNA expression levels, n-3 LC-PUFA and DHA levels were significantly up-regulated by the increase of dietary DHA proportions. Collectively, the positive relationship among dietary fatty acids, muscular fatty acids and acsl mRNA, indicated that T. ovatus Acsl1 and Acsl3 are beneficial for the C18 PUFA enrichment, and Acsl3, Acsl4 and Acsl6 are for n-3 LC-PUFA and DHA enrichment. The acquisition of fish Acsl potential function in the present study will play the foundation for ameliorating the fatty acids nutrition in farmed fish products.

Performance, Carcass Traits, and Meat Composition of Broiler Chickens Fed Diet Containing Fish Oil and Vitamin E

The study aimed to determine the efficacy of dietary vitamin E and fish oils on performance, carcass yield, cholesterol, omega-3, and omega-6 in the meats of broiler chickens. A total of 400 Lohmann day-old broiler chicks consisted of 200 males and 200 females were reared for 35 days. This experiment employed a completely randomized design with five treatments and four replicates. The treatments were T0: Control diet with 3% crude palm oil without vitamin E; T1: Diet containing 3% fish oil; T2: Diet containing 3% fish oil and 80 IU/kg vitamin E; T3: Diet containing 3% fish oil and 100 IU/kg vitamin E, and T4: Diet containing 3% fish oil and 120 IU/kg vitamin E. The result showed that dietary fish oil and vitamin E had no effect (p>0.05) on feed intake, body weight, weight gain, AME, AMEn, TME, and TMEn, but it tended to decrease the mortality rate. T3 significantly reduced (p<0.05) FCR in the finisher phase and meat cholesterol compared to the control. T1 and T3 significantly (p<0.05) reduced carcass weight percentage. Dietary fish oil and vitamin E increased omega-3 levels, and declined the ratio of omega-6 and omega-3. It is concluded that supplementation of 100 IU Vitamin E in the diet containing 3% fish oil improved feed efficiency by 9.95%, decreased cholesterol of the meat by 44.76%, increased omega-3 of the meat by 81.92%, and yielded the best ratio of omega-6: omega-3 of the meat, i.e., 10.34:1.

Dietary fish oil augments the tumor immune microenvironment in anti-PD-1 treated melanoma.

e21564 Background: Less than half of metastatic melanoma patients experience objective responses to first line anti-PD-1 immune checkpoint inhibition (αPD-1 ICI). Omega-3 fatty acids in dietary fish oil (FO) shift myeloid and T-cell populations to anti-inflammatory, pro-resolution phenotypes in immunity and cancer. We investigated whether dietary FO supplementation could augment tumor microenvironment (TME) immune profiles and improve ICI response in melanoma. Methods: C57-BL6/J mice were injected with YUMM 1.7 melanoma in the flank. Mice were fed control chow (CTL) or omega-3 rich (FO) chow (10% w/w, 30%kcal/kcal) starting 7 days post tumor implantation. Intraperitoneal αPD1 or IgG2a vehicle were injected q3-4 days starting day 12. To assess the temporal flux of TME immune populations, tumors from mice in analogous experiments were assessed for growth, harvested on day 12, day 22, or day 32, and characterized via flow cytometry. Results: In multiple models, FO decreased YUMM tumor growth vs. CTL by day 32 (&gt; 21% for all models). FO halved tumor associated macrophage content, including M2 macrophages (Arg1+, CD206+, CD68+, F480+), at day 12. Conversely, FO increased M2 macrophages at day 22, leveling even with CTL at day 32. At all three timepoints, FO increased TME monocytes (Ly6C+, Ly6G-). In the T cell compartment, FO decreased TME CD4 and CD8 T cell content (including PD1+ CD4 and PD1+ CD8) at day 12, an effect which was reversed by day 22 (increased CD4 and CD8s vs CTL). FO increased PD-L1+ CD4 T cells and CD8+ T cells, including PD1+ CD8 T cells, on day 32. When fish oil diets were started on day 12 (concurrent with immunotherapy), FO decreased tumor volume, increased monocytes (and PD-L1+ monocytes), and increased CD4 and PD1+ CD8 T cells by day 32, all less significantly than when starting diets 5 days prior to initiation of immunotherapy. All results significant (p &lt; 0.05) by 2-way ANOVA or t-test unless specified. Food eaten, water imbibed, and weight change did not vary between groups. Conclusions: Fish oil impairs in vivo murine melanoma tumor growth with and without αPD-1 ICI. Fish oil modulated myeloid and T cell lineages via delaying M2 macrophage and CD4 / CD8 T-cell appearance in the tumor microenvironment, with concomitant increases in monocytes and key T cell effectors involved in αPD-1 ICI responsiveness by the time decrements in tumor growth were noted. Dietary fish oil may benefit patients with advanced melanoma treated with αPD-1 immunotherapy; further study in humans is warranted.

Improved long-chain omega-3 polyunsaturated fatty acids in sago palm weevil (Rhynchophorus ferrugineus) larvae by dietary fish oil supplementation

The nutritional values of sago palm weevil larvae (SPWL) reared on mixed plant-based diets (ground sago palm trunk (GS), cornmeal, rice bran, soybean, and perilla seed), containing different levels of dietary fish oil (FO) were compared to those reared on commercial pig feed (PF) and GS. Increased FO content resulted in an increase in ω-3 fatty acids (FA) in SPWL (p < 0.05), especially α-linolenic acid and eicosapentaenoic acid. When fed FO-fortified diets instead of PF, the health-promoting indices of the SPWL lipid improved significantly (e.g., decreased ω-6/ω-3 ratio, thrombogenicity index, and hypercholesterolemic FA with increased PUFA content). The lipid, protein, and mineral contents of SPWL were increased while growth performance was maintained on a 1.5% FO-fortified diet. Higher FO levels (3–5%) had a negative impact on the nutritional values and growth performance of the SPWL. Thus, there was a reasonable chance of developing a high-nutrient alternative insect for human consumption.

Probing the Thermodynamics of Biomagnification in Zoo-Housed Polar Bears by Equilibrium Sampling of Dietary and Fecal Samples.

In a proof-of-concept study, we recently used equilibrium sampling with silicone films to noninvasively derive the thermodynamic limit to a canine’s gastrointestinal biomagnification capability (BMFlim) by determining the ratio of the products of the volume (V) and fugacity capacity (Z) of food and feces. In that earlier study, low contaminant levels prevented the determination of contaminant fugacities (f) in food and feces. For zoo-housed polar bears, fed on a lipid-rich diet of fish and seal oil, we were now able to measure the increase in f of nine native polychlorinated biphenyls (PCBs) upon digestion, providing incontestable proof of the process of gastrointestinal biomagnification. A high average BMFlim value of ∼171 for the bears was caused mostly by a remarkable reduction in fugacity capacity driven by a high lipid assimilation capacity. Lipid-rich diets increase the uptake of biomagnifying contaminants in two ways: because they tend to have higher contaminant concentrations and because they lead to a high Z value drop during digestion. We also confirmed that equilibrium sampling yielded similar Z values for PCBs originally present in food and feces and for isotopically labeled PCBs spiked onto those samples, which makes the method suitable for investigating the biomagnification capability of organisms, even if native contaminant concentrations in their diet and feces are low.

Evaluation of nutritional quality and fatty acid profile of carp (Cyprinus carpio) fed with diet based on oil sources

Background: The Cyprinus carpio as commercial fish in Iran contains nutritive components and plays an important role in human health. The present study research evaluated the nutritive quality of carp including proximate and fatty acid compositions. Objective: The aim of the present study was to investigate the effects of diet based on oil sources on the fatty acids composition of fish fillets of Cyprinus carpio. Methods: The carp (Cyprinus carpio) were fed with four diets based on soybean oil (SO), palm oil (PO), fish oil (FO), and (soybean and palm) oil (SPO). Results: The quality of fatty acids in the body of fish fed with SO and PO diets was found significantly better (p &lt;0.05) than those fish fed with FO diet. Total SFA (Saturated fatty acids) was highest significant in the fillet fat of the carp fish fed with PO diet, but there were no significant differences between the MUFA (Mono unsaturated fatty acids), PUFA (Poly unsaturated fatty acids), HUFA (High unsaturated fatty acids), and n-3/n-6 fatty acids of fillet in the carp fish fed with the experimental diets. Fillet fatty acid composition reflected dietary fatty acid profile. The highest level of α-linolenic acid, linoleic acid, and oleic acid was observed in fish fillets fed FO and SO, respectively. Although the eicosapentaenoic acid level of fish fillets fed diets FO and SPO was higher than other treatments, no significant difference was found in docosahexaenoic acid content among all dietary treatments. Conclusion: The present study showed that the suitable diet fat sources (SO, PO, SPO) fed by the carp, Cyprinus carpio, for 56 days, was suitable their productivity.

Complete replacement of fish oil by three microalgal products rich in n-3 long-chain polyunsaturated fatty acids in early weaning microdiets for gilthead sea bream (Sparus aurata)

The aim of the present study was to evaluate the effect of different n-3 LC-PUFA-rich microalgae replacing FO in larval diets, on performance, biochemical composition and health of gilthead sea bream (Sparus aurata). Dietary fish oil (FO) was replaced with oleic acid (OA) or 3 n-3 LC-PUFA-rich algae products (2 commercial products: All G Rich and DHA Gold, and a development product: MO060). The five early weaning microdiets were fed to 20-dah gilthead sea bream larvae for 21 days. Proximate composition and fatty acid profiles of total, neutral and polar lipids of seabream larvae were analysed, as well as hepatocyte morphology and the expression of selected genes related to lipid metabolism. OA diet significantly inhibited larval growth and survival after a stress challenge, whereas FO replacement by DHA Gold and MO60 led to a higher body weight, total length, and stress resistance. Larvae fed the diets containing microalgae had increased DHA content in whole body lipids and showed a down-regulation of expression of fads2, indicating an inhibition of LC-PUFA biosynthesis. Relative expression of genes related to lipid (ppar-α) or eicosanoids (cox-2 and 5-lox) metabolism were unaffected by the replacement of FO by any of the three microalgal products or OA. In conclusion, all the microalgae products tested were effective total replacers of FO in weaning microdiets for gilthead sea bream larvae, providing the necessary dietary n-3 LC-PUFA for optimal growth and survival.