Docosahexaenoic Acid Eicosapentaenoic Acid Research Articles

Nutritional value of the amphipod Bemlos quadrimanus sp. grown in shrimp biofloc ponds as influenced by different carbon sources

Natural food items like amphipods in bioflocs have been shown to provide a nutrient-rich live feed for aquaculture species. In the present study, we aimed to identify the major species of amphipods in the biofloc technology shrimp ponds at Shrimp Village, Surat-Thani, Thailand, determine its nutritional values, and enrich the amphipods in the biofloc technology system (BFS). Breeder stage amphipods were cultured in BFS with different carbon sources; molasses, rice bran, and corn flour at a carbon: nitrogen (C:N) ratio of 16:1 for 4 weeks. The number and the growth of spawned juveniles, and the nutritional compositions of the amphipods enriched bioflocs were examined. We found that the major species of amphipods in bioflocs produced in the cultured shrimp ponds was Bemlos quadrimanus sp. Proximate analysis revealed that the juvenile stage B. quadrimanus had higher levels of protein and lipid contents than those in other stages. Moreover, their essential amino acid index (EAAI) and ratios of polyunsaturated fatty acid/saturated fatty acid (PUFA/SFA) and docosahexaenoic acid/eicosapentaenoic acid (DHA/EPA) were similar to those values in fishmeal. The bioflocs produced with corn flour enhanced the growth and increased the number of juvenile amphipods greater than in bioflocs produced with the other two carbon sources, and had the highest levels of crude protein and lipid. In summary, this study demonstrates that amphipod B. quadrimanus provide an important source of protein that shows potential to replace fishmeal in shrimp feed, and reveals the benefit of a culture of amphipods with BFS in the aquaculture industry.

The correlation study between PCBs and δ15N values or FAs in fish collected from Dongting Lake

The toxicity of polychlorinated biphenyls (PCBs) and their transformation have been intensively investigated in recent years. However, the potential mechanisms of biotransformation in a lake food web remain unclear. To explore the correlation between the PCBs and δ15N values or FAs, six fish species were collected from Dongting Lake, and various tissues were dissected to analyze the δ15N values, FAs and PCBs. Based on the wet weight (ww), the concentration of ∑PCBs115 ranged from 0.04 to 9.77 ng g−1, and the highest level was found in the gonad of Cyprinus carpio. The toxicity equivalent (TEQ) of PCBs ranged from 0.003 to 2.39 pg g−1, and the highest level was found in the fat of Silurus asotusy. The PCB levels in fish collected from Dongting Lake were at the low end of the global range. PCB28, 52, 95, 99, 101, 105 110, 118, 138, 153, 155 and 209 were found in all tissues. PCBs were distributed in a tissue-specific and species-specific manner in fish. PCB153 and 138 had a positive correlation with the TEQ in liver, gill, intestine and skin of fish on the basis of lipid weight (lw). Docosahexaenoic acid/eicosapentaenoic acid (DHA/EPA) and polyunsaturated fatty acid/saturated fatty acid (PUFA/SFA) had a positive correlation with some PCB congeners in the intestine. PCB52, ∑tetra-PCBs and Ind-PCBs had a positive correlation with the δ15N values in liver of fish on the basis of ww. PUFA/SFA and DHA/EPA might be indicators for the transfer of PCB congeners.

Neuroprotective Effects of Diets Containing Olive Oil and DHA/EPA in a Mouse Model of Cerebral Ischemia.

Stroke is one of the leading causes of death worldwide and while there is increasing evidence that a Mediterranean diet might decrease the risk of a stroke, the effects of dietary fat composition on stroke outcomes have not been fully explored. We hypothesize that the brain damage provoked by a stroke would be different depending on the source of dietary fat. To test this, male C57BL/6J mice were fed for 4 weeks with a standard low-fat diet (LFD), a high-fat diet (HFD) rich in saturated fatty acids (HFD-SFA), an HFD containing monounsaturated fatty acids (MUFAs) from olive oil (HFD-OO), or an HFD containing MUFAs from olive oil plus polyunsaturated fatty acids (PUFAs) docosahexaenoic acid/eicosapentaenoic acid (DHA/EPA) (HFD-OO-ω3). These mice were then subjected to transient middle cerebral artery occlusion (tMCAo). Behavioural tests and histological analyses were performed 24 and/or 48 h after tMCAo in order to elucidate the impact of these diets with different fatty acid profiles on the ischemic lesion and on neurological functions. Mice fed with HFD-OO-ω3 displayed better histological outcomes after cerebral ischemia than mice that received an HFD-SFA or LFD. Furthermore, PUFA- and MUFA-enriched diets improved the motor function and neurological performance of ischemic mice relative to those fed with an LFD or HFD-SFA. These findings support the use of DHA/EPA-omega-3-fatty acid supplementation and olive oil as dietary source of MUFAs in order to reduce the damage and protect the brain when a stroke occurs.

Embryonic and larval development and fatty-acid profile of Epinephelus marginatus spawned in captivity: tools applied to captive rearing.

Development, ontogeny of the digestive system and the fatty-acid (FA) profile, were analysed during development of Epinephelus marginatus. Larvae were analysed 7 and 17 days post fertilization (dpf) to evaluate fatty-acid profile and morphological variables, respectively. Epinephelus marginatus larvae have relatively slow development of digestive structures, but were able to capture, ingest and digest prey by 5 dpf. Eggs were composed of high percentages of polyunsaturated fatty acids (PUFA) in phospholipids. The percentage of n3 PUFAs was higher than n6, especially docosahexaenoic acid (DHA), which exhibited higher levels compared with other marine species during the first 3days of development, both in terms of phospholipids and triglycerides. The larvae present a high content of docosahexaenoic acid-eicosapentaenoic acid (DHA-EPA) and, during this phase, live food of small size was required (copepods or SS-strain Brachionus rotundiformes), enriched with DHA-EPA. These results may guide future studies on the contribution of FAs required during this stage of the life cycle of E. marginatus, to advance knowledge of the use of these FAs throughout ontogeny and contribute to the culture of this species commercial production or restocking.

Statin Use Mitigate the Benefit of Omega-3 Fatty Acids Supplementation-A Meta-Regression of Randomized Trials.

During last 2 decades, multiple studies have evaluated omega-3 polyunsaturated fatty acids (ω-3 PUFA) supplementation for cardiovascular prevention. The benefit found in previous studies was not demonstrated in more contemporary trials. We aimed to investigate effect of study characteristics, particularly concomitant statin therapy on results of randomized controlled trials. We systematically searched electronic databases for randomized controlled trials evaluating ω-3 PUFA supplementation and reporting clinical outcomes. A meta-analysis was performed using a random effect model, followed by a meta-regression of dose, docosahexaenoic acid/eicosapentaenoic acid (DHA/EPA) ratio, and duration of treatment and use of lipid-lowering/statin therapy in control group. Twenty-three studies with 77,776 patients (38,910 PUFA; 38,866 controls) were included. PUFA had no effect on total mortality [risk ratio (RR) = 0.96; 95% confidence interval (CI), 0.92-1.01] and myocardial infarction (RR = 0.87; 95% CI, 0.73-1.02), but marginally reduced cardiovascular mortality (RR = 0.93; 95% CI, 0.87-0.98). Lower control group statin use (b = 0.222, P = 0.027) and higher DHA/EPA (b = -0.105, P = 0.033) ratio was associated with higher reduction in total mortality. Duration and dose had no effect. None of the variables except duration had significant effect on reduction in cardiovascular mortality by PUFA supplementation. There was evidence of publication bias. Statin use may mitigate, and higher DHA/EPA ratio is associated with the beneficial effect of PUFA supplementation.

Effects of Dietary DHA/EPA Ratios on Fatty Acid Composition, Lipid Metabolism‐related Enzyme Activity, and Gene Expression of Juvenile Grass Carp, Ctenopharyngodon idellus

AbstractTo determine the effects of docosahexaenoic acid/eicosapentaenoic acid (DHA/EPA) ratios on grass carp, Ctenopharyngodon idellus, a 38‐d feeding trial was conducted using six isonitrogenous and isoenergetic semi‐purified diets containing constant n‐3 long‐chain polyunsaturated fatty acid (LC‐PUFA) (0.5% of dry matter), but varying ratios of DHA to EPA and a control diet (no n‐3 LC‐PUFA was included). The results revealed higher final weight and specific growth rate in the DHA/EPA 0.21 group. The n‐3 LC‐PUFA content increased in the CK (control) groups compared with that in the control diet. Lipoprotein lipase (LPL) activity increased in the treatment groups. Malate dehydrogenase showed lower activity in the DHA/EPA 1.08 group, as well as to the change in the level of glucose‐6‐phosphate dehydrogenase (G6PDH). The gene expressions of LPL increased in the treatment groups and that of peroxisome proliferator‐activated receptor α gene showed higher expressions in DHA/EPA 1.08, 0.49, and 0.21 groups. However, no remarkable differences were found among the six groups in the peroxisome proliferator‐activated receptor γ gene expression. Our findings indicated that dietary n‐3 LC‐PUFA affected fatty acid composition and lipid metabolism of grass carp. Further, fish achieved the best effect in decreasing the lipid accumulation when dietary DHA/EPA ratio was not greater than 1.

Age-related macular degeneration (AMD); From pathogenesis and approved therapies to proposed treatments for prevention

Age-related macular degeneration (AMD) is one of the most severe vision-threatening diseases. Wet AMD, caused by choroidal neovascularization (CNV), progresses rapidly, while dry AMD, characterized by neural retinal atrophy followed by choroidal vascular atrophy, progresses slowly. In addition to systemic risk factors, such as a high body-mass index (BMI), smoking, hypertension, and atherosclerosis, light-induced local oxidative stress and inflammation promotes AMD. CNV can be induced by multiple pathways. The accumulation of lipofuscin, a product of the undigested outer segments of photoreceptor cells, causes chronic local inflammation. Extracellular lipoprotein deposits, which contain pro-inflammatory components, such as complement, can trigger local inflammation. A single nucleotide polymorphism (SNP) in some genes; i.e., complement factor H (CFH) and excision repair cross-complementing rodent repair deficiency complementation group 6 (ERCC6), which induce local inflammation, is a risk factor for AMD. Two treatments, photodynamic therapy (PDT) and anti-vascular endothelial growth factor (VEGF) therapy, have been approved worldwide to cause the regression of CNV. In addition, the suppression of CNV progression combined with retinal neural protection by anti-oxidative reagents such as lutein/zeaxanthin and/or docosahexaenoic acid / eicosapentaenoic acid (DHA/EPA) is a promising prospective therapeutic approach. This is the subject of an ongoing prospective, randomized, double-blind, multicenter clinical trial, the Age-Related Eye Disease Study 2 (AREDS2). In addition, molecular and biological analyses in animal models have provided data supporting this anti-oxidant therapy.

The effect of dietary n-3 HUFA levels and DHA/EPA ratios on growth, survival and osmotic stress tolerance of Chinese mitten crab Eriocheir sinensis larvae

The effect of varying levels of dietary n-3 highly unsaturated fatty acid (HUFA) and docosahexaenoic acid/eicosapentaenoic acid (DHA/EPA) ratios on growth, survival and osmotic stress tolerance of Eriocheir sinensis zoea larvae was studied in two separate experiments. In experiment I, larvae were fed rotifers and Artemia enriched with ICES emulsions with 0, 30 and 50% total n-3 HUFA levels but with the same DHA/EPA ratio of 0.6. In experiment II, larvae were fed different combinations of enriched rotifers and Artemia, in which, rotifers were enriched with emulsions containing 30% total n-3 HUFA, but different DHA/EPA ratio of 0.6, 2 and 4; while Artemia were enriched with the same emulsions, but DHA/EPA ratio of 0.6 and 4. In both experiments, un-enriched rotifers cultured on baker's yeast and newly-hatched Artemia nauplii were used as control diets. Larvae were fed rotifers at zoea 1 and zoea 2 stages; upon reaching zoea 3 stage, Artemia was introduced.Experiment I revealed no significant effect of prey enrichment on the survival of megalopa among treatments, but higher total n-3 HUFA levels significantly enhanced larval development (larval stage index, LSI) and resulted in higher individual dry body weight of megalopa. Furthermore higher dietary n-3 HUFA levels also resulted in better tolerance to salinity stress. Experiment II indicated that at the same total n-3 HUFA level, larvae continuously receiving a low dietary DHA/EPA ratio had significantly lower survival at the megalopa stage and inferior individual body weight at the megalopa stage, but no negative effect was observed on larval development (LSI). The ability to endure salinity stress of zoea 3, zoea 5 and megalopa fed diets with higher DHA/EPA ratio was also improved.

Sex-linked differences in fatty acid composition of rainbow trout ( Oncorhynchus mykiss) liver oil

Fatty acid analysis of the liver oil of male and female farmed rainbow trout ( Oncorhynchus mykiss) was carried out by gas-liquid chromatography with flame ionization detection (FID). The polyunsaturated fatty acid fraction was much higher in males than in females, while the opposite was true for the mono-unsaturated fatty acid fraction. The n − 3 series fatty acid content is greater than the n − 6 series fatty acid content. Docosahexaenoic acid (DHA) appears, in both types of sample, in greater amounts than eicosapentaenoic acid (EPA). In general, values found for female samples are in line with those reported in the literature. Male samples, although they followed the same pattern, showed significant differences ( P < 0.05) from females. The high DHA EPA ratios found in rainbow trout liver oil make it suitable for industrial uses, such as infant formula supplementation.