Krill Oil Group Research Articles

Comparison of Dietary Supplementation with Krill Oil, Fish Oil, and Astaxanthin on an Experimental Ethanol-Induced Gastric Ulcer Model: A Biochemical and Histological Study

Background/Objectives: Despite advances in ulcer treatment research, the search for new, safe, and effective strategies for preventing and treating ulcer diseases persists. Methods: In this study, the protective effects of dietary supplementation with krill oil (KO), fish oil (FO), and astaxanthin (ASX) on an ethanol-induced gastric ulcer model were compared during biochemical and histological observations. Sprague–Dawley (n = 64) rats randomly divided into four groups—normal control (vehicle), KO, FO, and ASX groups—received the supplements via the orogastric route at a rate of 2.5% (v/w) of their daily feed consumption for 4 weeks. Then, ulcer induction was performed with ethanol. Results: The ulcer group showed increased levels of malondialdehyde (MDA), chemiluminescence (CL), and myeloperoxidase (MPO) activity and decreased levels of glutathione in the gastric tissues. While KO, FO, and ASX supplementation decreased chemiluminescence levels in the ulcer group, only ASX supplementation decreased MDA levels and MPO activity. Conclusions: In conclusion, supplementation with KO or FO has a similar protective effect against ethanol-induced ulcer damage, as it inhibits ROS formation and reduces lipid peroxidation. However, ASX supplementation has a higher protective effect than KO or FO supplementations against experimental ethanol-induced gastric lesions in rats, as it inhibits ROS formation and reduces neutrophil infiltration and lipid peroxidation.

Cannabidiol plus krill oil supplementation improves chronic stifle osteoarthritis in dogs: A double-blind randomized controlled trial

Osteoarthritis (OA) is the most common orthopedic disorder characterized by chronic inflammation and pain in dogs and cats. Cannabis spp. contains cannabidiol (CBD), a substance with pain relief and anti-inflammatory properties in different animals including dogs with OA. The use of CBD supplements has been increasingly intertwining in veterinary medicine. This study aimed to evaluate the clinical efficacy of CBD + krill oil-supplemented biscuit against canine OA. In total, 30 dogs with stifle OA were randomized and divided into the placebo, krill oil, and CBD + krill oil groups. The Canine Brief Pain Inventory questionnaire was used to evaluate the efficacy of each treatment against pain. Stifle temperature was monitored to identify degrees of stifle inflammation. Two and one dogs in the placebo group were excluded from the study due to worsening lameness and increased pain interference score (PIS) and pain severity score (PSS) at days 14 and 28, respectively.The PIS and PSS scores of the krill oil and CBD + krill oil groups gradually and significantly improved after two weeks of treatment. The CBD + krill oil group had better PIS and PSS scores than the placebo and krill oil groups. However, there was no statistically significant difference in the PIS and PSS scores between the krill oil and CBD + krill oil groups. The stifle temperature of the three groups at different periods did not significantly differ. In conclusion, CBD + krill oil supplements are safe against canine OA. CBD can reduce pain and inflammation.

Krill oil supplementation improves transepidermal water loss, hydration and elasticity of the skin in healthy adults: Results from two randomized, double-blind, placebo-controlled, dose-finding pilot studies.

Dietary marine omega-3 fatty acids and phospholipids have individually shown favorable effects on skin barrier function. Krill oil offers a combination of omega-3 in phospholipid form which might enhance the efficacy in supporting skin health. The aim was to investigate the impact of two different doses of krill oil on skin transepidermal water loss (TEWL) in healthy adults. Secondary outcomes were skin hydration, elasticity and the omega-3 index. Two randomized, double-blind, placebo-controlled, pilot studies were conducted in healthy adults with a baseline TEWL of >10 and ≤24.9 g/m2/h. In study 1, 51 participants consumed 1 g of krill oil or placebo daily. In study 2, 50 participants consumed 2 g of krill oil or placebo daily. The outcomes were assessed at baseline, 6 and 12 weeks. The krill oil supplemented groups significantly increased their omega-3 index versus placebo in both studies. Furthermore, the krill oil groups in both studies showed statistically significant beneficial reductions in TEWL (from 14.47 ± 3.65 to 13.83 ± 3.78 in study 1 and from 14.25 ± 3.21 to 13.02 ± 2.76 in study 2) and increases in hydration and elasticity when compared to placebo. There were significant linear relationships between changes in the omega-3 index and changes in TEWL, hydration and elasticity in both studies. Daily oral supplementation with 1 and 2 g of krill oil showed significant and dose-dependent improvements in skin TEWL, hydration, and elasticity compared to placebo that correlated with changes in the omega-3 index.

The effect of LCn-3 PUFA supplementation on body weight, body composition, and muscle function during alternate-day fasting (ADF)

During weight loss the loss of body mass is associated not only with body fat reduction but also with a decrease in fat-free mass (FFM), related to the reduction in muscle mass and function(1). Supplementation with long-chain n-3 fatty acids (LCn-3 PUFA), in the absence of caloric restriction, results in a significant decrease in fat mass and an increase in FFM(2) along with improvements in muscle mass and strength(3). However, the impact of supplementation with LCn-3 PUFA during weight loss) remains unknown. Therefore, the aim of this study was to explore the effects of LCn-3 PUFA supplementation, in the form of Krill oil (KO), during alternate day fasting (ADF) on body weight, fat mass loss, FFM and muscle function changes in healthy overweight and obese adults.A total of 41 men and women (age: 39.35 ± 10.4 years, BMI: 31.05 ± 4.2 kg/m2) completed the study (NCT06001632), in which they were randomised into either a KO or Placebo (PL) groups. Both groups carried out 8-weeks of ADF combined with intake of 4 g/day of the corresponding supplements. ADF involved consuming no more than 500 calories on the 'fast day’ and consuming food ad libitum on each 'feed day’. Data on body weight and body composition (TBF-300, Tanita, Manchester, UK), handgrip strength (Handheld Hydraulic Dynamometer, Vernier Jamar; England, UK), and time to conduct 5 repetition of chair rising test were obtained pre-and post-intervention. Changes from baseline within groups were assessed using paired samples t-test. Mixed analysis of variance (Mixed-ANOVA) was used to measure 2-way interactions between time and group to identify the differences between groups. All statistical analysis were conducted using IBM Statistical Package for the Social Sciences SPSS 28.0.In both groups, body mass decreased significantly (KO:-4.7 ± 0.4kg, p<0.001; PL:-4.5 ± 0.4kg, p<0.001), along with a significant reduction in fat mass (KO:-2.4 ± 0.5kg p<0.001; PL:-2.3 ± 0.5kg p<0.001), and FFM (KO:-0.6 ± 0.2kg p<0.001; PL:-0.7 ± 0.2kg, p<0.001), with no differences between groups. In the PL group, there was a reduction in handgrip strength (-0.9 ± 0.7 kg, p<0.001), while there was no change in KO group (-0.2 ± 0.5 kg, p=0.1), with a significant difference between groups (p<0.001). In the KO group there was a significant reduction in time to conduct chair rising test (-1.8 ± 0.9s, p<0.05), with no change in the PL group (-0.3 ± 1.3s, p=0.2), with a significant difference between groups (p<0.001).Supplementation with LCn-3 PUFA (4 g/day) during 8 weeks of ADF, applied to individuals living with overweigh and obesity, does not facilitate body or fat mass loss and does not diminish the reduction in FFM. However, it attenuated the reduction in muscle function in healthy overweight and obese adults.

Krill Oil for Knee Osteoarthritis

Knee osteoarthritis is disabling, with few effective treatments. Preliminary evidence suggested that krill oil supplementation improved knee pain, but effects on knee osteoarthritis remain unclear. To evaluate efficacy of krill oil supplementation, compared with placebo, on knee pain in people with knee osteoarthritis who have significant knee pain and effusion-synovitis. Multicenter, randomized, double-blind, placebo-controlled clinical trial in 5 Australian cities. Participants with clinical knee osteoarthritis, significant knee pain, and effusion-synovitis on magnetic resonance imaging were enrolled from December 2016 to June 2019; final follow-up occurred on February 7, 2020. Participants were randomized to 2 g/d of krill oil (n = 130) or matching placebo (n = 132) for 24 weeks. The primary outcome was change in knee pain as assessed by visual analog scale (range, 0-100; 0 indicating least pain; minimum clinically important improvement = 15) over 24 weeks. Of 262 participants randomized (mean age, 61.6 [SD, 9.6] years; 53% women), 222 (85%) completed the trial. Krill oil did not improve knee pain compared with placebo (mean change in VAS score, -19.9 [krill oil] vs -20.2 [placebo]; between-group mean difference, -0.3; 95% CI, -6.9 to 6.4) over 24 weeks. One or more adverse events was reported by 51% in the krill oil group (67/130) and by 54% in the placebo group (71/132). The most common adverse events were musculoskeletal and connective tissue disorders, which occurred 32 times in the krill oil group and 42 times in the placebo group, including knee pain (n = 10 with krill oil; n = 9 with placebo), lower extremity pain (n = 1 with krill oil; n = 5 with placebo), and hip pain (n = 3 with krill oil; n = 2 with placebo). Among people with knee osteoarthritis who have significant knee pain and effusion-synovitis on magnetic resonance imaging, 2 g/d of daily krill oil supplementation did not improve knee pain over 24 weeks compared with placebo. These findings do not support krill oil for treating knee pain in this population. Australian New Zealand Clinical Trials Registry Identifier: ACTRN12616000726459; Universal Trial Number: U1111-1181-7087.

Krill oil showed a good application potential as the dietary lipid source on the growth, physiology, nutritional quality, and flavor of the edible meat of the oriental river prawns (Macrobrachium nipponense)

An 8-week feeding trial was conducted to evaluate the effects of dietary krill oil (KO), fish oil (FO) and soybean oil (SO) on growth, nutritional quality and flavor of the edible meat of the oriental river prawns (Macrobrachium nipponense). The results revealed that SO and KO diets promoted the growth performance (P < 0.05). The activity of alanine aminotransferase in hemolymph of the FO group was significantly lower than that in the SO group (P < 0.05). The contents of total cholesterol in hemolymph in the SO and FO groups were significantly lower than those in the KO group (P < 0.05). Superoxide dismutase activity and glutathione content in the hepatopancreas were the lowest in the SO group (P < 0.05). Lipoprtein lipase and trypsin activities of the hepatopancreas decreased significantly in the KO group (P < 0.05). Among the fatty acids in meat, the contents of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) increased significantly in M. nipponense after feeding on animal lipid sources (FO and KO) (P < 0.05). The contents of umami and bitter free amino acids in the SO and KO groups were significantly higher than those in the FO group (P < 0.05), and the contents of adenosine monophosphate and inosine monophosphate were highest in the KO group (P < 0.05). The contents of bitter nucleotides hypoxanthine and hypoxanthine ribonucleoside were lowest in the KO group (P < 0.05). In general, compared with FO, the use of KO and SO as lipid sources in feed promoted the growth of M. nipponense, and KO significantly improved the antioxidant index of the hepatopancreas. FO and KO increased the contents of EPA and DHA in the edible meat of M. nipponense, and KO further enhanced the contents of amino acids and nucleotides responsible for flavor in the meat.

The effect of krill oil on Wnt/β-catenin signaling pathway in acetaminophen-induced acute liver injury in mice

Abstract Objectives This study investigated the effect of krill oil (KO) on liver damage caused by acetaminophen (APAP). Methods In the present study, the control and APAP groups were given distilled water by gavage for 14 days. In addition, the KO and APAP+KO groups were given 500 mg/kg krill oil by gavage for 14 days. At the end of 14 days, 0.9 % sodium chloride solution (saline solution) administration was applied intraperitoneally to the control and KO groups. Meanwhile, 220 mg/kg acetaminophen was administered to the APAP and APAP+KO groups. While some biochemical parameters in plasma were examined, some oxidative stress parameters in plasma and liver tissue were evaluated. Apoptotic and inflammatory responses of some primer sequences determined by quantitative Real-Time PCR (qPCR) in liver tissue. After histopathological examination of liver tissue, immunohistochemical analysis was performed with Wnt inhibitory factor-1 (Wif-1), beta-catenin (β-Catenin), and 8-hydroxy-2′-deoxyguanosine (8-OHdG). Results The Wif-1 positivity in hepatocytes increased significantly in the APAP group (5.29 ± 0.71) compared to the control (1.14 ± 0.51), and KO (2.14 ± 0.55) groups (p&lt;0.001). The 8-OHdG positivity in hepatocytes increased significantly in the APAP group (19.57 ± 0.58) compared to the control (0.43 ± 0.20), KO (3.57 ± 0.48), and APAP+KO (4.00 ± 2.53) groups (p&lt;0.001). Conclusions As a result, krill oil could be used as a nutritional supplement to protect the liver against acetaminophen-induced liver injury.

Equal bioavailability of omega-3 PUFA from Calanus oil, fish oil and krill oil: A 12-week randomized parallel study.

The bioavailability of long-chain omega-3 polyunsaturated fatty acids (n3 PUFA) can be affected by the form in which they are bound. An alternative source of n3 PUFA is Calanus finmarchicus oil (CO), which, unlike fish oil (FO) and krill oil (KO), contains fatty acids primarily bound as wax esters. Recent studies have shown that n3 PUFA from CO are bioavailable to humans, but CO has not been compared to other marine oils such as FO or KO. Therefore, the aim of this study was to investigate the influence of 12 weeks supplementation with CO, FO and KO on the long-term n3 PUFA status in healthy volunteers. The Omega-3 Index (O3I), defined as red blood cell EPA + DHA content as a percentage of total identified fatty acids, was used as a measure to assess n3 PUFA status. Sixty-two participants (mean ± standard deviation [SD] age: 29.7 ± 8.43 years) completed the randomized parallel group study (CO group: n=21, 4 capsules/day, EPA + DHA dose: 242 mg/day; FO group: n=22, 1 capsule/day, EPA + DHA dose: 248 mg/day; KO group: n=19, 2 capsules/day, EPA + DHA dose: 286 mg/day). At baseline, the three groups showed comparable (mean ± SD) O3I values (CO: 5.13 ± 1.12%, FO: 4.90 ± 0.57%, KO: 4.87 ± 0.77%). The post-interventional (mean ± SD) O3I increase was comparable between the three groups (CO: 1.09 ± 0.55%; FO: 1.0 ± 0.53%; KO: 1.15 ± 0.65%, all p < 0.001). The study confirms that CO can increase the n3 PUFA status comparable to FO and KO and is therefore an alternative marine source of bioavailable n3 PUFA, especially with regard to sustainability.

Phosphatidylcholine in Krill Meal and Krill Oil as a Source of Choline for Prevention of Intestinal Steatosis in Atlantic Salmon

Intestinal steatosis, called lipid malabsorption syndrome (LMS) in severe cases, is a common condition in farmed Atlantic salmon, associated with choline deficiency causing low lipid transport in enterocytes, excessive lipid accumulation, and increased mucosal weight. A previous dose-response study supplying a plant-based diet with choline chloride indicated that 3.4 g/kg choline prevents LMS in Atlantic salmon. However, no similar documentation exists using phosphatidylcholine (PC) as a choline source. The present study therefore aimed to determine the ability of PC from krill meal (KM) and krill oil (KO) towards reducing steatosis in Atlantic salmon. Two diets with suboptimal PC levels (1.5 and 2.6 g/kg) were tested against two control diets, a choline-deficient diet with no supplementation (0.6 g/kg), and a high choline (4.0 g/kg choline chloride) diet. After 8 weeks of freshwater feeding, growth was significantly higher in KM and KO groups, at both PC levels, in comparison to the choline-deficient group. However, growth was significantly higher only in the KM and KO diets with 2.6 g/kg of PC when compared to the positive control. This indicated that suboptimal levels of PC from KM and KO satisfied choline needs for growth. A clear dose-dependent effect on the decreasing pyloric intestine (PI) somatic index was observed for KM and KO diets, with no significant difference between KM and KO diets (2.6 g/kg choline) and high choline reference diet. Accordingly, PC from both KM and KO significantly reduced lipid accumulation in the PI and liver when added to a choline-deficient diet. However, histological and lipid analyses also indicated that the optimal dietary choline requirement for full elimination of lipid accumulation in PI is higher than 2.6 g/kg with KM and KO as supplementary sources.

Evaluation of the Role of Soybean Lecithin, Egg Yolk Lecithin, and Krill Oil in Promoting Ovarian Development in the Female Redclaw Crayfish Cherax quadricarinatus.

The optimal supplementation of lipid nutrients in the diet showed crucial physiological functions in gonadal development and maturation in adult female aquatic animals. Four isonitrogenous and isolipidic diets with no extra lecithin supplementation (control), 2% soybean lecithin (SL), egg yolk lecithin (EL), or krill oil (KO) supplementation were formulated for Cherax quadricarinatus (72.32 ± 3.58 g). Ovary development and physiological characteristics of crayfish were evaluated after a 10-week feeding trial. The results indicated that SL, EL, or KO supplementation all significantly increased the gonadosomatic index, especially in the KO group. Crayfish fed the diet with SL showed the highest hepatosomatic index compared with those fed the other experimental diets. KO was more efficient than SL and EL in promoting triacylglycerol and cholesterol deposition in the ovary and hepatopancreas but also showed the lowest concentration of low-density lipoprotein cholesterol in the serum. KO significantly increased yolk granule deposition and accelerated oocyte maturation than other experimental groups. Furthermore, dietary phospholipids significantly enhanced the gonad-stimulating hormone concentration in the ovary and reduced the secretion of gonad-inhibiting hormones in the eyestalk. KO supplementation also significantly improved organic antioxidant capacity. From the ovarian lipidomics results, phosphatidylcholine and phosphatidylethanolamine are two main glycerophospholipids that respond to different dietary phospholipids. Polyunsaturated fatty acids (especially C18:2n-6, C18:3n-3, C20:4n-6, C20:5n-3, and C22:6n-3) were pivotal participants during ovarian development of crayfish regardless of lipid type. Combined with the ovarian transcriptome, the best positive function of KO was due to activated steroid hormone biosynthesis, sphingolipid signaling, retinol metabolism, lipolysis, starch and sucrose metabolism, vitamin digestion and absorption, and pancreatic secretion. As a consequence, dietary supplementation with SL, EL, or KO all improved the ovarian development quality of C. quadricarinatus, especially KO, which was the optimum choice for promoting ovary development in adult female C. quadricarinatus.

Preventive effects of standardized krill oil on alcohol hangovers in a clinical trial

• Intake of krill oil alleviated hangover symptoms including thirst and nausea. • Intake of krill oil decreased alcohol and acetaldehyde concentrations in blood. • The effects of krill oil on alcohol hangover might be due to its antioxidant capacity. • It is a potential ingredient as alleviation of alcohol hangover. In this study, we investigated the effect of standardized krill oil on alcohol hangover through a placebo-controlled, randomized, double-blind, and crossover clinical trial. Hangover symptoms including thirst and nausea were alleviated by krill oil at 3 and 4 h, and at 0.5 and 1 h after the alcohol consumption, respectively (p < 0.05). The breath and blood alcohol concentrations, and Acetaldehyde levels in plasma from the krill oil group were significantly lower than those from the placebo at 1, 3, and 5 h, and at 1, 4, and 5 h, and at 0.5 h after the alcohol consumption, respectively (p < 0.05). Also, krill oil relatively increased alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activity, and relatively lowered malondialdehyde (MDA) levels compared to placebo and positive control. Trolox equivalent antioxidant activity of krill oil was higher than the positive control. These results suggest that krill oil can be used as a potential anti-hangover ingredient.

Growth, Health, and Gut Microbiota of Female Pacific White Shrimp, Litopenaeus vannamei Broodstock Fed Different Phospholipid Sources.

Phospholipids have an important antioxidant effect on animals. The effects of different dietary phospholipid sources on the growth, antioxidant activity, immunity, and gut microbiota of female broodstock of Pacific white shrimp Litopenaeus vannamei were investigated. Four isoproteic and isolipid semi-purified diets containing 4% soybean lecithin (SL), egg yolk lecithin (EL), or krill oil (KO) and a control diet without phospholipid supplementation were fed to female broodstock of L. vannamei (34.7 ± 4.2 g) for 28 days. The growth performance, antioxidative capacity, and innate immunity of the female broodstock fed phospholipid supplemented diets were improved regardless of sources compared with the control shrimp. The effects on growth and antioxidant capacity in female shrimp fed the KO diet were highest. The innate immunity of female shrimp fed the EL and KO diets were significantly higher than shrimp fed the SL diet. Dietary phospholipid supplementation increased gut microbiota diversity and richness, and the Chao1 and ACE values in the KO group were significantly higher than in the control group. The richness of Proteobacteria, Photobacterium, and Vibrio decreased, whereas the richness of Firmicutes and Bacteroidetes increased in the shrimp fed the KO diet compared with the shrimp fed the SL and EL diets. The interactions of gut microbiota in shrimp fed the KO diet were the most complex, and the positive interaction was the largest among all the treatments. The functional genes of gut microbiota in shrimp fed the KO diet were significantly enriched in lipid metabolism and terpenoid/polyketide metabolism pathways. Spearman correlation analysis showed that Fusibacter had significantly positive correlations with antioxidant activity (total antioxidant capacity, superoxide dismutase, glutathione peroxidase), immune enzyme activity (phenoloxidase and lysozyme), and immune gene expression (C-type lectin 3, Caspase-1). All findings suggest that dietary phospholipids supplementation can improve the growth and health status of female L. vananmei broodstock. Krill oil is more beneficial in improving the antioxidant capacity and innate immunity than other dietary phospholipid sources. Furthermore, krill oil can help establish the intestinal immune barrier by increasing the richness of Fusibacter and promote the growth of female shrimp. Fusibacter may be involved in iron metabolism to improve the antioxidant capacity of female shrimp.

Enrichment of n-3 containing ether phospholipids in plasma after 30 days of krill oil compared with fish oil supplementation.

There are conflicting findings over the bioavailability of long-chain n-3 polyunsaturated fatty acids (n-3 PUFA) from krill oil (KO) compared with fish oil (FO) in short- and long-term studies. The aim of this study was to compare the effects of KO versus FO on the enrichment of molecular species of plasma phospholipids in young women following a 30-day consumption of the n-3 oils. Eleven healthy women aged 18-45 years consumed seven capsules of KO per day (containing a total of 1.27 g n-3 PUFA) or five capsules of FO per day (total of 1.44 g n-3 PUFA) for 30 days in a randomized crossover study, separated by at least a 30-day washout period. Fasting blood samples were collected at day zero (baseline), day 15 and day 30 and analyzed by HPLC-MS/MS for molecular species of phospholipids. Supplementation increased n-3 PUFA in main phospholipids classes in both groups. After 30 days of supplementation, 35 out of 70 molecular species containing eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPAn-3) had a significantly greater concentration in KO group compared with the FO treated group. The majority (89%) of the differentiated molecular species were choline and ethanolamine ether-phospholipids. These data reveal that analysis of plasma phospholipids following 30 days of consumption of KO (a marine oil rich in phospholipids, including ether phospholipids) resulted in an enrichment of n-3 PUFA in molecular species of ether-phospholipids compared with FO (a triacylglycerol-rich marine oil).

Krill-Oil-Dependent Increases in HS-Omega-3 Index, Plasma Choline and Antioxidant Capacity in Well-Conditioned Power Training Athletes.

There is evidence that both omega-3 polyunsaturated fatty acids (n-3 PUFAs) and choline can influence sports performance, but information establishing their combined effects when given in the form of krill oil during power training protocols is missing. The purpose of this study was therefore to characterize n-3 PUFA and choline profiles after a one-hour period of high-intensity physical workout after 12 weeks of supplementation. Thirty-five healthy power training athletes received either 2.5 g/day of Neptune krill oilTM (550 mg EPA/DHA and 150 mg choline) or olive oil (placebo) in a randomized double-blind design. After 12 weeks, only the krill oil group showed a significant HS-Omega-3 Index increase from 4.82 to 6.77% and a reduction in the ARA/EPA ratio (from 50.72 to 13.61%) (p < 0.001). The krill oil group showed significantly higher recovery of choline concentrations relative to the placebo group from the end of the first to the beginning of the second exercise test (p = 0.04) and an 8% decrease in total antioxidant capacity post-exercise versus 21% in the placebo group (p = 0.35). In conclusion, krill oil can be used as a nutritional strategy for increasing the HS-Omega-3 Index, recover choline concentrations and address oxidative stress after intense power trainings.

Hepatopancreas transcriptome analysis reveals the molecular responses to different dietary n-3 PUFA lipid sources in the swimming crab Portunus trituberculatus

n-3 LC-PUFA is vital to crustaceans for the growth, molting and development, while the precise molecular mechanism underlying the regulation of n-3 LC-PUFA is poorly investigated. Herein, an 8-week nutritional trial and transcriptome analysis were used to investigate the impacts of dietary n-3 PUFA lipid sources including fish oil (FO), krill oil (KO) and linseed oil (LO) on the transcriptome characteristics in hepatopancreas of swimming crab (Portunus trituberculatus). Crabs fed KO diet had significantly higher percent weight gain (PWG) and molting ratio (MR) than those of crabs fed other diets. The transcriptome analysis reveled that a total of 6567 unigenes were annotated in KEGG database, of which the expression of 1126 significantly altered in the KO vs FO group, while the expression of 921 unigenes changed in the LO vs FO group. The differentially expressed genes (DEGs) in KO vs FO comparison group involved in fat digestion and absorption, ABC transporters, adipocytokine signaling pathway, protein digestion and absorption, glycolysis/gluconeogenesis and HIF-1 signaling pathway. While dietary LO significantly altered the expression levels of genes involved in carbohydrate digestion and absorption, mineral absorption, protein processing in endoplasmic reticulum, glycosphingolipid biosynthesis and insect hormone biosynthesis. In addition, dietary KO significantly up-regulated the expression levels of cyp18a1 (participates in the process of ecdysteroids biosynthesis and further controls the molting of crustaceans), tryp (trypsin-like serine proteinases, resists the pathogen invasion), pla2 (phospholipase A2, regulates different inflammatory processes), ABC transporter (ATP-binding cassette transporter, transports amino acids, lipids and proteins into and out of the cell), cpt1 (carnitine palmitoyltransferase I, the major rate-limiting enzyme of mitochondrial fatty acid β-oxidation) and slc2 (solute carrier 2, mediates bidirectional glucose transport). Meanwhile, dietary LO could significantly down-regulated the expression level of cyp315a1 compared to dietary FO. To sum up, swimming crab fed with dietary krill oil could not only enhance the transport of glucose, lipids, fatty acids and other substrates, but also up-regulate the expression levels of genes related to molting, immunity and energy metabolism to promote molting and growth of swimming crab. The present study revealed the molecular responses of crabs to different dietary n-3 PUFA lipid sources, and further provided important clues with respect to elucidating the molecular mechanisms underlying the regulation of EPA and DHA on the molting and growth of swimming crab.

Comparison of the Cholesterol-Lowering Effect of Scallop Oil Prepared from the Internal Organs of the Japanese Giant Scallop (Patinopecten yessoensis), Fish Oil, and Krill Oil in Obese Type II Diabetic KK-A y Mice.

Due to the growing demand of n-3 polyunsaturated fatty acids (PUFA) as supplements and pharmaceutical products worldwide, there are concerns about the exhaustion of n-3 PUFA supply sources. We have successfully prepared high-quality scallop oil (SCO), containing high eicosapentaenoic acid and phospholipids contents, from the internal organs of the Japanese giant scallop (Patinopecten yessoensis), which is the largest unutilized marine resource in Japan. This study compared the cholesterol-lowering effect of SCO with fish oil (menhaden oil, MO) and krill oil (KO) in obese type II diabetic KK-A y mice. Four-week-old male KK-A y mice were divided into four groups; the control group was fed the AIN93G-modified high-fat (3 wt% soybean oil + 17 wt% lard) diet, and the other three groups (SCO, MO, and KO groups) were fed a high-fat diet, in which 7 wt% of the lard in the control diet was replaced with SCO, MO, or KO, respectively. After the mice were fed the experimental diet for 42 days, their serum, liver, and fecal lipid contents as well as their liver mRNA expression levels were evaluated. The SCO group had significantly decreased cholesterol levels in the serum and liver; this decrease was not observed in the MO and KO groups. The cholesterol-lowering effect of SCO was partly mediated by the enhancement of fecal total sterol excretion and expression of liver cholesterol 7α-hydroxylase, a rate-limiting enzyme for bile acid synthesis. These results indicate that dietary SCO exhibits serum and liver cholesterol-lowering effects that are not found in dietary MO and KO and can help prevent lifestyle-related diseases.

Krill Oil Has Different Effects on the Plasma Lipidome Compared with Fish Oil Following 30 Days of Supplementation in Healthy Women: A Randomized Controlled and Crossover Study

This is a follow-up of our previous postprandial study and it focused on the plasma lipidomic responses to 30 days of krill oil (KO) versus fish oil (FO) supplementations in healthy women. Eleven women (aged 18–50 years) consumed KO or FO for 30 days in a randomized, cross-over study, with at least a four-week washout period between supplementations. The daily supplements provided 1.27 g/day of long-chain (LC) omega-3 polyunsaturated fatty acids (PUFA) from KO (containing 0.76 g eicosapentaenoic acid (EPA), 0.42 g docosahexaenoic acid (DHA)) and 1.44 g/day from FO (containing 0.79 g EPA, 0.47 g DHA). Fasting plasma samples at days 0, 15, and 30 were analyzed using gas chromatography and liquid chromatography electrospray ionisation-tandem mass spectrometry. KO resulted in a significantly greater relative area under the curve (relAUC) for plasma EPA after 30 days. Lipidomic analysis showed that 26 of 43 lipid molecular species had a significantly greater relAUC in the KO group, while 17/43 showed a significantly lower relAUC compared with the FO group. More than 38% of the lipids species which increased more following KO contained omega-3 PUFA, while where FO was greater than KO, only 12% contained omega-3 PUFA. These data show that KO and FO do not have equivalent effects on the plasma lipidome.

Effects of Krill Oil and Race Distance on Serum Choline and Choline Metabolites in Triathletes: A Field Study.

Choline is an essential nutrient that has been implicated in athletic performance due to its role in maintaining normal muscle function. The concentration of free choline in serum may decrease during long-distance high-intensity exercise, yet few nutritional strategies to counteract this potentially performance-depleting loss in choline have been investigated outside the laboratory. This exploratory field study was performed to investigate if pre-race supplementation with phosphatidylcholine from krill oil can counteract the expected drop in choline and some of its metabolites during triathlon competitions. Forty-seven triathletes, 12 females and 35 males ranging in age from 25 to 61 years, were recruited from participants in the Ironman-distance Norseman Xtreme triathlon and the Sprint/Olympic-distance Oslo Triathlon. Twenty-four athletes were randomly allocated to the krill oil group, receiving 4 g of SuperbaBoost™ krill oil daily for 5 weeks prior to the race, and 23 athletes were randomly allocated to the placebo group, receiving 4 g of mixed vegetable oil daily. Blood samples were obtained before the race, immediately after completion of the race, and the day after the race for analysis of choline and its metabolites. The results showed that serum choline concentrations significantly decreased from pre-race to race finish in all races, with a more pronounced decrease observed in the Ironman-distance Norseman Xtreme triathlon (34% decrease) relative to the Sprint/Olympic-distance Oslo Triathlon (15% decrease). A reduction in betaine was also observed, while dimethylglycine (DMG) concentrations remained stable across all time points. Significantly higher concentrations of choline (9.4% on average) and DMG (21.4% on average) were observed in the krill oil compared to the placebo group, and the krill oil group showed a significantly greater increase in serum choline following race completion. In conclusion, krill oil may help to prevent that circulating choline concentrations become limiting during endurance competitions.

Krill Oil Addition to 8‐weeks of High‐fat Diet Enhances mTORSer2448 Phosphorylation in Rat Heart

Krill oil (KO) derived from shrimp‐like crustaceans, has been marketed as a substantial source of dietary long chain omega‐3 (LC n‐3) polyunsaturated fatty acids, particularly rich in eicosapentaenoic acid (EPA; 20:5 n‐3) and docosahexaenoic acid (DHA; 22:6 n‐3). Consumption of EPA and DHA has been linked to the reduction of cardiovascular disorders including coronary heart disease and myocardial infarction, however the cellular mechanism for these cardioprotective benefits is unclear. The mechanistic target of rapamycin (mTOR) is a Ser/Thr kinase that acts a nutrient sensor, subsequently controlling various key cellular processes including cell growth, cell survival, and protein synthesis. Diets high in saturated fat content have been associated with myocardial dysregulation through alteration of the mTOR signaling pathway, suggesting that interventions that ameliorate mTOR signaling may counter these deleterious effects in the heart. The goal of the current study is to determine the effect of krill oil supplementation to a high saturated fat diet on mTOR signaling in cardiac muscle. Male Sprague‐Dawley rats (approximately 12 months‐old), were assigned by mass to one of three isocaloric dietary groups for 8 weeks: control diet group (CON; 17% saturated fat, 54% carbohydrate, 29% protein; n=8), a high saturated fat group (HF; 42% saturated, 43% carbohydrate, 15% protein; n=12), and a high fat group with krill oil supplementation (KO; 34% saturated fat, 8% krill oil, 43% carbohydrate, 15% protein; n=12). All rats were given ad libitum access to food and water. Body weights and food consumption was recorded weekly. After 8 weeks of dietary intervention and an overnight fast, blood and hearts were collected from anesthetized rats during a terminal surgery. Western immunoblot analysis was used to determine phosphorylation levels of key mTOR signaling proteins including mTORSer2448, p70S6KThr389, 4E‐BP1Thr37/46, eIF4ESer209, and eIF2αSer51. There was no difference in body mass between dietary groups after 8 weeks of treatment. There was a significant increase (p&lt;0.05) in phosphorylation of mTORSer2448 in the KO group when compared to the HF and CON groups. Phosphorylation of downstream targets of mTOR was not different between groups. Eight weeks of KO supplementation can enhance phosphorylation of mTORSer2448, however the cardioprotective impact of this remains unknown. Further research is needed to examine how KO consumption can affect other key downstream mTOR‐related targets associated with improved cardiovascular health.Support or Funding InformationResearch was supported by intramural grants from the College of Health Professions and the Office of Research and Graduate Studies at Central Michigan University.

Lipid-modifying effects of krill oil vs fish oil: a network meta-analysis

Krill oil is a good source of n-3 phospholipids and has greater bioavailability than fish oil, which contains n-3 triglycerides. However, it is unclear whether krill oil affects circulating lipid concentrations more beneficially than fish oil. A network meta-analysis was conducted to compare the lipid-modifying effects of krill oil and fish oil. PubMed and Embase databases were searched. A total of 64 randomized controlled trials that determined the lipid-modifying effects of krill oil or fish oil were selected. The MetaXL program was used for meta-analysis. A subgroup analysis and a network meta-regression were conducted to investigate the dose-response effect of the n-3 fatty acid content of fish oil and krill oil. Krill oil was associated with significantly lower triglyceride levels than control supplements (weighted mean difference [WMD] -23.26 [95%CI, -38.84 to -7.69]). However, the net differences in triglycerides (WMD -4.07 [95%CI, -15.22 to 7.08]), low-density lipoprotein cholesterol (WMD 3.01 [95%CI, -5.49 to 11.51]), high-density lipoprotein cholesterol (WMD 1.37 [95%CI, -3.73 to 6.48]), and total cholesterol (WMD 1.69 [95%CI, -6.62 to 10.01]) were not significantly different between the krill oil and fish oil groups. One gram of n-3 fatty acids contained in fish oil and krill oil lowered median triglycerides by 8.971 mg/dL (95% credible interval [CrI], 2.27 to 14.04) and 9.838 mg/dL (95%CrI, 0.72 to 19.40), respectively. The lipid-modifying effects of krill oil and fish oil do not differ. The reduction in triglycerides depends on the dose of n-3 fatty acids consumed.