Advances in Technologies for Highly Active Omega-3 Fatty Acids from Krill Oil: Clinical Applications

Advances in encapsulation systems of Antarctic krill oil: From extraction to encapsulation, and future direction

Antarctic krill oil (AKO) is highly sought after by consumers and the food industry due to its richness in a variety of nutrients and physiological activities. However, current extraction methods are not sufficient to better extract AKO and its nutrients, and AKO is susceptible to lipid oxidation during processing and storage, leading to nutrient loss and the formation of off-flavors and toxic compounds. The development of various extraction methods and encapsulation systems for AKO to improve oil yield, nutritional value, antioxidant capacity, and bioavailability has become a research hotspot. This review summarizes the research progress of AKO from extraction to encapsulation system construction. The AKO extraction mechanism, technical parameters, oil yield and composition of solvent extraction, aqueous enzymatic extraction, supercritical/subcritical extraction, and three-liquid-phase salting-out extraction system are described in detail. The principles, choice of emulsifier/wall materials, preparation methods, advantages and disadvantages of four common encapsulation systems for AKO, namely micro/nanoemulsions, microcapsules, liposomes and nanostructured lipid carriers, are summarized. These four encapsulation systems are characterized by high encapsulation efficiency, low production cost, high bioavailability and high antioxidant capacity. Depending on the unique advantages and conditions of different encapsulation methods, as well as consumer demand for health and nutrition, different products can be developed. However, existing AKO encapsulation systems lack relevant studies on digestive absorption and targeted release, and the single product category of commercially available products limits consumer choice. In conjunction with clinical studies of AKO encapsulation systems, the development of encapsulation systems for special populations should be a future research direction.

Gestational Diabetes Mellitus: What Can Medical Nutrition Therapy Do?

Gestational diabetes mellitus (GDM) is one of the common complications during pregnancy. Numerous studies have shown that GDM is associated with a series of adverse effects on both mothers and offspring. Due to the particularity of pregnancy, medical nutrition treatment is considered to be the first choice for the treatment of GDM. This contribution reviews the research progress of medical nutrition treatment in GDM, summarizes the international recommendations on the intake of various nutrients and the influence of nutrients on the prevalence of GDM, and the improvement effect of nutritional intervention on it, in order to provide references for research in related fields of GDM and the targeted development of enteral nutrition.

Krill Oil and Its Bioactive Components as a Potential Therapy for Inflammatory Bowel Disease: Insights from In Vivo and In Vitro Studies

Krill oil is extracted from krill, a small crustacean in the Antarctic Ocean. It has received growing attention because of krill oil's unique properties and diverse health benefits. Recent experimental and clinical studies suggest that it has potential therapeutic benefits in preventing the development of a range of chronic conditions, including inflammatory bowel disease (IBD). Krill oil is enriched with long-chain n-3 polyunsaturated fatty acids, especially eicosapentaenoic and docosahexaenoic acids, and the potent antioxidant astaxanthin, contributing to its therapeutic properties. The possible underlying mechanisms of krill oil's health benefits include anti-inflammatory and antioxidant actions, maintaining intestinal barrier functions, and modulating gut microbiota. This review aims to provide an overview of the beneficial effects of krill oil and its bioactive components on intestinal inflammation and to discuss the findings on the molecular mechanisms associated with the role of krill oil in IBD prevention and treatment.

New Insights into Prospective Health Potential of ω-3 PUFAs

PURPOSE OF REVIEW

Docosahexaenoic acid and eicosapentaenoic acid are the two essential long-chain ω-3 polyunsaturated fatty acids (ω-3 PUFAs) promoting human health which are obtained from diet or supplementation. The eicosanoids derived from ω-6 and ω-3 PUFAs have opposite characteristics of pro- and anti-inflammatory activities. The proinflammatory effects of ω-6 PUFAs are behind the pathology of the adverse health conditions of PUFA metabolism like cardiovascular diseases, neurological disorders, and inflammatory diseases. A balanced ω-6 to ω-3 ratio of 1-4:1 is critical to prevent the associated disorders. But due to modern agricultural practices, there is a disastrous shift in this ratio to 10-20:1. This review primarily aims to discuss the myriad health potentials of ω-3 PUFAs uncovered through recent research. It further manifests the importance of maintaining a balanced ω-6 to ω-3 PUFA ratio.

RECENT FINDINGS

ω-3 PUFAs exhibit protective effects against diabetes mellitus-associated complications including diabetic retinopathy, diabetic nephropathy, and proteinuria. COVID-19 is also not an exception to the health benefits of ω-3 PUFAs. Supplementation of ω-3 PUFAs improved the respiratory and clinical symptoms in COVID-19 patients. ω-3 PUFAs exhibit a variety of health benefits including anti-inflammatory property and antimicrobial property and are effective in protecting against various health conditions like atherosclerosis, cardiovascular diseases, diabetes mellitus, COVID-19, and neurological disorders. In the present review, various health potentials of ω-3 PUFAs are extensively reviewed and summarized. Further, the importance of a balanced ω-6 to ω-3 PUFA ratio has been emphasized besides stating the diverse sources of ω-3 PUFA.

Comparison of the effects of a phospholipid-enhanced fish oil versus krill oil product on plasma levels of eicosapentaenoic and docosahexaenoic acids after acute administration: A randomized, double-blind, crossover study

OBJECTIVE

This randomized, double-blind, crossover study evaluated the bioavailability of eicosapentaenoic and docosahexaenoic acids (EPA+DHA) in a phospholipid-enhanced fish oil (PEFO) product versus a krill oil (KO) product (337 versus 206 mg EPA+DHA/1 g capsule) in healthy adults (N = 24). The aim of this study was to assess the plasma levels of EPA, DHA, and EPA+DHA following a single capsule of PEFO versus KO products in healthy adult men and women.

METHODS

Participants consumed a single dose of the assigned product, and plasma was obtained at baseline and periodically for 24 h after dosing.

RESULTS

The geometric mean ratio (GMR; 90% confidence interval) of incremental areas under the curve over 24 h PEFO:KO was 319/385 = 0.83 (0.60, 1.15 nmol/L*h), indicating a similar average increment for EPA+DHA with PEFO compared with KO across the 24-h period. The baseline-adjusted maximum concentration of EPA+DHA was greater for PEFO than KO (GMR: 1.25; 90% CI, 1.03-1.51). Finally, the geometric mean for the time to maximum concentration for EPA+DHA was lower for PEFO versus KO (P < 0.05).

CONCLUSION

Absorption of EPA+DHA from the two products was similar, but the absorption profiles differed (higher and earlier peak for PEFO).

Bioactive fatty acids from non-conventional lipid sources and their potential application in functional food development

There is growing evidence that bioactive fatty acids (BFAs), including eicosapentaenoic acid (EPA; 20:5-3), docosahexaenoic acid (DHA; 22:6-3), and conjugated fatty acids offer multiple biological benefits and constitute ingredients in functional food development. Despite their potential, novel and alternative/nonconventional sources with unique bioactive properties to meet growing demand remain largely unexplored, poorly characterized, and their effects are not well understood. We systematically reviewed the literature to identify studies on alternative sources of BFAs, their functions, extraction, and application in the food and nutraceutical industry. Twenty studies delved into alternate sources such as plants, bacteria, and algae. Six studies found EPA and DHA as the dominant FA in algal sources, while ten studies reported several BFAs from plant sources. Five studies assessed the health benefits of docosapentaenoic acid (DPA), arachidonic acid (ARA), EPA, γ-linolenic acid (GLA), and linoleic acid (LA). Eleven studies compared the quality of oil recovered by green solvents, pressurized liquid, supercritical fluid, and assisted extraction methods. Three studies assessed the effects of assisted extraction methods and reported that these approaches improved oil yield and quality, but the findings may have limited applicability to other lipid sources. The quality of nonconventional lipids largely depends on extraction techniques. Four studies suggested methods like 1D and 2D NMR spectroscopy, LC-MS/MS; however, their analytical differences make accurate comparison inadequate. Five studies found that the incorporation of algal and seafood biolipids during product development increased EHA and DHA contents.

Development and characterization of self-emulsifying high internal phase emulsions using endogenous phospholipids from Antarctic krill oil

High internal phase emulsions (HIPEs) have emerged as a promising structured oil system in food industry. This study developed self-emulsifying HIPEs (SHIPEs) using Antarctic krill oil (KO) with endogenous phospholipids as surfactant and algae oil as a diluent. The influence of phospholipids self-assembly on SHIPEs formation was investigated by evaluating the microstructures, particle size, rheological properties, and water distribution. Results demonstrated that the concentration and self-assembly behavior of phospholipids dominated the SHIPEs formation. Optimized SHIPEs with desirable gel properties contained 10 wt% krill oil in the oil phase at an 80 wt% oil phase level. Furthermore, these SHIPEs exhibited excellent performance in 3D printing applications. Hydrated phospholipids formed lamellar network at the oil-water interface, enhancing gel strength by crosslinking oil droplets. These findings shed light on the self-assembly of phospholipids during HIPEs formation and highlight the potential phospholipids-rich marine lipids in SHIPEs for functional food products development.

Impact of Antarctic krill oil supplementation on skeletal muscle injury recovery after resistance exercise

BACKGROUND

Antarctic krill oil (KO) is a natural source of n-3 polyunsaturated fatty acids (n-3 PUFAs), and is rich in phospholipids, Eicosapentaenoic acid (EPA), Docosahexaenoic acid (DHA), astaxanthin, flavonoids, vitamins, trace elements, and other bioactive substances. KO has been confirmed to have anti-inflammatory and immunomodulatory effects. n-3 PUFAs also have been purported to improve the recovery of muscular performance. Moreover, the phospholipids present in KO can enhance n-3 PUFA bioavailability because of its higher absorption rate in plasma compared to fish oil. Astaxanthin, found in Antarctic KO, is a red carotenoid and powerful antioxidant that inhibits oxidative stress after intense exercise. Hence, we examined the effect of KO supplementation on the recovery of exercise by measuring muscular performance, oxidant/antioxidant and anti-inflammatory activity, and the markers of muscle damage following a rigorous bout of resistance exercise.

METHODS

30 college-aged resistance-trained males (20.4 ± 0.92 years, 74.09 ± 7.23 kg, 180.13 ± 4.72 cm) were randomly supplemented with 3 g/d KO or placebo (PL) for 3 days and continued to consume after resistance exercise for 3 days until the experiment finished. Before supplementation, pre-exercise performance assessments of knee isokinetic strength, 20 m sprint, hexagon test, and blood serum creatine kinase (CK), lactate dehydrogenase (LDH), superoxide dismutase (SOD), total antioxidant capacity (T-AOC), reactive oxygen species (ROS), malondialdehyde (MDA), interleukin-2 (IL-2), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were completed. Then after 3 days of supplementation, participants completed a bout of muscle-damaging exercise, and subsequently, they performed and repeated the exercise performance assessments and blood-related indicators tests immediately (0 h), as well as at 6, 24, 48, and 72 h post-muscle-damaging exercise.

RESULTS

Compared to the PL group, the serum CK of KO group was significantly lower at 24 h and 48 h post-exercise; the hexagon test time of the KO group was significantly lower than that of the PL group at 6 h and 24 h post-exercise; the KO group's isokinetic muscle strength showed different degrees of recovery than that of the PL group at 24 h and 48 h, and even over-recovery at 72 h post-exercise; the SOD level of the KO group was significantly higher than that of the PL group at 0, 6, and 24 h after exercise; the T-AOC level of the KO group was significantly higher than that of the PL group at 0, 6, and 72 h after exercise; the MDA level of the KO group was significantly lower than that of the PL group at 6 h; and there was no significant difference in serum IL-2, IL-6, and TNF-α between the two groups.

CONCLUSION

Our results demonstrated that 3 g/d KO supplementation and continued supplementation after exercise can alleviate exercise-induced muscle damage (EIMD) and promote post-exercise recovery.

New Pyrroline Isolated from Antarctic Krill-Derived Actinomycetes Nocardiopsis sp. LX-1 Combining with Molecular Networking

Antarctic krill (Euphausia superba) of the Euphausiidae family comprise one of the largest biomasses in the world and play a key role in the Antarctic marine ecosystem. However, the study of E. superba-derived microbes and their secondary metabolites has been limited. Chemical investigation of the secondary metabolites of the actinomycetes Nocardiopsis sp. LX-1 (in the family of Nocardiopsaceae), isolated from E. superba, combined with molecular networking, led to the identification of 16 compounds a-p (purple nodes in the molecular network) and the isolation of one new pyrroline, nocarpyrroline A (1), along with 11 known compounds 2-12. The structure of the new compound 1 was elucidated by extensive spectroscopic investigation. Compound 2 exhibited broad-spectrum antibacterial activities against A. hydrophila, D. chrysanthemi, C. terrigena, X. citri pv. malvacearum and antifungal activity against C. albicans in a conventional broth dilution assay. The positive control was ciprofloxacin with the MIC values of <0.024 µM, 0.39 µM, 0.39 µM, 0.39 µM, and 0.20 µM, respectively. Compound 1 and compounds 7, 10, and 11 displayed antifungal activities against F. fujikuroi and D. citri, respectively, in modified agar diffusion test. Prochloraz was used as positive control and showed the inhibition zone radius of 17 mm and 15 mm against F. fujikuroi and D. citri, respectively. All the annotated compounds a-p by molecular networking were first discovered from the genus Nocardiopsis. Nocarpyrroline A (1) features an unprecedented 4,5-dihydro-pyrrole-2-carbonitrile substructure, and it is the first pyrroline isolated from the genus Nocardiopsis. This study further demonstrated the guiding significance of molecular networking in the research of microbial secondary metabolites.

Use of fish oil and mortality of patients with cardiometabolic multimorbidity: A prospective study of UK biobank

BACKGROUND AND AIMS

Cardiometabolic multimorbidity (CMM) has risen as a global issue of public health, with an in-creasing prevalence and more severe clinical prognosis. This study aimed to estimate the association between use of fish oil and mortality among patients with CMM.

METHODS AND RESULTS

In this prospective study based on UK Biobank, participants with ≥2 of cardiometabolic diseases (CMDs, including coronary heart disease [CHD], diabetes, hypertension, and stroke in this study) at recruitment were included. Use of fish oil was derived from touchscreen questionnaires at baseline. All-cause and cardiovascular mortality were accessed via electronic health-related records. Kaplan-Meier curves and flexible parametric Royston-Parmar proportion-hazard models were fitted to assess the as-sociations of fish-oil use with all-cause, cardiovascular mortality, and related life expectancy alterations. Among 30 068 participants from UK Biobank (67.9% men; mean age 61.75 years), 5357 deaths were reported during 12.03 years of follow-up. For patients with CMM, use of fish oil was associated with a 17% lower risk of all-cause mortality (95% confidence interval [95% CI] 0.78-0.88, P < 0.001), and 19% lower risk of cardiovascular mortality (95% CI 0.72-0.90, P < 0.001) in multivariable-adjusted models. At 45 years old, using fish oil was associated with 1.66 years of life expectancy gained.

CONCLUSION

Among patients with CMM, use of fish oil was associated with a significantly reduced risk of all-cause, cardiovascular mortality, and prolonged life expectancy.

Advances in enzyme biocatalysis for the preparation of functional lipids

Functional lipids, mainly ω-3 polyunsaturated fatty acids (n-3 PUFAs) such as eicosapentaenoic (EPA; 20:5n-3) and docosahexaenoic (DHA; 22:6n-3), are known to have a variety of health benefits. Lipases and phospholipases are widely used to prepare different forms of structured lipids, since biocatalytic methods can be carried out under mild conditions, preserving the quality of the products. On the other hand, many processes still are conducted at high temperatures and with organic solvents, which are conditions unfavorable for the production of nutritional products. This article gives an updated overview of enzyme biocatalysis methods for the preparation of different derivatives containing n-3 PUFAs, including specific reactions, enzyme immobilization research for high-efficiency catalysis, and enzyme engineering technologies (higher selectivity, stability, and activity). Furthermore, advanced control strategies of biocatalytic processes and reactors are presented. The future prospect and opportunities for marine functional lipids are also discussed. Therefore, the obtainment of enzymes endowed with superior properties and the development of optimized processes, still have to be pursued to achieve greener bio-catalyzed processes.

Characterization and activity-folding relationship of serine protease from Antarctic krill (Euphausia superba)

Euphausia superba (Antarctic krill) serine protease (ESP) was investigated to gain insights into the activity-structural relationship, folding behavior, and regulation of the catalytic function. We purified ESP from the krill muscle and characterized biochemical distinctions via enzyme kinetics. Studies of inhibition kinetics and unfolding in the presence of a serine residue modifier, such as phenylmethanesulfonyl fluoride, were conducted. Structural characterizations were measured by spectrofluorimetry, including 1-anilinonaphthalene-8-sulfonate dye labeling for hydrophobic residues. The computational simulations such as docking and molecular dynamics were finally conducted to detect key residues and folding behaviors in a nano-second range. The kinetic parameters of ESP were measured as K_m^BANH = 0.97 ± 0.15 mM and k_cat/K_m^BANH = 4.59 s^-1/mM. The time-interval kinetics measurements indicated that ESP inactivation was transformed from a monophase to a biphase process to form a thermodynamically stable state. Spectrofluorimetry measurements showed that serine is directly connected to the regional folding of ESP. Several osmolytes such as proline and glycine only partially protected the inactive form of ESP by serine modification. Computational molecular dynamics and docking simulations showed that three serine residues (Ser183, Ser188, and Ser207) and Cys184, Val206, and Gly209 are key residues of catalytic functions. Our study revealed the functional roles of serine residues as key residues of catalytic function at the active site and of the structural conformation as key folding factors, where ESP displays a flexible property of active site pocket compared to the overall structure.Communicated by Ramaswamy H. Sarma.

Lipidome reveals the alleviation of krill oil on the impairment of acrylamide

Krill oil has rich content of polyunsaturated fatty acids and various biological functions. Previous researches have demonstrated that krill oil is helpful to improve the locomotion via antioxidation and regulation...

Essential Fatty Acids as Biomedicines in Cardiac Health

The destructive impact of cardiovascular diseases on health, including heart failure, peripheral artery disease, atherosclerosis, stroke, and other cardiac pathological conditions, positions these health conditions as leading causes of increased global mortality rates, thereby impacting the human quality of life. The considerable changes in modern lifestyles, including the increase in food intake and the change in eating habits, will unavoidably lead to an unbalanced consumption of essential fatty acids, with a direct effect on cardiovascular health problems. In the last decade, essential fatty acids have become the main focus of scientific research in medical fields aiming to establish their impact for preventing cardiovascular diseases and the associated risk factors. Specifically, polyunsaturated fatty acids (PUFA), such as omega 3 fatty acids, and monounsaturated fatty acids from various sources are mentioned in the literature as having a cardio-protective role, due to various biological mechanisms that are still to be clarified. This review aims to describe the major biological mechanisms of how diets rich in essential fatty acids, or simply essential fatty acid administration, could have anti-inflammatory, vasodilatory, anti-arrhythmic, antithrombotic, antioxidant, and anti-atherogenic effects. This review describes findings originating from clinical studies in which dietary sources of FAs were tested for their role in mitigating the impact of heart disorders in human health.

Assessing the Potential of Nutraceuticals as Geroprotectors on Muscle Performance and Cognition in Aging Mice

Aging and frailty are associated with a decline in muscle force generation, which is a direct consequence of reduced muscle quantity and quality. Among the leading contributors to aging is the generation of reactive oxygen species, the byproducts of terminal oxidation. Their negative effects can be moderated via antioxidant supplementation. Krill oil and astaxanthin (AX) are nutraceuticals with a variety of health promoting, geroprotective, anti-inflammatory, anti-diabetic and anti-fatigue effects. In this work, we examined the functional effects of these two nutraceutical agents supplemented via pelleted chow in aging mice by examining in vivo and in vitro skeletal muscle function, along with aspects of intracellular and mitochondrial calcium homeostasis, as well as cognition and spatial memory. AX diet regimen limited weight gain compared to the control group; however, this phenomenon was not accompanied by muscle tissue mass decline. On the other hand, both AX and krill oil supplementation increased force production without altering calcium homeostasis during excitation-contraction coupling mechanism or mitochondrial calcium uptake processes. We also provide evidence of improved spatial memory and learning ability in aging mice because of krill oil supplementation. Taken together, our data favors the application of antioxidant nutraceuticals as geroprotectors to improve cognition and healthy aging by virtue of improved skeletal muscle force production.