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1.
Mar Drugs ; 20(6)2022 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-35736149

RESUMO

Chlorella pyrenoidosa is an excellent source of protein, and in this research, we assessed the antioxidant and emulsifying effects of Chlorella protein hydrolysate (CPH) using neutral proteases and alkaline proteases, as well as the properties of CPH-derived krill oil-in-water (O/W) emulsions. The CPHs exhibited the ability to scavenge several kinds of free radicals, including 1,1-diphenyl-2-picrylhydrazyl (DPPH), O2-, hydroxyl, and ABTS. Additionally, the CPHs (5 mg/mL) scavenged approximately 100% of the DPPH and ABTS. The CPHs showed similar emulsifying activities to Tween 20 and excellent foaming activities (max FS 74%), which helped to stabilize the krill oil-in-water emulsion. Less than 10 mg/mL CPHs was able to form fresh krill oil-in-water emulsions; moreover, the CPHs (5 mg/mL) in a krill O/W emulsion were homogenous, opaque, and stable for at least 30 days. Based on their inhibitory effects on the peroxide value (POV) and thiobarbituric acid reactive substances (TRABS), the CPHs were found to be able to inhibit lipid oxidation in both emulsifying systems and krill O/W emulsions. Thus, the CPHs could improve superoxide dismutase (SOD) activities by 5- or 10-fold and decrease the high reactive oxygen species (ROS) level caused by the addition of H2O2 in vitro. In conclusion, health-promoting CPHs could be applied in krill oil-in-water emulsions as both emulsifiers and antioxidants, which could help to improve the oxidative and physical stability of emulsions.


Assuntos
Chlorella , Euphausiacea , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Emulsões/química , Peróxido de Hidrogênio , Oxirredução , Peptídeo Hidrolases , Hidrolisados de Proteína/química , Hidrolisados de Proteína/farmacologia , Água/química
2.
Food Res Int ; 156: 111144, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35651016

RESUMO

Krill oil (KO) obtained from Euphausia superba is nutrient-rich and has a positive effect on human health. Here, we explored the efficacy of KO in inhibiting tumor progression and tumor vascularization. KO (100-300 µg/mL) repressed the proliferation of bladder tumor cell lines MBT-2 and T24. Treatment of cells with KO raised cell-cycle arrest at G0/G1-phase via modulation of positive regulators and negative regulators in bladder cancer cells. KO treatment regulated phosphorylation of proteins involved in PI3K/AKT and MAPK signaling pathways, including ERK, JNK, and p38 MAPK. Additionally, KO hampered the invasion and migration of both cell lines via reduction of MMP-9 expression levels by disrupting transcriptional binding of Sp-1, AP-1, and NF-κB motifs. Moreover, in animal studies, KO (150-300 mg/kg) significantly decreased tumor growth in xenograft mice bearing T24 tumor cells. No significant toxic effects were observed in acute toxicity tests, including biological analysis and H&E staining. The reduced level of CD31 expression in KO-treated tumor tissues prompted us to investigate the effect of KO on tumor angiogenesis. KO (5-40 µg/mL) treatment impeded VEGF-induced capillary tube formation and proliferation by inhibiting VEGFR2-modulated eNOS/AKT/ERK1/2 signaling axis in HUVECs. Treatment of HUVECs with KO inhibited VEGF-stimulated migration and invasion by reducing MMP-2 expression level. VEGF-driven sprouting capacity of neo-microvessels was suppressed in the presence of KO (20-40 µg/mL), as determined via an ex vivo aortic ring assay. Our results indicated that KO can regulate both tumor growth and tumor-associated angiogenesis via a novel mechanism. Thus, KO may be a promising antitumor candidate, potentially useful to prevent or treat bladder cancer.


Assuntos
Euphausiacea , Neoplasias da Bexiga Urinária , Inibidores da Angiogênese/farmacologia , Inibidores da Angiogênese/uso terapêutico , Animais , Células Endoteliais da Veia Umbilical Humana , Humanos , Camundongos , Neovascularização Patológica/tratamento farmacológico , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt/metabolismo , Neoplasias da Bexiga Urinária/tratamento farmacológico , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator A de Crescimento do Endotélio Vascular/uso terapêutico , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
3.
Clin Nutr ; 41(6): 1228-1235, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35504165

RESUMO

BACKGROUND & AIMS: The aim of this study was to determine the effect of krill oil supplementation, on muscle function and size in healthy older adults. METHODS: Men and women, aged above 65 years, with a BMI less than 35kg/m2, who participated in less than 1h per week of structured self-reported exercise, were enrolled in the study (NCT04048096) between March 2018 and March 2020. Participants were randomised to either control or krill oil supplements (4g/day) for 6 months in this double blind randomised controlled trial. At baseline, 6 weeks and 6 months, knee extensor maximal torque was measured as the primary outcome of the study. Secondary outcomes measured were grip strength, vastus lateralis muscle thickness, short performance physical battery test, body fat, muscle mass, blood lipids, glucose, insulin, and C-Reactive Protein, neuromuscular (M-Wave, RMS and voluntary activation), and erythrocyte fatty acid composition. RESULTS: A total of 102 men and women were enrolled in the study. Ninety-four participants (krill group (26 women and 23 men) and placebo group (27 women and 18 men)) completed the study (mean (SD): age 71.2 (5.1) years and weight 71.8 (12.3) kg). Six months supplementation with krill oil resulted in, an increase in knee extensor maximal torque, grip strength and vastus lateralis muscle thickness, relative to control (p<0.05). The 6-month treatment effects were 9.3% (95%CI: 2.8, 15.8%), 10.9% (95%CI: 8.3, 13.6%) and 3.5% (95%CI: 2.1, 4.9%) respectively. Increases in erythrocyte fatty acid profile were seen with krill oil for EPA 214% (95%CI: 166, 262%), DHA 36% (95%CI: 24, 48%) and the omega-3 index 61% (95%CI: 49, 73%), relative to control (p < 0.05). Krill oil resulted in an increased, relative to control (p < 0.05), M-Wave of 17% (95%CI: 12.7, 38.1%) but there was no effect of krill oil on RMS, voluntary activation, or on any other secondary outcomes such as performance of the short performance physical battery test or quality of life. CONCLUSION: Krill oil supplementation for 6 months results in statistically and clinically significant increases in muscle function and size in healthy older adults. GOV IDENTIFIER: NCT04048096.


Assuntos
Euphausiacea , Doenças Musculares , Idoso , Animais , Suplementos Nutricionais , Método Duplo-Cego , Ácidos Graxos/farmacologia , Feminino , Humanos , Masculino , Músculo Esquelético , Qualidade de Vida
4.
Molecules ; 27(9)2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35566118

RESUMO

Defatted Antarctic krill powder is the main by-product in the manufacturing of krill oil. Exploring a high value-added approach for utilizing this protein-rich material has received much attention in research and industry. Given this, the preparation and primary characterization of antifreeze peptides from defatted Antarctic krill (AKAPs) were carried out in this study. The cryoprotective effect of AKAPs on Lactobacillus rhamnosus ATCC7469 was also investigated. The results showed that Protamex was the optimum protease for AKAP preparation from defatted Antarctic krill. AKAPs were found to be rich in short peptides, with the MW ranging from 600 to 2000 Da (69.2%). An amino acid composition analysis showed that AKAPs were rich in glutamic acid (18.71%), aspartic acid (12.19%), leucine (7.87%), and lysine (7.61%). After freezing, the relative survival rate of Lactobacillus rhamnosus in the 1.0 mg/mL AKAP-treated group (96.83%) was significantly higher than in the saline group (24.12%) (p < 0.05). AKAPs also retarded the loss of acidifying activity of L. rhamnosus after freezing. AKAPs showed even better cryoprotective activity than three commercial cryoprotectants (sucrose, skim milk, and glycerol). In addition, AKAPs significantly alleviated the decrease in ß-galactosidase and lactic dehydrogenase activities of L. rhamnosus (p < 0.05). Furthermore, AKAPs effectively protected the integrity of L. rhamnosus cell membranes from freezing damage and alleviated the leakage of intracellular substances. These findings demonstrate that AKAPs can be a potential cryoprotectant for preserving L. rhamnosus, providing a new way to use defatted Antarctic krill.


Assuntos
Euphausiacea , Lactobacillus rhamnosus , Aminoácidos/metabolismo , Animais , Proteínas Anticongelantes/metabolismo , Euphausiacea/química , Peptídeos/metabolismo , Peptídeos/farmacologia
5.
Food Chem ; 388: 132995, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35453014

RESUMO

High acid value (AV) and fluorine content of Antarctic krill oil (AKO) extracted from frozen krill by ethanol limit its product development. In this study, a method was proposed to reduce the AV and fluorine content of AKO by carboxymethyl chitosan (CMCS) adsorption. The optimal adsorption condition was 12.5% (w/v) of CMCS at 30℃ for 15 min. At this condition, AV and fluorine content decreased by 78.0% and 61.4%, respectively. It is interesting that CMCS adsorption showed specificity to particular substances. Although free fatty acids content showed a significant reduction, free EPA and DHA, phospholipid and astaxanthin remained almost constant. Moreover, CMCS adsorption showed no influence on neuroprotective activity of AKO against H2O2-induced neuro-damage of PC12 cells. The reclaimed CMCS showed an undiminished antimicrobial activity against both Gram-positive and Gram-negative bacteria. The CMCS adsorption shows a potential development for refining AKO and other oils in food industry.


Assuntos
Quitosana , Euphausiacea , Adsorção , Animais , Antibacterianos , Quitosana/farmacologia , Flúor , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Peróxido de Hidrogênio , Óleos
6.
Comput Intell Neurosci ; 2022: 8771650, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35371201

RESUMO

This study aims to improve the efficiency and accuracy of image segmentation, and to compare and study traditional threshold-based image segmentation methods and machine learning model-based image segmentation methods. The krill herb optimization algorithm is combined with the traditional maximum between-class variance function to form a new graph segmentation algorithm. The pet dataset is used to train the algorithm model and build an image semantic segmentation system. The results show that when the traditional Ostu algorithm performs image single-threshold segmentation, the number of iterations is about 256. When double-threshold segmentation is performed, the number of iterations increases exponentially, and the execution time is about 2 s. The number of iterations of the improved Krill Herd algorithm in single-threshold segmentation is 6.95 times, respectively. The execution time for double-threshold segmentation is about 0.24 s. The number of iterations is only improved by a factor of 0.19. The average classification accuracy of the Unet network model and the SegNet network model is 86.3% and 91.9%, respectively. The average classification accuracy of the DC-Unet network model reaches 93.1%. This shows that the proposed fusion algorithm has high optimization efficiency and stronger practicability in multithreshold image segmentation. The DC-Unet network model can improve the image detail segmentation effect. The research provides a new idea for finding an efficient and accurate image segmentation method.


Assuntos
Euphausiacea , Algoritmos , Animais , Aprendizado de Máquina , Semântica
7.
Food Chem ; 384: 132620, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35413776

RESUMO

Amino-modified mesoporous silicawas prepared by modifying mesoporous silica with 3-aminopropyltriethoxysilane and used as adsorbents in matrix solid-phase dispersion (MSPD) to analyze free fatty acids (FFAs) in krill meals for the first time. The adsorption-desorption experiments and Fourier-transform infrared spectroscopy showed amino-modified mesoporous silica with ordered mesoporous structure was successfully synthesized. The adsorption experiments including static and dynamic adsorption showed thatabsorption capacity of amino-modified mesoporous silica towards FFAs was better than that of aminated silicon microspheres at all concentrations. Under optimal extraction conditions, outstanding linearity (0.1-12000 nmol g-1), low LODs (0.05-1.25 nmol g-1), satisfactory recoveries (82.17-96.43%) and precisions (0.19-5.26%) were obtained. Moreover, the application of MSPD for FFAs analysis avoided complicated lipid extraction procedures and accomplished the homogenization, crushing, extraction and cleaning of the samples in one step. Consequently, this approach provides an alternative choice to the existing approach for analyzing FFAs in solid and semi-solid samples.


Assuntos
Euphausiacea , Extração em Fase Sólida , Adsorção , Animais , Cromatografia Líquida de Alta Pressão/métodos , Ácidos Graxos não Esterificados , Refeições , Dióxido de Silício/química , Extração em Fase Sólida/métodos , Espectroscopia de Infravermelho com Transformada de Fourier
8.
Mar Drugs ; 20(4)2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35447908

RESUMO

We investigated pigment and mycosporine-like amino acid (MAA) concentrations of phytoplankton and Northern krill (Thysanoessa sp.) in sub-Arctic Kongsfjorden. Chlorophyll a (Chl-a) concentrations in the surface and middle-layer water were 0.44 µg L-1 (±0.17 µg L-1) and 0.63 µg L-1 (±0.25 µg L-1), respectively. Alloxanthin (Allo, a marker of cryptophytes) was observed at all stations, and its mean values for surface and middle-layer water were 0.09 µg L-1 (±0.05 µg L-1) and 0.05 (±0.02 µg L-1), respectively. The mean MAA-to-Chl-a ratios at the surface (3.31 ± 2.58 µg (µg Chl-a)-1) were significantly higher than those in the middle-layer water (0.88 ± 0.49 µg (µg Chl-a)-1), suggesting that these compounds play an important role in reducing UV photodamage. In gut pigment levels of Northern krill, the most abundant accessory pigment was Allo (2.79 ± 0.33 µg g-1 dry weight; d.w.), as was the accumulation of Chl-a (8.29 ± 1.13 µg g-1 d.w.). The average concentration of MAAs was 1.87 mg g-1 d.w. (±0.88 mg g-1 d.w.) in krill eyes, which was higher than that in all other body parts (0.99 ± 0.41 mg g-1 d.w.), except for the gut. Thysanoessa sp. was found to contain five identified MAAs (shinorine, palythine, porphyra-334, mycosporine-glycine, and M-332) in the krill eye, whereas shinorine and porphyra-334 were only observed in the krill body, not the eyes and gut. These findings suggest that Northern krill accumulate MAAs of various compositions through the diet (mainly cryptophytes) and translocate them among their body parts as an adaptation for photoprotection and physiological demands.


Assuntos
Euphausiacea , Fitoplâncton , Aminoácidos/química , Animais , Clorofila A , Estuários , Svalbard , Raios Ultravioleta , Água
9.
Mar Pollut Bull ; 178: 113624, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35397343

RESUMO

The study on the concentration of trace elements in Antarctic krill and in water in the deep areas of the Atlantic sector of the Antarctic was performed. Concentrations of 22 trace elements were studied to determine their spatial distribution in krill, and to assess the accumulation ability of the krill against 8 of them. The trace elements concentration in krill diminished in the following order: Fe > Cu > Zn > Bа > B > Se > As > Cr > Ni > Ag > Li > Mn > V > Mo > Cd > Co > Hg > Be. Concentrations of Pb, Ti, Tl, Sb were below their detection limits. Concentration factors of trace elements by krill varied from n × 102 to n × 104. The Cu and As concentrations in dry krill exceeded their MPC. Concentrations of all trace elements in wet mass of krill were not exceeded established regulative values.


Assuntos
Euphausiacea , Metaloides , Oligoelementos , Animais , Metais , Oligoelementos/análise , Água
10.
PLoS One ; 17(4): e0265934, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35390020

RESUMO

Changes in gray whale (Eschrichtius robustus) phenology and distribution are related to observed and hypothesized prey availability, bottom water temperature, salinity, sea ice persistence, integrated water column and sediment chlorophyll a, and patterns of wind-driven biophysical forcing in the northern Bering and eastern Chukchi seas. This portion of the Pacific Arctic includes four Distributed Biological Observatory (DBO) sampling regions. In the Bering Strait area, passive acoustic data showed marked declines in gray whale calling activity coincident with unprecedented wintertime sea ice loss there in 2017-2019, although some whales were seen there during DBO cruises in those years. In the northern Bering Sea, sightings during DBO cruises show changes in gray whale distribution coincident with a shrinking field of infaunal amphipods, with a significant decrease in prey abundance (r = -0.314, p<0.05) observed in the DBO 2 region over the 2010-2019 period. In the eastern Chukchi Sea, sightings during broad scale aerial surveys show that gray whale distribution is associated with localized areas of high infaunal crustacean abundance. Although infaunal crustacean prey abundance was unchanged in DBO regions 3, 4 and 5, a mid-decade shift in gray whale distribution corresponded to both: (i) a localized increase in infaunal prey abundance in DBO regions 4 and 5, and (ii) a correlation of whale relative abundance with wind patterns that can influence epi-benthic and pelagic prey availability. Specifically, in the northeastern Chukchi Sea, increased sighting rates (whales/km) associated with an ~110 km (60 nm) offshore shift in distribution was positively correlated with large scale and local wind patterns conducive to increased availability of krill. In the southern Chukchi Sea, gray whale distribution clustered in all years near an amphipod-krill 'hotspot' associated with a 50-60m deep trough. We discuss potential impacts of observed and inferred prey shifts on gray whale nutrition in the context of an ongoing unusual gray whale mortality event. To conclude, we use the conceptual Arctic Marine Pulses (AMP) model to frame hypotheses that may guide future research on whales in the Pacific Arctic marine ecosystem.


Assuntos
Euphausiacea , Baleias , Animais , Regiões Árticas , Biofísica , Clorofila A , Ecossistema , Oceanos e Mares , Água
11.
Genes (Basel) ; 13(3)2022 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-35328094

RESUMO

Much debate surrounds the importance of top-down and bottom-up effects in the Southern Ocean, where the harvesting of over two million whales in the mid twentieth century is thought to have produced a massive surplus of Antarctic krill. This excess of krill may have allowed populations of other predators, such as seals and penguins, to increase, a top-down hypothesis known as the 'krill surplus hypothesis'. However, a lack of pre-whaling population baselines has made it challenging to investigate historical changes in the abundance of the major krill predators in relation to whaling. Therefore, we used reduced representation sequencing and a coalescent-based maximum composite likelihood approach to reconstruct the recent demographic history of the Antarctic fur seal, a pinniped that was hunted to the brink of extinction by 18th and 19th century sealers. In line with the known history of this species, we found support for a demographic model that included a substantial reduction in population size around the time period of sealing. Furthermore, maximum likelihood estimates from this model suggest that the recovered, post-sealing population at South Georgia may have been around two times larger than the pre-sealing population. Our findings lend support to the krill surplus hypothesis and illustrate the potential of genomic approaches to shed light on long-standing questions in population biology.


Assuntos
Euphausiacea , Otárias , Animais , Regiões Antárticas , Euphausiacea/genética , Otárias/genética , Funções Verossimilhança , Densidade Demográfica
12.
J Med Food ; 25(3): 239-250, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35235416

RESUMO

The aim of this study was to investigate the effects of krill oil (FJH-KO) in monoiodoacetate (MIA)-induced osteoarthritis in rat models, and H2O2- or lipopolysaccharide (LPS)-treated primary chondrocytes and the SW982 synovial cell line. We found that 150 mg/kg b.w. FJH-KO supplementation increased running speed, stride, and foot pressure in MIA-induced osteoarthritic rats. In the H2O2-treated SW982 synovial cell line and primary chondrocytes, FJH-KO treatment prevented cell death and suppressed matrix degradation by increasing the levels of anabolic factors of cartilage tissue, including aggrecan, collagen type Ⅰ, collagen type Ⅱ, tissue inhibitors of metalloproteinase (TIMP)-1, and TIMP-3, and decreasing those of catabolic factors of cartilage tissue, including phosphorylation of Smad, MMP-3, and MMP-13. In addition, FJH-KO treatment suppressed the activation of inflammation and apoptosis pathways in the LPS-treated SW982 synovial cell line and primary chondrocytes. We suggest that FJH-KO supplementation may help prevent osteoarthritis progression because of its direct effects on inflammation and apoptosis of chondrocytes.


Assuntos
Cartilagem Articular , Euphausiacea , Animais , Linhagem Celular , Células Cultivadas , Condrócitos , Peróxido de Hidrogênio/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Ácido Iodoacético , Ratos
13.
Environ Pollut ; 304: 119199, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35337890

RESUMO

Under the climate change context, warming Southern Ocean waters may allow mercury (Hg) to become more bioavailable to the Antarctic marine food web (i.e., ice-stored Hg release and higher methylation rates by microorganisms), whose biomagnification processes are poorly documented. Biomagnification of Hg in the food web of the Antarctic Peninsula, one of the world's fastest-warming regions, was examined using carbon (δ13C) and nitrogen (δ15N) stable isotope ratios for estimating feeding habitat and trophic levels, respectively. The stable isotope signatures and total Hg (T-Hg) concentrations were measured in Antarctic krill Euphausia superba and several Antarctic predator species, including seabirds (gentoo penguins Pygoscelis papua, chinstrap penguins Pygoscelis antarcticus, brown skuas Stercorarius antarcticus, kelp gulls Larus dominicanus, southern giant petrels Macronectes giganteus) and marine mammals (southern elephant seals Mirounga leonina). Significant differences in δ13C values among species were noted with a great overlap between seabird species and M. leonina. As expected, significant differences in δ15N values among species were found due to interspecific variations in diet-related to their trophic position within the marine food web. The lowest Hg concentrations were registered in E. superba (0.007 ± 0.008 µg g-1) and the highest values in M. giganteus (12.090 ± 14.177 µg g-1). Additionally, a significant positive relationship was found between Hg concentrations and trophic levels (reflected by δ15N values), biomagnifying nearly 2 times its concentrations at each level. Our results support that trophic interaction is the major pathway for Hg biomagnification in Southern Ocean ecosystems and warn about an increase in the effects of Hg on long-lived (and high trophic level) Antarctic predators under climate change in the future.


Assuntos
Charadriiformes , Euphausiacea , Mercúrio , Spheniscidae , Animais , Regiões Antárticas , Bioacumulação , Charadriiformes/metabolismo , Ecossistema , Monitoramento Ambiental/métodos , Euphausiacea/metabolismo , Cadeia Alimentar , Mamíferos/metabolismo , Mercúrio/análise , Spheniscidae/metabolismo
14.
Food Res Int ; 154: 110996, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35337564

RESUMO

A novel heptapeptide LVDDHFL derived from Antarctic krill was used to assemble an iron complex, of which the iron-binding mode, in vitro digestion kinetics, and iron absorption behavior were explored. Fe2+ bound to one carboxyl oxygen atom of Asp at position 4 and the imidazole group of His at position 5 on the LVDDHFL peptide at a stoichiometric ratio of 1:2, which induced the folding of LVDDHFL to form a more orderly structure. LVDDHFL-iron significantly enhanced the solubility of iron as compared to FeSO4 in the gastroduodenal tract (P < 0.05), making it up to 80.92 ± 3.02% at the end of gastroduodenal digestion. Moreover, iron complexation can enhance the digestive stability of LVDDHFL with the peptide retention rate as 62.26 ± 2.60% and approximately 27.54% of LVDDHFL were degraded to hexapeptide LVDDHF. Nevertheless, the enhancement of LVDDHF - iron on iron absorption was comparable to that of LVDDHFL - iron, but better than that of FeSO4.


Assuntos
Euphausiacea , Ferro , Animais , Quelantes/química , Digestão , Euphausiacea/química , Ferro/química , Cinética
15.
Food Funct ; 13(7): 3853-3864, 2022 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-35274650

RESUMO

Acute liver injury is a life-threatening syndrome that often results from the actions of viruses, drugs and toxins. Herein, the protective effect and potential mechanism of krill oil (KO), a novel natural product rich in long-chain n-3 polyunsaturated fatty acids bound to phospholipids and astaxanthin, on lipopolysaccharide (LPS)-evoked acute liver injury in mice were investigated. Male C57BL/6J mice were administered intragastrically with 400 mg kg-1 KO or fish oil (FO) once per day for 28 consecutive days prior to LPS exposure (10 mg kg-1, intraperitoneally injected). The results revealed that KO pretreatment significantly ameliorated LPS-evoked hepatic dysfunction indicated by reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and attenuated hepatic histopathological damage. KO pretreatment also mitigated LPS-induced hepatic oxidative stress, as evidenced by decreased malondialdehyde (MDA) contents, elevated glutathione (GSH) levels, and elevated catalase (CAT) and superoxide dismutase (SOD) activities. Additionally, LPS-evoked overproduction of pro-inflammatory mediators in serum and the liver was inhibited by KO pretreatment. Furthermore, KO pretreatment suppressed LPS-induced activation of the hepatic toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB)/NOD-like receptor family pyrin domain containing 3 (NLRP3) signaling pathway. Interestingly, the hepatoprotective effect of KO was superior to that of FO. Collectively, the current findings suggest that KO protects against LPS-evoked acute liver injury via inhibition of oxidative stress and inflammation.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Euphausiacea , Animais , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Euphausiacea/metabolismo , Inflamação/metabolismo , Lipopolissacarídeos/metabolismo , Lipopolissacarídeos/toxicidade , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/genética , NF-kappa B/metabolismo , Estresse Oxidativo
16.
Int J Biol Macromol ; 207: 140-151, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35257727

RESUMO

Sodium alginate/krill protein/polyacrylamide (SA/AKP/PAM) hydrogel with "covalent bond-ion complex-hydrogen bond" multi-network structure was prepared by covalent cross-linking and complexion ion crosslinking using SA, AKP, and acrylamide (AM) as raw materials. The effects of ion species (Fe3+, Ba2+, Sr2+, Ca2+, and Zn2+) on the structure, morphology, and properties of multi-network hydrogels were studied in detail. The results showed that the mechanical strength of ionic cross-linked hydrogels increased significantly. The compressive strength of Fe3+ cross-linked hydrogels was 5.56 MPa, 16.13 times that of non-ionic crosslinked hydrogels. The results of ionic conductivity measurements showed that hydrogels had significant ionic conductivity and were sensitive to external forces. Interestingly, the hydrogel can be used as a capacitive pen in mobile phone writing, painting and dialing numbers. Moreover, ionic cross-linked hydrogels had a unique three-dimensional porous structure with gradient distribution, excellent shape memory effect, and good biocompatibility. Fe3+, Ba2+, Sr2+, and Ca2+ cross-linked hydrogels were nontoxic and conducive to the adhesion and growth of Schwann cells. These excellent properties of ionic cross-linked SA/AKP/PAM hydrogels have broad applications prospects in flexible electronic devices, sensors, soft electronic skins, and tissue engineering.


Assuntos
Euphausiacea , Hidrogéis , Resinas Acrílicas , Alginatos/química , Animais , Condutividade Elétrica , Hidrogéis/química , Íons
17.
BMC Complement Med Ther ; 22(1): 34, 2022 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-35120511

RESUMO

BACKGROUND: We have previously reported that the free fatty acid extract (FFAE) of krill oil (KO) significantly inhibits the proliferation and migration, and induces apoptosis of colorectal cancer (CRC) cells. This study aimed to investigate the in vivo efficacy of various doses of KO supplementation on the inhibition of CRC tumour growth, molecular markers of proliferation, angiogenesis, apoptosis, the epidermal growth factor receptor (EGFR) and its downstream molecular signalling. METHODS: Male Balb/c mice were randomly divided into four groups with five in each group. The control (untreated) group received standard chow diet; and other three groups received KO supplementation at 5%, 10%, and 15% of their daily dietary intake respectively for three weeks before and after the orthotopic implantation of CT-26 CRC cells in their caecum. The expression of cell proliferation marker Ki-67 and angiogenesis marker CD-31 were assessed by immunohistochemistry. The expression of EGFR, phosphorylated EGFR (pEGFR), protein kinase B (AKT), pAKT, extracellular signal-regulated kinase (ERK1/2), pERK1/2, cleaved caspase-7, cleaved poly (ADP-ribose) polymerase (PARP), and DNA/RNA damage were determined by western blot. RESULTS: KO supplementation reduced the CRC tumour growth in a dose-dependent manner; with 15% of KO being the most effective in reduction of tumour weight and volume (68.5% and 68.3% respectively, P < 0.001), inhibition of cell proliferation by 69.9% (P < 0.001) and microvessel density by 72.7% (P < 0.001). The suppressive effects of KO on EGFR and its downstream signalling, ERK1/2 and AKT, were consistent with our previous in vitro observations. Furthermore, KO exhibited pro-apoptotic effects on tumour cells as indicated by an increase in the expression of cleaved PARP by 3.9-fold and caspase-7 by 8.9-fold. CONCLUSIONS: This study has demonstrated that KO supplementation reduces CRC tumour growth by inhibiting cancer cell proliferation and blood vessel formation and inducing apoptosis of tumour cells. These anti-cancer effects are associated with the downregulation of the EGFR signalling pathway and activation of caspase-7, PARP cleavage, and DNA/RNA damage.


Assuntos
Neoplasias Colorretais , Euphausiacea , Animais , Suplementos Nutricionais , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Tomografia Computadorizada por Raios X
18.
Ecotoxicol Environ Saf ; 232: 113289, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35144128

RESUMO

Antibiotic resistance genes (ARGs) are ubiquitous in nature, especially in the current era of antibiotic abuse, and their existence is a global concern. In the present study, we discovered that Antarctic krill-related culturable bacteria are resistant to ß-lactam, tetracyclines, aminoglycosides, and sulphamethoxazole/trimethoprim based on the antibiotic efflux mechanism. In addition, the co-occurrence of ARGs with insertion sequence (IS) (tnpA, IS91) and Intl1 on the isolates and the phylogenetic analysis results of the whole-genome revealed low-frequency ARG transfer events, implying the transferability of these ARGs. These findings provide an early warning for the wide assessment of Antarctic microbiota in the spread of ARGs. Our work provides novel insights into understanding ARGs in culturable host-associated microorganisms, and their ecological risks and has important implications for future risk assessments of antibiotic resistance in extreme environments.


Assuntos
Antibacterianos , Euphausiacea , Animais , Bactérias/genética , Euphausiacea/genética , Genes Bacterianos , Filogenia
19.
J Agric Food Chem ; 70(6): 2018-2028, 2022 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-35107281

RESUMO

A novel heptapeptide QEELISK derived from Antarctic krill was used to assemble a calcium delivery system, of which the calcium binding mechanism of QEELISK, in vitro digestion kinetics, and calcium absorption behaviors were explored. QEELISK with continuous Glu possessed higher calcium binding capacity than that of QELEISK and QAALISK. Ca2+ bound to the carboxyl oxygen of Glu at position 3 of the QEELISK peptide at a stoichiometric ratio of 1:1 through charge-charge interaction; the formed QEELISK-Ca showed superior stability. Moreover, QEELISK-Ca underwent disaggregation and self-assembly during in vitro digestion reflected by visualization of calcium ions and circular dichroism spectra. QELEISK was partially stable during gastrointestinal digestion, and calcium chelation improved the digestive stability of QELEISK. In addition, a significant enhancement of calcium absorption with QELEISK-Ca occurred in the duodenum and ileum when compared to CaCl2 absorption, which indicated that QEELISK might carry calcium ions through the gastrointestinal tract.


Assuntos
Euphausiacea , Animais , Regiões Antárticas , Cálcio , Cálcio na Dieta , Digestão , Peptídeos
20.
Proc Biol Sci ; 289(1969): 20212361, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-35193400

RESUMO

Antarctic krill swarms are one of the largest known animal aggregations, and yet, despite being the keystone species of the Southern Ocean, little is known about how swarms are formed and maintained. Understanding the local interactions between individuals that provide the basis for these swarms is fundamental to knowing how swarms arise in nature, and what potential factors might lead to their breakdown. Here, we analysed the trajectories of captive, wild-caught krill in 3D to determine individual-level interaction rules and quantify patterns of information flow. Our results demonstrate that krill align with near neighbours and that they regulate both their direction and speed relative to the positions of groupmates. These results suggest that social factors are vital to the formation and maintenance of swarms. Furthermore, krill operate a novel form of collective organization, with measures of information flow and individual movement adjustments expressed most strongly in the vertical dimension, a finding not seen in other swarming species. This research represents a vital step in understanding the fundamentally important swarming behaviour of krill.


Assuntos
Euphausiacea , Animais , Regiões Antárticas , Euphausiacea/fisiologia
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