•This study evaluates the time-dependent effects of EPA-PL from Cucumaria frondosa on lipid metabolism.•EPA-PL strongly suppresses the hepatic TG accumulation (3 days) and the white adipose tissue mass (7 days).•The mechanism of EPA-PL relies on upregulation of the β-oxidation in the liver and WAT.•EPA-PL group remains higher hepatic DHA concentration during reversal.Recent study demonstrated that dietary eicosapentaenoic acid (EPA) could alleviate metabolism disorders. However, the onset time of EPA-enriched phospholipid (EPA-PL) on lipid metabolism was rarely been reported. The aim of the present study was to evaluate the time-dependent changes in lipid profile and genes of lipometabolism induced by EPA-PL from Cucumaria frondosa. Male C57BL/6J mice were fed a standard diet with or without EPA-PL for 3, 7, or 14 days. Additionally, we examined gene expression 1 week after removing EPA-PL from the diet. Our results indicated that 3-day EPA-PL supplementation significantly increased the expression of genes related to β-oxidation (UCP2, Ehhadh, Acaa1) in the liver and epididymal adipose tissue, whereas no differences were observed in the mRNA expression of selected genes between groups 1 week after EPA-PL removal. It is concluded that EPA-PL served as a rapid regulator of fat burning and could be a functional food for obesity disorders.

A fast and efficient shotgun lipidomics strategy was applied to analyze phospholipids (PL) in the oyster Crassostrea plicatula, including 29 species of phosphatidylcholine (PtdCho), 23 species of phosphatidylethanolamine (PtdEtn), 11 species of phosphatidylserine (PtdSer), 6 species of phosphatidylinositol (PtdIns), and 17 species of lysophospholipids (Lyso-PL). During storage at 4 °C for 7 days, the PL content decreased by 68.08%, but a significant increase in the FFA content was observed (from 63.11 to 318.72 μg/g). PtdCho and PtdIns decreased relatively by 64.97 and 67.49%, and PtdSer decreased most markedly by 74.15%. However, the PtdEtn content increased slightly during the early stages of storage but subsequently began to decrease. Moreover, PL with eicosapentaenoic acid (EPA-PL) and docosahexaenoic acid (DHA-PL) decreased by 51.77 and 50.61%, whereas plasmalogens were relatively stable showing only a 25.46% decrease. In particular, through enzyme activity analysis of lipase, phospholipase A1 (PLA1), phospholipase A2 (PLA2), phospholipase C (PLC), and phospholipase D (PLD), it was observed that the activities of all these enzymes increased at the early stage at 4 °C, but their activities were at lower levels when the oysters were stored at −20 °C. During the storage period at 4 °C, correlation analysis suggests that the degradation of PtdCho was mostly correlated to PLA2 (p < 0.05), whereas PtdEtn and PtdSer were more markedly correlated to lipase and PLD, respectively. The above result indicates that the hydrolysis mechanism of PL during seafood storage was correlated to the lipid hydrolytic enzyme activities under different storage temperatures.

Erratum to: Lipids DOI 10.1007/s11745-017-4305-7The authors would like to correct two figures from the original version of their article. The corrections to Figs. 4 and 7 are as follows:1. Fig. 4Open image in new windowFig. 4−ESI/MS2 product ion spectrum of a precursor ion at m/z 750.6 PakEtn (18:0/20:5) from the oyster Crassostrea plicatulaThe three CH2 groups between O and NH2 have been corrected to show two CH2 groups. For EPA, the vertical dashed line from the O=C–O bond has been moved to the O–CH bond.2. Fig. 7Open image in new windowFig. 7Hydrolyzation mechanism of PtdCho (16:0/20:5) by the corresponding enzymes during storage at 4 °CThe first diglyceride produced by PtdCho should have contained an oxygen atom, thus the vertical dashed line from the CH2–O bond has been moved to the O–P bond. The same is true for PtdOH, so the vertical dashed line from the P–O bond has been moved to the O–CH2 bond. For Lyso-PtdCho (16:0), the vertical dashed line from the O–CH bond has been moved to the O=C–O bond. In addition, the carbon number of EPA has been corrected to 20, instead of 22, near the CH2–C=O bond.

•The neuroprotection of sea urchin gangliosides was studied in PC12 and AD mice.•SU-GLSs exhibited a dose-dependent and structure-selective neuroprotection in PC12.•SU-GLSs resulted in a dramatic reduction of Aβ1-40 and Aβ1-42 in SAMP8 mice.•SU-GLSs resisted AD via ameliorating neurite loss and mitochondrial apoptosis.Gangliosides (GLSs), abundant in the mammalian brain, have been shown to affect neuronal plasticity and neurodegenerative diseases, especially Alzheimer’s disease. However, the biological activity and neuroprotective mechanism have not yet been established for sea urchin GLSs (SU-GLSs). Herein, we evaluated the neuroprotective effect of Strongylocentrotus nudus GM4(1S), GD4(1S), GD4(2A), and GD4(2G) in Aβ25-35-induced PC12 cells and in vivo using a GLSs mixture administered to SAMP8 mice. It was established that the pre-treatment of SU-GLSs decreased the loss of cell viability and the levels of Aβ1-40 and Aβ1-42 in the hippocampus significantly, and relieved the cognitive deficiency of SAMP8 mice. Mechanistic studies found that SU-GLSs down regulated the expression of Bax, Caspase-3, and Caspase-9, while it upregulated the expression of Bcl-2, synaptophysin, and GAP-43 significantly. Thus, SU-GLSs promoted resistance to AD in a dose-dependent and structure-selective manner, probably via reducing the loss of neurites and blocking the mitochondrial apoptosis pathway.

Herein, we investigated the potential relationship between sphingolipids and Alzheimer's disease (AD) with special attention to the relationship between dietary sea cucumber glucocerebrosides (SCGs) and sphingolipid metabolism. We assessed animal behavior using the Morris water maze test, determined Aβ1-42 concentration in the hippocampus using ELISA, and assessed the sphingolipid profile of the hippocampus and the cortex in normal mice (SAMR1), AD mice (SAMP8), and AD mice (SAMP8) fed with SCG using liquid chromatography-triple quadrupole mass spectrometry. We found that the SAMP8 mice had impaired memory and an SCG diet significantly rescued spatial memory deficits in these mice. As expected, we found that the profiles of sphingolipid species and the levels of total cerebrosides (CBS), ceramides (Cer), and sulfatides (ST) were significantly different in both the hippocampus and the cortex between the three groups; moreover, there were significantly lower ST levels and higher Cer and CBS levels in these regions in the SAMP8 mice. In the AD-SCG group, Cer and ST levels were altered only in the hippocampus, in contrast to the AD group. The major molecular species ST (d18:1-C24:1) and Cer (d18:1/18:0) were especially different between those of the two groups. Unexpectedly, sphingolipid profiles, including the nonhydroxylated fatty acid-ST/hydroxylated fatty acid-ST, very long fatty acid-galactocerebroside/long fatty acid-galactocerebroside, nonhydroxylated fatty acid-galactocerebroside/hydroxylated fatty acid-galactocerebroside and galactocerebroside/glucocerebroside ratios, were affected by AD. Thus, the ST and Cer levels and the profiles of sphingolipid species in the AD-SCG group were significantly different compared to those of the AD model group. Therefore, SCG has potential ameliorative effects in AD, and exogenous sphingolipid intake may potentially influence sphingolipid metabolism in vivo.

•DHA/EPA-PL could ameliorate motor deficiency induced by MPTP.•DHA/EPA-PL have clear role in preventing brain MPTP-induced oxidative stress.•The mechanism was probably associated with the inhibition of phosphorylated P38 and JNK in DHA/EPA-PL group mice.The n-3 polyunsaturated fatty acids (PUFAs) are essential for brain and nervous system growth. The phospholipid forms of docosahexaenoic acid and eicosapentaenoic acid (DHA/EPA-PL) produce remarkable benefits regarding brain development and neurological function. This study investigated the effects of different n-3 PUFA formulations on brain oxidative injury induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Administration of MPTP (30 mg/kg, i.p., 7 days) induced movement disorder and altered the oxidant–antioxidant status of the brain by reducing intracellular GSH levels and antioxidant enzyme activities, and increasing intracellular lipid peroxidation. In comparison to fish oil (DHA/EPA-TG) and algae oil (DHA-TG), pretreatment with DHA/EPA-PL was more effective in preventing nerve oxidative stress and attenuating motor abnormalities. The anti-apoptosis effect of DHA/EPA-PL was superior to DHA-TG. Additionally, DHA/EPA-PL distinctly reduced the phosphorylation of p38 and Jun N-terminal kinase (JNK). The results indicate that DHA/EPA-PL could offer an efficient strategy to explore novel functional food for neuroprotection.

In this paper, the preparation, characterization, and ameliorative effect on high-fat high-sucrose diet-induced hyperglycemia, insulin resistance, oxidative stress in mice of novel oxovanadium(IV)/chitosan (OV/CS) nanocomposites were investigated. The nanobiocomposite was produced by chemical reduction by chitosan and L-ascorbic acid using microwave heating, under environment-friendly conditions, using aqueous solutions, and notably, by using both mediators as reducing and stabilizing agents. In addition, OV/CS nanocomposites were characterized by transmission electron microscopy, energy dispersive spectroscopy, particle size, and zeta potential measurements. In vivo experiments were designed to examine whether the OV/CS nanocomposites would provide additional benefits on oxidative stress, hyperglycemia, and insulin resistance in mice with type 2 diabetes. The results rendered insulin resistant by treating with OV/CS nanocomposites alleviate insulin resistance and improve oxidative stress. Such nanocomposite seem to be a valuable therapy to achieve and/or maintain glycemic control and therapeutic agents in the treatment arsenal for insulin resistance and type 2 diabetes.

To investigate the relationship between structure and activity, three glucocerebroside series (CFC-1, CFC-2 and CFC-3), ceramides (CF-Cer) and long-chain bases (CF-LCB) of sea cucumber Cucumaria frondosa (C. frondosa) were isolated and evaluated in HepG2 cells. The molecular species of CFC-1, CFC-2 and CFC-3 and CF-Cer were identified using reversed-phase liquid chromatography with heated electrospray ionization coupled to high-resolution mass spectrometry (RPLC-HESI-HRMS), and determined on the basis of chemical and spectroscopic evidence: For the three glucocerebroside series, fatty acids (FA) were mainly saturated (18:0 and 22:0), monounsaturated (22:1, 23:1 and 24:1) and 2-hydroxyl FA (2-HFA) (23:1 h and 24:1 h), the structure of long-chain bases (LCB) were dihydroxy (d17:1, d18:1 and d18:2) and trihydroxy (t16:0 and t17:0), and the glycosylation was glucose; For CF-Cer, FA were primarily saturated (17:0) and monounsaturated (16:1 and 19:1), the structure of LCB were dihydroxy (d17:1 and d18:1), and trihydroxy (t16:0). The results of cell experiment indicated that all of three glucocerebroside series, CF-Cer and CF-LCB exhibited an inhibitory effects on cell proliferation. Moreover, CFC-3 was most effective in three glucocerebrosides to HepG-2 cell viability. The inhibition effect of CF-LCB was the strongest, and the inhibition effect of CF-Cer was much stronger than glucocerebrosides.

The objective of this study is to investigate the levels, inter-species-specific, locational differences and seasonal variations of vanadium in sea cucumbers and to validate further several potential factors controlling the distribution of metals in sea cucumbers. Vanadium levels were evaluated in samples of edible sea cucumbers and were demonstrated exhibit differences in different seasons, species and sampling sites. High vanadium concentrations were measured in the sea cucumbers, and all of the vanadium detected was in an organic form. Mean vanadium concentrations were considerably higher in the blood (sea cucumber) than in the other studied tissues. The highest concentration of vanadium (2.56 μg g−1), as well as a higher degree of organic vanadium (85.5 %), was observed in the Holothuria scabra samples compared with all other samples. Vanadium levels in Apostichopus japonicus from Bohai Bay and Yellow Sea have marked seasonal variations. Average values of 1.09 μg g−1 of total vanadium and 0.79 μg g−1 of organic vanadium were obtained in various species of sea cucumbers. Significant positive correlations between vanadium in the seawater and Vorg in the sea cucumber (r = 81.67 %, p = 0.00), as well as between vanadium in the sediment and Vorg in the sea cucumber (r = 77.98 %, p = 0.00), were observed. Vanadium concentrations depend on the seasons (salinity, temperature), species, sampling sites and seawater environment (seawater, sediment). Given the adverse toxicological effects of inorganic vanadium and positive roles in controlling the development of diabetes in humans, a regular monitoring programme of vanadium content in edible sea cucumbers can be recommended.

•The paper demonstrated the identification of sia 2-6 hexose by ESI-MS/MS.•The cleavage pathway of sulfated sialic acid was proposed.•The retention versus ceramide carbon numbers were fitted to exponential equations.Sea urchin gangliosides have been proved to contain neuritogenic activities, which related to their molecular compositions. This study reports a method utilizing reversed-phase chromatography coupled to mass spectrometry for structure investigation and molecular species determination of the monosialogangliosides from sea urchin Strongylocentrotus nudus. Two types of sulfated and nonsulfated monosialogangliosides were isolated from the sea urchin ovary. In MS2 spectra of both nonsulfated monosialoganglioside and sulfated monosialoganglioside, 2-6 linked sialic acids were identified by the characteristic fragments of 0,4A2-CO2 and 0,2A1. Fragment ions at m/z 139.1 and m/z 169.1 of nonsulfated monosialoganglioside might be characteristic for 8-sulfated sialic acid residue. Retention time of the molecules was effectively used in the characterization of unknown molecules, and molecules that differ in mass by only 0.04 Da were easily differentiated.

There is mounting evidence demonstrating causative links between hyperglycemia, oxidative stress, and insulin resistance, the core pathophysiological features of type 2 diabetes mellitus. Using a combinational approach, we synthesized a vanadium–antioxidant (i.e., l-ascorbic acid) complex and examined its effect on insulin resistance and oxidative stress. This study was designed to examine whether vanadyl(IV)-ascorbate complex (VOAsc) would reduce oxidative stress, hyperglycemia, and insulin resistance in high-fat high-sucrose diet (HFSD)-induced type 2 diabetes in mice. Male C57BL/6J mice were fed a HFSD for 12 weeks to induce insulin resistance, rendering them diabetic. Diabetic mice were treated with rosiglitazone, sodium l-ascorbate, or VOAsc. At the end of treatment, fasting blood glucose, fasting serum insulin, homeostasis model assessment-insulin resistance index, and serum adipocytokine levels were measured. Serum levels of nitric oxide (NO) parameters were also determined. The liver was isolated and used for determination of malondialdehyde, reduced glutathione, and catalase levels, and superoxide dismutase and glutathione peroxidase activities. VOAsc groups exhibited significant reductions in serum adipocytokine and NO levels, and oxidative stress parameters compared to the corresponding values in the untreated diabetic mice. The results indicated that VOAsc is non-toxic. In conclusion, we identified VOAsc as a potentially effective adjunct therapy for the management of type 2 diabetes.

Usually, the chemical structures of cerebrosides in sea creatures are more complicated than those from terrestrial plants and animals. Very little is known about the method for high-throughput molecular profiling of cerebrosides in sea cucumbers. In this study, cerebrosides from four species of edible sea cucumbers, specifically, Apostichopus japonicas, Thelenota ananas, Acaudina molpadioides and Bohadschia marmorata, were rapidly identified using reversed-phase liquid chromatography–quadrupole-time-of-flight mass spectrometry (RPLC-QToF-MS). [M + H]+ in positive electrospray ionization (ESI) mode were used to obtain the product ion spectra. The cerebroside molecules were selected according to the neutral loss fragments of 180 Da and then identified according to pairs of specific products of long-chain bases (LCB) and their precursor ions. A typical predominant LCB was 2-amino-1,3-dihydroxy-4-heptadecene (d17:1), which was acylated to form saturated and monounsaturated non-hydroxy and monohydroxy fatty acids with 17–25 carbon atoms. Simultaneously, the occurrence of 2-hydroxy-tricosenoic acid (C23:1h) was characteristic of sea cucumber cerebrosides, whereas this molecule was rarely discovered in plants, mammals, or fungi. The profiles of LCB and fatty acids (FA) distribution might be related to the genera of sea cucumber. These data will be useful for identification of cerebrosides using RPLC-QToF-MS.

The distribution of α 2–3 and α 2–6 linked sialoglycoproteins in edible bird’s nest (EBN) was analyzed by Maackia amurensis agglutinin (MAA) and Sambucus nigra agglutinin (SNA) lectin blotting. Q Sepharose Fast Flow, Superdex 75 and Sephadex G-25 columns were combined to enrich sialoglycoproteins from EBN extraction. For purification and identification of α 2–3 linked sialoglycoprotein and α 2–6 linked sialoglycoprotein, MAA-Sepharose-4B, SNA-Sepharose-4B lectin affinity chromatography and matrix-assisted laser desorption–ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) tandem mass spectrometry (MS) were employed successively. The contents of protein, carbohydrate and sialic acid of EBN extraction were 65.43, 20.97 and 10.47 %, respectively; EBN extraction contained high-abundance glycoproteins with the molecular weights of 128 kDa (19.1 %), 106 kDa (18.5 %) and 43 kDa (29.4 %); the 43 kDa glycoproteins contained terminal α 2–3 and α 2–6 sialic acid linkage were successively enriched by three chromatography columns; α 2–3 linked sialoglycoprotein and α 2–6 linked sialoglycoprotein were further purified by affinity chromatography eluted with 0.3 and 0.5 M lactose, respectively. In addition, MALDI-TOF/TOF MS analysis showed that α 2–3 linked sialoglycoprotein was an acidic mammalian chitinase-like protein, and α 2–6 linked sialoglycoprotein was an acidic mammalian chitinase. This method is proved to be a simple and effective approach to purify sialoglycoproteins from high-abundance glycoproteins in EBN.

•Dietary EPA-PL was superior to DHA-PL on reducing atherosclerosis via distinct pathway.•EPA-PL significantly reduced serum cholesterol level, while DHA-PL was ineffective.•DHA-PL was superior to EPA-PL in suppressing arotic inflammatory.Dietary fish oil could prevent and treat atherosclerosis by improving lipid metabolism; in apolipoprotein E-deficient (apoE−/−) mice, it was ineffective at lowering serum lipid levels but still showed anti-atherosclerosis action. To date, no direct evidence has comparatively evaluated the effect of docosahexaenoic acid-enriched and eicosapentaenoic acid-enriched phospholipids (DHA-PL and EPA-PL) on atherosclerosis in apoE−/− mice. The present study suggested that both 1% dietary DHA-PL and EPA-PL could significantly reduce atherosclerotic lesions (37.4% and 53.4%, respectively) in high fat diet apoE−/− mice. EPA-PL significantly decreased serum and hepatic lipid levels, by mediating mRNA and protein levels of genes related to hepatic cholesterol metabolism, whereas DHA-PL was ineffective. In the suppression of aortic proinflammatory cytokines, DHA-PL was superior to EPA-PL at reducing TNF-α, IL-6, and IL-1β transcription. In conclusion, the action of DHA-PL was simply anti-inflammatory, and that of EPA-PL was mainly the improvement of lipid metabolism in the amelioration of atherosclerosis.

•Lipases TLIM was more effective than phospholipases and other lipases for esterification of GPC and n−3 PUFA.•Optimal conditions were a temperature of 45 °C, a mole ratio of 1:20 (GPC to n−3 PUFA) under vacuum for 64 h.•The 1-acyl-sn-glycero-3-lysophosphatidylcholine (2-LPC) was predominant in the reaction.The n−3 polyunsaturated fatty acids (PUFA)-rich lysophosphatidylcholine (LPC) was successfully synthesized by Thermomyces lanuginosus lipase (TL IM)-catalyzed esterification of glycerylphosphorylcholine (GPC) and n−3 PUFA-rich fatty acids in a solvent-free system. Effects of reaction temperature, enzyme loading and substrate mole ratio on the yield of LPC and incorporation of n−3 PUFA were evaluated. The acyl-specificities of five enzymes were tested for direct esterification of n−3 PUFA, and Lipozyme TL IM was found to be more effective than others for production of LPC with n−3 PUFA. Substrate mole ratio and reaction temperature, however, had no significant effect on the incorporation. The maximal yield of LPC was obtained under the following conditions: temperature 45 °C, enzyme loading 15% by weight and substrate mole ratio (GPC/n−3 PUFA) 1:20. Furthermore, the composition of products were further investigated in the study. The 1-acyl-sn-glycero-3-lysophosphatidylcholine (2-LPC) was predominant in the mixtures at early stages of reaction, whereas less increment of 2-acyl-sn-glycero-3-lysophosphatidylcholine (1-LPC) and PC was observed at later stages.