Amino acids, fatty acids and sterols profile of some marine organisms from Portuguese waters

Toxicological effects of cobalt on common carp: oxidative stress, ionic imbalance, fatty acid disruption, and gill histopathology

Cobalt (Co) is an essential element to fish and other organisms that become toxic at high concentrations. This element is emerging as a concerning pollutant in water bodies, potentially endangering the health of marine biota. The aim of this study was to investigate the short-term subcellular toxicity of cobalt in the common carp Cyprinus carpio (0, 1.13, 11.34, 22.68 and 45.37 µg/L of Co2+ for 72 h), with emphasis on oxidative balance (enzymatic and non-enzymatic antioxidants), fatty acid composition, Na+K+/Mg2+ATPases activities and histopathological changes. Co exposure increased the levels of the ferric reducing antioxidant power, hydrogen peroxide, malondialdehyde and protein carbonyl along with enzymatic and non-enzymatic antioxidant-related markers. The observed prooxidant-antioxidant imbalance in exposed fish was solidified by histological sections confirming alterations in the histomorphological structure of C. carpio gills. Results showed that increases in Co2+ exposure of fish altered the ATPases activities revealing changes in osmoregulation. Additionally, the analysis of fatty acids (FA) underscored shifts in the fish's fatty acid profile, which is indicative of Co2+ impact on C. carpio overall metabolism and immune response. Significant changes occurred in some major FA which were associated with lipid peroxidation increase and the inhibition of Na+K+ and Mg2+ ATPases activities. Overall, the current results suggest that the mechanism of Co2+ toxicity involves oxidative damage, disruption of ionic balance, cellular homeostasis and the normal physiological function of the fish gills.

Unusual polyunsaturated fatty acids in edible marine worms identified by covalent adduct chemical ionization mass spectrometry

Non-traditional seafood, such as spoon worms (Urechis unicinctus) and peanut worms (Sipunculus nudus), serves as both delicacies and potential solutions to the global food insecurity crisis. Despite being consumed primarily in parts of China, Korea, and Japan, the nutritional values especially the complex fatty acid compositions of these marine worms are difficult to characterize. To overcome this obstacle, we employed covalent adduct chemical ionization (CACI) tandem mass spectrometry for the de novo identification of their unusual polyunsaturated fatty acids (PUFA). Through this method, we identified several PUFA with polymethylene-interrupted (PMI) double bond configurations, including 22:3(7Z,13Z,16Z), a novel PUFA derived from sciadonic acid. U. unicinctus exhibits an exceptionally low n-6/n-3 PUFA ratio of 0.15, making it a potential functional food to counterbalance the n-6/n-3 imbalance in modern diets. S. nudus boasts notably high concentrations (∼3 %, wt/wt) of branched chain fatty acids (BCFA), exceeding typical levels found in dairy products.

Review on retention of long-chain omega-3 polyunsaturated fatty acids (EPA and DHA) in fish as affected by cooking methods

Fatty acids are essential building blocks for the structural components of the cells, tissues, organs, and certain biologically active substances synthesis. Omega-3 polyunsaturated fatty acids are long-chain fatty acids essential for several biological functions including oxidative stress reduction and cardiovascular safety. Diet rich in omega-3 fatty acids is well acknowledged as beneficial to one's health and well-being. For the development of balanced diets, the nutrient content of raw and cooked foods is crucial. However, cooking method, animal age, and carcass characteristics might affect nutrient retention during cooking, and these factors are often unique to specific countries. This review thus provides a general overview of several cooking effects on long-chain omega-3 retention in fish. It can be concluded that the DHA and EPA's true retention values are correlated to the impact of different cooking treatments.

Quality assessment of yellowtail (Seriola quinqueradiata) meat cultured in an offshore floating flexible facility

Commercial aquaculture of yellowtail (Seriola quinqueradiata) is challenging, owing to deterioration of aquaculture environments. Offshore aquaculture may be a means of overcoming these problems. Here, we assessed the quality of flesh from offshore yellowtail (OY) bred for 1 year in an offshore floating flexible facility compared with coastal yellowtail (CY) cultured simultaneously in a coastal cage facility. The survival rate of the OY group was 94.46%, which was slightly lower than that of CY (98.18%). The feeding rate (feeding weight/fish weight) of CY was 0.4-0.5, whereas that of OY was only 0.3, possibly because poor weather conditions prevented feeding at the offshore facility. However, final fish weights did not differ significantly between both groups. In sensory tests, OY was inferior to CY in terms of oily taste. The lipid content in CY was significantly higher than that in OY. Hardness analysis revealed that OY muscles were harder than those of CY. There were no significant differences between OY and CY in overall sensory evaluations; thus, OY was judged as having equivalent value as a food product with CY. The redness of dark muscles was not significantly different on day 1 of refrigeration. However, the redness value of OY was significantly higher than that of CY on day 2. The inferior fattiness of OY relative to that of CY can be overcome by improving the feeding method. Therefore, offshore aquaculture with negligible environmental pollution may be effective for further development of aquaculture.

Extraction, structural characterization, and antioxidant and immunomodulatory activities of a polysaccharide from Notarchus leachii freeri eggs

The crude polysaccharides (NLCEP) were extracted from Notarchus leachii freeri eggs strings by the saltextractionmethod. The extraction conditions were optimized using the single-factorexperimentmethod and response surface method (RSM). The results showed that the maximum extraction yield of NLCEP was obtained under the following conditions: NaCl solution concentration of 2.96 %, raw material to liquid ratio of 1: 40 g/mL, extraction time of 2 h and extraction temperature of 69 °C. A new novel pure polysaccharide fraction named as NLCEPs-1 was fractionated from NLCEP by using DEAE-Cellulose 52 and Sephadex G-100. Its structure and immunomodulatory and antioxidant activities were analyzed. The results exhibited that the molecular weight of NLCEPs-1 was 31.4 kDa and it was composed of rhamnose, glucose, galactose, xylose and arabinose in the molar percentage of 11.128: 63.770: 5.439: 6.585: 13.077. The backbone of NLCEPs-1 was mainly consisted of → )4-α-d-Glcp (1→, →6)-α-d-Glcp (1→, →1)-β-d-Galp and β-d-Galp-(1→. NLCEPs-1 exhibited the strong antioxidant activity in scavenging ability of various free radicals and immunomodulatory activity by the enhancement of the pinocytic capacity, nitric oxide (NO) and cytokines.

Comparative metabolomic analysis of the body wall from four varieties of the sea cucumber Apostichopus japonicus

The sea cucumber, Apostichopus japonicas, is an important economic species with high nutritive value. In recent years, driven by significant market demand, the sea cucumber breeding industry has developed rapidly. Body color and number of papillae are important factors that determine the value and price of sea cucumbers. In this study, metabolite profiling of four sea cucumber varieties (green, white, purple and spiny) was performed using ultra-performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry (UPLC-QTOF-MS) combined with multivariate analysis. Orthogonal partial least-squares discriminant analysis (OPLS-DA) clearly discriminated the body wall metabolites of four sea cucumber varieties. Differential metabolites included fatty acids, phospholipids, and sugars. KEGG metabolic pathway analysis revealed that carbohydrate, protein, and phospholipid metabolism were highly conserved among the varieties. These results provide a comprehensive insight into differences in the metabolite profile of four A. japonicus varieties and a deeper understanding of sea cucumber varieties breeding.

Recent Advances in Marine-Based Nutraceuticals and Their Health Benefits

The oceans have been the Earth's most valuable source of food. They have now also become a valuable and versatile source of bioactive compounds. The significance of marine organisms as a natural source of new substances that may contribute to the food sector and the overall health of humans are expanding. This review is an update on the recent studies of functional seafood compounds (chitin and chitosan, pigments from algae, fish lipids and omega-3 fatty acids, essential amino acids and bioactive proteins/peptides, polysaccharides, phenolic compounds, and minerals) focusing on their potential use as nutraceuticals and health benefits.

The chemical composition and lipid profile of the chub mackerel (Scomber colias) show a strong seasonal dependence: Contribution to a nutritional evaluation

The seasonal variation in chemical and lipid composition of chub mackerel (Scomber colias) was evaluated monthly over one year (proximate chemical composition and lipid profile: fatty acid (FA) and lipid classes distribution). Significant seasonal changes regarding fat content were noticed (1.3-10.3 g/100 g), with the lowest fat content obtained in February (during spawning period), and the highest in September. Regarding the FA profile, the main fluctuations were recorded in saturated (SFA) and polyunsaturated fatty acids (PUFA). The highest SFA content was registered between March and August (25.3-32.3%). PUFA (the most abundant group) reached its maximum percentual content between December and February (60.9 and 66.9%, respectively). In absolute terms, PUFA attained 5352.6 mg/100 g edible part in September, where 2473.8 mg/100 g of docosahexaenoic acid (DHA, C22:6n-3), representing 46.2% of total PUFA. DHA lowest level was 519.8 mg/100 g, registered in low-fat chub mackerel. Together DHA and EPA (eicosapentaenoic acid, C20:5n-3) represented 75% of the total PUFA and 84% of n-3 PUFA. Triacylglycerols (TAG) with 82.2-92.1% of total lipid content) and phospholipids (4.4-8.4%) were the main lipid classes. Polar lipid fraction (phospholipids), was predominantly constituted by PUFA (68.6-74.5%), mainly DHA (45.2-55.1%), with the highest percentage recorded in low-fat chub mackerel. High relative contents of PUFA (36.6-49.1%) were also found in TAG. Having into account the data obtained, chub mackerel is a privileged source of DHA even in a lean species whereby its consumption should be recommended as part a healthy dietary regime.

Evaluation of Long Sea Snail Hinia reticulata (Gastropod) from the Middle Adriatic Sea as a Possible Alternative for Human Consumption

In mid Adriatic Sea the common sea snail is the habitual snail eaten, but over the years fishermen started to capture also the long sea snail, a possible alternative for human consumption. This study aims to compare the quality traits of the edible fraction in the common and long sea snails. In this study, common and long sea snail samples were provided by fishermen in November 2018 and March 2019. Total weight (meat and shell), fractions of meat and shell (after having extracted the edible part), fatty acid, elements in meat, and calcium content in shells were determined. Meat quality traits showed high nutritional value without significant differences between the two species. The fatty acid profile showed n3/n6 ratio significantly different both considering the season of sampling (November: 4.1; March: 2.38) and the species of sea snail (common: 4.98; long: 2.86). The long species showed a higher yield in the total body and calcium content concentrations. However, the long sea snail showed 50% lower meat yield compared with the common sea snail. In conclusion, the long sea snail can be used as an alternative to the common sea snail for human consumption.

Fatty acid composition analyses of commercially important fish species from the Pearl River Estuary, China

Evaluation of fish nutritional content information could provide essential guidance for seafood consumption and human health protection. This study investigated the lipid contents, fatty acid compositions, and nutritional qualities of 22 commercially important marine fish species from the Pearl River Estuary (PRE), South China Sea. All the analyzed species had a low to moderate lipid content (0.51-7.35% fat), with no significant differences in fatty acid profiles among fishes from different lipid categories (p > 0.05). Compared with previous studies from other regions, the examined fish species exhibited higher proportions of saturated fatty acids (SFAs, 39.1 ± 4.00%) and lower contents of polyunsaturated fatty acids (PUFAs, 21.6 ± 5.44%), presumably due to the shifted diet influence from increased diatoms and decreased dinoflagellate over the past decades in the PRE. This study further revealed that there was a significantly negative correlation between the trophic levels and levels of PUFAs in the examined species (Pearson's r = -0.42, p = 0.04), likely associated with their differed dietary composition. Considering the health benefit of PUFAs, a few marine fish in PRE with low levels of PUFAs might have no significant contribution to the cardiovascular disease prevention, although fish with different fatty acid profiles most likely contribute differently towards human health. Additional studies are needed in order to comprehensively analyze the nutritional status of fish species in the PRE.

In vitro anti-proliferative activities of the sterols and fatty acids isolated from the Persian Gulf sponge; Axinella sinoxea

PURPOSE

Marine sponges are rich sources of anticancer metabolites. Axinella sinoxea is a less studied sponge, found in the Larak Island's waters, of the Persian Gulf. In the present study, we have explored the cytotoxic properties and chemical constituents of A. sinoxea.

METHODS

Repeated silica gel flash column chromatography of methanol extract of the Axinella sinoxea sponge, yielded fatty acid and sterol fractions. These fractions were analyzed by GC-MS and their anti-proliferative activities were evaluated by MTT assay against three human cancer cell lines including MOLT-4, MCF-7 and HT-29 as well as NIH/3 T3 fibroblast cells. The sterol-rich fractions were pooled and purified by HPLC and its sub fractions' cytotoxic activities were evaluated by MTT assay against MOLT-4 and NIH/3 T3 cells.

RESULTS

The GC-MS spectral analysis of a fraction eluted with hexane: diethyl ether (90: 10), resulted in the identification of twelve fatty acids, including five linear chain saturated fatty acids; tetrdecanoic acid (1), pentadecanoic acid (3), hexadecanoic acid (5), heptadecanoic acid (7), and octadecanoic acid (10); one branched chain isoprenoid fatty acid, 4,8,12-trimethyltridecanoic acid (2); four monoenoic fatty acids; 9-hexadecenoic acid (4), 7-methyl-6-hexadecanoic acid (6), 9-octadecenoic acid (8) and 11-octadecenoic acid (9) and two polyunsaturated fatty acids; 5,8,11,14-eicosatetraenoic acid (11) and 4,7,10,13,16,19-docosahexaenoic acid (12). Spectral analysis of a non-polar fraction eluted with hexane: diethyl ether (85: 15), resulted in the identification of eight steroids including: cholesta-5,22-dien-3β-ol (13), cholest-5-en-3β-ol (14), ergosta-5,22-dien-3β-ol (15), ergost-5-en-3β-ol (16), stigmasta-5,22-dien-3β-ol (17), γ-sitosterol (18), 33-norgorgosta-5,24(28)-dien-3β-ol (19) and stigmasta-5,24(28)-dien-3β-ol (20). Fatty acids-containing fraction was active against HT-29 cell line with IC₅₀ 26.52 ± 8.19 μg/mL, while the steroids-rich fraction was active against the three above mentioned cell lines with IC₅₀ values of 1.20 ± 0.24, 4.12 ± 0.40 and 2.47 ± 0.31 μg/mL, respectively. All of the above-mentioned fractions and sub-fractions were inactive (IC₅₀s > 50 μg/mL) when assayed against normal fibroblast cells.

CONCLUSION

The present study suggests A. sinoxea as a potential natural source of cancer chemotherapeutics. Graphical abstract Cytotxic constituents of Axinella sinoxea.

Effect of oil spill stress on fatty acid stable carbon isotope composition of Ulva pertusa

Petroleum is one of the most important pollutants in the marine ecosystem, and oil spills have a long-term effect on the marine environment. After an oil spill, petroleum continues to diffuse, flowing to the intertidal zone where it accumulates. Ulva pertusa is the main macroalgae species in the intertidal zone of the ocean, and petroleum is toxic to marine macroalgae. Fatty acids, which are involved in various physiological activities, including metabolism, are indispensable substances in organisms. Thus, an organism's fatty acid composition reflects its physiological state. Because fatty acids are carbon-rich compounds, their stable carbon isotope composition can be measured to assess the state of the organism. In this study, the effects of the water accommodated fraction (WAF) of different concentrations of 180# fuel oil and 0# diesel oil on the chlorophyll a and fatty acid carbon stable isotope composition (δ¹³C_FAs) of U. pertusa were assessed. The fatty acid carbon stable isotope value varied among the different petroleum treatments, and high WAF concentrations significantly inhibited the synthesis of unsaturated fatty acids. Thus, exposure to petroleum products affected the synthesis of fatty acids in U. pertusa and also caused carbon stable isotope fractionation during the fatty acid synthesis process. The results indicate that the saturated fatty acid δ¹³C_16:0 and the unsaturated fatty acid δ¹³C_18:1 can be used as biomarkers to evaluate the degree of petroleum-induced stress in U. pertusa and that carbon stable isotope analysis of U. pertusa can be used as an environmental risk assessment tool in the intertidal zone.

Trace elements in wild edible Aplysia species: Relationship with the desaturation-elongation indexes of fatty acids

The profile of essential and non-essential elements was traced in the edible sea hares Aplysia depilans Gmelin, Aplysia fasciata Poiret and Aplysia punctata Cuvier. Manganese (Mn), iron (Fe), zinc (Zn), copper (Cu) and selenium (Se) were identified as the major essential elements. Risk assessment evidenced that the levels of cadmium (Cd) and lead (Pb) did not exceed the maximum limit value established by the European Regulation, the contents of chromium (Cr), nickel (Ni) and arsenic (As) being also below the levels established by the FDA guide. A correlation between trace elements levels and desaturation-elongation indexes of fatty acids was found. While Cd, Se and molybdenum (Mo) seem to promote the desaturation-elongation process involved on the production of C20:4n-6c, Ni, Cr and Fe may potentiate the conversion of C18:3n-3c to C20:5n-3c. Furthermore, cobalt (Co), Ni and Cu appear to decrease Δ9 desaturation index. Besides the suggested biosynthetic switch modulated by trace elements, the nutritional value of the species is further strengthened.

The changes in chemical composition of Holothuria tubulosa (Gmelin, 1788) with ambient-drying and oven-drying methods

In this study, the nutritional properties of fresh (F), boiled (B), ambient-dried (Holothuria tubulosa) (DA, 23 ± 2°C) and oven-dried sea cucumber (DO, 45 ± 1°C) were compared in terms of proximate composition and fatty acid profiles. The results of the proximate analyses showed that the highest moisture content (86.76%) was determined in fresh samples, whereas the lowest moisture content (9.35%) was obtained in the oven-dried group (DO). The crude fat and protein contents were in the range of 0.19% (B) to 0.87% (DA) and 12.30% (F) to 62.13% (DA), respectively. The highest ash content (30.30%) was obtained in group DO, while the lowest ash content (0.61%) was observed in the boiled samples (B). According to fatty acid analyses, there were no significant differences (p > 0.05) between the two drying methods. The monounsaturated fatty acid (MUFA) (21.405%) and polyunsaturated fatty acid (PUFA) (36.018%) contents of H. tubulosa were high. Holothuria tubulosa can be used as protein and PUFA sources. Comparing the two methods, oven-drying is better in terms of preservation, whereas drying at the ambient temperature is better in terms of nutrient value.

Fatty acid profile of the sea snail Gibbula umbilicalis as a biomarker for coastal metal pollution

Metals are among the most common environmental pollutants with natural or anthropogenic origin that can be easily transferred through the food chain. Marine gastropods are known to accumulate high concentrations of these metals in their tissues. Gibbula umbilicalis ecological importance and abundant soft tissues, which enables extent biochemical assessments, makes this particular organism a potentially suitable species for marine ecotoxicological studies. Fatty acids are carbon-rich compounds that are ubiquitous in all organisms and easy to metabolize. Their biological specificity, relatively well-studied functions and importance, and the fact that they may alter when stress is induced, make fatty acids prospect biomarkers. This work aimed to assess fatty acid profile changes in the gastropod G. umbilicalis exposed to three metal contaminants. After a 168h exposure to cadmium, mercury, and nickel, the following lipid related endpoints were measured: total lipid content; lipid peroxidation; and fatty acid profile (FAP). The analysis of the FAP suggested an alteration in the fatty acid metabolism and indicated a link between metals exposure and homeoviscous adaptation and immune response. In particular, five fatty acids (palmitic, eicosatrienoic, arachidonic, eicosapentaenoic, and docosahexaenoic acids), demonstrated to be especially good indicators of G. umbilicalis responses to the array of metals used, having thus the potential to be used as biomarkers for metal contamination in this species. This work represents a first approach for the use of FAP signature as a sensitive and informative parameter and novel tool in environmental risk assessment (ERA) of coastal environments, using G. umbilicalis as model species.

Influence of seasonal and environmental patterns on the lipid content and fatty acid profiles in gonads of the edible sea urchin Paracentrotus lividus from Sardinia

The influence of seasonal and environmental patterns on the lipid fraction of Paracentrotus lividus gonads was investigated. For this purpose, sea urchins were collected monthly over a year from two Sardinian coastal areas. Total lipids in gonads follow an annual cyclical trend, described by a sine wave curve, that it is more influenced by season than by growing area. The lowest lipid content in gonads corresponds to a high percentage of mature reproductive stages (i.e. winter season), independently of sampling area. A variation in total lipid content follows a change in photoperiod, while it is related to sea surface temperature. Multivariate analysis on fatty acid profiles of gonads, detected by gas chromatography, clusters the collected specimens mainly according to the sampling area, secondly according to the sites within the same sampling area and finally according to season.

Digestive Gland from Aplysia depilans Gmelin: Leads for Inflammation Treatment

The exploitation of marine organisms for human nutritional and pharmaceutical purposes has revealed important chemical prototypes for the discovery of new drugs, stimulating compounds isolation and syntheses of new related compounds with biomedical application. Nowadays, it is well known that inflammatory processes are involved in many diseases and the interest in the search for marine natural products with anti-inflammatory potential has been increasing. The genus Aplysia belongs to the class Gastropoda, having a wide geographical distribution and including several species, commonly known as sea hares. Aplysia depilans Gmelin is usually found in the Mediterranean Sea and in the Atlantic Ocean, from West Africa to the French coast. In these marine organisms, most of the digestion and nutrient absorption occurs in the digestive gland. This work aimed to explore the chemical composition and bioactivity of the methanol extract from A. depilans digestive gland. Therefore, fatty acids and carotenoids were determined by GC-MS and HPLC-DAD, respectively. Twenty-two fatty acids and eight carotenoids were identified for the first time in this species. The A. depilans digestive gland revealed to be essentially composed by polyunsaturated fatty acids (PUFA) and xanthophylls. Regarding the anti-inflammatory potential in RAW 264.7 cells stimulated with lipopolysaccharide, it was observed that this matrix has capacity to reduce nitric oxide (NO) and L-citrulline levels, which suggests that its compounds may act by interference with inducible nitric oxide synthase. Taking into account the results obtained, A. depilans digestive gland may be a good source of nutraceuticals, due to their richness in health beneficial nutrients, such as carotenoids and long-chain PUFA.

Quantitative analysis of 17 amino acids in tobacco leaves using an amino acid analyzer and chemometric resolution

A method was developed for quantifying 17 amino acids in tobacco leaves by using an A300 amino acid analyzer and chemometric resolution. In the method, amino acids were eluted by the buffer solution on an ion-exchange column. After reacting with ninhydrin, the derivatives of amino acids were detected by ultraviolet detection. Most amino acids are separated by the elution program. However, five peaks of the derivatives are still overlapping. A non-negative immune algorithm was employed to extract the profiles of the derivatives from the overlapping signals, and then peak areas were adopted for quantitative analysis of the amino acids. The method was validated by the determination of amino acids in tobacco leaves. The relative standard deviations (n = 5) are all less than 2.54% and the recoveries of the spiked samples are in a range of 94.62-108.21%. The feasibility of the method was proved by analyzing the 17 amino acids in 30 tobacco leaf samples.

Fatty acids from edible sea hares: anti-inflammatory capacity in LPS-stimulated RAW 264.7 cells involves iNOS modulation

The inclusion of marine organisms in the diet is gaining importance due to their richness in health beneficial nutrients.

Bioactive compounds derived from echinoderms

This is the first review paper devoted exclusively to natural compounds isolated from echinoderms with special emphasis on bioactive compounds.