High-Resolution Lipidomics of the Early Life Stages of the Red Seaweed Porphyra dioica.

Porphyra dioica is a commercial seaweed consumed all over the world, mostly in the shape of nori sheets used for "sushi" preparation. It is a well-known part of the Asian diet with health benefits, which have been associated, among others, to the high levels of n-3 and n-6 fatty acids in this red alga. However, other highly valued lipids of Porphyra are polar lipids that remain largely undescribed and can have both nutritional value and bioactivity, thus could contribute to the valorization of this seaweed. In this context, the present work aims to identify the lipidome of two life cycle stages of the Atlantic species Porphyra dioica: the early life stage conchocelis produced in an indoor-nursery, and young blades produced outdoors using an integrated multitrophic aquaculture (IMTA) framework. Both the blades (gametophyte) and conchocelis (sporophyte) are commercialized in the food and cosmetics sectors. Liquid chromatography coupled to Q-Exactive high resolution-mass spectrometry (MS) platform was used to gain insight into the lipidome of these species. Our results allowed the identification of 110 and 100 lipid molecular species in the lipidome of the blade and conchocelis, respectively. These lipid molecular species were distributed as follows (blade/conchocelis): 14/15 glycolipids (GLs), 93/79 phospholipids (PLs), and 3/6 betaine lipids. Both life stages displayed a similar profile of GLs and comprised 20:4(n-6) and 20:5(n-3) fatty acids that contribute to n-3 and n-6 fatty acid pool recorded and rank among the molecular species with higher potential bioactivity. PLs' profile was different between the two life stages surveyed, mainly due to the number and relative abundance of molecular species. This finding suggests that differences between both life stages were more likely related with shifts in the lipids of extraplastidial membranes rather than in plastidial membranes. PLs contained n-6 and n-3 precursors and in both life stages of Porphyra dioica the n-6/n-3 ratio recorded was less than 2, highlighting the potential benefits of using these life stages in human diet to prevent chronic diseases. Atherogenic and thrombogenic indexes of blades (0.85 and 0.49, respectively) and conchocelis (0.34 and 0.30, respectively) are much lower than those reported for other Rhodophyta, which highlights their potential application as food or as functional ingredients. Overall, MS-based platforms represent a powerful tool to characterize lipid metabolism and target lipids along different life stages of algal species displaying complex life cycles (such as Porphyra dioica), contributing to their biotechnological application.

Valorization of Lipids from Gracilaria sp. through Lipidomics and Decoding of Antiproliferative and Anti-Inflammatory Activity.

The lipidome of the red seaweed Gracilaria sp., cultivated on land-based integrated multitrophic aquaculture (IMTA) system, was assessed for the first time using hydrophilic interaction liquid chromatography-mass spectrometry and tandem mass spectrometry (HILIC-MS and MS/MS). One hundred and forty-seven molecular species were identified in the lipidome of the Gracilaria genus and distributed between the glycolipids classes monogalactosyl diacylglyceride (MGDG), digalactosyl diacylglyceride (DGDG), sulfoquinovosyl monoacylglyceride (SQMG), sulfoquinovosyl diacylglyceride (SQDG), the phospholipids phosphatidylcholine (PC), lyso-PC, phosphatidylglycerol (PG), lyso-PG, phosphatidylinositol (PI), phosphatidylethanolamine (PE), phosphatic acid (PA), inositolphosphoceramide (IPC), and betaine lipids monoacylglyceryl- and diacylglyceryl-N,N,N-trimethyl homoserine (MGTS and DGTS). Antiproliferative and anti-inflammatory effects promoted by lipid extract of Gracilaria sp. were evaluated by monitoring cell viability in human cancer lines and by using murine macrophages, respectively. The lipid extract decreased cell viability of human T-47D breast cancer cells and of 5637 human bladder cancer cells (estimated half-maximal inhibitory concentration (IC50) of 12.2 µg/mL and 12.9 µg/mL, respectively) and inhibited the production of nitric oxide (NO) evoked by the Toll-like receptor 4 agonist lipopolysaccharide (LPS) on the macrophage cell line RAW 264.7 (35% inhibition at a concentration of 100 µg/mL). These findings contribute to increase the ranking in the value-chain of Gracilaria sp. biomass cultivated under controlled conditions on IMTA systems.

Lipophilic Fraction of Cultivated Bifurcaria bifurcata R. Ross: Detailed Composition and In Vitro Prospection of Current Challenging Bioactive Properties.

Macroalgae have been seen as an alternative source of molecules with promising bioactivities to use in the prevention and treatment of current lifestyle diseases. In this vein, the lipophilic fraction of short-term (three weeks) cultivated Bifurcaria bifurcata was characterized in detail by gas chromatography-mass spectrometry (GC-MS). B. bifurcata dichloromethane extract was composed mainly by diterpenes (1892.78 ± 133.97 mg kg-1 dry weight (DW)), followed by fatty acids, both saturated (550.35 ± 15.67 mg kg-1 DW) and unsaturated (397.06 ± 18.44 mg kg-1 DW). Considerable amounts of sterols, namely fucosterol (317.68 ± 26.11 mg kg-1 DW) were also found. In vitro tests demonstrated that the B. bifurcata lipophilic extract show antioxidant, anti-inflammatory and antibacterial activities (against both Gram-positive and Gram-negative bacteria), using low extract concentrations (in the order of µg mL-1). Enhancement of antibiotic activity of drug families of major clinical importance was observed by the use of B. bifurcata extract. This enhancement of antibiotic activity depends on the microbial strain and on the antibiotic. This work represents the first detailed phytochemical study of the lipophilic extract of B. bifurcata and is, therefore, an important contribution for the valorization of B. bifurcata macroalgae, with promising applications in functional foods, nutraceutical, cosmetic and biomedical fields.

Effect of Dietary Laminaria digitata with Carbohydrases on Broiler Production Performance and Meat Quality, Lipid Profile, and Mineral Composition.

We hypothesized that dietary inclusion of 15% Laminaria digitata, supplemented or not with carbohydrases, could improve the nutritional value of poultry meat without impairing animal growth performance. A total of 120 22-day old broilers were fed the following dietary treatments (n = 10) for 14 days: cereal-based diet (control); control diet with 15% L. digitata (LA); LA diet with 0.005% Rovabio® Excel AP (LAR); LA diet with 0.01% alginate lyase (LAE). Final body weight was lower and feed conversion ratio higher with LA diet than with the control. The ileal viscosity increased with LA and LAR diets relative to control but without differences between LAE and control. The pH of thigh meat was higher, and the redness value of breast was lower with LA diet than with control. Meat overall acceptability was positively scored for all treatments. The γ-tocopherol decreased, whereas total chlorophylls and carotenoids increased in meat with alga diets relative to control. The percentage of n-3 polyunsaturated fatty acids (PUFA) and accumulation of bromine and iodine in meat increased with alga diets compared with control. Feeding 15% of L. digitata to broilers impaired growth performance but enhanced meat quality by increasing antioxidant pigments, with beneficial effects on n-3 PUFA and iodine.

Enzyme-Assisted Release of Antioxidant Peptides from Porphyra dioica Conchocelis.

The conchocelis life cycle stage of P. dioica represents an unexplored source of bioactive compounds. The aim of this study was to generate and characterise, for the first time, hydrolysates of conchocelis using a specific combination of proteases (Prolyve® and Flavourzyme®). Hydrolysate molecular mass distribution and free amino acid contents were assessed, and the antioxidant activity was determined using a range of in vitro assays. The protein content and the total amino acid profiles of conchocelis were also studied. Conchocelis contained ~25% of protein (dry weight basis) and had a complete profile of essential amino acids. Direct sequential enzymatic treatment modified the profile of the generated compounds, increasing the amount of low molecular weight peptides (<1 kDa). There was a significant improvement in the antioxidant activity of the hydrolysates compared with the control (up to 2.5-fold), indicating their potential as a novel source of antioxidant ingredients.