Seaweeds as Nutraceutical Elements and Drugs for Diabetes Mellitus: Future Perspectives.

Diabetes mellitus is a chronic metabolic condition marked by high blood glucose levels caused by inadequate insulin synthesis or poor insulin use. This condition affects millions of individuals worldwide and is linked to a variety of consequences, including cardiovascular disease, neuropathy, nephropathy, and retinopathy. Diabetes therapy now focuses on controlling blood glucose levels through lifestyle changes, oral medicines, and insulin injections. However, these therapies have limits and may not successfully prevent or treat diabetic problems. Several marine-derived chemicals have previously demonstrated promising findings as possible antidiabetic medicines in preclinical investigations. Peptides, polyphenols, and polysaccharides extracted from seaweeds, sponges, and other marine species are among them. As a result, marine natural products have the potential to be a rich source of innovative multitargeted medications for diabetes prevention and treatment, as well as associated complications. Future research should focus on the chemical variety of marine creatures as well as the mechanisms of action of marine-derived chemicals in order to find new antidiabetic medicines and maximize their therapeutic potential. Based on preclinical investigations, this review focuses on the next step for seaweed applications as potential multitargeted medicines for diabetes, highlighting the bioactivities of seaweeds in the prevention and treatment of this illness.

Dietary sulfated polysaccharides extracted from Caulerpa sp. and Padina sp. modulated physiological performance, antibacterial activity and ammonia challenge test in juvenile rainbow trout (Oncorhynchus mykiss).

Nowadays, the use of seaweed derivatives in aquaculture has drawn attention for their potential as an immunostimulant and growth promotor. The sulfated polysaccharide extracted (SPE ) from green (Caulerpa sp.; SPC) and brown (Padina sp.; SPP) seaweeds with two concentrations (0.05% and 0.1%); nominated in four groups: SPC0.05 , SPC0.1 , SPP0.05 , SPP0.1 and control group (free of SPE ) were used for juvenile rainbow trout (Oncorhynchus mykiss) diet. Fish (N: 150; 8.5 ± 0.2 g) were selected aleatory distributed in 15 circular tanks (triplicate for the group) and fed test diets for 56 days. The outcomes revealed that the supplementation of SPE up to 1 g kg-1 failed to show significant differences in the organosomatic indices as compared to the control group. The most inferior protein value of dress-out fish composition was observed in the fish fed the control diet, which was statistically lower than the SCP0.1 group (p < 0.05), while no significant difference was observed in other macronutrient composition among the treatments. Total monounsaturated fatty acid (MUFA) had lower trend in the carcass of fish fed SPE supplemented diets, so that lowest MUFA were observed in SPC0.05 group (p < 0.05; 25.22 ± 4.29%). The lowest value of docosahexaenoic acid was observed in the control diet compared to the SPE -supplemented diets (p < 0.05). The serum alternative complement pathway levels in all treatments tend to promote compared to the control treatment. A similar trend was observed for lysozyme activity. According to the results, the superoxide dismutase (SOD) value were highest in SPC0.05 and SPC0.1 compared to the other treatments (p < 0.05), while a further elevation of the SPE Padina sp. extracted level (SPP0.1 ) leads to a decrease in SOD value. Thiobarbituric acid reactive substances of plasma was indicated not to influence by sulfated polysaccharide extracts in the refrigerated storage. The lowest serum stress indicators were observed in fish fed SPP0.05 group postchallenge test. Taken together, our outcomes revealed that SPE of two species of seaweeds bestows benefits in some of the immunity and antioxidant system. Also, notable elevations in HUFA were observed in juvenile rainbow trout fed supplemented with SPE .

Anti-Inflammatory Effects of Bioactive Compounds from Seaweeds, Bryozoans, Jellyfish, Shellfish and Peanut Worms.

Inflammation is a defense mechanism of the body in response to harmful stimuli such as pathogens, damaged cells, toxic compounds or radiation. However, chronic inflammation plays an important role in the pathogenesis of a variety of diseases. Multiple anti-inflammatory drugs are currently available for the treatment of inflammation, but all exhibit less efficacy. This drives the search for new anti-inflammatory compounds focusing on natural resources. Marine organisms produce a broad spectrum of bioactive compounds with anti-inflammatory activities. Several are considered as lead compounds for development into drugs. Anti-inflammatory compounds have been extracted from algae, corals, seaweeds and other marine organisms. We previously reviewed anti-inflammatory compounds, as well as crude extracts isolated from echinoderms such as sea cucumbers, sea urchins and starfish. In the present review, we evaluate the anti-inflammatory effects of compounds from other marine organisms, including macroalgae (seaweeds), marine angiosperms (seagrasses), medusozoa (jellyfish), bryozoans (moss animals), mollusks (shellfish) and peanut worms. We also present a review of the molecular mechanisms of the anti-inflammatory activity of these compounds. Our objective in this review is to provide an overview of the current state of research on anti-inflammatory compounds from marine sources and the prospects for their translation into novel anti-inflammatory drugs.

Marine-Derived Components: Can They Be a Potential Therapeutic Approach to Parkinson's Disease?

The increase in the life expectancy average has led to a growing elderly population, thus leading to a prevalence of neurodegenerative disorders, such as Parkinson's disease (PD). PD is the second most common neurodegenerative disorder and is characterized by a progressive degeneration of the dopaminergic neurons in the substantia nigra pars compacta (SNpc). The marine environment has proven to be a source of unique and diverse chemical structures with great therapeutic potential to be used in the treatment of several pathologies, including neurodegenerative impairments. This review is focused on compounds isolated from marine organisms with neuroprotective activities on in vitro and in vivo models based on their chemical structures, taxonomy, neuroprotective effects, and their possible mechanism of action in PD. About 60 compounds isolated from marine bacteria, fungi, mollusk, sea cucumber, seaweed, soft coral, sponge, and starfish with neuroprotective potential on PD therapy are reported. Peptides, alkaloids, quinones, terpenes, polysaccharides, polyphenols, lipids, pigments, and mycotoxins were isolated from those marine organisms. They can act in several PD hallmarks, reducing oxidative stress, preventing mitochondrial dysfunction, α-synuclein aggregation, and blocking inflammatory pathways through the inhibition translocation of NF-kB factor, reduction of human tumor necrosis factor α (TNF-α), and interleukin-6 (IL-6). This review gathers the marine natural products that have shown pharmacological activities acting on targets belonging to different intracellular signaling pathways related to PD development, which should be considered for future pre-clinical studies.

Evaluation of the antioxidant potential of brown seaweeds extracted by different solvents and characterization of their phenolic compounds by LC-ESI-QTOF-MS/MS.

Seaweeds, serving as valuable natural sources of phenolic compounds (PCs), offer various health benefits like antioxidant, anti-inflammatory properties, and potential anticancer effects. The efficient extraction of PCs from seaweed is essential to harness their further applications. This study compares the effectiveness of different solvents (ethanol, methanol, water, acetone, and ethyl acetate) for extracting PCs from four seaweed species: Ascophyllum sp., Fucus sp., Ecklonia sp., and Sargassum sp. Among them, the ethanol extract of Sargassum sp. had the highest content of total phenolics (25.33 ± 1.45 mg GAE/g) and demonstrated potent scavenging activity against the 2,2-diphenyl-1-picrylhydrazyl radical (33.65 ± 0.03 mg TE/g) and phosphomolybdate reduction (52.98 ± 0.47 mg TE/g). Ecklonia sp. had the highest content of total flavonoids (0.40 ± 0.02 mg QE/g) in its methanol extract, whereas its ethyl acetate extract contained the highest content of total condensed tannins (8.09 ± 0.12 mg CE/g). Fucus sp. demonstrated relatively strong antioxidant activity, with methanolic extracts exhibiting a scavenging ability against 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (54.41 ± 0.24 mg TE/g) and water extracts showing ferric-reducing antioxidant power of 36.24 ± 0.06 mg TE/g. Likewise, liquid chromatography-mass spectrometry identified 61 individual PCs, including 17 phenolic acids, 32 flavonoids, and 12 other polyphenols. Ecklonia sp., particularly in the ethanol extract, exhibited the most diverse composition. These findings underscore the importance of selecting appropriate solvents based on the specific seaweed species and desired compounds, further providing valuable guidance in the pharmaceutical, nutraceutical, and cosmetic industries. PRACTICAL APPLICATION: The PCs, which are secondary metabolites present in terrestrial plants and marine organisms, have garnered considerable attention due to their potential health advantages and diverse biological effects. Using various organic/inorganic solvents during the extraction process makes it possible to selectively isolate different types of PCs from seaweed species. The distinct polarity and solubility properties of each solvent enable the extraction of specific compounds, facilitating a comprehensive assessment of the phenolic composition found in the seaweed samples and guiding industrial production.

Fucoxanthin, a marine derived carotenoid, attenuates surgery-induced cognitive impairments via activating Akt and ERK pathways in aged mice.

BACKGROUND: Fucoxanthin is the most abundant marine carotenoid derived from brown seaweeds, possesses antioxidant, anti-inflammatory, and neuroprotective properties, and might be benefit for the treatment of neurological disorders. Post-operative cognitive dysfunction (POCD) is a neurological symptom with learning and memory impairments, mainly affecting the elderly after surgery. However, there is no effective treatments for this symptom. PURPOSES: In this study, we evaluated the neuroprotective effects of fucoxanthin against POCD in aged mice after surgery. STUDY DESIGN AND METHODS: The animal model of POCD was established in 12 - 14 month aged mice with a laparotomy. Curcumin was used as a positive control. The beneficial effects of fucoxanthin on POCD was analyzed by behavioral tests. Pro-inflammatory cytokines were measured by Enzyme-linked Immunosorbent Assay (ELISA). And the expressions of key proteins in the Akt and ERK signaling pathways were analyzed by Western blotting analysis. The morphology of microglial cells and astrocytes was explored by immunohistochemical staining. The activity of antioxidant superoxide dismutase (SOD) and catalase (CAT) were measured by anti-oxidative enzyme activity assays. RESULTS: Fucoxanthin at 100 - 200 mg/kg significantly attenuated cognitive dysfunction, with a similar potency as curcumin, in aged mice after surgery. In addition, fucoxanthin and curcumin significantly increased the expression of pAkt, prevented the activation of microglial cells and astrocytes, and inhibited the secretion of pro-inflammatory interleukin-1ß (IL - 1ß) and tumor necrosis factor-α (TNF-α). Furthermore, fucoxanthin and curcumin elevated the ERK pathway and potently increased the activity of antioxidant enzymes. Most importantly, U0126, an inhibitor of the ERK pathway, and wortmannin, an inhibitor of the Akt pathway, significantly abolished the cognitive-enhancing effects, as well as the inhibition of neuroinflammation and the reduction of oxidative stress, induced by fucoxanthin in aged mice after surgery. CONCLUSION: Fucoxanthin might be developed as a functional food or drug for the treatment of POCD by inhibiting neuroinflammation and enhancing antioxidant capacity via the activation of the Akt and ERK signaling pathways.

Nutrient Composition, Physicobiochemical Analyses, Oxidative Stability and Antinutritional Assessment of Abundant Tropical Seaweeds from the Arabian Sea.

Foods enriched with nutritional compounds and biological activities, especially antioxidants, are considered healthier for human and/or animal consumption. Seaweeds are rich sources of biologically active metabolites and are used as functional foods. In this study, proximate compositions, physicobiochemical characteristics and oil oxidative stability were analyzed for 15 abundant tropical seaweeds (four green-Acrosiphonia orientalis, Caulerpa scalpelliformis, Ulva fasciata, Ulva lactuca; six brown-Iyengaria stellata, Lobophora variegate, Padina boergesenii, Sargassum linearifolium, Spatoglossum asperum, Stoechospermum marginatum; and five red-Amphiroa anceps, Grateloupia indica, Halymenia porphyriformis, Scinaia carnosa, Solieria chordalis). All seaweeds were analyzed for the proximate composition, including moisture content, ash content, total sugar content, total proteins, total lipids, crude fiber, carotenoid content, total chlorophyll content, proline, iodine content, nitrogen-free extract, total phenolic content and total flavonoid content. Green seaweeds showed higher nutritional proximate composition, followed by brown and red seaweeds. Among the different seaweeds, Ulva, Caulerpa, Sargassum, Spatoglossum and Amphiroa showed high nutritional proximate composition compared to other seaweeds. High cation scavenging, free radical scavenging and total reducing activities were observed for Acrosiphonia, Caulerpa, Ulva, Sargassum, Spatoglossum and Iyengaria. It was also observed that 15 tropical seaweeds contained negligible amounts of antinutritional compounds, including tannic acid, phytic acid, saponins, alkaloids and terpenoids. Nutritionally, green and brown seaweeds provided higher sources of energy (150-300 calories per 100 g) compared to red seaweeds (80-165 calories per 100 g). Additionally, this study also confirmed that tropical seaweeds improved the oxidative stability of food oils and, therefore, might be recommended as natural antioxidant additives. The overall results confirm that tropical seaweeds are potential sources of nutrition and antioxidants and may be explored as functional food, dietary supplementation or animal feed. Additionally, they may also be explored as food supplements for fortifying food products, as food toppings or for garnishing and seasoning foods. However, a human or animal toxicity analysis is required before any conclusive recommendation for daily food or feed intake can be made.

An Overview on Antimicrobial Potential of Edible Terrestrial Plants and Marine Macroalgae Rhodophyta and Chlorophyta Extracts.

Antibiotics are used to prevent and treat bacterial infections. After a prolonged use of antibiotics, it may happen that bacteria adapt to their presence, developing antibiotic resistance and bringing up health complications. Nowadays, antibiotic resistance is one of the biggest threats to global health and food security; therefore, scientists have been searching for new classes of antibiotic compounds which naturally express antimicrobial activity. In recent decades, research has been focused on the extraction of plant compounds to treat microbial infections. Plants are potential sources of biological compounds that express several biological functions beneficial for our organism, including antimicrobial activity. The high variety of compounds of natural origin makes it possible to have a great bioavailability of antibacterial molecules to prevent different infections. The antimicrobial activity of marine plants, also called seaweeds or macroalgae, for both Gram-positive and Gram-negative, and several other strains infective for humans, has been proven. The present review presents research focused on the extraction of antimicrobial compounds from red and green macroalgae (domain Eukarya, kingdom Plantae). Nevertheless, further research is needed to verify the action of macroalgae compounds against bacteria in vitro and in vivo, to be involved in the production of safe and novel antibiotics.

Applications of Antioxidant Secondary Metabolites of Sargassum spp.

Sargassum is one of the largest and most diverse genus of brown seaweeds, comprising of around 400 taxonomically accepted species. Many species of this genus have long been a part of human culture with applications as food, feed, and remedies in folk medicine. Apart from their high nutritional value, these seaweeds are also a well-known reservoir of natural antioxidant compounds of great interest, including polyphenols, carotenoids, meroterpenoids, phytosterols, and several others. Such compounds provide a valuable contribution to innovation that can translate, for instance, into the development of new ingredients for preventing product deterioration, particularly in food products, cosmetics or biostimulants to boost crops production and tolerance to abiotic stress. This manuscript revises the chemical composition of Sargassum seaweeds, highlighting their antioxidant secondary metabolites, their mechanism of action, and multiple applications in fields, including agriculture, food, and health.

Algal nutraceuticals: A perspective on metabolic diversity, current food applications, and prospects in the field of metabolomics.

The current consumers' demand for food naturalness is urging the search for new functional foods of natural origin with enhanced health-promoting properties. In this sense, algae constitute an underexplored biological source of nutraceuticals that can be used to fortify food products. Both marine macroalgae (or seaweeds) and microalgae exhibit a myriad of chemical constituents with associated features as a result of their primary and secondary metabolism. Thus, primary metabolites, especially polysaccharides and phycobiliproteins, present interesting properties to improve the rheological and nutritional properties of food matrices, whereas secondary metabolites, such as polyphenols and xanthophylls, may provide interesting bioactivities, including antioxidant or cytotoxic effects. Due to the interest in algae as a source of nutraceuticals by the food and related industries, novel strategies should be undertaken to add value to their derived functional components. As a result, metabolomics is considered a high throughput technology to get insight into the full metabolic profile of biological samples, and it opens a wide perspective in the study of algae metabolism, whose knowledge is still little explored. This review focuses on algae metabolism and its applications in the food industry, paying attention to the promising metabolomic approaches to be developed aiming at the functional characterization of these organisms.

Anti-Dengue Activity of ZnO Nanoparticles of Crude Fucoidan from Brown Seaweed S.marginatum.

Dengue fever is a rapidly spreading infection that affects people all over the tropics and subtropics, posing a significant public health threat. The brown seaweed Stoechospermum marginatum was found all over the world, from South Africa (Indian Ocean) to Australia (Pacific Ocean), among other places. In India, it is only available along the coast of the Bay of Bengal, which is a small region. Various metal oxides were proved to be successful in the formation of nanoparticles and zinc is one among them. In this present study, an attempt was made to study the anti-dengue activity of green synthesized zinc oxide nanoparticles of crude fucoidan isolated from brown seaweed S. marginatum. The fucoidan was isolated from the seaweed by acid extraction method and then characterized by UV, HPLC, and Fourier Transform Infra-Red (FT-IR) Spectroscopy. Then it was biosynthesized into ZnO nanoparticles and characterized by SEM-EDAX analysis. The results showed the formation of fucoidans and SEM studies showed the crystalline nature of the synthesized nanoparticles. The size of nanoparticles was in the range of 80-126 nm. The synthesized nanoparticles were tested with the C6/36 cell line and it was shown 99.09% of anti-dengue activity against the tested cell line. As an antiviral agent, the ZnO nanoparticles of fucoidans have been shown to be an excellent lead molecule for the treatment of dengue fever.

Variation in Anti-inflammatory, Anti-arthritic, and Antimicrobial Activities of Different Extracts of Common Egyptian Seaweeds with an Emphasis on Their Phytochemical and Heavy Metal Contents.

The anti-inflammatory, anti-arthritic, and antimicrobial activities of some common Egyptian seaweeds in addition to their phytochemical and heavy metal contents were investigated. Phytochemical screening of the seaweed extracts showed the presence of different primary and secondary metabolites with different concentrations according to their species and the used solvent. The ethanolic extract of Colpmenia sinuosa (CSBE2) exhibited the maximum anti-inflammatory and anti-arthritic activity at 1000 µg/ml concentration compared to other seaweed extracts. The dichloromethane extract of Corallina officinalis (CORM) exerted the highest antimicrobial activity with an average inhibition zone diameter (AV) = 15.29 mm and activity index (AI) = 1.53 and with the highest antagonistic activity against Escherichia coli (28 mm). It is followed by Ulva linza ethanolic extract (ULGE2) which recorded (AV) of 14.71 mm and (AI) of 1.30 with the highest antifungal activity against Candida albicans (30 mm). The collected seaweeds would therefore be a very promising source for treating inflammatory, arthritic, and microbial diseases. Moreover, the investigated seaweeds showed variable concentrations of heavy metals among various species. The mean concentrations of the heavy metals took the following order: Fe > Zn > Mn > Ba > Cu > As > Cr > Ni > Pb > V > Cd > Se > Co > Mo. Based on the permissible limits set by the WHO and CEVA, Pb and Ni in the studied seaweeds were found to be within the permissible limits, whereas Cd and Zn contents were at the borderline. Significant correlations were observed between studied parameters. The estimated daily intakes for most heavy metals were lower than the recommended daily intakes.

Halimeda gracilis (Kadarpassi chooranam) Phytochemical analysis and biological significance - a novel Siddha drug.

OBJECTIVES: To evaluate biological activity and the phytochemical analysis of kadarpassi chooranam. Seaweeds are the marine macro algae, species belonging to Protista kingdom that has no true system, internal vascular systems, seeds and flowers. It has a lot of biological activity and has been proven to have a lot of medicinal benefits. Since time immemorial, their usage in traditional medicine has been recognized. METHODS: Halimeda gracilis has been standardized as per siddha pharmacopoeia standard protocol guidelines and prepared kadarpassi Chooranam curtained for Phytochemical analysis (qualitative and quantitative) and carried out various pharmacological activity. RESULTS: The antioxidant, anti-inflammatory, and anti-cancer actions of kadarpassi Chooranam have been associated to alkaloids, phenols, flavonoids, cardiac glycosides, saponins, tannins, and diterpenes. CONCLUSIONS: The Siddha medicine, kadarpassi chooranam has various phytochemical bioactive compounds, and because of its pharmacological activity can be a potential drug candidate for human use.

Antiproliferative and apoptosis-inducing effects of aqueous extracts from Ecklonia maxima and Ulva rigida on HepG2 cells.

This study examined the antiproliferative and apoptotic-inducing effects of Ecklonia maxima (KP) and Ulva rigida (URL) extracts in the human liver cancer (HepG2) cell line model. HepG2 cells were cultured and grown in an incubator (5% CO2 ) at 37°C. Cell viability was determined, while the effect of the extracts on apoptosis, ROS production, mitochondria membrane potential, and antioxidant enzymes were also assessed. KP and URL induced cytotoxic effects on HepG2 cells at the concentrations tested (0-1000 µg/ml). The morphological characteristics of the cells after treatment with KP and URL revealed cell shrinkage of the nucleus, cell injury, and damage compared to the control. The fluorescent micrographs from the apoptotic assay revealed induction of apoptosis and necrosis in HepG2 cells after treatment with KP and URL (200 and 400 µg/ml). The extracts also induced ROS production and reduced mitochondria membrane potential in HepG2 cells. The apoptotic-inducing effects, activation of ROS generation, and disruption of antioxidant enzymes are associated with the cytotoxic effects of the seaweed extracts. KP and URL showed good anticancer properties and could be explored as a good source of nutraceuticals, food additives, and dietary supplements to prevent uncontrolled proliferation of HepG2 cells. PRACTICAL APPLICATIONS: Seaweeds are reservoirs of nutrients and naturally occurring biologically active compounds, including sterols, phlorotannins, and polyunsaturated fatty acids. Due to the presence of these compounds, they are used as emulsifying agents, nutraceuticals, and additives in functional foods. Evidence suggests that seaweed bioactives may inhibit uncontrolled cell proliferation and induce apoptosis in cancer cells. Hence, exploring the antiproliferative and apoptotic-inducing effects of Ecklonia maxima and Ulva rigida will provide insights into their anticancer potentials as functional foods and nutraceuticals.

Phytochemical and Potential Properties of Seaweeds and Their Recent Applications: A Review.

Since ancient times, seaweeds have been employed as source of highly bioactive secondary metabolites that could act as key medicinal components. Furthermore, research into the biological activity of certain seaweed compounds has progressed significantly, with an emphasis on their composition and application for human and animal nutrition. Seaweeds have many uses: they are consumed as fodder, and have been used in medicines, cosmetics, energy, fertilizers, and industrial agar and alginate biosynthesis. The beneficial effects of seaweed are mostly due to the presence of minerals, vitamins, phenols, polysaccharides, and sterols, as well as several other bioactive compounds. These compounds seem to have antioxidant, anti-inflammatory, anti-cancer, antimicrobial, and anti-diabetic activities. Recent advances and limitations for seaweed bioactive as a nutraceutical in terms of bioavailability are explored in order to better comprehend their therapeutic development. To further understand the mechanism of action of seaweed chemicals, more research is needed as is an investigation into their potential usage in pharmaceutical companies and other applications, with the ultimate objective of developing sustainable and healthier products. The objective of this review is to collect information about the role of seaweeds on nutritional, pharmacological, industrial, and biochemical applications, as well as their impact on human health.

Red and brown seaweeds extracts: A source of biologically active compounds.

The biological activities of Porphyra sp., Gracilaria gracilis, Alaria esculenta and Saccharina latissima extracts prepared by enzymatic and ball milling-assisted methods and hot water were evaluated. Enzyme-assisted methods allowed the highest extraction yields. Alcalase-assisted extraction (EAA) was the most effective in the recovery of polyphenolic compounds and Porphyra sp. had the highest content. The efficiency of flavonoids extraction was highly dependent on the used method. Globally, Porphyra sp. and EAA extracts exhibited the highest antioxidant and chelating activities. The highest α-amylase inhibitory activity was determined in HW Porphyra sp. extract while EAA A. esculenta extract had the highest α-glucosidase inhibitory activity. The highest ACE inhibitory activity was obtained in EAA from S. latissima. None of the extracts showed antimicrobial activity against the tested bacteria. The results showed that Porphyra sp. and S. latissima are potentially useful as ingredient in functional foods and nutraceuticals.

Positional Assignment of C-C Double Bonds in Fatty Acyl Chains of Intact Arsenosugar Phospholipids Occurring in Seaweed Extracts by Epoxidation Reactions.

Water-soluble diacyl arsenosugar phospholipids (As-PL) are natural products widespread in marine animals and algae, including the brown alga Undaria pinnatifida, also known as wakame. The systematic recognition of As-PL has been hampered by the lack of standard and of qualitative methods to establish the carbon-carbon double bond positions of unsaturated fatty acyl chains. Here, the epoxidation reaction of fatty acyl substituents of As-PL was carried out with high selectivity by meta-chloroperoxybenzoic acid and the C-C double bond localization was established by collision-induced dissociation of epoxidized species as deprotonated molecules, [epoM - H]-. Reversed-phase liquid chromatography (RPLC) separation and a sequential triple-stage MS (i.e., MS3) analysis of unsaturated and epoxidized As-PL were very helpful to characterize the carbon-carbon double bond locations of both sn-1 and sn-2 fatty acyl chains, starting from a diagnostic product ion pair with 16.0 Da mass difference. These results indicate that intact As-PL can be annotated in terms of fatty acyl chain composition and in terms of their C-C double bond position(s). Interestingly, hexadecenoic (16:1 Δ9) and octadecenoic (18:1 Δ9) along with octadecadienoic (18:2 Δ9,12) and octadecatrienoic (18:3 Δ9,12,15) were found to be the most abundant unsaturated fatty acyl chains of As-PL in the brown alga wakame, thus confirming it as a good source of essential fatty acids with a balanced ω6/ω3 ratio. Although the toxicity of As-including metabolites of algal As-PL is still a matter of debate and needs to be studied in more detail, the described approach can be exploited to assess if As-PL could contribute to the supply of essential fatty acids related to the use of algae as nutritious food.

Antioxidant effects of seaweeds and their active compounds on animal health and production - a review.

Natural antioxidants applied as feed additives can improve not only animals' health and overall performance but also increase their resistance to environmental stress such as heat stress, bad housing conditions, diseases, etc. Marine organisms, for example seaweeds - red, brown, and green macroalgae contain a plethora of biologically active substances, including phenolic compounds, polysaccharides, pigments, vitamins, micro- and macroelements, and proteins known for their antioxidant activity, which can help in the maintenance of appropriate redox status in animals and show pleiotropic effects for enhancing good health, and productivity. The dysregulated production of free radicals is a marked characteristic of several clinical conditions, and antioxidant machinery plays a pivotal role in scavenging the excessive free radicals, thereby preventing and treating infections in animals. Supplementation of seaweeds to animal diet can boost antioxidant activity, immunity, and the gut environment. Dietary supplementation of seaweeds can also enhance meat quality due to the deposition of marine-derived antioxidant components in muscles. The use of natural antioxidants in the meat industry is a practical approach to minimize or prevent lipid oxidation. However, overconsumption of seaweeds, especially brown macroalgae, should be avoided because of their high iodine content. An important point to consider when including seaweeds in animal feed is their variable composition which depends on the species, habitat, location, harvest time, growing conditions such as nutrient concentration in water, light intensity, temperature, etc. This review highlights the beneficial applications of seaweeds and their extracted compounds, which have antioxidant properties as feed additives and impact animal health and production.

Therapeutic Potential and Nutraceutical Profiling of North Bornean Seaweeds: A Review.

Malaysia has a long coastline surrounded by various islands, including North Borneo, that provide a suitable environment for the growth of diverse species of seaweeds. Some of the important North Bornean seaweed species are Kappaphycus alvarezii, Eucheuma denticulatum, Halymenia durvillaei (Rhodophyta), Caulerpa lentillifera, Caulerpa racemosa (Chlorophyta), Dictyota dichotoma and Sargassum polycystum (Ochrophyta). This review aims to highlight the therapeutic potential of North Bornean seaweeds and their nutraceutical profiling. North Bornean seaweeds have demonstrated anti-inflammatory, antioxidant, antimicrobial, anticancer, cardiovascular protective, neuroprotective, renal protective and hepatic protective potentials. The protective roles of the seaweeds might be due to the presence of a wide variety of nutraceuticals, including phthalic anhydride, 3,4-ethylenedioxythiophene, 2-pentylthiophene, furoic acid (K. alvarezii), eicosapentaenoic acid, palmitoleic acid, fucoxanthin, ß-carotene (E. denticulatum), eucalyptol, oleic acid, dodecanal, pentadecane (H. durvillaei), canthaxanthin, oleic acid, pentadecanoic acid, eicosane (C. lentillifera), pseudoephedrine, palmitic acid, monocaprin (C. racemosa), dictyohydroperoxide, squalene, fucosterol, saringosterol (D. dichotoma), and lutein, neophytadiene, cholest-4-en-3-one and cis-vaccenic acid (S. polycystum). Extensive studies on the seaweed isolates are highly recommended to understand their bioactivity and mechanisms of action, while highlighting their commercialization potential.

Dietary red macroalgae (Halopithys incurva) improved systemic an mucosal immune and antioxidant parameters and modulated related gene expression in zebrafish (Danio rerio).

In the present study, the effects of dietary Halopithys incurva, a red macroalgae species, (0.25, 0.50, 1%) on whole-body serum and skin mucus immune system, antioxidant system and expression of various genes in zebrafish were investigated. At the end of the 8-week study, total protein, total immunoglobulin and lysozyme activities in whole-body serum and skin mucus increased in fish fed H. incurva (P < 0.05). While an increase was observed in superoxide dismutase (SOD), Catalase (CAT) and glutathione peroxidase (GPx) which are antioxidant enzyme activities in whole-body serum and skin mucus, a decrease in malondialdehyde (MDA) levels was detected (P < 0.05). All of the immune-related genes examined, such as Interleukin-1 beta (IL-1ß), Tumor necrosis factor-alpha (TNF-α), Interferon-gamma (INF- γ), were upregulated by the addition of 0.5% H. incurva (P < 0.05). While SOD and GPx, which are antioxidant enzyme-related genes, were remarkably upregulated in macroalgae fed fish (P < 0.05), no change was observed in CAT gene expression (P > 0.05). Based on the results of this study, it is considered that the addition of 0.5% H. incurva to the diets of commercially farmed fish will increase their immune and antioxidant defences and may contribute to the aquaculture sector for more sustainability.