Bioactive Polysaccharides from Seaweeds

The roles of algal polysaccharides in modulating tumor immune microenvironment

BACKGROUND

Polysaccharides from algae provide a range of biology and health benefits. Lately, there has been a significant interest in how algal polysaccharides affect the immune microenvironment around tumors.

PURPOSE

To elucidate the subtle interactions between algal polysaccharides and the tumor immune microenvironment to further understand the medicinal potential of algal polysaccharides.

STUDY DESIGN

To give a summary of the sources, bioactivities and characteristics of the tumor immune microenvironment of algal polysaccharides, and to analyze alteration of the immunological milieu surrounding tumors by algal polysaccharides and their potential as immunomodulators of chemotherapeutic agents.

METHODS

Search popular academic search engines using selected keywords for articles ending before September 2024 using selected keywords Google Scholar, PubMed, ScienceDirect, Scopus, Web of Science, Springer, and official websites.

RESULTS

Algal polysaccharides can fight tumors by changing how immune cells work and affecting inflammation in different ways. Moreover, algal polysaccharides have shown promise in mitigating the adverse effects associated with conventional cancer treatments, such as chemotherapy. Algal polysaccharides, through their immunomodulatory effects, can alleviate some of these side effects, leading to an enhanced overall treatment outcome.

CONCLUSION

As research continues to uncover the underlying mechanisms of their antitumor effects, algal polysaccharides are poised to become a vital component in the development of novel cancer treatments, providing new hope for patients and advancing the field of oncology.

Astaxanthin in cancer therapy and prevention (Review)

Astaxanthin (AXT), a carotenoid primarily derived from marine organisms such as shrimp, krill and the microalga Haematococcus pluvialis, has gained significant attention for its potent antioxidant, anti-inflammatory and anti-proliferative properties. The present comprehensive review explored the role of AXT in cancer prevention and treatment, emphasizing its cytotoxic mechanisms and modulation of key molecular pathways involved in cancer progression. AXT has demonstrated efficacy across a variety of cancer types, including nervous system, breast and gastrointestinal cancers, through its ability to induce apoptosis, inhibit metastasis and disrupt cell growth. The present review detailed both in vitro and in vivo studies highlighting the effectiveness of AXT in sensitizing cancer cells to chemotherapy, thereby enhancing therapeutic outcomes and potentially reducing treatment-related side effects. The incorporation of AXT in nanoparticle-based delivery systems has further improved its bioavailability and targeted action, showcasing its potential in advanced cancer therapies. However, despite promising experimental results, more comprehensive in vivo studies and clinical trials are necessary to validate the efficacy and safety of AXT in human populations. Such research would help standardize dosing, confirm interactions with conventional treatments and support the integration of AXT into clinical oncology as a natural, complementary approach to existing cancer treatments.

Recent advances in recovering bioactive compounds from macroalgae and microalgae using subcritical water extraction: Prospective compounds and biological activities

Algae, widely as a valuable marine biomass, are appreciated globally for their unique chemical compositions and exceptional nutritional benefits. Scientists are increasingly focusing on valorizing algae biomass to recover polysaccharides and bioactive extracts. Conventional methods commonly used to extract bioactive compounds have several limitations. Subcritical water extraction (SWE) is a green extraction technology for extracting bioactive compounds from natural products. SWE has garnered significant attention attributed to its use of safe solvent (water), high extraction efficiency, economical, promising application potential and environmental friendliness. The factors influencing the extraction of bioactive compounds using SWE, including temperature, pressure, extraction time, particle size, and solid-to-solvent ratio, were thoroughly discussed. Furthermore, these bioactive compounds exhibit antioxidant, antimicrobial, antihypertensive, anticancer, and antidiabetic properties. The bioactive compounds from the hydrolysates were not purified, but future research could address this for potential applications. This study provides valuable reference points for both academia and industrial-scale commercialization.

Advancing sustainable agriculture: the potential of seaweed-derived bio pesticides from marine biomass

The exploitation of marine biomass, particularly seaweeds, presents significant opportunities for sustainable biopesticide production. Seaweeds, or macroalgae are diverse photosynthetic organisms found in marine environments, rich in bioactive compounds such as terpenoids, polyphenols, and sulphated polysaccharides. These compounds exhibit potent pesticide properties, offering environmentally friendly alternatives to conventional chemical pesticides. The biopesticides derived from seaweeds are biodegradable, exhibit low toxicity to non-target organisms, and align with the principles of environmental sustainability. The growing demand for organic and sustainable agricultural products further underscores the economic potential of seaweed-based biopesticides. However, challenges such as scalability of production, extraction efficiency, and standardization of bioactivity must be addressed to realize this potential fully. Advances in biorefinery approaches, extraction technologies, and formulation techniques are critical to overcoming these challenges. Additionally, ongoing research into the synergistic effects of different seaweed compounds and the development of innovative delivery systems will enhance the efficacy and commercial viability of seaweed-derived biopesticides. This review highlights the promising role of seaweeds in biopesticide production, emphasizing the need for continued research and interdisciplinary collaboration to integrate these natural compounds into sustainable agricultural practices.

The biotechnological and economic potential of macroalgae in the Baltic Sea

MAIN CONCLUSION

Baltic Sea macroalgae exhibit unique bioactive compounds and diverse applications, supporting sustainable industries in food, cosmetics, and medicine while promoting environmental restoration. Common in the Baltic Sea, macroalgae hold great biotechnological and commercial promise in various industries, such as food, cosmetics, and medicines. The present study investigates the various uses of the Baltic macroalgae, emphasizing their nutritional worth, which encompasses vital amino acids, vitamins, and minerals, as well as their suitability as natural gelling agents, food additives, and dietary supplements. Additionally, these macroalgae's bioactive chemicals show promise as therapeutic agents due to their antiviral and anticancer capabilities, making them essential assets for the pharmaceutical and medical sectors. A lot of research has been done on macroalgae, but not much on Baltic species. With an emphasis on their unique qualities and possible benefits to environmental preservation and sustainability, this paper attempts to present a thorough review of the uses of the Baltic macroalgae.

Seaweed in the Diet as a Source of Bioactive Metabolites and a Potential Natural Immunity Booster: A Comprehensive Review

Seaweed plays an essential role in the survival of marine life, provides habitats and helps in nutrient recycling. It is rich in valuable nutritious compounds such as pigments, proteins, polysaccharides, minerals, vitamins, omega-rich oils, secondary metabolites, fibers and sterols. Pigments like fucoxanthin and astaxanthin and polysaccharides like laminarin, fucoidan, galactan and ulvan possess immune-modulatory and immune-enhancing properties. Moreover, they show antioxidative, antidiabetic, anticancer, anti-inflammatory, antiproliferative, anti-obesity, antimicrobial, anticoagulation and anti-aging properties and can prevent diseases such as Alzheimer's and Parkinson's and cardiovascular diseases. Though seaweed is frequently consumed by Eastern Asian countries like China, Japan, and Korea and has gained the attention of Western countries in recent years due to its nutritional properties, its consumption on a global scale is very limited because of a lack of awareness. Thus, to incorporate seaweed into the global diet and to make it familiar as a functional food, issues such as large-scale cultivation, processing, consumer acceptance and the development of seaweed-based food products need to be addressed. This review is intended to give a brief overview of the present status of seaweed, its nutritional value and its bioactive metabolites as functional foods for human health and diseases owing to its immunity-boosting potential. Further, seaweed as a source of sustainable food and its prospects along with its issues are discussed in this review.

A Comprehensive, Analytical Narrative Review of Polysaccharides from the Red Seaweed Gracilaria: Pharmaceutical Applications and Mechanistic Insights for Human Health

Gracilaria species, a widely distributed genus of red macroalgae, have gathered significant attention for their diverse medical applications attributable to their bioactive sulphated polysaccharides (SPs). This review examines the global narrative of various Gracilaria SP applications in terms of their therapeutic potential and mechanistic insights into the use of these SPs against a range of medical conditions, including cancer, inflammation, neurodegenerative disorders, diabetes, and immune dysfunctions. SPs extracted from G. lemaneiformis and G. fisheri have demonstrated potent anti-tumour activities by inducing apoptosis through various mechanisms, including the upregulation of CD8+ T cells and IL-2, inhibition of EGFR/MAPK/ERK signalling pathways, and activation of the Fas/FasL pathway. Selenium nanoparticles (SeNPs) conjugated with SPs further enhanced the targeted delivery and efficacy of these SPs against glioblastoma by the downregulation of ROS followed by the activation of p53, MAPK, and AKT pathways. The anti-inflammatory properties of SPs are evidenced by key suppressive inflammatory markers like NO, TNF-α, IL-1β, and IL-6 in mutant rodent models. SPs from G. cornea and G. birdiae effectively reduce neutrophil migration and vascular permeability, offering potential treatments for acute inflammation and conditions such as colitis by modulating pathways involving COX-2 and NF-κB. Neuroprotective effects by SPs (from G. cornea and G. gracili) studied in 6-OHDA-induced rats, which mitigate oxidative stress and enhance neuronal cell viability, facilitate the management of neurodegenerative diseases like Parkinson's and Alzheimer's. Regarding the hypoglycaemic effect, SPs from G. lemaneiformis exhibit a glucose-modulating response by improving insulin regulation, inhibiting α-amylase activity, repairing pancreatic β-cells, and modulating lipid metabolism. Moreover, immunomodulatory activities of Gracilaria-derived SPs include the stimulation of macrophages, T-cell proliferation, and cytokine production, underscoring their potential as functional food and immunotherapeutic agents. Recently, Gracilaria-derived SPs have been found to modulate gut microbiota, promote SCFA production, and enhance gut microbials, suggesting their potential as prebiotic agents (G. rubra and G. lemaneiformis). This review highlights the multifaceted medical applications of Gracilaria sulphated polysaccharides, providing detailed mechanistic insights and suggesting avenues for future clinical translation and therapeutic innovations.

Sustainable and biocompatible hybrid materials-based sulfated polysaccharides for biomedical applications: a review

Sustainable biomaterials that are both efficient and environmentally friendly are the subject of research and development efforts among scientists and academics from a variety of contemporary scientific disciplines. Due to their significant involvement in several physiological and pathological processes, sulfated polysaccharides (SPs) have garnered growing interest across various application domains, including biomedicine. Nevertheless, mechanical and thermal stability are issues for unmodified polysaccharide materials. Interactions between polymers, such as the mixing of biopolymers with synthetic or biopolymers through chemical interaction or grafting into the main chain structure of raw materials to enhance their therapeutic effects, are essential to meet the high standards of biomedical features. Another way to improve the mechanical and thermal properties is to graft appropriate fillers onto the polysaccharide backbone. The characteristics of polysaccharide bio-nanocomposites in comparison to more traditional polymers have attracted a lot of interest. With an emphasis on anti-inflammatory, anticancer, antiviral, immunoregulatory, and anticoagulant properties, this review delves into the most recent biological uses of sulfated polysaccharides. As well as thoroughly outlining the factors that impact the biological properties, such as the extraction process, molecular weight (Mw), the degree of sulfation, distribution/position, modification procedures, and the filler size, etc., this review aims to: (1) provide a systematic and critical overview of the cutting-edge research on SPs and hybrid sulfated polysaccharide bio-nanocomposites; (2) identify the key factors, mechanisms, methods, and challenges impacting SPs bio-nanocomposites; (3) elucidate the current and potential biomedical applications, advantages, manufacturing challenges, and opportunities associated with SPs bio-nanocomposites; (4) offer insights into future research directions by suggesting improvements for bio-nanocomposites, including novel materials, and advanced processing techniques.

Exploring the Antineoplastic Properties of the Lebanese Jania rubens Against Colorectal Cancer

BACKGROUND/OBJECTIVE

Colon cancer poses a significant health burden, with current treatments often associated with severe side effects and limited effectiveness for some patients. Natural products are gaining interest as adjuvant therapies, potentially reducing side effects and improving responses to conventional treatments. We previously highlighted the potent antineoplastic effects of organic extracts derived from the Lebanese red algae Jania rubens. This study, investigated the anticancer activities of polysaccharide, protein, and lipid extracts from J. rubens, which may serve as adjuvant therapies to enhance conventional treatments.

METHODS

we employed colorimetric assays, wound healing assays, and cell cycle analysis to evaluate the anticancer activities of the extracts. The polysaccharide extract was characterized for sulfate content and structure using barium chloride-gelatin and FT-IR methods.

RESULTS

All J. rubens extracts exhibited significant anticancer effects, with the polysaccharide extract showing particularly strong cytotoxicity, apoptosis induction, and antiproliferative and anti-migratory activities.

CONCLUSION

These findings confirm that J. rubens is a source of bioactive compounds with anticancer potential. Further investigations are needed to elucidate the molecular pathways targeted by J. rubens extracts in cancer cells.

Unlocking the Therapeutic Potential of Algae-Derived Compounds in Hematological Malignancies

Algae are a rich source of bioactive compounds that have a wide range of beneficial effects on human health and can show significant potential in the treatment of hematological malignancies such as leukemia, lymphoma, and multiple myeloma. These diseases often pose a therapeutic challenge despite recent advances in treatment (e.g., the use of immunomodulatory drugs, proteasome inhibitors, CD38 monoclonal antibodies, stem cell transplant, and targeted therapy). A considerable number of patients experience relapses or resistance to the applied therapies. Algal compounds, alone or in combination with chemotherapy or other more advanced therapies, have exhibited antitumor and immunomodulatory effects in preclinical studies that may improve disease outcomes. These include the ability to induce apoptosis, inhibit tumor growth, and improve immune responses. However, most of these studies are conducted in vitro, often without in vivo validation or clinical trials. This paper summarizes the current evidence on the in vitro effects of algae extracts and isolated compounds on leukemia, lymphoma, and myeloma cell lines. In addition, we address the current advances in the application of algae-derived compounds as targeted drug carriers and their synergistic potential against hematologic malignancies.

Phlorofucofuroeckol-A: A Natural Compound with Potential to Attenuate Inflammatory Diseases Caused by Airborne Fine Dust

Background and Objectives: Persistent exposure to airborne fine dust (FD) particles contributing to air pollution has been linked to various human health issues, including respiratory inflammation, allergies, and skin diseases. We aimed to identify potential seaweed anti-inflammatory bioactive reagents and determine their effects on systemic inflammatory responses induced by FD particles. Materials and Methods: While exploring anti-inflammatory bioactive reagents, we purified compounds with potential anti-inflammatory effects from the seaweed extracts of Ecklonia cava, Ecklonia stolonifera, and Codium fragile. Structural analyses of the purified compounds siphonaxanthin (Sx), fucoxanthin (Fx), dieckol (Dk), and phlorofucofuroeckol-A (PFF-A) were performed using NMR and LC-MS/MS. Results: Notably, these compounds, especially PFF-A, showed significant protective effects against FD-induced inflammatory responses in RAW 264.7 cells without cytotoxicity. Further investigation of inflammatory-associated signaling demonstrated that PFF-A inhibited IL-1β expression by modulating the NF-κB/MAPK signal pathway in FD-induced RAW 264.7 cells. Additionally, gene profiling revealed the early activation of various signature genes involved in the production of inflammatory cytokines and chemokines using gene profiling. Treatment with PFF-A markedly reduced the expression levels of pro-inflammatory and apoptosis-related genes and even elevated the Bmp gene families. Conclusions: These results suggested that PFF-A is a potential natural therapeutic candidate for managing FD-induced inflammatory response.

A Comparative Review of Alternative Fucoidan Extraction Techniques from Seaweed

Fucoidan is a sulfated polysaccharide found in brown seaweed. Due to its reported biological activities, including antiviral, antibacterial and anti-inflammatory activities, it has garnered significant attention for potential biomedical applications. However, the direct relationship between fucoidan extracts' chemical structures and bioactivities is unclear, making it extremely challenging to predict whether an extract will possess a given bioactivity. This relationship is further complicated by a lack of uniformity in the recent literature in terms of the assessment and reporting of extract properties, yield and chemical composition (e.g., sulfate, fucose, uronic acid and monosaccharide contents). These inconsistencies pose significant challenges when directly comparing extraction techniques across studies. This review collected data on extract contents and properties from a selection of available studies. Where information was unavailable directly, efforts were made to extrapolate data. This approach enabled a comprehensive examination of the correlation between extraction techniques and the characteristics of the resulting extracts. A holistic framework is presented for the selection of fucoidan extraction methods, outlining key heuristics to consider when capturing the broader context of a seaweed bioprocess. Future work should focus on developing knowledge within these heuristic categories, such as the creation of technoeconomic models of each extraction process. This framework should allow for a robust extraction selection process that integrates process scale, cost and constraints into decision making. Key quality attributes for biologically active fucoidan are proposed, and areas for future research are identified, such as studies for specific bioactivities aimed at elucidating fucoidan's mechanism of action. This review also sets out future work required to standardize the reporting of fucoidan extract data. Standardization could positively enhance the quality and depth of data on fucoidan extracts, enabling the relationships between physical, chemical and bioactive properties to be identified. Recommendations on best practices for the production of high-quality fucoidan with desirable yield, characteristics and bioactivity are highlighted.

Seaweed-Derived Bioactive Compounds: Potent Modulators in Breast Cancer Therapy

Cancer remains a major global health concern, with breast cancer being particularly challenging. To address this, new therapeutic strategies are being explored, including natural alternatives. Seaweeds, rich in bioactive compounds, have gained attention for their therapeutic potential. Traditionally valued for their nutritional content, seaweed-derived compounds such as polysaccharides, polyphenols, sterols, vitamins, minerals, and carotenoids have shown anticancer properties. These compounds can modulate key cellular processes like apoptosis, angiogenesis, and inflammation-crucial in cancer progression. Their antioxidant, anti-inflammatory, and immunomodulatory effects make them promising candidates for complementary cancer therapies. Key bioactive components like fucoidans, laminarins, phlorotannins, and carotenoids exhibit antiproliferative, proapoptotic, antiangiogenic, and antimetastatic properties. Recent studies focus on the ability of these compounds to induce apoptosis in cancer cells. This review highlights the chemical constituents of various seaweed species with antitumor activity, their mechanisms of action, and the potential for integration into cancer treatments. It also addresses challenges in clinical applications and outlines future research directions for leveraging these marine resources in breast cancer therapy.

Algal carbohydrates: Sources, biosynthetic pathway, production, and applications

Algae play a significant role in the global carbon cycle by utilizing photosynthesis to efficiently convert solar energy and atmospheric carbon dioxide into various chemical compounds, notably carbohydrates, pigments, lipids, and released oxygen, making them a unique sustainable cellular factory. Algae mostly consist of carbohydrates, which include a broad variety of structures that contribute to their distinct physical and chemical properties such as degree of polymerization, side chain, branching, degree of sulfation, hydrogen bond etc., these features play a crucial role in regulating many biological activity, nutritional and pharmaceutical properties. Algal carbohydrates have not received enough attention in spite of their distinctive structural traits linked to certain biological and physicochemical properties. Nevertheless, it is anticipated that there will be a significant increase in the near future due to increasing demand, sustainable source, biofuel generation and their bioactivity. This is facilitated by the abundance of easily accessible information on the structural data and distinctive characteristics of these biopolymers. This review delves into the different types of saccharides such as agar, alginate, fucoidan, carrageenan, ulvan, EPS and glucans synthesized by various macroalgal and microalgal systems, which include intracellular, extracellular and cell wall saccharides. Their structure, biosynthetic pathway, sources, production strategies and their applications in various field such as nutraceuticals, pharmaceuticals, biomedicine, food and feed, cosmetics, and bioenergy are also elaborately discussed. Algal polysaccharide has huge a scope for exploitation in future due to their application in food and pharmaceutical industry and it can become a huge source of capital and income.

Impact of Ultrasound- and Microwave-Assisted Extraction on Bioactive Compounds and Biological Activities of Jania rubens and Sargassum muticum

This study represents the first investigation into the ultrasonic and microwave extraction of bioactive metabolites from Jania rubens (J. rubens) (red seaweed) and Sargassum. muticum (S. muticum) (brown seaweed), with a focus on their biological activities. The research compares ultrasound-assisted extraction (UAE) with microwave-assisted extraction (MAE) utilizing a hydromethanolic solvent to evaluate their effects on these seaweeds' bioactive compounds and biological activities. The assessment included a series of antioxidant essays: DPPH, ABTS, phenanthroline, and total antioxidant capacity, followed by enzyme inhibition activities: alpha-amylase and urease. Results revealed significant proportions of phenolic compounds, ranging from 48.31 ± 0.32 to 74.42 ± 0.80 μg GAE/mg, depending on the extraction method. The extracts demonstrated a high antioxidant activity, with IC50 values ranging from 26.58 ± 0.39 to 87.55 ± 0.69 μg/mL. Notably, the MAE extract of S. muticum showed a value of 48.11 ± 2.75 μg/mL for alpha-amylase inhibition, which is strictly superior to the reference acarbose with an IC50 equal to 3431.01 μg/mL. UPLC-ESI-MS/MS analysis identified 14 bioactive compounds. The proportion of riboflavin with MAE was 70.58% and 59.11% for J. rubens and S. muticum fractions, respectively. These findings underscore the critical influence of extraction technique selection on bioactive compounds' yield and efficiency, highlighting the potential of algal biomass as a sustainable alternative in various applications.

Natural Antimicrobial Agents from Algae: Current Advances and Future Directions

Infectious diseases have significantly shaped human history, leading to significant advancements in medical science. The discovery and development of antibiotics represented a critical breakthrough, but the rise of antibiotic-resistant pathogens now presents a serious global health threat. Due to the limitations of current synthetic antimicrobials, such as toxicity and environmental concerns, it is essential to explore alternative solutions. Algae, particularly microalgae and cyanobacteria, have emerged as promising sources of bioactive antimicrobial compounds. This review provides a comprehensive analysis of the antimicrobial properties of algal-derived compounds, including polysaccharides, fatty acids, and phenols, which have shown effectiveness against multi-drug-resistant bacteria. A co-occurrence bibliometric analysis using VOSviewer highlighted five key research clusters: antibiotic resistance, algal extracts, biosynthesis, water treatment, and novel pharmacological compounds. Furthermore, the primary mechanisms of action of these bioactive compounds, such as the inhibition of protein synthesis and cell membrane disruption, were identified, demonstrating their potential against both common and multi-resistant pathogens. Future research should prioritize optimizing algal biomass production, utilizing genetic and metabolic engineering, and creating innovative delivery systems to enhance the efficient production of bioactive compounds.

Extraction, structural features, and pharmacological effects of the polysaccharides from Porphyra yezoensis: A review

Porphyra yezoensis, an important medicinal seaweed extensively cultivated and consumed in China, Japan, and South Korea, is traditionally considered a precious healthy food and food additive. Published studies showed that the polysaccharides are major bioactive macromolecules from P. yezoensis with great potential for the development of nutraceuticals and functional foods. As an important component of P. yezoensis, P. yezoensis polysaccharide (PYP) is mainly extracted by hot water extraction, ultrasonic-assisted extraction, and microwave-assisted extraction methods. Subsequently obtained by decolorization, deproteinization, removal of other small molecules, and separation on various chromatographic columns. The main structural components of PYP were (1 → 3)-linked β-D-galactose and (1 → 4)-linked 3,6-anhydro-α-L-galactose. Accumulating evidence has revealed that PYP has diverse biological activities, such as antioxidant, suppressing kidney stones, immunomodulatory, etc. This review systematically summarizes the recent preparation progress, chemical structures, bioactivities, and the underlying mechanisms of PYP. Information from this review provides insights into the further development of PYP as therapeutic agents and functional foods. Although there have been extensive studies on PYP, there are gaps in establishing quality standard, toxicological research, clinical application and other aspects. To enhance the utility of P. yezoensis, it is necessary to strengthen the research on these aspects.

A study on anticancer and antioxidant ability of selected brown algae biomass yielded polysaccharide and their chemical and structural properties analysis by FT-IR and NMR analyses

The study was conducted to determine the chemical and structural properties of polysaccharides extracted from the marine macroalgae Nemalion cari-cariense. Furthermore, evaluate the anticancer and free radical scavenging activity of purified N. cari-cariense polysaccharide. Approximately 41.6% (w/w) of crude polysaccharide was extracted from N. cari-cariense macroalgae biomass. After deproteinization, the purified polysaccharide's major chemical composition was found to be 92.6%, with all protein content removed. The purified polysaccharide had ash and moisture % of 23.01% and 4.03%, respectively. The C, H, and N of the test polysaccharide were analyzed using GC-MS, with results of 39.21%, 5.87%, and 4.29%, respectively. Furthermore, this analysis also revealed the monosaccharide composition such as glucose, galactose, mannose, xylose, and rhamnose glucose, galactose, mannose, xylose, and rhamnose 54.62%, 29.64%, 2.8%, 5.9%, and 6.8% respectively. The molecular weight of purified polysaccharide was found as 49 kDa through PAGE analysis. The FT-IR analysis revealed that the presence of functional groups exactly attributed to polysaccharide and 1H and 13C-NMR analyses confirmed the structural properties of N. cari-cariense polysaccharide. The free radicals scavenging ability of purified N. cari-cariense polysaccharide was investigated by various assays such as total antioxidant assay (22.3%-72.5% at 50-250 μg mL-1), DPPH assay (23.6%-76.9% at 10-160 μg mL-1), OH radical scavenging assay (13.6%-70.2% at 50-250 μg mL-1 dosage, and SO radical scavenging assay (27.6-68.41% at 50-250 μg mL-1 concentration). The polysaccharide demonstrated 82.63% anticancer activity towards the A549 lung cancer cell line at 1000 μg mL-1 dosage. The findings suggest that this polysaccharide has biological applications.

Red Seaweed (Rhodophyta) Phycocolloids: A Road from the Species to the Industry Application

Seaweed polysaccharides are versatile both in their functions in seaweed physiology and in their practical applications in society. However, their content and quality vary greatly. This review discusses the main factors that influence the yield and quality of polysaccharides, specifically carrageenans and agars (sulfated galactans) found in red algae species (Rhodophyta). In addition, its historical, current, and emerging applications are also discussed. Carrageenan has been influenced mainly by photosynthetically active radiation (PAR) and nitrogen, while its relationship with temperature has not yet been replicated by recent studies. Agar's seasonal trend has also been found to be more ambiguous than stated before, with light, temperature, nutrients, and pH being influencing factors. In this review, it is also shown that, depending on the compound type, seaweed polysaccharides are influenced by very different key factors, which can be crucial in seaweed aquaculture to promote a high yield and quality of polysaccharides. Additionally, factors like the extraction method and storage of polysaccharides also influence the yield and quality of these compounds. This review also highlights the drawbacks and inadequacy inherent from the conventional (or current) extraction technology approaches.

Seaweed-based biopolymers for food packaging: A sustainable approach for a cleaner tomorrow

With the increasing environmental and health consequences of uncontrolled plastic use, the scientific community is progressively gravitating toward biodegradable and ecofriendly packaging alternatives. Seaweed polysaccharides have attracted attention recently because of their biodegradability, nontoxicity, antioxidant properties, and superior film-forming ability. However, it has some limitations for packaging applications, such as low tensile strength, water solubility, and only modest antimicrobial properties. The incorporation of biopolymers, nanoparticles, or organic active ingredients enhances these characteristics. This review encapsulates the contemporary research landscape pivoting around the role of seaweed polysaccharides in the development of bioplastics, active packaging solutions, edible films, and protective coatings. A meticulous collation of existing literature dissects the myriad food application avenues for these marine biopolymers, emphasizing their multifaceted physical, mechanical, thermal, and functional attributes, including antimicrobial and antioxidant. A key facet of this review spotlights environmental ramifications by focusing on their biodegradability, reinforcing their potential as a beacon of sustainable innovation. This article delves into the prevalent challenges that stymie large-scale adoption and commercialization of seaweed-centric packaging, offering a comprehensive perspective on this burgeoning domain.

Effect of soybean and seaweed-based diets on growth performance, feed utilization, and gut microbiota of tilapia: A systematic review and meta-analysis

Tilapia, a significant aquaculture species globally, relies heavily on feed for its production. While numerous studies have investigated the impact of soybean and seaweed-based diets on tilapia, a comprehensive understanding remains elusive. This review aimed at evaluating and synthesizing the existing literature on these diets' effects, focusing on growth performance, feed utilization, and gut microbiota. A systematic search of databases was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and a total of 57 studies were included in the qualitative analysis and 24 in the meta-analysis. The results indicated that soybean-based diets, at a 59.4% inclusion level improved the Specific Growth Rate (SGR) of tilapia with an effect size of -2.14 (95% CI: -2.92, -1.37; p < 0.00001; I2 = 99%) and did not improve the feed conversion rate (FCR), as the effect size was 1.80 (95% CI: 0.72, 2.89; p = 0.001; I2 = 100%). For seaweed-based diets, at a 15,9% inclusion level did not improve SGR, with an effect size of -0.74 (95% CI: -1.70, 0.22; p = 0.13; I2 = 99%), and the FCR with an effect size of -0.70 (95% CI: -1.94, 0.54; p = 0.27; I2 = 100%). Regarding the gut microbiota, was noted a lack of studies meeting the inclusion criteria for tilapia. However, findings from studies on other farmed fishes suggested that soybean and seaweed-based diets could have diverse effects on gut microbiota composition and promote the growth of beneficial microbiota. This study suggests that incorporating soybean-based diets at 59.4% inclusion can improve the SGR of tilapia. Seaweed-based diets, while not demonstrating improvement in the analyzed parameters with an inclusion level of 15.9%, have the potential to contribute to the sustainability of the aquaculture industry when incorporated at lower levels.

A Comparative Analysis of the Anti-Tumor Activity of Sixteen Polysaccharide Fractions from Three Large Brown Seaweed, Sargassum horneri, Scytosiphon lomentaria, and Undaria pinnatifida

Searching for natural products with anti-tumor activity is an important aspect of cancer research. Seaweed polysaccharides from brown seaweed have shown promising anti-tumor activity; however, their structure, composition, and biological activity vary considerably, depending on many factors. In this study, 16 polysaccharide fractions were extracted and purified from three large brown seaweed species (Sargassum horneri, Scytosiphon lomentaria, and Undaria pinnatifida). The chemical composition analysis revealed that the polysaccharide fractions have varying molecular weights ranging from 8.889 to 729.67 kDa, and sulfate contents ranging from 0.50% to 10.77%. Additionally, they exhibit different monosaccharide compositions and secondary structures. Subsequently, their anti-tumor activity was compared against five tumor cell lines (A549, B16, HeLa, HepG2, and SH-SY5Y). The results showed that different fractions exhibited distinct anti-tumor properties against tumor cells. Flow cytometry and cytoplasmic fluorescence staining (Hoechst/AO staining) further confirmed that these effective fractions significantly induce tumor cell apoptosis without cytotoxicity. qRT-RCR results demonstrated that the polysaccharide fractions up-regulated the expression of Caspase-3, Caspase-8, Caspase-9, and Bax while down-regulating the expression of Bcl-2 and CDK-2. This study comprehensively compared the anti-tumor activity of polysaccharide fractions from large brown seaweed, providing valuable insights into the potent combinations of brown seaweed polysaccharides as anti-tumor agents.

Green (Ulva fenestrata) and Brown (Saccharina latissima) Macroalgae Similarly Modulate Inflammatory Signaling by Activating NF-κB and Dampening IRF in Human Macrophage-Like Cells

Macroalgae are considered healthy food ingredients due to their content in numerous bioactive compounds, and the traditional use of whole macroalgae in Asian cuisine suggests a contribution to longevity. Although much information is available about the bioactivity of pure algal compounds, such as different polyphenols and polysaccharides, documentation of potential effects of whole macroalgae as part of Western diets is limited. Lifestyle- and age-related diseases, which have a high impact on population health, are closely connected to underlying chronic inflammation. Therefore, we have studied crude extracts of green (Ulva fenestrata) and brown (Saccharina latissima) macroalgae, as two of the most promising food macroalgae in the Nordic countries for their effect on inflammation in vitro. Human macrophage-like reporter THP-1 cells were treated with macroalgae extracts and stimulated with lipopolysaccharide (LPS) to induce inflammatory signalling. Effects of the macroalgae extracts were assessed on transcription factor activity of NF-κB and IRF as well as secretion and/or expression of the cytokines TNF-α and IFN-β and chemokines IL-8 and CXCL10. The crude macroalgae extracts were further separated into polyphenol-enriched and polysaccharide-enriched fractions, which were also tested for their effect on transcription factor activity. Interestingly, we observed a selective activation of NF-κB, when cells were treated with macroalgae extracts. On the other hand, pretreatment with macroalgae extracts selectively repressed IRF activation when inflammatory signaling was subsequently induced by LPS. This effect was consistent for both tested species as well as for polyphenol- and polysaccharide-enriched fractions, of which the latter had more pronounced effects. Overall, this is the first indication of how macroalgae could modulate inflammatory signaling by selective activation and subsequent repression of different pathways. Further in vitro and in vivo studies of this mechanism would be needed to understand how macroalgae consumption could influence the prevention of noncommunicable, lifestyle- and age-related diseases that are highly related to unbalanced inflammatory processes.

The Effect of κ-Carrageenan on Porcine Sperm Cryo-Survival

κ-Carrageenan is a sulfated polysaccharide from red seaweed with substantial antioxidant activities. This study aimed to investigate the effect of κ-Carrageenan treatment on frozen-thawed (FT) porcine semen quality. Therefore, the spermatozoa were diluted and cryopreserved in a freezing extender supplemented with 0 (control), 0.2, 0.4, 0.6, and 0.8 mg/mL κ-Carrageenan. Sperm kinematics were assessed immediately after thawing (AT) and post-incubation for 120 min. The viability, acrosome integrity, lipid peroxidation, mitochondrial membrane potential (MMP), and intracellular caspase activity were measured AT. The results indicated that 0.2 mg/mL κ-Carrageenan increased total and progressive motility AT and post-incubation for 120 min (p < 0.05). Moreover, the viable sperm percentage and MMP after 0.2 mg/mL treatment were higher than those after control and other κ-Carrageenan concentration treatments. The proportion of acrosome-intact spermatozoa was significantly higher after 0.2 and 0.4 mg/mL κ-Carrageenan treatment than that after control and other κ-Carrageenan concentration treatments. The intracellular caspase activity was not significantly different among the experimental groups. However, the MDA concentration after 0.2 mg/mL κ-Carrageenan treatment was lower (p < 0.05) than that after the control treatment. Taken together, adding κ-Carrageenan to the porcine semen freezing extender improved the FT sperm quality mainly by influencing membrane stability and protecting against oxidative stress.

Phospho-Chitooligosaccharides below 1 kDa Inhibit HIV-1 Entry In Vitro

Despite present antiviral agents that can effectively work against HIV-1 replication, side effects and drug resistance have pushed researchers toward novel approaches. In this context, there is a continued focus on discovering new and more effective antiviral compounds, particularly those that have a natural origin. Polysaccharides are known for their numerous bioactivities, including inhibiting HIV-1 infection and replication. In the present study, phosphorylated chitosan oligosaccharides (PCOSs) were evaluated for their anti-HIV-1 potential in vitro. Treatment with PCOSs effectively protected cells from HIV-1-induced lytic effects and suppressed the production of HIV-1 p24 protein. In addition, results show that PCOSs lost their protective effect upon post-infection treatment. According to the results of ELISA, PCOSs notably disrupted the binding of HIV-1 gp120 protein to T cell surface receptor CD4, which is required for HIV-1 entry. Overall, the results point out that PCOSs might prevent HIV-1 infection at the entry stage, possibly via blocking the viral entry through disruption of virus-cell fusion. Nevertheless, the current results only present the potential of PCOSs, and further studies to elucidate its action mechanism in detail are needed to employ phosphorylation of COSs as a method to develop novel antiviral agents.

Anti-biofilm activity of marine algae-derived bioactive compounds

A large number of microbial species tend to communicate and produce biofilm which causes numerous microbial infections, antibiotic resistance, and economic problems across different industries. Therefore, advanced anti-biofilms are required with novel attributes and targets, such as quorum sensing communication system. Meanwhile, quorum sensing inhibitors as promising anti-biofilm molecules result in the inhibition of particular phenotype expression blocking of cell-to-cell communication, which would be more acceptable than conventional strategies. Many natural products are identified as anti-biofilm agents from different plants, microorganisms, and marine extracts. Marine algae are promising sources of broadly novel compounds with anti-biofilm activity. Algae extracts and their metabolites such as sulfated polysaccharides (fucoidan), carotenoids (zeaxanthin and lutein), lipid and fatty acids (γ-linolenic acid and linoleic acid), and phlorotannins can inhibit the cell attachment, reduce the cell growth, interfere in quorum sensing pathway by blocking related enzymes, and disrupt extracellular polymeric substances. In this review, the mechanisms of biofilm formation, quorum sensing pathway, and recently identified marine algae natural products as anti-biofilm agents will be discussed.

Effect of extraction method on the structure and bioactivity of polysaccharides from activated sludge

Resource recovery is a pivotal facet of waste activated sludge treatment, particularly within the framework of carbon neutrality and the circular economy. Polysaccharides are emerging as a valuable resource from waste activated sludge, and the choice of extraction method affects the properties of the polysaccharides, which is of utmost importance for subsequent application. This investigation examined the effects of six extraction methods (i.e., acidic, alkaline, ultrasonication, hot-water, microwave, and electric treatments) on the yield, chemical composition, structural characteristics, and bioactivities of polysaccharides extracted from sludge. For each extraction method, two operational parameters, namely the treatment time and strength (e.g., the acid and alkali concentration), were initially optimized in terms of the polysaccharide yield. The polysaccharide yield varied from 1.03 ± 0.12 % to 5.34 ± 0.10 % adopting the extraction methods under optimized conditions, and the alkaline extraction method had the highest yield of polysaccharides with a treatment time of 120 min and NaOH concentration of 1 %. At least one polysaccharide fraction was successfully purified from the crude polysaccharide of each extraction method. The compositions and structures of these fractions, including carbohydrate, protein, sulfate, uronic acid contents, and monosaccharide compositions, were determined. Carbohydrate was the dominant component, with the hot-water-2 fraction having the highest carbohydrate content (77.90 % ± 2.02 %). Monosaccharides in the polysaccharides were measured, with mannose, rhamnose, glucose, and xylose being found in all fractions, whereas ribose was exclusively found in the acid-1 fraction. The molecular weights of these fractions ranged between 1.60 × 104 Da and 7.11 × 106 Da. Furthermore, the bioactivities of the polysaccharides, encompassing five anti-oxidant and three anti-coagulant properties, were assessed, with the ultrasonication-1 fraction having superior performance in seven of the assays. Finally, the association among the fractions in terms of composition and bioactivity was assessed adopting cluster analysis and regression methods. The findings underscore the effect of the extraction method on the properties of polysaccharides extracted from sludge, thereby providing valuable insights for the prospective applications of polysaccharides.

Bioaccessibility of toxic heavy metals/metalloids in edible seaweeds: Exposure and health risk assessment

This study assesses the health risk due to heavy metals/metalloids (HMs/Ms) in edible seaweeds (Caulerpa racemosa, Kappaphycus alvarezii, and Ulva lactuca) through an in vitro bioaccessibility study. The percentage of bioabsorbed HMs/Ms in unprocessed and processed C. racemosa, U. lactuca, and K. alvarezii ranged from 3 % to 46 %, 3 % to 42 %, and 3 % to 40 %, respectively. The levels of HMs/Ms in seawater, sediment, and seaweeds were below the levels recommended by the European Commission (EC) and World Health Organization/Food and Agriculture Organization (WHO/FAO). The maximum accumulation of HMs/Ms was found during monsoons and post-monsoon seasons, and Cd, Pb, Hg, Cr, As, and Pb were predominant in all the samples. Tukey's post hoc test and t-test confirmed that thermal processing significantly reduced HMs/Ms in seaweeds. On the basis of the bioabsorption of HMs/Ms, the TTHQ values were found to be < 1, and the LCR values were within the acceptable limit (10-06 to 10-04), indicating no carcinogenic risks through seaweeds.

Depolymerized carrageenan expresses elicitor-like activity on Mentha arvensis L. under arsenic stress: Insights into arsenic resilience and monoterpene synthesis

Heavy metals contaminate agricultural land by limiting the productivity of crops and making them or their products unfit for consumption. Arsenic (As) is a potentially hazardous metalloid that severely impacts plants' survival. Menthol mint (Mentha arvensis L.) bears volatile compounds that are harshly exaggerated by diverse environmental factors like drought, salinity, heavy metal, temperature, photoperiod, and luminosity stresses. In this study, the phytotoxicity of As was examined in M. arvensis L. and its alleviation through the supplementation of oligomers of carrageenan. Noticeably, scanty information is available regarding the effect of irradiated carrageenan (ICA) on As-stressed plants. In order to observe the same in the case of M. arvensis L., the effect of ICA on As-treated plants was explored. The ICA concentration (foliar-applied) selected for the study was 80 mg L-1, 100 mg L-1 and 120 mg L-1, and that of As (soil-applied) was 80 mg kg-1 soil. Excess accumulation of As resulted in reduced growth, enzymatic activities, and yield and quality parameters of M. arvensis L. under As toxicity. However, the foliage application of ICA strengthens the antioxidant machinery and other physiological and oxidative stress biomarkers of the plant by facilitating the activity of superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), and proline, and, therefore aids in alleviating the toxicity generated by As. Nevertheless, ICA supplementation proves beneficial in enhancing the monoterpene synthesis (essential oil production and its active constituents) of M. arvensis L. by maintaining a steady-state equilibrium between reactive oxygen species (ROS) production and its scavenging process.

Preparations, application of polysaccharide-protein nanoparticles and their assembly at the oil-water interface

With the development of nanotechnology, nanoparticles have played an important role in pharmaceuticals, foods and materials, in particular, protein/polysaccharide based composite nanoparticles have received attention from researchers for safety and green production. This paper summarized in detail the preparation methods, applications of protein/polysaccharide nanoparticles (PPNPs) in recent years, especially the mechanism of stabilizing the oil-water interface. Currently, the polysaccharides applied are more traditional, such as chitosan, pectin and carboxymethyl cellulose, so there is still a lot of room for the development of raw materials that can be used to prepare PPNPs. Based on this, we also proposed three promising polysaccharides: seaweed polysaccharide, lycium barbarum polysaccharide and lactobacillus exopolysaccharides, describing their characteristics as well as their application prospects, this article can serve as a reference for interested researchers.

Resolving the dynamics of chrysolaminarin regulation in a marine diatom: A physiological and transcriptomic study

Diatom containing different active biological macromolecules are thought to be an excellent microbial cell factory. Phaeodactylum tricornutum, a model diatom, is a superb chassis organism accumulating chrysolaminarin with important bioactivities. However, the characteristic of chrysolaminarin accumulation and molecular mechanism of the fluctuated chrysolaminarin in diatom are still unknown. In this study, physiological data and transcriptomic analysis were carried out to clarify the mechanism involved in chrysolaminarin fluctuation. The results showed that chrysolaminarin content fluctuated, from 7.41 % dry weight (DW) to 40.01 % DW during one light/dark cycle, increase by day and decrease by night. The similar fluctuated characteristic was also observed in neutral lipid content. Genes related to the biosynthesis of chrysolaminarin and neutral lipid were up-regulated at the beginning of light-phase, explaining the accumulation of these biological macromolecules. Furthermore, genes involved in carbohydrate degradation, cell cycle, DNA replication and mitochondria-localized β-oxidation were up-regulated at the end of light phase and at the beginning of dark phase hinting an energy transition of carbohydrate to cell division during the dark period. Totally, our findings provide important information for the regulatory mechanism in the diurnal fluctuation of chrysolaminarin. It would also be of great help for the mass production of economical chrysolaminarin in marine diatom.

Role of some structural features in EPS from microalgae stimulating collagen production by human dermal fibroblasts

Exopolysaccharides (EPS) from the microalgae Porphyridium cruentum, Chrysotila dentata, Pavlova sp., Diacronema sp., Glossomastix sp., Phaeodactylum tricornutum, and Synechococcus sp. were isolated and depolymerized. First, EPS were submitted to a high pressure pre-treatment step, followed by a solid acid-catalyzed hydrolysis step carried out in a batch or recycle fixed-bed reactor, using a strong acidic cation-exchange resin. Twenty-eight different EPS forms were thus obtained. After characterization of their main structural features (weight- and number-averaged molecular weight, polydispersity index, sulfate and uronic acid contents), we investigated the structure-function relationship of their pro-collagen activity. We found that native microalgae EPS were able to inhibit until 27% of human matrix metalloproteinase-1 (MMP-1) activity while the depolymerized forms were able to enhance collagen production by two different human fibroblast lines, used as cell models due to their major role in dermal collagen biosynthesis. The most active EPS forms, obtained by depolymerization in the recycle fixed-bed reactor of D. ennorea and Glossomastix sp. EPS, led to 390% increase in collagen production. Finally, principal component (PCA) and Pearson analyses indicated that MMP-1 inhibition was strongly correlated to the sulfate group content of EPS whereas collagen production by fibroblasts was mostly related to their proportion of low molecular weight polysaccharides (<10 kDa). Uronic acid content of EPS was also shown essential but only if the size of EPS was reduced in the first place. Altogether, these results gave new insights of the dermo-cosmetic potential of microalgae EPS as well as the key parameters of their activity.

Unraveling the bioactive interplay: seaweed polysaccharide, polyphenol and their gut modulation effect

Seaweed is rich in many unique bioactive compounds such as polyphenols and sulfated polysaccharides that are not found in terrestrial plant. The discovery of numerous biological activities from seaweed has made seaweed an attractive functional food source with the potential to be exploited for human health benefits. During food processing and digestion, cell wall polysaccharide and polyphenols commonly interact, and this may influence the nutritional properties of food. Interactions between cell wall polysaccharide and polyphenols in plant-based system has been extensively studied. However, similar interactions in seaweed have received little attention despite the vast disparity between the structural and chemical composition of plant and seaweed cell wall. This poses a challenge in extracting seaweed bioactive compounds with intact biological properties. This review aims to summarize the cell wall polysaccharide and polyphenols present in brown, red and green seaweed, and current knowledge on their potential interactions. Moreover, this review gives an overview of the gut modulation effect of seaweed polysaccharide and polyphenol.

High-sulfated derivative of polysaccharide from Ulva pertusa improves Adriamycin-induced nephrotic syndrome by suppressing oxidative stress

Nephrotic syndrome (NS) is characterized by proteinuria, hyperlipidemia, and hypoalbuminemia. Ulva pertusa, a green seaweed, is a nutritional supplement. In this study, the high-sulfated derivative of Ulva pertusa polysaccharide (HU) was prepared by combining U pertusa polysaccharide with chlorosulfonic acid. The NS rat model was established by tail vein single injection of Adriamycin (6.0 mg kg-1). Normal rats were used as the control group. NS rat models were treated with HU or U (173 mg kg-1 day-1). After treatment for 6 weeks, we assessed urine protein, renal function, and blood lipids, and observed morphology and histologic injury of the kidney and glomerular microstructure. Furthermore, we detected antioxidant enzyme activity and expression level of the Keap1/Nrf2 signaling pathway to explore the potential mechanism of HU. Results showed that HU not only alleviated hyperlipidemia and hypoalbuminemia, but also reduced urine protein by inhibiting podocyte detachment, thickening of the glomerular basement membrane, and expression of kidney fibrosis markers (collagens I and IV). In addition, HU enhanced antioxidant enzyme activity (GSH-Px, CAT, SOD) in both serum and the kidney, which may be due to upregulating the expression of Nrf2 and downregulating the expression of Keap1. In conclusion, HU appears to be effective in attenuating NS in rats through suppressing oxidative stress by regulating the Keap1/Nrf2 signaling pathway.

The utility of algae as sources of high value nutritional ingredients, particularly for alternative/complementary proteins to improve human health

As the global population continues to grow, the demand for dietary protein is rapidly increasing, necessitating the exploration of sustainable and nutritious protein sources. Algae has emerged as a promising food source due to their high value ingredients such as proteins, as well as for their environmental sustainability and abundance. However, knowledge gaps surrounding dietary recommendations and food applications restrict algae's utilization as a viable protein source. This review aims to address these gaps by assessing the suitability of both microalgae and macroalgae as alternative/complementary protein sources and exploring their potential applications in food products. The first section examines the potential suitability of algae as a major food source by analyzing the composition and bioavailability of key components in algal biomass, including proteins, lipids, dietary fiber, and micronutrients. Secondly, the biological effects of algae, particularly their impact on metabolic health are investigated with an emphasis on available clinical evidence. While evidence reveals protective effects of algae on glucose and lipid homeostasis as well as anti-inflammatory properties, further research is required to understand the longer-term impact of consuming algal protein, protein isolates, and concentrates on metabolic health, including protein metabolism. The review then explores the potential of algal proteins in food applications, including ways to overcome their sensory limitations, such as their dark pigmentation, taste, and odor, in order to improve consumer acceptance. To maximize algae's potential as a valuable protein source in the food sector, future research should prioritize the production of more acceptable algal biomass and explore new advances in food sciences and technology for improved consumer acceptance. Overall, this paper supports the potential utility of algae as a sustainable and healthy ingredient source for widespread use in future food production.

A Novel Polysaccharide from Sargassum weizhouense: Extraction Optimization, Structural Characterization, Antiviral and Antioxidant Effects

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most economically important pathogens in the global swine industry over the past three decades. There is no licensed antiviral medication that can effectively control this infection. In the present study, the structure of SP-1 isolated and purified from Sargassum weizhouense was analyzed, and its antioxidant capacity and antiviral effect in MARC-145 cells against PRRSV were investigated. The results showed that SP-1 is a novel polysaccharide which mainly is composed of →4)-β-D-ManpA-(1→, →4)-α-L-GulpA-(1→ and a small amount of →4)-β-D-GalpA-(1→. PRRSV adsorption, replication, and release were all suppressed by SP-1. SP-1 therapy down-regulated mRNA expression of the CD163 receptor while increasing the antioxidant gene expression of Nrf2, TXNIP, and HO-1; increasing the protein expression of NQO1 and HO-1; and drastically reducing the protein expression of p-p65. The findings indicated that SP-1 reduces PRRSV adsorption, replication, and release through blocking the expression of the crucial CD163 receptor during infection. Meanwhile, SP-1 exerts antioxidant effects in PRRSV-infected cells through the activation of the Nrf2-HO1 signaling pathway.

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.

Novel Fucoidan Pharmaceutical Formulations and Their Potential Application in Oncology-A Review

Fucoidan belongs to the family of marine sulfated, L-fucose-rich polysaccharides found in the cell wall matrix of various brown algae species. In the last few years, sulfated polysaccharides have attracted the attention of researchers due to their broad biological activities such as anticoagulant, antithrombotic, antidiabetic, immunomodulatory, anticancer and antiproliferative effects. Recently the application of fucoidan in the field of pharmaceutical technology has been widely investigated. Due to its low toxicity, biocompatibility and biodegradability, fucoidan plays an important role as a drug carrier for the formulation of various drug delivery systems, especially as a biopolymer with anticancer activity, used for targeted delivery of chemotherapeutics in oncology. Furthermore, the presence of sulfate residues with negative charge in its structure enables fucoidan to form ionic complexes with oppositely charged molecules, providing relatively easy structure-forming properties in combination with other polymers. The aim of the present study was to overview essential fucoidan characteristics, related to its application in the development of pharmaceutical formulations as a single drug carrier or in combinations with other polymers. Special focus was placed on micro- and nanosized drug delivery systems with polysaccharides and their application in the field of oncology.

Utilization of Macroalgae for the Production of Bioactive Compounds and Bioprocesses Using Microbial Biotechnology

To achieve sustainable development, alternative resources should replace conventional resources such as fossil fuels. In marine ecosystems, many macroalgae grow faster than terrestrial plants. Macroalgae are roughly classified as green, red, or brown algae based on their photosynthetic pigments. Brown algae are considered to be a source of physiologically active substances such as polyphenols. Furthermore, some macroalgae can capture approximately 10 times more carbon dioxide from the atmosphere than terrestrial plants. Therefore, they have immense potential for use in the environment. Recently, macroalgae have emerged as a biomass feedstock for bioethanol production owing to their low lignin content and applicability to biorefinery processes. Herein, we provided an overview of the bioconversion of macroalgae into bioactive substances and biofuels using microbial biotechnology, including engineered yeast designed using molecular display technology.

Microalgae, Seaweeds and Aquatic Bacteria, Archaea, and Yeasts: Sources of Carotenoids with Potential Antioxidant and Anti-Inflammatory Health-Promoting Actions in the Sustainability Era

Carotenoids are a large group of health-promoting compounds used in many industrial sectors, such as foods, feeds, pharmaceuticals, cosmetics, nutraceuticals, and colorants. Considering the global population growth and environmental challenges, it is essential to find new sustainable sources of carotenoids beyond those obtained from agriculture. This review focuses on the potential use of marine archaea, bacteria, algae, and yeast as biological factories of carotenoids. A wide variety of carotenoids, including novel ones, were identified in these organisms. The role of carotenoids in marine organisms and their potential health-promoting actions have also been discussed. Marine organisms have a great capacity to synthesize a wide variety of carotenoids, which can be obtained in a renewable manner without depleting natural resources. Thus, it is concluded that they represent a key sustainable source of carotenoids that could help Europe achieve its Green Deal and Recovery Plan. Additionally, the lack of standards, clinical studies, and toxicity analysis reduces the use of marine organisms as sources of traditional and novel carotenoids. Therefore, further research on the processing of marine organisms, the biosynthetic pathways, extraction procedures, and examination of their content is needed to increase carotenoid productivity, document their safety, and decrease costs for their industrial implementation.

Exploring Bioactive Compounds in Brown Seaweeds Using Subcritical Water: A Comprehensive Analysis

In this study, we characterized the bioactive properties of three important brown seaweed species, Sargassum thunbergii, Undaria pinnatifida, and Saccharina japonica, by subcritical water extraction (SWE), as these species are well known for their beneficial health effects. Their physiochemical properties, including potential antioxidant, antihypertensive, and α-glucosidase inhibitory activity, and the antibacterial activity of the hydroysates were also analyzed. The highest total phlorotannin, total sugar content, and reducing sugar content in the S. thunbergii hydrolysates were 38.82 ± 0.17 mg PGE/g, 116.66 ± 0.19 mg glucose/g dry sample, and 53.27 ± 1.57 mg glucose/g dry sample, respectively. The highest ABTS⁺ and DPPH antioxidant activities were obtained in the S. japonica hydrolysates (124.77 ± 2.47 and 46.35 ± 0.01 mg Trolox equivalent/g, respectively) and the highest FRAP activity was obtained in the S. thunbergii hydrolysates (34.47 ± 0.49 mg Trolox equivalent/g seaweed). In addition, the seaweed extracts showed antihypertensive (≤59.77 ± 0.14%) and α-glucosidase inhibitory activity (≤68.05 ± 1.15%), as well as activity against foodborne pathogens. The present findings provide evidence of the biological activity of brown seaweed extracts for potential application in the food, pharmaceutical, and cosmetic sectors.

The Potential of Algae in the Nutricosmetic Sector

Seaweeds or algae are marine autotrophic organisms. They produce nutrients (e.g., proteins, carbohydrates, etc.) essential for the survival of living organisms as they participate in biochemical processes and non-nutritive molecules (such as dietary fibers and secondary metabolites), which can improve their physiological functions. Seaweed polysaccharides, fatty acids, peptides, terpenoids, pigments, and polyphenols have biological properties that can be used to develop food supplements and nutricosmetic products as they can act as antibacterial, antiviral, antioxidant, and anti-inflammatory compounds. This review examines the (primary and secondary) metabolites produced by algae, the most recent evidence of their effect on human health conditions, with particular attention to what concerns the skin and hair's well-being. It also evaluates the industrial potential of recovering these metabolites from biomass produced by algae used to clean wastewater. The results demonstrate that algae can be considered a natural source of bioactive molecules for well-being formulations. The primary and secondary metabolites' upcycling can be an exciting opportunity to safeguard the planet (promoting a circular economy) and, at the same time, obtain low-cost bioactive molecules for the food, cosmetic, and pharmaceutical industries from low-cost, raw, and renewable materials. Today's lack of methodologies for recovering bioactive molecules in large-scale processes limits practical realization.

Potential use of seaweed polysaccharides as prebiotics for management of metabolic syndrome: a review

Seaweed polysaccharides (SPs) obtained from seaweeds are a class of functional prebiotics. SPs can regulate glucose and lipid anomalies, affect appetite, reduce inflammation and oxidative stress, and therefore have great potential for managing metabolic syndrome (MetS). SPs are poorly digested by the human gastrointestinal tract but are available to the gut microbiota to produce metabolites and exert a series of positive effects, which may be the mechanism by which SPs render their anti-MetS effects. This article reviews the potential of SPs as prebiotics in the management of MetS-related metabolic disturbances. The structure of SPs and studies related to the process of their degradation by gut bacteria and their therapeutic effects on MetS are highlighted. In summary, this review provides new perspectives on SPs as prebiotics to prevent and treat MetS.

Edible Seaweeds Extracts: Characterization and Functional Properties for Health Conditions

Seaweeds are popular foods due to claimed beneficial health effects, but for many there is a lack of scientific evidence. In this study, extracts of the edible seaweeds Aramé, Nori, and Fucus are compared. Our approach intends to clarify similarities and differences in the health properties of these seaweeds, thus contributing to target potential applications for each. Additionally, although Aramé and Fucus seaweeds are highly explored, information on Nori composition and bioactivities is scarce. The aqueous extracts of the seaweeds were obtained by decoction, then fractionated and characterized according to their composition and biological activity. It was recognized that fractioning the extracts led to bioactivity reduction, suggesting a loss of bioactive compounds synergies. The Aramé extract showed the highest antioxidant activity and Nori exhibited the highest potential for acetylcholinesterase inhibition. The identification of the bioactive compounds in the extracts allowed to see that these contained a mixture of phloroglucinol polymers, and it was suggested that Nori’s effect on acetylcholinesterase inhibition may be associated with a smaller sized phlorotannins capable of entering the enzyme active site. Overall, these results suggest a promising potential for the use of these seaweed extracts, mainly Aramé and Nori, in health improvement and management of diseases, namely those associated to oxidative stress and neurodegeneration.

Marine Natural Products as Innovative Cosmetic Ingredients

Over the course of the last 20 years, numerous studies have identified the benefits of an array of marine natural ingredients for cosmetic purposes, as they present unique characteristics not found in terrestrial organisms. Consequently, several marine-based ingredients and bioactive compounds are under development, used or considered for skin care and cosmetics. Despite the multitude of cosmetics based on marine sources, only a small proportion of their full potential has been exploited. Many cosmetic industries have turned their attention to the sea to obtain innovative marine-derived compounds for cosmetics, but further research is needed to determine and elucidate the benefits. This review gathers information on the main biological targets for cosmetic ingredients, different classes of marine natural products of interest for cosmetic applications, and the organisms from which such products can be sourced. Although organisms from different phyla present different and varied bioactivities, the algae phylum seems to be the most promising for cosmetic applications, presenting compounds of many classes. In fact, some of these compounds present higher bioactivities than their commercialized counterparts, demonstrating the potential presented by marine-derived compounds for cosmetic applications (i.e., Mycosporine-like amino acids and terpenoids’ antioxidant activity). This review also summarizes the major challenges and opportunities faced by marine-derived cosmetic ingredients to successfully reach the market. As a future perspective, we consider that fruitful cooperation among academics and cosmetic industries could lead to a more sustainable market through responsible sourcing of ingredients, implementing ecological manufacturing processes, and experimenting with inventive recycling and reuse programs.

Holistic understanding of the response of grapevines to foliar application of seaweed extracts

Viticulture is highly dependent on phytochemicals to maintain good vineyard health. However, to reduce their accumulation in the environment, green regulations are driving the development of eco-friendly strategies. In this respect, seaweeds have proven to be one of the marine resources with the highest potential as plant protective agents, representing an environmentally-friendly alternative approach for sustainable wine production. The current work follows an interdisciplinary framework to evaluate the capacity of Ulva ohnoi and Rugulopteryx okamurae seaweeds to induce defense mechanisms in grapevine plants. To our knowledge, this is the first study to evaluate Rugulopteryx okamurae as a biostimulator . This macroalgae is relevant since it is an invasive species on the Atlantic and Mediterranean coast causing incalculable economic and environmental burdens. Four extracts (UL1, UL2, RU1 and RU2 developed from Ulva and Rugulopteryx, respectively) were foliar applied to Tempranillo plants cultivated under greenhouse conditions. UL1 and RU2 stood out for their capacity to induce defense genes, such as a PR10, PAL, STS48 and GST1, mainly 24 hours after the first application. The increased expression level of these genes agreed with i) an increase in trans-piceid and trans-resveratrol content, mainly in the RU2 treated leaves, and, ii) an increase in jasmonic acid and decrease in salicylic acid. Moreover, an induction of the activity of the antioxidant enzymes was observed at the end of the experiment, with an increase in superoxide dismutase and catalase in the RU2-treated leaves in particular. Interestingly, while foliar fungal diversity was not influenced by the treatments, alga extract amendment modified fungal composition, RU2 application enriching the content of various groups known for their biocontrol activity. Overall, the results evidenced the capacity of Rugulopteryx okamurae for grapevine biostimulation, inducing the activation of several secondary metabolite pathways and promoting the abundance of beneficial microbiota involved in grapevine protection. While further studies are needed to unravel the bioactive compound(s) involved, including conducting field experiments etc., the current findings are the first steps towards the inclusion of Rugulopteryx okamurae in a circular scheme that would reduce its accumulation on the coast and benefit the viticulture sector at the same time.

Seaweed-Derived Sulfated Polysaccharides; The New Age Chemopreventives: A Comprehensive Review

Seaweed-derived bioactive compounds are regularly employed to treat human diseases. Sulfated polysaccharides are potent chemotherapeutic or chemopreventive medications since it has been discovered. They have exhibited anti-cancer properties by enhancing immunity and driving apoptosis. Through dynamic modulation of critical intracellular signalling pathways, such as control of ROS generation and preservation of essential cell survival and death processes, sulfated polysaccharides' antioxidant and immunomodulatory potentials contribute to their disease-preventive effectiveness. Sulfated polysaccharides provide low cytotoxicity and good efficacy therapeutic outcomes via dynamic modulation of apoptosis in cancer. Understanding how sulfated polysaccharides affect human cancer cells and their molecular involvement in cell death pathways will showcase a new way of chemoprevention. In this review, the significance of apoptosis and autophagy-modulating sulfated polysaccharides has been emphasized, as well as the future direction of enhanced nano-formulation for greater clinical efficacy. Moreover, this review focuses on the recent findings about the possible mechanisms of chemotherapeutic use of sulfated polysaccharides, their potential as anti-cancer drugs, and proposed mechanisms of action to drive apoptosis in diverse malignancies. Because of their unique physicochemical and biological properties, sulfated polysaccharides are ideal for their bioactive ingredients, which can improve function and application in disease. However, there is a gap in the literature regarding the physicochemical properties and functionalities of sulfated polysaccharides and the use of sulfated polysaccharide-based delivery systems in functional cancer. Furthermore, the preclinical and clinical trials will reveal the drug's efficacy in cancer.

Antiblood Cell Adhesion of Mussel-Inspired Chondroitin Sulfate- and Caffeic Acid-Modified Polycarbonate Membranes

We fabricated a mussel-inspired hemocompatible polycarbonate membrane (PC) modified by the cross-linking of chondroitin sulfate and caffeic acid polymer using CA-CS via a Schiff base and Michael addition reaction and named it CA-CS-PC. The as-fabricated CA-CS-PC membrane shows excellent hydrophilicity with a water contact angle of 0° and a negative surface charge with a zeta potential of -32 mV. The antiadhesion property of the CA-CS-modified PC membrane was investigated by enzyme-linked immunosorbent assay (ELISA), using human plasma protein fibrinogen adsorption studies, and proved to have excellent antiadhesion properties, because of the lower fibrinogen adsorption. In addition, the CA-CS-PC membrane also shows enhanced hemocompatibility. Finally, blood cell attachment tests of the CA-CS-PC membrane were observed by CLSM and SEM, and the obtained results proved that CA-CS-PC effectively resisted cell adhesion, such as platelets and leucocytes. Therefore, this work disclosed a new way to design a simple and versatile modification of the membrane surface by caffeic acid and chondroitin sulfate and apply it for cell adhesion.