The Role of Seaweeds in Blue Bioeconomy

The blue bioeconomy represents a transformative approach to harnessing the vast potential of marine resources for sustainable development. As the demand for food, energy, and materials continues to rise, the sustainable utilization of marine ecosystems offers a promising solution to meet these challenges while conserving terrestrial resources. The blue bioeconomy encompasses a broad range of sectors, including fisheries, aquaculture, marine biotechnology, and coastal tourism, among others. By capitalizing on the inherent biological diversity of the oceans, it seeks to unlock innovative pathways for economic growth, job creation, and environmental stewardship. This transition from traditional practices to a more sustainable and knowledge-based approach requires careful consideration of ecological, social, and economic factors. One of the primary advantages of the blue bioeconomy lies in its potential to provide alternative sources of protein and other essential nutrients through sustainable fisheries and responsible aquaculture practices. Additionally, marine biotechnology offers vast potential for the development of novel drugs, biomaterials, and biofuels, leveraging the unique properties of marine organisms. These innovations are Promising in addressing pressing global challenges, such as food security, climate change mitigation, and the transition to renewable energy sources. The blue bioeconomy represents a transformative pathway towards sustainable development, utilizing the diverse resources and ecosystems of our oceans. By adopting a holistic approach that integrates environmental, social, and economic considerations, the blue bioeconomy holds the potential to drive economic growth, enhance food and energy security, and contribute to the conservation and restoration of marine ecosystems. Embracing this approach is crucial for building a more sustainable and resilient future for our planet and future generations.

Seaweeds are rich sources of various nutrients and bioactive compounds, which offer several health benefits. They contain high levels of vitamins, minerals, fiber, and protein, making them a valuable addition to a balanced diet. Seaweeds are particularly rich in iodine, an essential mineral that plays a crucial role in thyroid function and overall metabolism. They also contain significant amounts of iron, calcium, magnesium, potassium, and other trace minerals that are essential for human health. Moreover, seaweeds are known for their bioactive compounds, such as polysaccharides, phlorotannins, carotenoids, and polyunsaturated fatty acids, which have been linked to several health benefits, including anti-inflammatory, antioxidant, antimicrobial, and anticancer properties. Studies have shown that consuming seaweed may help to reduce the risk of chronic diseases, such as cardiovascular disease, diabetes, and certain types of cancer. Seaweeds may also improve gut health by acting as a prebiotic, promoting the growth of beneficial gut bacteria. In the present chapter, the authors focus on briefly summarizing the bioactive properties of secondary metabolites identified from seaweeds and their therapeutic potential as supportive information for the next chapters in this book. 

Functional foods are foods with therapeutic properties that enhance health along with nutritional properties. This review provides information about the potential of using marine ingredients to develop functional foods by elaborating on the nutritional and therapeutic effects of bioactive compounds found in marine bioresources. Microalgae, marine fungi, bacteria, marine invertebrates, vertebrates, and marine plants are marine resources, and some of the bioactive compounds obtained from marine resources are polysaccharides, fatty acids proteins, peptides, amino acids, many types of essential macro and trace elements, pigments, and phenolic compounds. Marine bioactive compounds have shown many therapeutic properties, including anticancer, antimicrobial, antioxidant, anti-proliferative, anti-inflammatory, antidiabetic, and immune regulatory activities. These compounds can be used in the functional food industry in the form of nano or micro-particles, liposomes, gels, liquids, solids, pastes, and emulsions to overcome the challenges that could occur during product formulation and processing. Overall, this book chapter reveals the important facts about marine bioresources (except Seaweeds) and their functional potentials that the majority are unaware of. It also identifies that future research studies should be carried out.

Inflammation is a complex adaptive response to harmful circumstances such as infection and tissue damage. While inflammation is curable in the acute stage, continuous inflammation can lead to chronic diseases such as diabetes, arthritis, neurodegenerative and cardiovascular diseases, inflammatory bowel disease, and metabolic diseases. The inhibition of inflammatory cell infiltration and excessive cytokine production is beneficial to reduce chronic inflammation. Seaweeds have significant medicinal value due to their bioactive compounds, including seaweed metabolites with anti-inflammatory properties such as sulfated polysaccharides, polyphenols, terpenes, and fatty acids. Marine algal compounds with anti-inflammatory characteristics have recently gained attention in medical research as natural therapeutics that provide a significant protective effect over synthetic drugs. Therefore, this review aims to summarize the current knowledge on the anti-inflammatory activity of seaweed metabolites, including their underlying mechanisms and impact on several chronic inflammatory diseases.

Fucoidans exhibit various biological activities, including immunomodulation, anti-cancer, and pathogenic inhibition. This approach can be used to isolate numerous natural resources and various applications in the pharmaceutical, food, and cosmetic industries. Fucoidan surrounds sulfated L-fucose as a vital monosaccharide and small amounts of mannose, galactose, glucose, xylose, arabinose, uronic acid, and glucuronic acid. Structural analysis revealed that purified fucoidan consists of a carbohydrate chain composed mainly of (1→3)-linked or (1→4)-linked Lfucose residues, with sulfate groups at C-2 and C-4 positions. Fucose residues at C-3 or C-4 serve as branch sites for galactose residues with 1–4)-linkages. Low molecular weight fucoidan, medium molecular weight fucoidan, and high molecular weight fucoidan are the three different types of fucoidan based on molecular weights. The structure of fucoidan determines its bioactivity and its economic and commercial value depending on the species, geographical location, and harvest season. Therefore, shortened phases, low temperatures, and low acidity are used in the extraction technique to determine the distinct structures of fucoidans. In industrial manufacturing, the extraction techniques must be environmentally friendly and cost-effective. In this chapter, classical extraction and purification procedures such as hot water, acidic or alkaline extractions, and chromatographic techniques are discussed and detailed. Microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), and enzyme-assisted extraction (EAE) are innovative techniques for fucoidan extraction. Optimization strategies for pH, temperature, pretreatment conditions, extraction time, and yield parameters also discussed in detail. 

Several functional proteins are identified and extracted from seaweeds. Red seaweeds contain a higher amount of proteins compared to green and brown seaweeds. Based on the structure, functional proteins in seaweeds can be categorized as glycoproteins and lectins, phycobiliproteins, mycosporine-like amino acids, and peptides and hydrolysates. Glycoproteins are oligosaccharides (glycans) bound to the proteins with N-glycosylation or O-glycosyl linkages. Lectins are also a type of glycoprotein with a carbohydrate-binding domain that binds to specific sugar residues. Phycobiliproteins (PBP) are water-soluble fluorescent pigments mostly found in red seaweeds. There are several types of phycobiliproteins, such as phycoerythrin, phycocyanin, phycoerythrocyanins, and allophycocyanin. Mycosporine-like amino acids (MAA) are secondary metabolites produced by marine organisms, including seaweeds. Peptides and hydrolysates are produced by gastrointestinal digestion or hydrolyzation processes. Several studies suggested that seaweed functional proteins exert unique health benefits, including antioxidant, anti-obesity, antimicrobial and antihypertensive activities. In this chapter, we will briefly describe the bioactive properties of proteins isolated from seaweeds.

Seaweeds are known as a delicacy and are a well-known source of vital dietary components. Seaweeds make up some of the most important sources of novel medicinal substances for human use. Additionally, as food, they have been proven to possess diverse health benefits. The distinctive characteristics of the marine environment where seaweed grows are thought to be primarily responsible for most of its traits. Compared to terrestrial plants, marine seaweeds contain higher amounts of health-promoting molecules and materials. Clinical trials and mechanistic research on isolated and extracted compounds from seaweeds have shown potential benefits to gastrointestinal health. The present review emphasizes the major seaweed compounds having nutritive value with special reference to the potential to improve gastrointestinal disorders and gut health.

Seaweeds are a promising therapeutic target in drug development and nutraceuticals due to the presence of structurally different bioactive constituents in their composition. Diabetes mellitus (DM) is a major metabolic disorder that causes impaired insulin secretion, insulin action by the pancreas, or both. Despite the currently available synthetic antidiabetic drugs and insulin injections, there is a necessity for an effective natural approach to preventing or managing DM without long-term diabetes complications by eradicating adverse risk factors. Therefore, exploring the anti-diabetic properties of seaweeds has been revealed as an emerging and intact alternative target. Because of the significant contribution of bioactive metabolites in antidiabetic seaweed-based therapeutics, it is important to summarize the determinant factors, including the rich abundance of polyunsaturated fatty acids, minerals, dietary fibers, polyphenolic compounds, and carotenoids. In addition, seaweed extracts and their bioactive elements have anti-diabetic potential as they inhibit carbohydrate hydrolyzing enzymes in vitro and reduce blood glucose levels in vivo in random and postprandial blood glucose assays. Furthermore, they have been attributed to decreased weight gain in mice and rats, presumably by reducing mRNA expression of pro-inflammatory cytokines while raising mRNA expression of anti-inflammatory cytokines. Their advantageous effect on serum and hepatic lipid profiles, as well as antioxidant enzymes, suggests that seaweeds protect against free radical-mediated oxidative stressinduced hyperglycemia and related hyperlipidemia. Hence, seaweed-based therapeutic efforts for DM have a considerable potential to be used as perspective drugs or dietary supplements. 

Cancer is a major public health concern, and there are no entirely effective treatments. Therefore, natural product-based alternative therapies have been suggested as effective therapeutics against cancer. Marine algae are a promising research tool considered a natural source of bioactive compounds embedded in marine ecology. Algae synthesize a vast variety of bioactive compounds, including polysaccharides, polyphenols, sterols, alkaloids, flavonoids, tannins, proteins, essential fatty acids, enzymes, vitamins, and carotenoids. These pure compounds are composed of intricate structures and exhibit a wide array of possible capabilities, including anticancer potency, in a plethora of in vitro and in vivo settings. Further, these bioactive constituents derived from seaweeds target crucial molecules that control the development of cancer. So, this chapter mainly focuses on the anti-cancer properties of pure compounds isolated from seaweeds and their therapeutic potential against a wide array of cancer types.

Marine seaweed bio-resources (MSBR) have long been recognized for their therapeutic and disease-prevention benefits. They are utilized to prevent various noncommunicable and communicable diseases as active components. In recent years, biotechnologists and pharmacologists have become interested in MSBR as a viable and almost limitless source of various biologically active compounds against a broad spectrum of diseases. The most recent global pandemic Covid-19 raised the scientific world's attention to discovering novel anti-viral agents against viruses. Oceans provide unlimited biological resources to develop therapeutic drugs for treating various human viral diseases. Our major intention of writing this chapter was to draw attention to the anti-viral potential of MSBR against various human viral diseases and gain the strength to conquer future viral pandemics.

Aging is a natural phenomenon that occurs due to diverse changes in cells and tissues over time, and it is impossible to halt or reverse the process. However, extrinsic skin aging, caused by environmental factors, is largely preventable. Natural products have long been used in skin anti-aging treatments. Seaweeds are multicellular, large-sized marine organisms that have a variety of economic values. They are used in cosmetics, cosmeceuticals, and nutricosmetics due to their versatility and richness in valuable bioactive compounds and other nutrients found in different species of seaweed. This category includes phenolic compounds [flavonoids (flavones, flavanols, flavanones, flavonols, anthocyanins, isoflavones); non-flavonoids (tannins, phlorotannins, lignans & stilbenes)], polysaccharides (sulfated galactans, ulvan, sulphuric acid polysaccharides, alginic acid, carrageenans, fucoidan or sulfated fucose, laminarin), peptides and amino acids, fatty acids (docosahexaenoic acid, eicosapentaenoic acid, stearidonic acid and eicosatrienoic acid), vitamins (vitamin B: B1, B2, B3, B5, B6 & B8, vitamin C, vitamin E), vitamin precursors (α-tocopherol, βcarotene, lutein, and zeaxanthin), pigments (chlorophylls, xanthophylls, and carotenoids), and minerals. The presence of these important bioactive compounds plays important roles in cosmeceutical applications by mediating antioxidant, photoprotective, anti-wrinkling, anti-inflammatory, antimicrobial, anti-collagenase, anti-elastase, and anti-metalloproteinase activities through multiple pathways. Furthermore, seaweed nutrients play vital roles in nutricosmetics and are also involved in vital technical features such as moisturizing, thickening, gelling, and emulsifying effects in different skincare products. This chapter specifically describes the skin antiaging properties of seaweeds via different biological activities due to their unique composition.

An excessive buildup of body fat is a sign of the metabolic disease known as obesity. The primary etiological factor for obesity is thought to be an imbalance between energy intake and expenditure, where genetic factors can also play a significant role. The rise in obesity rates over the past few years has encouraged a focus on adipose tissue biology and the precise processes behind adipocyte differentiation and adipogenesis. Due to the advent of several in vitro cell models and molecular biology tools, adipocyte commitment and differentiation have become complicated processes that may be studied to gain a better knowledge of adipogenesis and adipocyte malfunction related to obesity. As the available anti-obesity drugs and surgical interventions cause adverse effects, it is important to rely on natural-based therapeutics in order to manage obesity and its associated complications. Seaweeds are a rich source of natural bioactive compounds that exhibit human beneficial effects. Fucoxanthin, phlorotannins, fucoidan, and alginate are some of the bioactive compounds present in seaweeds exhibiting anti-obesity potential mainly via the inhibition of digestive enzymes and adipocyte differentiation. Therefore, this chapter mainly focuses on the anti-obesity potential of seaweeds proved by many animal and human cell culture models using in vitro and in vivo mechanisms.

Antimicrobial activity is defined as the ability to destroy or inhibit the growth of microorganisms. Antimicrobial compounds are naturally occurring or synthetic organic compounds having antimicrobial activity. Recently, scientists have discovered many pharmaceutically active compounds that have antibacterial, antifungal, antiviral and antiprotozoal activities in seaweeds. To thrive in various environmental stresses, seaweed produces different metabolites such as polyphenols, polysaccharides, proteins, fatty acids, and pigments. These bioactive compounds are responsible for the antimicrobial activity exerted by seaweed. The antimicrobial activity of seaweed is influenced by various factors, such as the type of seaweed extract used, the target microorganisms, and the environmental conditions. The composition of the bioactive compounds from seaweed may depend on the extraction method and the solvent. It also depends on the seaweed sample, such as fresh or dried sample. Different mechanisms are followed by seaweed extract to acquire antimicrobial activities. Seaweed extracts exhibit various inhibition mechanisms, including disruption of the cell membrane, inhibition of target microorganism enzymes, and prevention of microorganism association with cellular receptors of the host cell. The location, salinity, temperature, etc. of the marine environment may affect the chemical composition of the bioactive compounds present in the seaweeds. The antimicrobial activity of seaweed can be evaluated in both in vitro and in vivo assays. Antimicrobial susceptibility tests and antimicrobial resistance tests are carried out by in vitro methods. The antimicrobial activity of seaweed can be a promising source in many applications, such as therapeutic applications, food industries, aquaculture, and biofouling.

Cardiovascular diseases encompass a wide range of disorders that can be categorized into several groups depending on different criteria. The prevalence of cardiac disease is rapidly accelerating in the world. Cardiovascular disorders are responsible for roughly 17.9 million annual fatalities, or nearly 32% of the total mortality globally. The etiology of cardiovascular disease is complex, consisting of both modifiable and non-modifiable risk factors, including metabolic abnormalities, aberrant protein function, genetic mutations, and other contributing elements. Atherosclerosis continues to be the most significant risk factor since it primarily defines the pathogenic processes of cardiovascular diseases. Both pharmacotherapy and surgical interventions are currently in use to alleviate disease symptoms and reduce fatalities. Nevertheless, they have limitations. Therefore, there is an urgent need to develop a novel treatment for cardiovascular disease. Seaweeds are comprised of bioactive compounds with different biological and chemical properties. These can be classified into two groups: primary metabolites and secondary metabolites. Constituents such as phlorotannins, polysaccharides (ulvan, fucoidan, carrageenan), peptides, sterols, and carotenoids (fucoxanthin and astaxanthin) have depicted beneficial effects in preventing cardiovascular diseases. Therefore, this chapter mainly focuses on the bioactive constituents derived from seaweeds and their composition that may benefit in preventing and treating cardiovascular diseases.

Seaweed is considered the most important marine bioresource within marine ecology, enriched with ideal bioactive components, including macro and micronutrients, vitamins, amino acids, proteins, phytohormones, minerals, lipids, carbohydrates, antimicrobial compounds, and osmoprotectants. Currently, seaweed is a potential candidate for the production of human food, animal feed, fuels, fertilizers, chemicals, pharmaceuticals, phytoremediation, nutraceuticals, and hydrocolloids. Within the agricultural sector, seaweed-derived biofertilizers play a vital role. The utilization of seaweed compounds in agriculture and horticulture to nourish and condition the soil, as well as for the enhancement of pest management, are some of the major considerations that have enhanced the growth of the worldwide seaweed extracts market. Seaweed extracts are available as biofertilizers in various forms, including liquid fertilizers, powder, and flakes. In this chapter, our goal is to emphasize the utilization of seaweed-derived biofertilizers in sustainable agriculture and its significance in organic farming, which is a more environmentally friendly option for current and upcoming generations.

Seaweeds are a diverse group of plants with a complicated and contentious taxonomy. In general, seaweeds are classified into three groups, brown (Phaeophyceae), red (Rhodophyceae), and green (Chlorophyceae), based on pigment variability. Seaweeds have tremendous potential for human consumption, cosmetics, fertilizers, industrial gums, and chemicals. Researchers have also discovered that seaweeds have been used as animal feed in the livestock sector for thousands of years. However, out of the approximately 10,000 types of seaweeds, only a few are used in animal consumption, such as Ascophyllum nodosum, Laminaria species, Lithothamnion species, Macrocystis pyrifera, Sargassum species, Palmaria palmata, and Ulva species. According to previous studies, seaweeds have been incorporated into the diet of cows at less than 2% of the dry ingredients, but the isolation of compounds responsible for reducing methane production by cattle has not been done yet. It is crucial to isolate the various bioactive compounds in seaweeds and incorporate them into traditional animal feed to improve their nutritional and functional characteristics. Seaweeds have also been utilized in fish feed, where finely ground seaweed meal made from brown seaweeds acts as a binder in formulated feeds, with the alginate present in seaweed functioning as the binder. Although successful results have been achieved with seaweed consumption for animal feed, researchers have raised concerns about metal uptake from the surrounding water.