Nutritional Composition of Beach-Cast Marine Algae from the Brazilian Coast: Added Value for Algal Biomass Considered as Waste

Algae-derived compounds: Bioactivity, allergenicity and technologies enhancing their values

As a rapidly growing source of human nutrients, algae biosynthesize diverse metabolites which have promising bioactivities. However, the potential allergenicity of algal components hinder their widespread adoption. This review provides a comprehensive review of various macro and micronutrients derived from algal biomass, with particular focus on bioactive compounds, including peptides, polyphenols, carotenoids, omega-3 fatty acids and phycocyanins. The approaches used to produce algal bioactive compounds and their health benefits (antioxidant, antidiabetic, cardioprotective, anti-inflammatory and immunomodulatory) are summarised. This review particularly focuses on the state-of-the-art of precision fermentation, encapsulation, cold plasma, high-pressure processing, pulsed electric field, and subcritical water to reduce the allergenicity of algal compounds while increasing their bioactivity and bioavailability. By providing insights into current challenges of algae-derived compounds and opportunities for advancement, this review contributes to the ongoing discourse on maximizing their application potential in the food nutraceuticals, and pharmaceuticals industries.

Biotechnological Potential of Macroalgae during Seasonal Blooms for Sustainable Production of UV-Absorbing Compounds

Marine macroalgae (seaweeds) are important primary global producers, with a wide distribution in oceans around the world from polar to tropical regions. Most of these species are exposed to variable environmental conditions, such as abiotic (e.g., light irradiance, temperature variations, nutrient availability, salinity levels) and biotic factors (e.g., grazing and pathogen exposure). As a result, macroalgae developed numerous important strategies to increase their adaptability, including synthesizing secondary metabolites, which have promising biotechnological applications, such as UV-absorbing Mycosporine-Like Amino Acid (MAAs). MAAs are small, water-soluble, UV-absorbing compounds that are commonly found in many marine organisms and are characterized by promising antioxidative, anti-inflammatory and photoprotective properties. However, the widespread use of MAAs by humans is often restricted by their limited bioavailability, limited success in heterologous expression systems, and low quantities recovered from the natural environment. In contrast, bloom-forming macroalgal species from all three major macroalgal clades (Chlorophyta, Phaeophyceae, and Rhodophyta) occasionally form algal blooms, resulting in a rapid increase in algal abundance and high biomass production. This review focuses on the bloom-forming species capable of producing pharmacologically important compounds, including MAAs, and the application of proteomics in facilitating macroalgal use in overcoming current environmental and biotechnological challenges.

Trace metals and macrominerals in common seaweeds in the Marchica (a restored lagoon, Mediterranean Sea): Nutritional value and health risk assessment

This study investigated the contents of macrominerals (Na, K, Ca, Mg and P) and essential trace metals (Fe, Mn, Cu, Zn and Se) in four species of seaweeds (Gracilaria sp., Alsidium corallinum, Caulerpa prolifera, and Chaetomorpha sp.) from Marchica Lagoon. The contents of macrominerals with mean values (% dw) can be sequenced in this descending order, [Ca > Mg > Na > K > P] for Caulerpa prolifera, and the decreasing sequence [K > Ca > Mg > P > Na] for Chaetomorpha sp. In red seaweeds, Gracilaria sp. and Alsidiumcorallinum followed these orders: [K > Ca > Na > Mg > P] and [K > Na > Ca > Mg > P] respectively. The essential trace metals mean values (mg kg-1) followed the decreasing order [Fe > Mn > Zn > Cu > Se] for Alsidiumcorallinum, Chaetomorpha sp. and Gracilaria sp., and the following order [Fe > Mn > Zn > Se > Cu] for Caulerpa prolifera. Based on the calculated recommended dietary allowance (RDA), targeted hazard quotient (THQ) and the hazard index (HI), the studied seaweeds did not pose any health risk for human consumption.

Anti-Inflammatory Activity of Fucan from Spatoglossum schröederi in a Murine Model of Generalized Inflammation Induced by Zymosan

Fucans from marine algae have been the object of many studies that demonstrated a broad spectrum of biological activities, including anti-inflammatory effects. The aim of this study was to verify the protective effects of a fucan extracted from the brown algae Spatoglossum schröederi in animals submitted to a generalized inflammation model induced by zymosan (ZIGI). BALB/c mice were first submitted to zymosan-induced peritonitis to evaluate the treatment dose capable of inhibiting the induced cellular migration in a simple model of inflammation. Mice were treated by the intravenous route with three doses (20, 10, and 5 mg/kg) of our fucan and, 1 h later, were inoculated with an intraperitoneal dose of zymosan (40 mg/kg). Peritoneal exudate was collected 24 h later for the evaluation of leukocyte migration. Doses of the fucan of Spatoglossum schröederi at 20 and 10 mg/kg reduced peritoneal cellular migration and were selected to perform ZIGI experiments. In the ZIGI model, treatment was administered 1 h before and 6 h after the zymosan inoculation (500 mg/kg). Treatments and challenges were administered via intravenous and intraperitoneal routes, respectively. Systemic toxicity was assessed 6 h after inoculation, based on three clinical signs (bristly hair, prostration, and diarrhea). The peritoneal exudate was collected to assess cellular migration and IL-6 levels, while blood samples were collected to determine IL-6, ALT, and AST levels. Liver tissue was collected for histopathological analysis. In another experimental series, weight loss was evaluated for 15 days after zymosan inoculation and fucan treatment. The fucan treatment did not present any effect on ZIGI systemic toxicity; however, a fucan dose of 20 mg/kg was capable of reducing the weight loss in treated mice. The treatment with both doses also reduced the cellular migration and reduced IL-6 levels in peritoneal exudate and serum in doses of 20 and 10 mg/kg, respectively. They also presented a protective effect in the liver, with a reduction in hepatic transaminase levels in both doses of treatment and attenuated histological damage in the liver at a dose of 10 mg/kg. Fucan from S. schröederi presented a promising pharmacological activity upon the murine model of ZIGI, with potential anti-inflammatory and hepatic protective effects, and should be the target of profound and elucidative studies.

Enzyme-Assisted Extraction of Ulvan from the Green Macroalgae Ulva fenestrata

Ulvan is a sulfated polysaccharide extracted from green macroalgae with unique structural and compositional properties. Due to its biocompatibility, biodegradability, and film-forming properties, as well as high stability, ulvan has shown promising potential as an ingredient of biopolymer films such as sustainable and readily biodegradable biomaterials that could replace petroleum-based plastics in diverse applications such as packaging. This work investigates the potential of Ulva fenestrata as a source of ulvan. Enzyme-assisted extraction with commercial cellulases (Viscozyme L and Cellulysin) and proteases (Neutrase 0.8L and Flavourzyme) was used for cell wall disruption, and the effect of the extraction time (3, 6, 17, and 20 h) on the ulvan yield and its main characteristics (molecular weight, functional groups, purity, and antioxidant capacity) were investigated. Furthermore, a combined process based on enzymatic and ultrasound extraction was performed. Results showed that higher extraction times led to higher ulvan yields, reaching a maximum of 14.1% dw with Cellulysin after 20 h. The combination of enzymatic and ultrasound-assisted extraction resulted in the highest ulvan extraction (17.9% dw). The relatively high protein content in U. fenestrata (19.8% dw) makes the residual biomass, after ulvan extraction, a potential protein source in food and feed applications.

Seaweeds and Corals from the Brazilian Coast: Review on Biotechnological Potential and Environmental Aspects

Brazil has a megadiversity that includes marine species that are distributed along 800 km of shoreline. This biodiversity status holds promising biotechnological potential. Marine organisms are important sources of novel chemical species, with applications in the pharmaceutical, cosmetic, chemical, and nutraceutical fields. However, ecological pressures derived from anthropogenic actions, including the bioaccumulation of potentially toxic elements and microplastics, impact promising species. This review describes the current status of the biotechnological and environmental aspects of seaweeds and corals from the Brazilian coast, including publications from the last 5 years (from January 2018 to December 2022). The search was conducted in the main public databases (PubChem, PubMed, Science Direct, and Google Scholar) and in the Espacenet database (European Patent Office-EPO) and the Brazilian National Property Institute (INPI). Bioprospecting studies were reported for seventy-one seaweed species and fifteen corals, but few targeted the isolation of compounds. The antioxidant potential was the most investigated biological activity. Despite being potential sources of macro- and microelements, there is a literature gap regarding the presence of potentially toxic elements and other emergent contaminants, such as microplastics, in seaweeds and corals from the Brazilian coast.

Seaweed Derived Lipids Are a Potential Anti-Inflammatory Agent: A Review

Chronic, low-grade inflammation is linked to the development of non-communicable diseases, including cancer, cardiovascular disease, obesity, insulin resistance, diabetes, and others which together contribute to more than 50% of deaths globally. Modulation of inflammatory responses may be a promising strategy, and n-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA) may offer a new therapeutic option in inflammatory conditions. Seaweeds are characterised by high nutritional quality and are a good source of many bioactive compounds, including n-3 LC-PUFA. This review addresses the potential anti-inflammatory properties of seaweed derived lipids, and their immunomodulating mechanisms in order to identify the possible applications of seaweed as an anti-inflammatory functional food ingredient or dietary supplement. A few studies have evaluated the anti-inflammatory activity of seaweed lipids using crude lipid extracts, lipid fractions and isolated complex lipids from several seaweeds belonging to the Ochrophyta and Rhodophyta phyla, with only three Ulva rigida, Ulva sp. and Codium tomentosum within the Chlorophyta phylum. It was reported that seaweed derived lipids suppress inducible nitric oxide synthase and cyclooxygenase-2 expression and reduce nuclear factor κB p100 and myeloid differentiation primary response 88 protein levels leading to the downregulation of the production of several pro-inflammatory cytokines and nitric oxide. Further investigations are required to unravel the complex mechanisms underlying their preventive action against chronic inflammation and their potential use as a new functional food ingredient and/or health supplement.

Glyceroglycolipids in marine algae: A review of their pharmacological activity

Glyceroglycolipids are major metabolites of marine algae and have a wide range of applications in medicine, cosmetics, and chemistry research fields. They are located on the cell surface membranes. Together with glycoproteins and glycosaminoglycans, known as the glycocalyx, they play critical roles in multiple cellular functions and signal transduction and have several biological properties such as anti-oxidant and anti-inflammatory properties, anti-viral activity, and anti-tumor immunity. This article focused on the sources and pharmacological effects of glyceroglycolipids, which are naturally present in various marine algae, including planktonic algae and benthic algae, with the aim to highlight the promising potential of glyceroglycolipids in clinical treatment.