Search Results (123)

Macroalgae (seaweeds) produce unique bioactive metabolites that have enabled their survival for millions of years, offering significant potential for human benefits. In the Israeli Mediterranean Sea, no comprehensive systematic surveys of seaweeds have been published since the 1990s, and their chemical composition remains largely unexplored. This study presents an extensive survey of intertidal seaweed communities along the shallow Israeli coastline, documenting their spatial, temporal, and biochemical diversity. Of the 320 specimens collected, 55 seaweed species were identified: 29 red (Rhodophyta), 14 brown (Phaeophyceae), and 12 green (Chlorophyta). A significant shift in species abundance was documented, with a single dominant annual bloom occurring during spring, unlike previously reported biannual blooms. Chemical analysis of the dominant species revealed significant seasonal variations in compound levels, with higher protein content in winter and increased antioxidant capacity during spring. Phenolic and natural sunscreen compounds (mycosporine-like amino acids, MAAs) showed no general seasonal trend. These findings highlight the optimal environmental conditions for seaweed growth and underscore their potential for aquaculture and biotechnology. We hypothesize that the ecologically unique conditions of the Israeli Mediterranean Sea may foster resilient seaweed species enriched with distinctive chemical properties, suitable for nutritional, health, pharmaceutical, and nutraceutical applications, particularly as climate-adaptive bioresources. Full article

An ancient repertoire of ultraviolet (UV)-absorbing pigments which survive today in the phylogenetically oldest extant photosynthetic organisms, the cyanobacteria, point to a direction in evolutionary adaptation of the pigments and their associated biota; from largely UV-C absorbing pigments in the Archean to pigments covering ever more of the longer wavelength UV and visible regions in the Phanerozoic. Since photoprotection is not dependent on absorption, such a scenario could imply selection of photon dissipation rather than photoprotection over the evolutionary history of life, consistent with the thermodynamic dissipation theory of the origin and evolution of life which suggests that the most important hallmark of biological evolution has been the covering of Earth’s surface with organic pigment molecules and water to absorb and dissipate ever more completely the prevailing surface solar spectrum. In this article we compare a set of photophysical, photochemical, biosynthetic, and other inherent properties of the two dominant classes of cyanobacterial UV-absorbing pigments, the mycosporine-like amino acids (MAAs) and scytonemins. We show that the many anomalies and paradoxes related to these biological pigments, for example, their exudation into the environment, spectral coverage of the entire high-energy part of surface solar spectrum, their little or null photoprotective effect, their origination at UV-C wavelengths and then spreading to cover the prevailing Earth surface solar spectrum, can be better understood once photodissipation, and not photosynthesis or photoprotection, is considered as being the important variable optimized by nature. Full article

The microalgal defense strategies for different white light intensities (70–700 μmol m⁻² s⁻¹) were investigated in isolates from unexplored habitats, focusing on photosynthetic performance. Chlorella sorokiniana strain F4 from a Mediterranean inland swamp and two strains related to Pectinodesmus pectinatus (PEC) and Ettlia pseudoalveolaris (ETI) from an Ecuadorian highland lake were exposed to light over 18 h. The results showed that PSII photochemical efficiency was affected with increasing light due to photoinhibition or photodamage. F4 showed a low threshold of saturation light intensity, after which NPQ was compromised and total antioxidant levels were increased, leading to a reduction in its PSII photochemistry performance. F4 exhibited limited capacity for antennae reorganization in response to light stress. ETI and PEC differed in their photophysiological responses, although they came from the same habitat. ETI maintained high Chlb to Chla (i.e., large antennae), exhibited sustained energy dissipation, and preserved a high antioxidant pool (i.e., mycosporine-like amino acids) in all lights. Differently, in PEC, NPQ, antennae rearrangement, and reactive oxygen species scavenger pool were induced in a light-dependent manner. This study revealed the complex relationship between light parameters and microalgal physiology affected by environmental constraint adaptation and phylogenetic diversity. Full article

This study presents the results obtained from extracting and quantifying cosmetically valuable metabolites such as phenolic compounds and mycosporine-like amino acids (MAAs) from 12 samples of marine macroalgae collected in the Colombian Caribbean Sea. Natural deep eutectic solvents (NADESs) were prepared, physicochemically tested (viscosity, surface tension, pH, and conductivity), and then compared with water as the reference solvent to quantify phenolic compounds using the Folin–Ciocalteau test. With a simple extraction assay with water and ultrasound followed by ultraviolet spectral scanning the presence of MAAs was easily determined in several of the analysed samples, and then they were identified by HPLC-DAD. Hydrochloric acid solution at 5% extracted a higher content of phenolic compounds than NADES and water. The NADES that showed the highest phenolic compound extraction yield was a mixture of betaine, glucose, and water with 1:1:5 molar ratio. Sargassum cf. ramifolium and Sargassum fluitans showed the highest contents of phenolic compounds extracted with NADES, with 29.2 and 21.9 mg GAE/g DW, respectively. The results show that NADESs are an interesting alternative for the more efficient extraction of cosmetically valuable compounds such as phenolic compounds and mycosporine-type amino acids from marine macroalgae. Full article

Marine microalgae have emerged as promising biofactories for the sustainable production of high-value bioactive compounds with significant applications in human health, cosmetics, and functional foods. This review offers a comprehensive overview of the primary classes of bioactives synthesised by marine microalgae, including polyunsaturated fatty acids, carotenoids, phycobiliproteins, peptides, sterols, polysaccharides, phenolic compounds, vitamins, mycosporine-like amino acids, and alkaloids. These compounds demonstrate diverse biological activities, such as antioxidant, anti-inflammatory, antimicrobial, anticancer, immunomodulatory, and photoprotective effects, increasingly validated through in vitro, and clinical studies. Their mechanisms of action and roles in disease prevention and wellness promotion are examined in detail, with an emphasis on pharmaceutical (e.g., cardiovascular, neuroprotective), cosmetic (e.g., anti-ageing, UV protection), and nutraceutical (e.g., metabolic and immune-enhancing) applications. The review also addresses critical challenges in strain selection, cultivation technologies, downstream processing, product standardisation, and regulatory approval. Simultaneously, emerging opportunities driven by synthetic biology, omics integration, and circular biorefinery approaches are transforming marine microalgae into precise platforms for next-generation bioproducts. By summarising current knowledge and future directions, this work underscores the essential role of marine microalgae in advancing the blue bioeconomy and tackling global sustainability challenges. Full article

Nostoc flagelliforme, a filamentous cyanobacterium inhabiting desert biological soil crusts (BSCs), has developed exceptional strategies to endure extreme environmental stresses, including severe desiccation, intense ultraviolet (UV) radiation, and drastic temperature fluctuations. These organisms must effectively sense and predict environmental changes, particularly the onset of desiccation. This review explores recent advancements in the molecular mechanisms that enable N. flagelliforme to survive under such harsh conditions, with a focus on stress signal sensing, transduction pathways, and photosynthetic adjustments. Key molecular adaptations include the production of extracellular polysaccharide (EPS) sheaths for water retention, the accumulation of compatible solutes like trehalose, and the synthesis of UV-absorbing compounds such as scytonemin and mycosporine-like amino acids (MAAs). Furthermore, N. flagelliforme utilizes a complex signal transduction network, including light-sensing pathways, to regulate responses to rehydration and desiccation cycles. This review emphasizes the integrative nature of N. flagelliforme’s adaptive mechanisms and highlights their potential for biotechnological applications, such as enhancing drought tolerance in crops and advancing ecological restoration in arid regions. Full article

Microalgae offer a sustainable and versatile source of bioactive compounds. Their rapid growth, efficient CO₂ utilization, and adaptability make them a promising alternative to traditional production methods. Key compounds, such as proteins, polyunsaturated fatty acids (PUFAs), polyphenols, phytosterols, pigments, and mycosporine-like amino acids (MAAs), hold significant commercial value and are widely utilized in food, nutraceuticals, cosmetics, and pharmaceuticals, driving innovation across multiple industries. Their antiviral and enzyme-producing capabilities further enhance industrial and medical applications. Additionally, microalgae-based biostimulants and plant elicitor peptides (PEPs) contribute to sustainable agriculture by enhancing plant growth and resilience to environmental stressors. The GRAS status of several species facilitates market integration, but challenges in scaling and cost reduction remain. Advances in biotechnology and metabolic engineering will optimize production, driving growth in the global microalgae industry. With increasing consumer demand for natural, eco-friendly products, microalgae will play a vital role in health, food security, and environmental sustainability. Full article

The depletion of the ozone layer and climate change have increased exposure to ultraviolet (UV) radiation, driving the search for natural photoprotective agents. Marine macroalgae, particularly Gracilaria sp. (Rhodophyta) and Sargassum polyceratium (Ochrophyta), are rich in UV-absorbing bioactives, such as mycosporine-like amino acids (MAAs) and fucoxanthin, offering natural alternatives to synthetic sunscreens. This study aimed to develop and optimize a nanoemulsion incorporating both algal extracts, with MAAs and fucoxanthin strategically distributed in the aqueous and oil phases, respectively, to enhance synergistic broad-spectrum UV protection. MAAs were quantified in Gracilaria sp. using UHPLC-DAD, revealing 8.03 mg/g dry weight, primarily composed of shinorine and porphyra-334. Fucoxanthin was identified in S. polyceratium at 0.98 mg/g dry weight. A Box–Behnken design (BBD) was employed to optimize the nanoemulsion, targeting minimal droplet size and optimal ζ potential. The resulting formulation achieved a droplet size less than 100 nm and a ζ potential less than −25.0 mV. In vitro spectrophotometric analysis demonstrated significant photoprotective potential. The nanoemulsion containing only 375 ppm of algal extracts exhibited a UVA ratio of 1.25 and a critical wavelength of 379 nm, meeting the criteria for broad-spectrum protection and outperforming the commercial natural filter Helioguard^®365. These results confirm the efficacy of combining red and brown algae extracts in a nanoemulsion platform to deliver sustainable, low-dose photoprotection. This work presents, for the first time, the incorporation of red and brown algae extracts into a single nanoemulsion system, representing a novel strategy to maximize the combined photoprotective potential of MAAs and fucoxanthin. Ultimately, this investigation contributes to the growing field of marine-derived sunscreens and supports the advancement of “blue beauty” innovations aligned with eco-conscious formulation principles. Full article

Shinorine is a mycosporine-like amino acid isolated from laver (Porphyra dentata), and interest in its functionality has increased recently due to increased production using yeast. There have been few reports on the pharmacological activity of shinorine, and we sought to find the pharmacological significance of shinorine. In the present study, we investigated the pharmacological effects of shinorine purified from Porphyra dentata on ARPE-19 cells. First, when ARPE-19 cells were treated with bis-retinoid N-retinyl-N-retinylidene ethanolamine (A2E) and blue light (BL), cytotoxicity increased, and apoptosis was observed. We investigated the effects of shinorine on A2E- and BL-induced cytotoxicity and changes in apoptotic factors, inflammation, and carbonyl stress. A2E and BL exposure increased ARPE-19 cell apoptosis, but this increase was attenuated by shinorine in a concentration-dependent manner. Treatment with A2E and BL induced ARPE-19 cell apoptosis, but treatment with shinorine decreased the apoptotic factors, such as MAPKs. Shinorine reduced p-JNK and p-P38, which were increased by A2E and BL. In addition, shinorine was found to regulate inflammatory proteins and proteins associated with carbonyl stress. In conclusion, shinorine may suppress cell damage caused by A2E treatment and BL exposure at the cellular level by regulating various cell death and inflammatory response pathways. Full article

Non-photosynthetic photoreceptors detecting different wavelength ranges in the UV and visible region of spectra may trigger algal acclimation and homeostasis. We studied Plocamium cartilagineum responses based on the saturation of photosynthesis by Amber light and supplementation by different light qualities, applying an experimental design able to simulate a daily cycle in a fully automated system. Thalli were exposed to Amber, Amber + UV-A, Amber + Blue and Amber + Green radiation treatments under two nitrate levels (60 and 240 μM) for enrichment lasting two weeks. P. cartilagineum photosynthesis and biochemistry were measured during different experimental periods. Photosynthesis showed only slight variations, emphasizing that other response variations could be activated by photomorphogenic pathways. Nitrate assimilation was higher in the treatments containing blue and green lights, potentially caused by increasing nitrate reductase activity. Photosynthetic pigments and mycosporine-like amino acids were affected over the two weeks, being mostly influenced by UV-A and blue radiations with the highest nitrate concentration. The shinorine content of thalli under blue radiation with 240 μM of nitrate increased at day 7, possibly modulated by a blue light photoreceptor. The increase in the bioactive compounds in the short-term by specific light qualities under optimal photosynthetic performance was found to be a relevant biotechnological strategy. Full article

Background/Objectives: This study explores the bioactive potential of Bovistella utriformis biomass and its polysaccharides (PsBu) through comprehensive biochemical and bioactivity analyses, focusing on their antioxidant, cytotoxic, and antihyperglycemic properties. Methods: Elemental analysis determined the biomass’s chemical composition. Antioxidant activity was assessed using ABTS and DPPH assays. Monosaccharide composition was analyzed via gas chromatography-mass spectrometry (GC-MS). In vitro cytotoxicity assays were conducted on cancer and normal cell lines to determine IC₅₀ values and selectivity indices (SI). Zebrafish embryo toxicity was evaluated for teratogenic effects, and an in vivo antihyperglycemic study was performed in diabetic rat models. Results: The biomass exhibited high carbon content (around 41%) and nitrogen levels, with a balanced C/N ratio nearing 5. Protein content exceeded 50%, alongside significant carbohydrate, fiber, and ash levels. Antioxidant assays revealed inhibition rates of approximately 89% (ABTS) and 64% (DPPH). GC-MS analysis identified glucose as the predominant sugar (>80%), followed by galactose and mannose. Additionally, HPLC detected a photoprotective compound, potentially a mycosporin-like amino acid. Cytotoxicity assays demonstrated PsBu’s selective activity against colon, lung, and melanoma cancer cell lines (IC₅₀: 100–500 µg·mL⁻¹), while effects on normal cell lines were lower (IC₅₀ > 1300 µg·mL⁻¹ for HaCaT, >2500 µg·mL⁻¹ for HGF-1), with SI values approaching 27, supporting PsBu’s potential as a targeted anticancer agent. Zebrafish embryo assays yielded LC₅₀ values ranging from 1.4 to 1.8 mg·mL⁻¹. In vivo, PsBu reduced fasting blood glucose levels in hyperglycemic rats (approximately 210 mg·dL⁻¹ vs. 230 mg·dL⁻¹ in controls) and preserved pancreatic β-cell integrity (around 80% vs. 65% in controls). Conclusions: These findings suggest that B. utriformis biomass and PsBu exhibit strong antioxidant activity, selective cytotoxicity against cancer cells, and antihyperglycemic potential, making them promising candidates for further biomedical applications. Full article

Porphyra specimens are red macroalgae with significant economic importance for food and pharmaceutical industries due to their physiological activities resulting from their bioactive compounds (BACs). Due to its economic importance, this research aimed to characterize the photosynthetic and biochemical aspects of the conchocelis and blade phases of Porphyra linearis to understand and help improve production of this algae. The algae were cultured for 7 days with nutrients for blade phase measurements, while another portion was cultured without nutrients for 21 days to release carpospores, which were cultivated for 4 months. For both phases, the content of BACs (chlorophyll a, carotenoids, phycobiliproteins, phenols, carbohydrates, proteins, mycosporine-like amino acids), antioxidant activity, and photosynthetic parameters were analyzed. Most of the parameters showed the blade phase had better results than conchocelis, except for carbohydrates. Phycobiliproteins showed no statistical differences between the phases. These findings highlight that conchocelis is not a good BACs source compared to the blade phase, but it is a crucial phase in the life cycle of Porphyra. Understanding the key parameters for maintaining the cultivation of conchocelis stocks for the development of the blade phase is a way to produce macroscopic biomass of this economically important algae throughout the year. Full article

Mycosporine-like amino acids (MAAs) and glyceroglycolipids have promising applications in various fields, but limited research exists on their simultaneous extraction from macroalgae. This study optimized the key parameters (liquid–solid ratio, extraction temperature and extraction time) in the extraction of MAAs and glyceroglycolipids from Ecklonia kurome and Ulva lactuca using single factor and response surface experiments. The yields of MAAs from E. kurome and U. lactuca were 169.71 mg/g and 177.33 mg/g, respectively, while glyceroglycolipids were extracted from the residue with yields of 163.51 mg/g and 213.45 mg/g, respectively. Both extracts showed concentration-dependent antioxidant activities, with the MAAs extracted from U. lactuca demonstrating the strongest effect. The addition of MAA extract to flaxseed oil significantly reduced oxidation rancidity, highlighting its potential as a natural antioxidant for oils. The glyceroglycolipid extract from E. kurome exhibited significant moisture absorption, and a water-retaining agent prepared from this extract showed excellent moisture retention and resistance to high temperatures, freezing, and pressure. A silica gel column chromatography method confirmed the presence of MGDG in the purified glyceroglycolipid extract. These findings suggested that E. kurome and U. lactuca can be converted into high-value-added compounds with potential applications in food, cosmetics, and pharmaceuticals. Full article

Algae have great therapeutic value and have attracted a great deal of attention due to the abundance of bioactive compounds they contain, which may be the key to fighting diseases of various origins, such as skin cancer, breast cancer, or osteosarcoma. In this regard, global trends indicate that cancer is likely to become the leading cause of death and the main obstacle to increased life expectancy in the 21st century, which is related to multiple factors, including the various effects of climate change, which will continue to cause afflictions to human health. Then, excess exposure to ultraviolet radiation (UVR) causes damage to DNA, proteins, enzymes, and various cellular structures and leads to the development of cancer, premature aging of the skin (wrinkles, dryness, dilation of blood vessels, and loss of collagen and elastin), or alterations of the immune system. In addition, multidrug resistance (MDR) is characterized by the overexpression of efflux pumps, such as P-glycoprotein or P-gp, that expel chemotherapeutic drugs out of the cancer cell being the main obstacle to their efficacy. Some molecules inhibit efflux pumps when co-administered with antineoplastic agents, such as glycolipids. Mycosporin-like amino acids and glycolipids isolated from Sargassum have shown an important role as potential anticancer agents. The results show that glycolipids and mycosporin-like amino acids present in brown algae of the genus Sargassum exhibit cytotoxic effects on different types of cancer, such as breast cancer, leukemia, and osteosarcoma, which is a key criterion to be considered as a natural anti-cancer strategy; but, more in-depth in vitro studies are needed to represent them at the in vivo level, as well as their validation in preclinical assays. Full article

Mycosporine-glycine (M-Gly), a member of the mycosporine-like amino acid (MAA) family, is known for its potent antioxidant and anti-inflammatory properties. However, its in vivo efficacy in alleviating acute skin photodamage, primarily caused by oxidative stress, has not been well explored. In this investigation, 30 female ICR mice were divided into four groups: a control group and three Ultraviolet B (UVB)-exposed groups treated with saline or M-Gly via intraperitoneal injection for 30 days. At the end of the experiment, UVB exposure caused erythema, wrinkling, collagen degradation, and mast cell infiltration in mouse dorsal skin. M-Gly treatment improved skin appearance and reduced mast cell numbers, while also elevating antioxidant levels, including superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). Furthermore, M-Gly reduced inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and IL-1β, typically upregulated after UVB exposure. M-Gly also protected skin collagen by upregulating type I procollagen and decreasing MMP-1 levels. Skin metabolomic profiling identified 34 differentially abundant metabolites, and transcriptomic analysis revealed 752 differentially expressed genes. The combined metabolomic and transcriptomic data indicate that M-Gly’s protective effects may involve the regulation of ion transport, cellular repair, metabolic stability, collagen preservation, and the Nrf2/HO-1 pathway. These findings highlight M-Gly’s potential as an endogenous antioxidant for protecting skin from UVB-induced damage. Full article