Marine Drugs

51 pages, 1527 KB

Open AccessArticle

Cultivation of Limnospira platensis (Spirulina) in Full Seawater with Medium Recycling: A Promising Source of Protein and Phycocyanin for Arid Coastal Regions

by Monserrat Alemán, Marianna Venuleo, Juan Luis Gómez-Pinchetti, Eduardo Portillo and Flavio Guidi

Mar. Drugs 2026, 24(4), 141; https://doi.org/10.3390/md24040141 - 16 Apr 2026

Abstract

Protein and phycocyanin production is challenged by freshwater scarcity in arid coastal regions. This study assessed and optimized the cultivation of Limnospira platensis BEA 1257B in full seawater. Eight cultivation phases were conducted in 10,000 L raceways under a greenhouse to evaluate the [...] Read more.

Protein and phycocyanin production is challenged by freshwater scarcity in arid coastal regions. This study assessed and optimized the cultivation of Limnospira platensis BEA 1257B in full seawater. Eight cultivation phases were conducted in 10,000 L raceways under a greenhouse to evaluate the effects of seawater content, nutrient availability, shading, CO₂ supply, and medium recycling on biomass productivity and biochemical composition. Freshwater, energy, and fertilizer savings, together with effluent characteristics of the optimized full-seawater recirculation strategy (SWR), were evaluated against a conventional freshwater cultivation process. Lower productivity was associated with high salinity and irradiance. Under long-term optimized conditions (615 days), the strain achieved stable productivities of 4.1 ± 1.4 gDW m⁻² day⁻¹ (14.8 ± 5.0 tDW ha⁻¹ year⁻¹). Increasing salinity promoted carbohydrate accumulation in the biomass (26.0% AFWD), while protein (64.4%) and C-phycocyanin (9.9%) moderately decreased. Nevertheless, protein quality, phycocyanin, and essential fatty acids remained high. Spray-dried biomass exhibited nutritionally relevant contents of K, Mg, Ca, Fe, and Mn, and complied with international food safety standards. SWR reduced energy demand by 10.5% and freshwater consumption by 12% on a surface basis, although these advantages were partially offset when expressed per unit of product, while clearly supporting environmentally sustainable and regulatory-compliant Limnospira production. Full article

(This article belongs to the Special Issue Algal Cultivation for Obtaining High-Value Products, 2nd Edition)

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23 pages, 16145 KB

Open AccessArticle

Antioxidant Peptides from Skipjack tuna: Ameliorate Function on Cigarette Smoke Extract-Induced COPD in Cell Model by Targeting Oxidative Stress, Inflammation and Apoptosis

by Yu-Hui Zeng, Yang-Yan Jin, Yan Sheng, Chang-Feng Chi and Bin Wang

Mar. Drugs 2026, 24(4), 140; https://doi.org/10.3390/md24040140 - 16 Apr 2026

Abstract

Antioxidant peptides show significant activity and can be developed into functional foods for treating chronic diseases. Cigarette smoke components can cause damage or even apoptosis of lung cells, eventually leading to chronic lung diseases. Therefore, this study aimed to investigate the protective effects [...] Read more.

Antioxidant peptides show significant activity and can be developed into functional foods for treating chronic diseases. Cigarette smoke components can cause damage or even apoptosis of lung cells, eventually leading to chronic lung diseases. Therefore, this study aimed to investigate the protective effects and mechanisms of Skipjack tuna peptides against in vitro cigarette smoke extract (CSE)-induced chronic obstructive pulmonary disease (COPD). The results demonstrated that tuna peptides DVGRG (S1), PHPR (S5), GRVPR (S6), and SVTEV (S7) significantly enhanced the activities of SOD, CAT, and GSH-Px by upregulating the mRNA transcription levels of Keap1 and Nrf2, consequently reducing ROS and MDA levels in CSE-induced COPD model of MLE-12 cells. Molecular docking analysis revealed that S1, S6, and S7 competitively inhibited the Keap1-Nrf2 interaction by binding to the Kelch domain of Keap1, whereas S5 operated through a non-competitive mechanism. These peptides also downregulated p65 mRNA expression and upregulated IκBα mRNA expression, leading to a significant reduction in inflammatory cytokines of IL-1β, IL-6, and TNF-α, thereby alleviating inflammatory responses. Furthermore, these peptides significantly inhibited CSE-induced apoptosis by restoring mitochondrial membrane potential and upregulating the Bcl-2/Bax ratio. Additionally, S1, S5, S6, and S7 promoted MLE-12 cell migration in a concentration-dependent manner, suggesting a role in lung epithelial repair and regeneration. In conclusion, tuna peptides S1, S5, S6, and S7 exert antioxidant, anti-inflammatory, anti-apoptotic, and cell migration-promoting effects through the regulation of the Keap1/Nrf2 and NF-κB signaling pathways, as well as Bcl-2/Bax apoptotic balance, providing a promising strategy for mitigating CSE-induced lung injury. Full article

(This article belongs to the Special Issue Marine Bioactive Peptides—Structure, Function and Application, 3rd Edition)

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26 pages, 1069 KB

Open AccessReview

A Review of Omega-3 Fatty Acids from Marine Source Supplements and Enhanced Food Effects on Children’s Development, Neurological and Metabolic Disorders and General Health

by Maria Dimopoulou, Stavroula Savvidi, Panagiotis Madesis, Aliki Dimopoulou, Dimitrios Stagos and Olga Gortzi

Mar. Drugs 2026, 24(4), 139; https://doi.org/10.3390/md24040139 - 15 Apr 2026

Abstract

Long-chain polyunsaturated fatty acids (LC-PUFAs) of omega-3 family, particularly docosahexaenoic acid and eicosapentaenoic acid, are essential nutrients that play a critical role in children’s growth and health. This review examines the evidence on the effects of omega-3 supplements and omega-3-enhanced foods on children’s [...] Read more.

Long-chain polyunsaturated fatty acids (LC-PUFAs) of omega-3 family, particularly docosahexaenoic acid and eicosapentaenoic acid, are essential nutrients that play a critical role in children’s growth and health. This review examines the evidence on the effects of omega-3 supplements and omega-3-enhanced foods on children’s development, as well as on neurological and metabolic disorders. Research consistently highlights the importance of DHA in brain and visual development, especially during early childhood, when rapid neural growth occurs. PubMed, Web of Science, Scopus and the Cochrane Library databases were searched for relevant articles published up to January 2026. Adequate omega-3 intake has been associated with improvements in cognitive performance, attention, and learning outcomes. In children with neurodevelopmental conditions such as attention-deficit/hyperactivity disorder and autism spectrum disorder, omega-3 supplementation shows modest but potential benefits in reducing behavioral symptoms and supporting executive function, although results remain mixed. Additionally, omega-3 fatty acids exhibit anti-inflammatory properties that may positively influence metabolic health, including lipid profiles, insulin sensitivity, and obesity-related risk factors in children. Omega-3-enhanced foods provide an alternative to supplements and may improve adherence and overall dietary quality. However, variability in dosage, study design, and baseline nutritional status limits definitive conclusions. Overall, omega-3 fatty acids appear to support healthy development and may aid in managing certain neurological and metabolic disorders in children. Full article

(This article belongs to the Special Issue Effects of Marine Natural Products in Brain Health and Metabolic Diseases, 2nd Edition)

33 pages, 17563 KB

Open AccessReview

Marine Bioactives in Liver Aging: Mechanistic Insights and Translational Potential

by Ricardo Moreno Traspas and Zachariah Tman

Mar. Drugs 2026, 24(4), 138; https://doi.org/10.3390/md24040138 - 15 Apr 2026

Abstract

The liver is a central regulator of systemic metabolism and exhibits exceptional regenerative capacity, yet aging progressively impairs hepatic resilience through metabolic dysregulation, mitochondrial dysfunction, epigenetic instability, and chronic inflammation. Marine ecosystems constitute a vast and underexplored source of structurally diverse bioactive compounds [...] Read more.

The liver is a central regulator of systemic metabolism and exhibits exceptional regenerative capacity, yet aging progressively impairs hepatic resilience through metabolic dysregulation, mitochondrial dysfunction, epigenetic instability, and chronic inflammation. Marine ecosystems constitute a vast and underexplored source of structurally diverse bioactive compounds that have evolved to modulate conserved stress response and homeostatic pathways. This review synthesizes current preclinical evidence demonstrating how marine-derived metabolites target key molecular axes implicated in liver aging, including energy sensing, redox balance, mitochondrial quality control, inflammatory signaling, and chromatin-associated regulation. Rather than focusing solely on isolated hepatoprotective effects, we frame marine bioactives within an aging biology perspective, highlighting their ability to modulate pathways associated with cellular plasticity and resilience. We further propose that this mechanistic convergence provides a theoretical framework for exploring marine compounds as potential adjunctive modulators within emerging, experimental liver rejuvenation strategies, including partial cellular reprogramming approaches that require coordinated metabolic and epigenetic control. While acknowledging that direct reversal of liver aging remains to be clinically established, integrating marine chemodiversity with contemporary aging and regenerative biology outlines a conceptual roadmap for developing liver-directed interventions targeting aging-related vulnerability as a fundamental driver of disease. Full article

(This article belongs to the Special Issue Marine Antioxidants 2026)

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14 pages, 2562 KB

Open AccessArticle

Development of an Integrated Screening Framework for Marine-Derived Bacillus Probiotics

by Yaoying Lu, Xiaojing Chen and Yunjiang Feng

Mar. Drugs 2026, 24(4), 137; https://doi.org/10.3390/md24040137 - 15 Apr 2026

Abstract

Probiotics are known to improve gut microbiota balance, enhance food digestion, and support overall health. Among these, Bacillus species are particularly promising due to their safety, spore-forming ability, environmental resilience, and diverse enzymatic activities. However, most Bacillus probiotics used in industry are of [...] Read more.

Probiotics are known to improve gut microbiota balance, enhance food digestion, and support overall health. Among these, Bacillus species are particularly promising due to their safety, spore-forming ability, environmental resilience, and diverse enzymatic activities. However, most Bacillus probiotics used in industry are of terrestrial origin, leaving marine-derived strains largely unexplored. Utilising the untapped potential of marine microbial biomass, this study presents a multi-stage methodology for identifying and evaluating marine-derived Bacillus strains with probiotic potential. A structured screening pipeline was applied to 67 microbial isolates from the Great Barrier Reef sponges. Initial selection focused on essential probiotic characteristics, including growth, stability, safety, and survival under gastrointestinal conditions. Strains meeting these criteria were then assessed for desirable properties, including digestive enzyme production and pathogen inhibition. Using this workflow, three marine-derived Bacillus strains were identified as potential probiotics, one of which demonstrated strong antimicrobial activity against Salmonella enterica at 5 and 10 mg/mL (p < 0.01). These findings demonstrate the capability of marine-associated Bacillus as novel bioproducts with functional antimicrobial properties. Full article

(This article belongs to the Special Issue From Marine Natural Products to Marine Bioproducts)

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18 pages, 6172 KB

Open AccessArticle

Macroalgal Bloom Biomass as a Source of Bioactive Compounds and Antimicrobial Peptides

by Nedeljka Rosic, Isidora Skrlin and Carol Thornber

Mar. Drugs 2026, 24(4), 136; https://doi.org/10.3390/md24040136 - 15 Apr 2026

Abstract

Macroalgal species are widely distributed throughout the world’s oceans and are well recognised for their biotechnological, ecological, and pharmacological potentials, containing a wide range of diverse bioactive compounds. In many coastal habitats worldwide, excessive accumulations of algal biomass (including rapidly growing blooms and [...] Read more.

Macroalgal species are widely distributed throughout the world’s oceans and are well recognised for their biotechnological, ecological, and pharmacological potentials, containing a wide range of diverse bioactive compounds. In many coastal habitats worldwide, excessive accumulations of algal biomass (including rapidly growing blooms and drift accumulations resulting from dislodgement from benthic habitats) are commonplace and can pose environmental and economic challenges. In this study, we report occurrences of algal blooms and drift accumulations during 2024 and 2025 involving three major macroalgal clades, Chlorophyta, Phaeophyceae, and Rhodophyta, from two distinct marine regions: the North Atlantic Ocean and the South Pacific Ocean. Species identified included Grateloupia turuturu, Polyides rotundus, Ascophyllum nodosum, Ulva spp., Sargassum spp. and Fucus spp., among others. The indicated species are known for their diverse pharmacological properties, including antimicrobial, antioxidant, and anti-inflammatory effects. Specialised bioinformatic tools were employed to assess the potential of identified macroalgae as a source of antimicrobial peptides (AMPs). For selected macroalgal species, in silico screening of publicly available databases was performed to identify previously reported and characterised AMPs associated with these species. This in silico approach presents a promising strategy for discovering novel antimicrobial agents with potential activity, especially against drug-resistant bacteria. Finally, applying proteomics methodologies for in silico evaluation of the selected algal species advances modern technologies for the sustainable use of natural resources. Full article

(This article belongs to the Special Issue Proteomic Studies for the Identification and Characterization of Marine Bioactive Molecules, 2nd Edition)

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19 pages, 1367 KB

Open AccessArticle

Freeze-Drying Blue Crab Roe, Sea Urchin, and Beluga Caviar: Impact on Nutritional, Biochemical, and Sensory Properties

by Antonia Angou, Spyros Didos, Konstantina Tsotsouli, Ioannis S. Boziaris and Anagnostis Argiriou

Mar. Drugs 2026, 24(4), 135; https://doi.org/10.3390/md24040135 - 12 Apr 2026

Abstract

The growing demand for clean-label food ingredients drives interest in novel marine flavorings. This study evaluated the physicochemical, antioxidant, volatile (GC-MS), and sensory profiles of freeze-dried powders from blue crab roe (Callinectes sapidus), sea urchin roe (Paracentrotus lividus), and [...] Read more.

The growing demand for clean-label food ingredients drives interest in novel marine flavorings. This study evaluated the physicochemical, antioxidant, volatile (GC-MS), and sensory profiles of freeze-dried powders from blue crab roe (Callinectes sapidus), sea urchin roe (Paracentrotus lividus), and beluga caviar (Huso huso) to assess their culinary potential. Results revealed that sensory quality is governed by the synergy between a matrix’s lipid composition and endogenous antioxidant capacity. Sea urchin powder, possessing a low polyunsaturated fatty acid (PUFA) profile and high carotenoid content, exhibited exceptional oxidative stability, yielding a concentrated marine aldehyde signature and top consumer scores. Blue crab roe demonstrated a robust PUFA matrix buffered by high phenolic content, facilitating controlled lipid peroxidation into desirable savory volatiles (ketones and aldehydes). Conversely, the high-fat, monounsaturated-dominant beluga caviar lacked sufficient antioxidants, leading to lipid degradation, oxidized hydrocarbons, earthy off-flavors, and poor texture. Both crab and caviar powders exhibited favorable Atherosclerosis and Thrombogenicity indices. Ultimately, balancing lipid composition and endogenous antioxidants is crucial for flavor stability, highlighting the commercial and environmental potential of transforming underutilized or invasive species like blue crab into stable, nutrient-dense marine flavoring agents. Full article

(This article belongs to the Special Issue Research on Marine-Derived Functional Foods)

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42 pages, 951 KB

Open AccessFeature PaperReview

Human and Marine Host Defense Peptides for Healthy Skin

by Svetlana V. Guryanova, Oksana Yu. Belogurova-Ovchinnikova and Tatiana V. Ovchinnikova

Mar. Drugs 2026, 24(4), 134; https://doi.org/10.3390/md24040134 - 10 Apr 2026

Abstract

The skin serves as the first line barrier of innate immunity, protecting the body from external influences and maintaining its homeostasis. Exogenous and endogenous stress factors alter the structure and functional properties of the skin. The search for compounds capable of counteracting these [...] Read more.

The skin serves as the first line barrier of innate immunity, protecting the body from external influences and maintaining its homeostasis. Exogenous and endogenous stress factors alter the structure and functional properties of the skin. The search for compounds capable of counteracting these processes has allowed the identification of peptides as promising ingredients of products for medicinal and cosmetic applications. This review comprehensively examines the mechanisms of action and dermatological applications of two distinct classes of natural products—endogenous human peptides and those derived from marine organisms. Human peptides exhibit numerous biological functions, including antimicrobial and immunomodulatory ones, as well as promoting antioxidant protection and wound healing. Microbiome-associated peptides are an underestimated but powerful regulator of skin aging through immunomodulation, inflammation control, barrier function maintenance, and selection of the proper microbial community. Peptides from marine organisms exhibit significant structural diversity and a broad spectrum of biological activity, including regenerative effects and effects on antibiotic-resistant microorganisms. This review summarizes current data obtained from in vitro, ex vivo, and clinical studies demonstrating a broad potential of peptides for maintaining skin health. Both peptide classes represent powerful, targeted strategies for innovative dermatological interventions aimed at promoting skin rejuvenation, protection, and overall homeostasis. Full article

(This article belongs to the Special Issue Marine Bioactive Peptides: Structure, Function, and Therapeutic Potential, 5th Edition)

63 pages, 4383 KB

Open AccessReview

Marine Pharmacology in 2022–2023: Marine Compounds with Antibacterial, Antidiabetic, Antifungal, Anti-Inflammatory, Antiprotozoal, Antituberculosis and Antiviral Activities, Affecting the Immune and Nervous Systems, and Other Miscellaneous Mechanisms of Action

by Alejandro M. S. Mayer, Veronica A. Mayer, Michelle Swanson-Mungerson, Marsha L. Pierce, Cai M. Roberts, Abimael D. Rodríguez, Fumiaki Nakamura and Orazio Taglialatela-Scafati

Mar. Drugs 2026, 24(4), 133; https://doi.org/10.3390/md24040133 - 9 Apr 2026

Abstract

During 2022–2023, research groups from 40 nations contributed to the preclinical pharmacology of 173 structurally defined marine-derived compounds, unveiling innovative mechanisms of action. Peer-reviewed publications in the field of marine natural product pharmacology during 2022–2023 included mechanism-of-action studies with 43 compounds showing antibacterial, [...] Read more.

During 2022–2023, research groups from 40 nations contributed to the preclinical pharmacology of 173 structurally defined marine-derived compounds, unveiling innovative mechanisms of action. Peer-reviewed publications in the field of marine natural product pharmacology during 2022–2023 included mechanism-of-action studies with 43 compounds showing antibacterial, antifungal, antiprotozoal, antitubercular, and antiviral activity. Additional mechanism-of-action studies were reported for 74 marine compounds that exhibited antidiabetic and anti-inflammatory properties, as well as significant effects on both the immune and nervous systems. Finally, while 65 marine compounds revealed unique and diverse pharmacological mechanisms, further investigation will be required to determine whether they will contribute to a particular therapeutic category. Collectively, the pharmacology of 2022–2023 preclinical marine natural products demonstrated robust activity, offering both novel mechanistic insights and promising chemical scaffolds to enrich the 2026 marine pharmaceutical development pipeline (https://www.marinepharmacology.org/) which currently consists of 17 marine-derived pharmaceuticals approved for clinical use and 29 compounds in either Phase I, II or III of clinical pharmaceutical development. Full article

(This article belongs to the Section Marine Pharmacology)

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21 pages, 4092 KB

Open AccessReview

Secondary Metabolites Isolated from the Genus Psammocinia Sponges: Mapping Their Chemistry and Biological Activities

by Dele Abdissa Keneni, Tarryn Swart, Alyson Bennett, Michelle Isaacs and Rosemary Dorrington

Mar. Drugs 2026, 24(4), 132; https://doi.org/10.3390/md24040132 - 1 Apr 2026

Abstract

This review paper covers publications from 2013 to July 2025, and describes brominated and non-brominated indole alkaloids, ircinianins, terpenoids, and polyketide compound classes from the marine sponge of the genus Psammocinia. It provides an overview of the reported secondary metabolites, their source [...] Read more.

This review paper covers publications from 2013 to July 2025, and describes brominated and non-brominated indole alkaloids, ircinianins, terpenoids, and polyketide compound classes from the marine sponge of the genus Psammocinia. It provides an overview of the reported secondary metabolites, their source organisms, geographic origins, and associated biological activities. Also, the structure-activity relationship study and biosynthetic pathways of the reported compounds are illustrated. Herein, 15 new secondary metabolites, including 11 terpenoids and four akaloids, were identified in the Psammocinia sponge species during this period. Briefly, the biological activities of these secondary metabolites involve molecular, cellular, and microbial targets. Full article

(This article belongs to the Special Issue From Marine Natural Products to Marine Bioproducts)

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22 pages, 1042 KB

Open AccessReview

Sulfated Polysaccharides in Cancer Therapy: A Focus on Algal-Derived Bioactive

by N. M. Liyanage, D. S. Dissanayake, Yiqiao Li, Kyung Yuk Ko, D. P. Nagahawatta and You-Jin Jeon

Mar. Drugs 2026, 24(4), 131; https://doi.org/10.3390/md24040131 - 31 Mar 2026

Abstract

Sulfated polysaccharides (SPs), biologically active macromolecules from marine and terrestrial organisms, hold significant potential in revolutionizing cancer therapy. Characterized by their unique sulfate ester groups and structural diversity, SPs exhibit a broad spectrum of bioactivities, including immunomodulation, apoptosis induction, metastasis suppression, and angiogenesis [...] Read more.

Sulfated polysaccharides (SPs), biologically active macromolecules from marine and terrestrial organisms, hold significant potential in revolutionizing cancer therapy. Characterized by their unique sulfate ester groups and structural diversity, SPs exhibit a broad spectrum of bioactivities, including immunomodulation, apoptosis induction, metastasis suppression, and angiogenesis inhibition. Prominent SPs, such as fucoidan from brown algae and carrageenan from red algae, have shown remarkable anticancer properties, either as standalone agents or in synergy with conventional therapies like chemotherapy and radiotherapy. Their mechanisms of action involve targeting critical pathways such as NF-kB, VEGF, and PI3K/Akt, disrupting cancer cell proliferation, invasion, and tumor microenvironment dynamics. SPs also enhance immune system responses, reduce chemotherapy-induced side effects, and exhibit antioxidant properties, making them versatile candidates in cancer treatment. Innovations like SP-based nanoparticles are addressing bioavailability and drug delivery challenges, providing targeted and sustained therapeutic effects while minimizing off-target toxicity. Despite their promise, challenges such as structural complexity, scalability, and clinical validation hinder their widespread adoption. This review provides a comprehensive analysis of SPs’ therapeutic potential, mechanisms, and emerging applications in oncology. It emphasizes the need for advanced extraction, characterization techniques, and clinical research to unlock their full potential, paving the way for novel, efficient, and safer cancer therapies. Full article

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17 pages, 2745 KB

Open AccessArticle

Phaseolorin J Alleviates Cellular Inflammation and Oxidative Stress by Inhibiting NLRP3 Inflammasome Expression via the Nrf2/HO-1 Pathway

by Yuanjie Chen, Ting Feng, Xiaojing Li, Jing Xu and Juren Cen

Mar. Drugs 2026, 24(4), 130; https://doi.org/10.3390/md24040130 - 31 Mar 2026

Abstract

Phaseolorin J (TT-55), a chromone compound isolated and purified from the fermentation products of Phomopsis asparagi DHS-48, is an endophytic fungus obtained from mangrove forests. Preliminary experimental studies have revealed its potent antioxidant and anti-inflammatory activities, though its mechanism of action remains unclear. [...] Read more.

Phaseolorin J (TT-55), a chromone compound isolated and purified from the fermentation products of Phomopsis asparagi DHS-48, is an endophytic fungus obtained from mangrove forests. Preliminary experimental studies have revealed its potent antioxidant and anti-inflammatory activities, though its mechanism of action remains unclear. In this study, we aimed to investigate the molecular mechanisms underlying the antioxidant and anti-inflammatory effects of TT-55, following initial evidence of its potency, by employing an LPS-induced RAW264.7 macrophage model in vitro. The results revealed that in the LPS-induced inflammatory model of RAW264.7 cells, the TT-55 dose dependently inhibited the expression of LPS-induced inflammatory cytokines (TNF-α, IL-18, IL-1β, IL-6) and the production of oxidative stress markers (reactive oxygen species, SOD, MDA). Following combined treatment with the Nrf2 pathway inhibitor ML385 and TT-55, the inhibitory effects of TT-55 on inflammatory cytokines and oxidative stress markers were reversed by ML385. Meanwhile, ML385 also attenuated the ability of TT-55 to suppress LPS-induced upregulation of NLRP3 inflammasome-related genes. In conclusion, TT-55 may exert its antioxidant and anti-inflammatory effects by activating the Nrf2/HO-1 signaling pathway and suppressing the upregulation of NLRP3 inflammasome-related genes. Full article

(This article belongs to the Special Issue Marine Bioactive Compound Discovery Through OSMAC Approach—2nd Edition)

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26 pages, 1295 KB

Open AccessReview

Recent Advance in Marine Polysaccharides: Structure, Anti-Inflammatory Mechanisms, and Functional Applications

by Yuchen Wang, Jingyi Luo, Chao Xu, Dongyu Hu, Yimeng Li, Yanzuo Ye, Jun Yang, Xianxiang Chen, Chuan Li and Kexue Zhu

Mar. Drugs 2026, 24(4), 129; https://doi.org/10.3390/md24040129 - 31 Mar 2026

Cited by 1

Abstract

Inflammation is pivotal to the pathogenesis of chronic disorders, including diabetes and cardiovascular disorders. Conventional pharmaceuticals used in the treatment of inflammation and related diseases face several challenges. In recent years, polysaccharides isolated from marine organisms have attracted extensive research attention due to [...] Read more.

Inflammation is pivotal to the pathogenesis of chronic disorders, including diabetes and cardiovascular disorders. Conventional pharmaceuticals used in the treatment of inflammation and related diseases face several challenges. In recent years, polysaccharides isolated from marine organisms have attracted extensive research attention due to their good safety profile, easy availability, and powerful anti-inflammatory properties. However, there is still a lack of systematic elucidation of their anti-inflammatory mechanisms and functional effects. In this review, the sources and structural characteristics of marine polysaccharides were reviewed. Moreover, the anti-inflammatory mechanisms of marine polysaccharides and their advanced applications were discussed. Finally, the current challenges of marine polysaccharides in anti-inflammatory research and food industry applications, as well as future research directions, were proposed. This review deepens the understanding of the anti-inflammatory effects of marine polysaccharides and provides feasible guidance for the development and clinical application of novel anti-inflammatory drugs. Full article

(This article belongs to the Section Marine-Derived Ingredients for Drugs, Cosmeceuticals and Nutraceuticals)

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12 pages, 982 KB

Open AccessArticle

Chemical Diversity and Antitumor Metabolites from Soft Coral-Derived Fungus Aspergillus sclerotiorum SCSIO 41031 via OSMAC Strategy

by Juan Gao, Jieyi Long, Xiaoyan Pang, Xuefeng Zhou, Yonghong Liu and Bin Yang

Mar. Drugs 2026, 24(4), 128; https://doi.org/10.3390/md24040128 - 31 Mar 2026

Abstract

Microorganisms provide critical lead compounds for drug development, yet most biosynthetic gene clusters remain silent under standard culture conditions. The OSMAC strategy activates these clusters by adjusting cultivation parameters, thereby enabling the discovery of novel compounds from a single strain. Here, we applied [...] Read more.

Microorganisms provide critical lead compounds for drug development, yet most biosynthetic gene clusters remain silent under standard culture conditions. The OSMAC strategy activates these clusters by adjusting cultivation parameters, thereby enabling the discovery of novel compounds from a single strain. Here, we applied OSMAC to explore the metabolic potential of the soft coral-derived fungus Aspergillus sclerotiorum SCSIO 41031. Three different culture media were employed for the large-scale fermentation process. After isolation by chromatography, the compounds were structurally characterized using NMR, MS, and X-ray single-crystal diffraction, and their absolute configurations were determined by electronic circular dichroism (ECD) calculations. In total, three new compounds, named 6,6′-diacetyl-1,1′-dihydroxy-3,3′-dimethoxydibenzyl ether (1), esterwortmannolol (17) and pestalpolyol I (20), along with 19 known compounds (2–16, 18–19 and 21–22) were obtained. This study validates the efficacy of the OSMAC strategy and underscores that A. sclerotiorum SCSIO 41031 serves as a valuable resource for producing structurally diverse natural products with potent biological activities. Full article

(This article belongs to the Special Issue Marine Bioactive Compound Discovery Through OSMAC Approach—2nd Edition)

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15 pages, 5502 KB

Open AccessArticle

Preparation of Alginate Oligosaccharides by Autoclaving Pretreatment Combined with Enzymatic Method

by Feiyu Niu, Ziqiang Gu, Zihan Yu, Zhi Bao, Jichao Li, Peng Yang, Dongyu Li, Haijin Mou and Changliang Zhu

Mar. Drugs 2026, 24(4), 127; https://doi.org/10.3390/md24040127 - 30 Mar 2026

Abstract

The enzymatic method is the primary focus for alginate oligosaccharide (AOS) production. However, the high viscosity of sodium alginate (SA) substrate often limits enzymatic efficiency. Pretreatment strategies aimed at reducing SA viscosity offer a promising and innovative solution to enhance process efficiency. This [...] Read more.

The enzymatic method is the primary focus for alginate oligosaccharide (AOS) production. However, the high viscosity of sodium alginate (SA) substrate often limits enzymatic efficiency. Pretreatment strategies aimed at reducing SA viscosity offer a promising and innovative solution to enhance process efficiency. This study compared the effects of three pretreatment methods—high-pressure vapor (HP-v), high-pressure solution (HP-s), and atmospheric-pressure air (AP-a)—on the physicochemical properties of SA. These pretreatments reduced SA viscosity and induced visible color changes in the order HP-v > HP-s > AP-a. Additionally, the effects of high-pressure treatments on molecular weight, M/G ratio, and chemical structure of SA were analyzed, confirming the feasibility of pretreatment-assisted enzymolysis. Molecular weight distribution and ESI-MS analysis of AOS after enzymolysis demonstrated that brief HP-v treatment maximizes the catalytic potential of alginate lyase, facilitating efficient AOS production without altering its structural characteristics. Full article

(This article belongs to the Special Issue Innovations in Marine Algal Biotechnology: From Bioprocessing to Applications)

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24 pages, 7162 KB

Open AccessArticle

Orally Administered Rhamnan Sulfate from Monostroma nitidum Significantly Inhibits Melanoma Metastasis in Lungs and Aorta of Mice Implanted with B16 Cells

by Keiichi Hiramoto, Masashi Imai, Masahiro Terasawa and Koji Suzuki

Mar. Drugs 2026, 24(4), 126; https://doi.org/10.3390/md24040126 - 29 Mar 2026

Abstract

Tumor metastasis is closely associated with coagulation and inflammation, particularly via thrombin–PAR1 signaling. However, the potential of natural polysaccharides such as rhamnan sulfate (RS) to modulate these pathways and suppress metastasis remains unclear. We aimed to investigate the effects of orally administered RS [...] Read more.

Tumor metastasis is closely associated with coagulation and inflammation, particularly via thrombin–PAR1 signaling. However, the potential of natural polysaccharides such as rhamnan sulfate (RS) to modulate these pathways and suppress metastasis remains unclear. We aimed to investigate the effects of orally administered RS derived from Monostroma nitidum on melanoma metastasis and its underlying mechanisms. Male C57BL/6J mice were orally administered water or RS daily. On day 8, saline or B16 melanoma cells were injected intravenously. Mice were treated for 21 days and divided into four groups (control, RS-only, M + W, and M + RS; n = 5/group). Metastasis and related molecular factors were analyzed in plasma, lung, and aortic tissues. Significant lung and aortic metastases were observed in the M + W group but were markedly suppressed in the M + RS group. RS reduced the expression of inflammatory factors (e.g., IL-6, PAR1), proteases, leukocyte activation markers, complement factors, angiogenic factors, and EMT-related factors. Conversely, thrombin, thrombomodulin, plasmin, TAFIa, and tight junction proteins were increased in RS-treated mice. RS suppresses melanoma metastasis by modulating thrombin–PAR1-mediated inflammation and associated pathways. These findings suggest RS as a potential therapeutic agent, although further mechanistic and clinical studies are required. Full article

(This article belongs to the Special Issue Marine Natural Products as Anticancer Agents—6th Edition)

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16 pages, 6676 KB

Open AccessArticle

Anti-Neuroinflammatory Naphtho-γ-Pyrones from a Deep-Sea-Derived Fungus Aspergillus niger 3A00562

by Zi-Han Xu, Zheng-Biao Zou, Chun-Xiu Wang, Chen Li, Xian-Wen Yang and Jun-Song Wang

Mar. Drugs 2026, 24(4), 125; https://doi.org/10.3390/md24040125 - 27 Mar 2026

Abstract

Inhibition of inflammation and oxidative stress is increasingly recognized as a promising therapeutic strategy for neurodegenerative diseases. In this study, we isolated two new dimeric naphtho-γ-pyrone (aS)-fonsecinones B and D (1 and 2) and 14 known compounds [...] Read more.

Inhibition of inflammation and oxidative stress is increasingly recognized as a promising therapeutic strategy for neurodegenerative diseases. In this study, we isolated two new dimeric naphtho-γ-pyrone (aS)-fonsecinones B and D (1 and 2) and 14 known compounds (3–16) from the deep-sea-derived fungus Aspergillus niger 3A00562. Their structures were unambiguously determined through integrated physicochemical and spectroscopic analyses. Screening for neuroinflammatory inhibitors using a BV2 microglial cell model identified TMC 256 A1 (10) as the most potent candidate. Compound 10 significantly suppressed LPS-induced inflammation in BV2 cells without cytotoxicity. It concurrently inhibited LPS-triggered ROS overproduction and neutrophilic infiltration in zebrafish. Subsequent proteomics revealed that 10 targets NOS2 to modulate Alzheimer’s disease (AD)-associated pathways and the KEAP1-NRF2 axis. Molecular docking and dynamics simulations demonstrated that 10 occupies the NOS2 heme-binding pocket, thereby preventing dimerization and inhibiting enzymatic activity. Finally, 10 ameliorated locomotor deficits in an AD zebrafish model. Collectively, these findings highlight compound 10 as a candidate compound for preventing inflammatory and oxidative stress damage during treatment of neurodegenerative diseases, particularly AD. Full article

(This article belongs to the Special Issue The Deep Sea as a Treasure Trove: Discovery, Characterization and Applications of Microorganisms and Their Metabolites)

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34 pages, 7037 KB

Open AccessArticle

On the Design of Chlorella vulgaris Composition for Potential Food Uses via Manipulation of Cultivation Conditions

by Ana S. Pinto, Joana Oliveira, Ana F. Esteves, Susana Casal, Gustavo Mil-Homens, Francisco X. Malcata, José C. M. Pires and Tânia G. Tavares

Mar. Drugs 2026, 24(4), 124; https://doi.org/10.3390/md24040124 - 26 Mar 2026

Abstract

Interest in microalgae-based technologies has emerged in recent years as a response to environmental challenges and the global food crisis, for providing alternative and sustainable food products. This study used temperature variations between 18 and 32 °C and nitrogen-to-phosphorus (N:P) ratios between 1.9 [...] Read more.

Interest in microalgae-based technologies has emerged in recent years as a response to environmental challenges and the global food crisis, for providing alternative and sustainable food products. This study used temperature variations between 18 and 32 °C and nitrogen-to-phosphorus (N:P) ratios between 1.9 and 42.6 to model and optimize growth and composition of Chlorella vulgaris, a nutritionally interesting species. Lower temperatures appear ideal for this strain. An increase in average biomass productivity was observed with decreasing temperature, leading to a maximum of 122.27 mg_dw L⁻¹ d⁻¹ at 18 °C on the fourth day of cultivation. The maximum productivities for total proteins, fatty acids, carbohydrates, and pigments were, respectively, 26.9 mg L⁻¹ d⁻¹, 26.4 mg L⁻¹ d⁻¹, 16.0 mg L⁻¹ d⁻¹, and 2.41 mg L⁻¹ d⁻¹, all referring to 18 °C. The fatty acid, carotenoid, and amino acid profiles were also ascertained; several indicators suggested that cultivation of these microalgae under the aforementioned optimal conditions holds potential for the food industry. The high proportion of polyunsaturated fatty acids—including two essential fatty acids; the high production of lutein, and the presence of several essential amino acids are among the favorable indicators. Overall, the information generated by this study is helpful to support future pilot studies aimed at the commercial production of microalgae-derived products. Full article

(This article belongs to the Special Issue Applications of Marine Microalgal Biotechnology)

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19 pages, 4509 KB

Open AccessArticle

Molecular Characterization and Mechanistic Insights of a Thermostable Neoagarobiose Hydrolase Aga2457 from Alteromonas sp.

by Jiang Li, Xinning Pan, Long Chen, Qian Zhang, Zhiyan Wang, Dewi Seswita Zilda and Zhou Zheng

Mar. Drugs 2026, 24(4), 123; https://doi.org/10.3390/md24040123 - 25 Mar 2026

Abstract

The enzymatic valorization of agarose, a major polysaccharide in red algae, is critical for its application in the food, pharmaceutical, and biotechnology industries. In this study, a gene encoding a thermostable α-neoagarobiose hydrolase, aga2457, was cloned from an epiphytic bacterium associated with [...] Read more.

The enzymatic valorization of agarose, a major polysaccharide in red algae, is critical for its application in the food, pharmaceutical, and biotechnology industries. In this study, a gene encoding a thermostable α-neoagarobiose hydrolase, aga2457, was cloned from an epiphytic bacterium associated with Indonesian macroalgae. Unlike typical mesophilic GH117 enzymes, recombinant Aga2457 displayed a higher optimal temperature at 50 °C and retained 55% activity after 12 days of incubation at 50 °C. The enzyme specifically hydrolyzes neoagarobiose into D-galactose and 3,6-anhydro-L-galactose, thereby facilitating the complete depolymerization of agarose. Combined molecular dynamics (MD) simulations and site-directed mutagenesis revealed that residues P253, N256, and Q285 are pivotal for substrate recognition and active site stability. These findings highlight Aga2457 as a robust biocatalyst for industrial agar processing and provide structural insights for the rational design of thermostable agarolytic enzymes. Full article

(This article belongs to the Special Issue Marine-Derived Polysaccharide-Degrading Enzyme)

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