The marine environment represents the largest ecosystem on the Earth's surface. Marine-derived fungi are of remarkable importance as they are a promising pool of diverse classes of bioactive metabolites. Bergamotane sesquiterpenoids are an uncommon class of terpenoids. They possess diverse biological properties, such as plant growth regulation, phototoxic, antimicrobial, anti-HIV, cytotoxic, pancreatic lipase inhibition, antidiabetic, anti-inflammatory, and immunosuppressive traits. The current work compiles the reported bergamotane sesquiterpenoids from fungal sources in the period ranging from 1958 to June 2022. A total of 97 compounds from various fungal species were included. Among these metabolites, 38 compounds were derived from fungi isolated from different marine sources. Furthermore, the biological activities, structural characterization, and biosynthesis of the compounds are also discussed. The summary in this work provides a detailed overview of the reported knowledge of fungal bergamotane sesquiterpenoids. Moreover, this in-depth and complete review could provide new insights for developing and discovering new valuable pharmaceutical agents from these natural metabolites.

Long-term exposure to ultraviolet-B (UVB) can cause photoaging. Peptides from Pinctada martensii meat have been shown to have anti-photoaging activities, but their mechanism of action is rarely studied. In this study, Pinctada martensii meat hydrolysates (PME) were prepared by digestive enzymes and then separated by ultrafiltration and Sephadex G-25 gel filtration chromatography to obtain a purified fraction (G2). The fraction G2 was identified by ultra-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS), and peptide sequences were synthesized by solid-phase synthesis. The mechanism of anti-photoaging activities was investigated using a human immortalised epidermal (HaCaT) cell model. Results showed that peptides from Pinctada martensii meat increased UVB-induced cell viability and reduced the contents of interstitial collagenase (MMP-1) and matrix lysing enzyme (MMP-3) in HaCaT cells. Furthermore, the fraction of G2 significantly downregulated the expression of p38, EKR, JNK, MMP-1, and MMP-3 in HaCaT cells. The peptide sequences Phe-His (FH), Ala-Leu (AL), Met-Tyr (MY), Ala-Gly-Phe (AGF), and Ile-Tyr-Pro (IYP) were identified and synthesized. Besides, FH reduced the contents of MMP-1 and MMP-3 in HaCaT cells, combining them effectively in molecular docking analysis. Thus, peptides from Pinctada martensii meat showed anti-photoaging activities and might have the potential to be used as an anti-photoaging agent in functional foods.

Over the past few years, new technological and scientific advances have reinforced the field of natural product discovery. The spirotetronate class of natural products has recently grown with the discovery of phocoenamicins, natural actinomycete derived compounds that possess different antibiotic activities. Exploring the MEDINA's strain collection, 27 actinomycete strains, including three marine-derived and 24 terrestrial strains, were identified as possible phocoenamicins producers and their taxonomic identification by 16S rDNA sequencing showed that they all belong to the Micromonospora genus. Using an OSMAC approach, all the strains were cultivated in 10 different media each, resulting in 270 fermentations, whose extracts were analyzed by LC-HRMS and subjected to High-throughput screening (HTS) against methicillin-resistant Staphylococcus aureus (MRSA), Mycobacterium tuberculosis H37Ra and Mycobacterium bovis. The combination of LC-UV-HRMS analyses, metabolomics analysis and molecular networking (GNPS) revealed that they produce several related spirotetronates not disclosed before. Variations in the culture media were identified as the most determining factor for phocoenamicin production and the best producer strains and media were established. Herein, we reported the chemically diverse production and metabolic profiling of Micromonospora sp. strains, including the known phocoenamicins and maklamicin, reported for the first time as being related to this family of compounds, as well as the bioactivity of their crude extracts. Although our findings do not confirm previous statements about phocoenamicins production only in unique marine environments, they have identified marine-derived Micromonospora species as the best producers of phocoenamicins in terms of both the abundance in their extracts of some major members of the structural class and the variety of molecular structures produced.

Organosulfur natural products (NPs) refer to the different kinds of small molecular-containing sulfur (S) elements. Sulfur-containing NPs tightly link to the biochemical processes and play an important role in the pharmaceutical industry. The majority of S-containing NPs are generally isolated from Alliaceae plants or bacteria, and those from fungi are still relatively rare. In recent years, an increasing number of S-containing metabolites have been discovered in marine and terrestrial fungi, but there is no comprehensive and targeted review to summarize the studies. In order to make it more straightforward to better grasp the fungal-derived S-containing NPs and understand the particularity of marine S-containing NPs compared to those from terrestrial fungi, we summarized the chemical structures and biological activities of 89 new fungal-derived S-containing metabolites from 1929 when the penicillin was discovered to the present in this current review. The structural and bioactive diversity of these S-containing metabolites were concluded in detail, and the preliminary mechanism for C-S bond formation in fungi was also discussed briefly.

Cyanobacteria ascribed to the genus Lyngbya (Family Oscillatoriaceae) represent a potential therapeutic gold mine of chemically and biologically diverse natural products that exhibit a wide array of biological properties. Phylogenetic analyses have established the Lyngbya 'morpho-type' as a highly polyphyletic group and have resulted in taxonomic revision and description of an additional six new cyanobacterial genera in the same family to date. Among the most prolific marine cyanobacterial producers of biologically active compounds are the species Moorena producens (previously L. majuscula, then Moorea producens), M. bouillonii (previously L. bouillonii), and L. confervoides. Over the years, compounding evidence from in vitro and in vivo studies in support of the significant pharmaceutical potential of 'Lyngbya'-derived natural products has made the Lyngbya morphotype a significant target for biomedical research and novel drug leads development. This comprehensive review covers compounds with reported anti-infective activities through 2022 from the Lyngbya morphotype, including new genera arising from recent phylogenetic re-classification. So far, 72 anti-infective secondary metabolites have been isolated from various Dapis, Lyngbya, Moorea, and Okeania species. These compounds showed significant antibacterial, antiparasitic, antifungal, antiviral and molluscicidal effects. Herein, a comprehensive literature review covering the natural source, chemical structure, and biological/pharmacological properties will be presented.

Marine macroalgae are considered an untapped source of healthy natural metabolites and their market demand is rapidly increasing. Intertidal macroalgae present chemical defense mechanisms that enable them to thrive under changing environmental conditions. These intracellular chemicals include compounds that can be used for human benefit. The aim of this study was to test cultivation protocols that direct seaweed metabolic responses to enhance the production of target antioxidant and photoprotective biomaterials. We present an original integrated multi-trophic aquaculture (IMTA) design, based on a two-phase cultivation plan, in which three seaweed species were initially fed by fish effluents, and subsequently exposed to various abiotic stresses, namely, high irradiance, nutrient starvation, and high salinity. The combined effect of the IMTA's high nutrient concentrations and/or followed by the abiotic stressors enhanced the seaweeds' content of mycosporine-like amino acids (MAAs) by 2.3-fold, phenolic compounds by 1.4-fold, and their antioxidant capacity by 1.8-fold. The Sun Protection Factor (SPF) rose by 2.7-fold, and the chlorophyll and phycobiliprotein synthesis was stimulated dramatically by an order of magnitude. Our integrated cultivation system design offers a sustainable approach, with the potential to be adopted by emerging industries for food and health applications.

Airborne particulate matter (PM) originating from industrial processes is a major threat to the environment and health in East Asia. PM can cause asthma, collateral lung tissue damage, oxidative stress, allergic reactions, and inflammation. The present study was conducted to evaluate the protective effect of eckmaxol, a phlorotannin isolated from Ecklonia maxima, against PM-induced inflammation in MH-S macrophage cells. It was found that PM induced inflammation in MH-S lung macrophages, which was inhibited by eckmaxol treatment in a dose-dependent manner (21.0-84.12 µM). Eckmaxol attenuated the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in PM-induced lung macrophages. Subsequently, nitric oxide (NO), prostaglandin E-2 (PGE-2), and pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) were downregulated. PM stimulated inflammation in MH-S lung macrophages by activating Toll-like receptors (TLRs), nuclear factor-kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) pathways. Eckmaxol exhibited anti-inflammatory properties by suppressing the activation of TLRs, downstream signaling of NF-κB (p50 and p65), and MAPK pathways, including c-Jun N-terminal kinase (JNK) and p38. These findings suggest that eckmaxol may offer substantial therapeutic potential in the treatment of inflammatory diseases.

Complex pathological diseases, such as cancer, infection, and Alzheimer's, need to be targeted by multipronged curative. Various omics technologies, with a high rate of data generation, demand artificial intelligence to translate these data into druggable targets. In this study, 82 marine venomous animal species were retrieved, and 3505 cryptic cell-penetrating peptides (CPPs) were identified in their toxins. A total of 279 safe peptides were further analyzed for antimicrobial, anticancer, and immunomodulatory characteristics. Protease-resistant CPPs with endosomal-escape ability in Hydrophis hardwickii, nuclear-localizing peptides in Scorpaena plumieri, and mitochondrial-targeting peptides from Synanceia horrida were suitable for compartmental drug delivery. A broad-spectrum S. horrida-derived antimicrobial peptide with a high binding-affinity to bacterial membranes was an antigen-presenting cell (APC) stimulator that primes cytokine release and naïve T-cell maturation simultaneously. While antibiofilm and wound-healing peptides were detected in Synanceia verrucosa, APC epitopes as universal adjuvants for antiviral vaccination were in Pterois volitans and Conus monile. Conus pennaceus-derived anticancer peptides showed antiangiogenic and IL-2-inducing properties with moderate BBB-permeation and were defined to be a tumor-homing peptide (THP) with the ability to inhibit programmed death ligand-1 (PDL-1). Isoforms of RGD-containing peptides with innate antiangiogenic characteristics were in Conus tessulatus for tumor targeting. Inhibitors of neuropilin-1 in C. pennaceus are proposed for imaging probes or therapeutic delivery. A Conus betulinus cryptic peptide, with BBB-permeation, mitochondrial-targeting, and antioxidant capacity, was a stimulator of anti-inflammatory cytokines and non-inducer of proinflammation proposed for Alzheimer's. Conclusively, we have considered the dynamic interaction of cells, their microenvironment, and proportional-orchestrating-host- immune pathways by multi-target-directed CPPs resembling single-molecule polypharmacology. This strategy might fill the therapeutic gap in complex resistant disorders and increase the candidates' clinical-translation chance.

Xestospongia muta is a marine sponge belonging to the family Petrosiidae. It is an important source of biologically active marine natural products, with different kinds of essential fatty acids. Scavenger receptor class B type I (SR-BI) is the main receptor for high-density lipoprotein (HDL) cholesterol, which plays a pivotal role in preventing atherosclerosis. It removes cholesterol from HDL cholesterol, returning lipid-poor lipoprotein into blood circulation. The present study investigated the effects of X. muta Fraction-7 and linoleic acid on SR-BI gene expression and HDL cholesterol uptake. In vitro studies of the activity of X. muta and linoleic acid against the therapeutic target for hypercholesterolemia were conducted using the HDL receptor SR-BI via luciferase assay and HepG2 cells. In the present study, Fraction-7 of X. muta showed the highest expression level of the SR-BI gene via luciferase assay. Profiling of Fraction-7 of X. muta by GC-MS revealed 58 compounds, comprising various fatty acids, particularly linoleic acid. The in vitro study in HepG2 cells showed that the Fraction-7 of X. muta and linoleic acid (an active compound in X. muta) increased SR-BI mRNA expression by 129% and 85%, respectively, compared to the negative control. Linoleic acid increased HDL uptake by 3.21-fold compared to the negative control. Thus, the Fraction-7 of X. muta and linoleic acid have the potential to be explored as adjuncts in the treatment of hypercholesterolemia to prevent or reduce the severity of atherosclerosis development.

Polysaccharide from the edible alga Enteromorpha clathrata has been demonstrated to exert beneficial effects on human health. However, what effect it has on inflammatory bowel diseases has not been investigated. Here, using a mouse model of dextran sulfate sodium (DSS)-induced ulcerative colitis, we illustrate that Enteromorpha clathrata polysaccharide (ECP) could alleviate body weight loss, reduce incidences of colonic bleeding, improve stool consistency and ameliorate mucosal damage in diseased mice. 16S rRNA high-throughput sequencing and bioinformatic analysis indicated that ECP significantly changed the structure of the gut microbiota and increased the abundance of Parabacteroides spp. in DSS-fed mice. In vitro fermentation studies further confirmed that ECP could promote the growth of Parabacteroides distasonis F1-28, a next-generation probiotic bacterium isolated from the human gut, and increase its production of short-chain fatty acids. Additionally, Parabacteroides distasonis F1-28 was also found to have anti-ulcerative colitis effects in DSS-fed mice. Altogether, our study demonstrates for the first time a beneficial effect of ECP on ulcerative colitis and provides a possible basis for understanding its therapeutic mechanisms from the perspective of symbiotic gut bacteria Parabacteroides distasonis.

Marine sponges represent one of the richest sources of natural marine compounds with anticancer potential. Plocabulin (PM060184), a polyketide originally isolated from the sponge Lithoplocamia lithistoides, elicits its main anticancer properties binding tubulin, which still represents one of the most important targets for anticancer drugs. Plocabulin showed potent antitumor activity, in both in vitro and in vivo models of different types of cancers, mediated not only by its antitubulin activity, but also by its ability to block endothelial cell migration and invasion. The objective of this review is to offer a description of plocabulin's mechanisms of action, with special emphasis on the antiangiogenic signals and the latest progress on its development as an anticancer agent.

Coumarin and its derivatives have significantly attracted the attention of medicinal chemists and chemical biologists due to their huge range of biological, and in particular, pharmacological properties. Interesting families of coumarins have been found from marine sources, which has accelerated the drug discovery process by inspiring innovation or even by the identification of analogues with remarkable biological properties. The purpose of this review is to showcase the most interesting marine-derived coumarins from a medicinal chemistry point of view, as well as the novel and useful synthetic routes described to date to achieve these chemical structures. The references that compose this overview were collected from PubMed, Mendeley and SciFinder.

Cystoseira abies-marina (reclassified as Gongolaria abies-marina) is a brown seaweed species rich in meroterpenoids, presenting interesting antioxidant, antitumor, and anti-inflammatory activities. However, there is still a lot to uncover regarding the bioactive potential of this species, as evidenced by the lack of records of antiaging activities from Cystoseira abies-marina, making this macroalga an excellent candidate for studies of its cosmeceutical potential. Ultrasound-(UAE) and microwave-assisted extraction (MAE) are advanced sustainable technologies that are very efficient in enhancing bioactive compound extraction. Applying these extraction techniques to a new biological matrix often calls for optimizing the parameters toward the best extraction yield. Since Cystoseira abies-marina is a new matrix for both UAE and MAE techniques, the present work proposes the optimization of the extraction process, using a novel approach: instead of only focusing on increasing the yield, the goal of this work is to determine the parameters for UAE and MAE that lead to extracts with better antiaging activities. For this bio-guided approach, several Cystoseira abies-marina extracts were prepared by UAE and MAE under varying conditions of solvent, time, and algae/solvent ratios. Their antiaging activities were then determined, and all the results combined to unveil the conditions yielding extracts with higher cosmeceutical potential. Using statistical tools, it was found that, for UAE, the best conditions were ethyl acetate, 15 min, and a ratio of 1:4, which led to an extract with high yield, and causing the strong inhibition of tyrosinase and elastase. In turn, ethanol, 10 min, and a ratio of 1:4 were the best conditions for MAE, leading to the extract with the best antioxidant activity. The results show that the proposed bio-guided approach was effective in obtaining extracts with high cosmeceutical potential, unveiling the possibility of modulating an extract's activity by changing the extraction method.

The aim of this study was to evaluate the antiangiogenic and immunomodulatory potential of sulfated polysaccharides from the marine algae Macrocystis integrifolia characterized by FTIR. The cytotoxicity of sulfated polysaccharides was evaluated using the 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT) assay. Antiangiogenic activity was evaluated using the chicken chorioallantoic membrane (CAM) assay. Immunomodulatory activity was determined on macrophage functionality and allergic response. The results showed that sulfated polysaccharides significantly decreased angiogenesis in chicken chorioallantoic membranes (p < 0.05). Likewise, they inhibited in vivo chemotaxis and in vitro phagocytosis, the transcription process of genes that code the enzymes cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and nitric oxide synthase-2 (NOS-2) and the nuclear factor kappa-light chain enhancer of activated B cells (NF-κB), showing immunomodulatory properties on the allergic response, as well as an in vivo inhibitory effect in the ovalbumin-induced inflammatory allergy model (OVA) and inhibited lymphocyte proliferation specific to the OVA antigen in immunized mice. Finally, these compounds inhibited the histamine-induced skin reaction in rats, the production of immunoglobulin E (IgE) in mice, and the passive response to skin anaphylaxis in rats. Therefore, the results of this research showed the potential of these compounds to be a promising source for the development of antiangiogenic and immunomodulatory drugs.

The inhibitor of human α-N-acetylgalactosaminidase (α-NaGalase) was isolated from a water-ethanol extract of the brown algae Costaria costata. Currently, tumor α-NaGalase is considered to be a therapeutic target in the treatment of cancer. According to NMR spectroscopy and mass spectrometric analysis, it is a high-molecular-weight fraction of phlorethols with a degree of polymerization (DP) equaling 11-23 phloroglucinols (CcPh). It was shown that CcPh is a direct inhibitor of α-NaGalases isolated from HuTu 80 and SK-MEL-28 cells (IC50 0.14 ± 0.008 and 0.12 ± 0.004 mg/mL, respectively) and reduces the activity of this enzyme in HuTu 80 and SK-MEL-28 cells up to 50% at concentrations of 15.2 ± 9.5 and 5.7 ± 1.6 μg/mL, respectively. Molecular docking of the putative DP-15 oligophlorethol (P15OPh) and heptaphlorethol (PHPh) with human α-NaGalase (PDB ID 4DO4) showed that this compound forms a complex and interacts directly with the Asp 156 and Asp 217 catalytic residues of the enzyme in question. Thus, brown algae phlorethol CcPh is an effective marine-based natural inhibitor of the α-NaGalase of cancer cells and, therefore, has high therapeutic potential.

Two new chlorinated metabolites, 8-chlorine-5-hydroxy-2,3-dimethyl-7-methoxychromone (1) and 3,4-dichloro-1H-pyrrole-2,5-dione (3), and eight known compounds (2 and 4-9) were isolated from the mangrove sediments-derived fungus Mollisia sp. SCSIO41409. Their structures were elucidated by physicochemical properties and extensive spectroscopic analysis. The absolute configuration of stemphone C (4) was established for the first time by the X-ray crystallographic analysis. Compounds 3 and 4 showed different intensity of antimicrobial activities against several pathogenic fungi and bacteria, and antiproliferative activities against two human prostate cancer cell lines (IC50 values 2.77 to 9.60 μM). Further, stemphone C (4) showed a reducing PC-3 cell colony formation, inducing apoptosis and blocking the cell cycle at S-phase in a dose-dependent manner; thus, it could be considered as a potential antiproliferative agent and a promising anti-prostate cancer lead compound.

Inflammation and oxidative stress are often the common denominators of most modern chronic diseases and disorders, resulting in serious problems for health care systems [...].

Phycoerythrin (PE) is a pink/red-colored pigment found in rhodophytes, cryptophytes, and blue-green algae (cyanobacteria). The interest in PE is emerging from its role in delivering health benefits. Unfortunately, the current cyanobacterial-PE (C-PE) knowledge is still in the infant stage. It is essential to acquire a more comprehensive understanding of C-PE. This study aimed to review the C-PE structure, up and downstream processes of C-PE, application of C-PE, and strategies to enhance its stability and market value. In addition, this study also presented a strengths, weaknesses, opportunities, and threats (SWOT) analysis on C-PE. Cyanobacteria appeared to be the more promising PE producers compared to rhodophytes, cryptophytes, and macroalgae. Green/blue light is preferred to accumulate higher PE content in cyanobacteria. Currently, the prominent C-PE extraction method is repeated freezing-thawing. A combination of precipitation and chromatography approaches is proposed to obtain greater purity of C-PE. C-PE has been widely exploited in various fields, such as nutraceuticals, pharmaceuticals, therapeutics, cosmetics, biotechnology, food, and feed, owing to its bioactivities and fluorescent properties. This review provides insight into the state-of-art nature of C-PE and advances a step further in commercializing this prospective pigment.

The soft coral Sarcophyton trocheliophorum, which was frequently encountered on Indo-Pacific and Red Sea coral reefs, furnished a wealth of secondary metabolites. Notably, terpenoids dominated the chemical profile of this species. In this review, we summarized the discovery of 156 terpenoids from the soft coral S. trocheliophorum specimens in different geographical areas. The structures comprised 13 terpenoidal classes with various functionalities. We covered the era from the first report of S. trocheliophorum-derived metabolites in 1976 up to October 2022. The biological effects of these chemical compositions on a vast array of potential pharmacological activities such as protein tyrosine phosphatase 1B (PTP1B) inhibitory, neuroprotective, cytotoxic, anti-inflammatory, antibacterial, antivirus, and immunomodulatory activities were also presented. This review also revealed an immense demand to explore the terpene biosynthetic gene clusters of this species besides the chemo- and bio-investigations.

Recent reviews have reinforced sponge-associated bacteria as a valuable source of structurally diverse secondary metabolites with potent biological properties, which makes these microbial communities promising sources of new drug candidates. However, the overall diversity of secondary metabolite biosynthetic potential present in bacteria is difficult to access due to the fact that the majority of bacteria are not readily cultured in the laboratory. Thus, use of cultivation-independent approaches may allow accessing "silent" and "cryptic" secondary metabolite biosynthetic gene clusters present in bacteria that cannot yet be cultured. In the present study, we investigated the diversity of secondary metabolite biosynthetic gene clusters (BGCs) in metagenomes of bacterial communities associated with three sponge species: Clathria reinwardti, Rhabdastrella globostellata, and Spheciospongia sp. The results reveal that the three metagenomes contain a high number of predicted BGCs, ranging from 282 to 463 BGCs per metagenome. The types of BGCs were diverse and represented 12 different cluster types. Clusters predicted to encode fatty acid synthases and polyketide synthases (PKS) were the most dominant BGC types, followed by clusters encoding synthesis of terpenes and bacteriocins. Based on BGC sequence similarity analysis, 363 gene cluster families (GCFs) were identified. Interestingly, no GCFs were assigned to pathways responsible for the production of known compounds, implying that the clusters detected might be responsible for production of several novel compounds. The KS gene sequences from PKS clusters were used to predict the taxonomic origin of the clusters involved. The KS sequences were related to 12 bacterial phyla with Actinobacteria, Proteobacteria, and Firmicutes as the most predominant. At the genus level, the KSs were most related to those found in the genera Mycolicibacterium, Mycobacterium, Burkholderia, and Streptomyces. Phylogenetic analysis of KS sequences resulted in detection of two known 'sponge-specific' BGCs, i.e., SupA and SwfA, as well as a new 'sponge-specific' cluster related to fatty acid synthesis in the phylum Candidatus Poribacteria and composed only by KS sequences of the three sponge-associated bacterial communities assessed here.

Marine sponge-derived fungi have been proven to be a prolific source of bioactive natural products. Two new alkaloids, polonimides E (1) and D (2), and a new butenolide derivative, eutypoid F (11), were isolated from the Beibu Gulf sponge-derived fungus, Penicillium sp. SCSIO 41413, together with thirteen known compounds (3-10, 12-16). Their structures were determined by detailed NMR, MS spectroscopic analyses, and electronic circular dichroism (ECD) analyses. Butenolide derivatives 11 and 12 exhibited inhibitory effect against the enzyme PI3K with IC50 values of 1.7 μM and 9.8 μM, respectively. The molecular docking was also performed to understand the inhibitory activity, while 11 and 12 showed obvious protein/ligand-binding effects to the PI3K protein. Moreover, 4 and 15 displayed obvious inhibitory activity against LPS-induced NF-κB activation in RAW264.7 cells at 10 µM.

A novel strain, isolate 5K15T, which belongs to difficult-to-cultivate phylum Verrucomicrobiota, was recovered from kelp collected from Li Island, Rongcheng, China. The genome sequence of the strain (genome size 3.95 Mbp) showed the presence of four putative biosynthetic gene clusters (BGCs), namely, two terpene biosynthetic gene clusters, one aryl polyene biosynthetic cluster, and one type III PKS cluster. Genomic analysis revealed 79 sulfatase-encoded genes, 24 sulfatase-like hydrolase/transferase-encoded genes, and 25 arylsulfatase-encoded genes, which indicated the great potential of 5K15T to degrade sulfated polysaccharides. Comparative analysis of 16S rRNA gene sequence showed that the novel strain was most closely related to Oceaniferula marina N1E253T (96.4%). On the basis of evidence from a polyphasic study, it is proposed that the strain 5K15T (= KCTC 82748T = MCCC 1H00442T = SDUM 810003T) be classified as Oceaniferula flavus sp. nov. The strain has the ability of carbohydrate transport and metabolism. This ability allows it to survive in carbohydrate-rich materials such as kelp. It has the potential to be used in the marine drug industry using seaweed.

Plant bacterial pathogens can be devastating and compromise entire crops of fruit and vegetables worldwide. The consequences of bacterial plant infections represent not only relevant economical losses, but also the reduction of food availability. Synthetic bactericides have been the most used tool to control bacterial diseases, representing an expensive investment for the producers, since cyclic applications are usually necessary, and are a potential threat to the environment. The development of greener methodologies is of paramount importance, and some options are already available in the market, usually related to genetic manipulation or plant community modulation, as in the case of biocontrol. Seaweeds are one of the richest sources of bioactive compounds, already being used in different industries such as cosmetics, food, medicine, pharmaceutical investigation, and agriculture, among others. They also arise as an eco-friendly alternative to synthetic bactericides. Several studies have already demonstrated their inhibitory activity over relevant bacterial phytopathogens, some of these compounds are known for their eliciting ability to trigger priming defense mechanisms. The present work aims to gather the available information regarding seaweed extracts/compounds with antibacterial activity and eliciting potential to control bacterial phytopathogens, highlighting the extracts from brown algae with protective properties against microbial attack.

In recent years, the study of anticancer bioactive compounds from marine sources has received wide interest. Contextually, world regulatory authorities have approved several marine molecules, and new synthetic derivatives have also been synthesized and structurally improved for the treatment of numerous forms of cancer. However, the administration of drugs in cancer patients requires careful evaluation since their interaction with individual biological macromolecules, such as proteins or nucleic acids, determines variable downstream effects. This is reflected in a constant search for personalized therapies that lay the foundations of modern medicine. The new knowledge acquired on cancer mechanisms has certainly allowed advancements in tumor prevention, but unfortunately, due to the huge complexity and heterogeneity of cancer, we are still looking for a definitive therapy and clinical approaches. In this review, we discuss the significance of recently approved molecules originating from the marine environment, starting from their organism of origin to their structure and mechanism of action. Subsequently, these bio-compounds are used as models to illustrate possible bioinformatics approaches for the search of new targets that are useful for improving the knowledge on anticancer therapies.

Peptic ulcer is a widespread disease, with a lifetime frequency of 5-10% among the general population and an annual incidence of 0.1-0.3%. Ovothiol A is naturally produced from sea urchin eggs with special antioxidant activity. Gastric ulcers were induced in rats by a single ethanol dose (5 mL/kg). The rats were divided into control, ulcer, and ulcer with 250 and 500 mg/kg ovothiol A doses. Molecular docking studies were used to examine the interactions between ovothiol A and the H+/K+ ATPase active site residues. Ovothiol A led to a significant decline (p < 0.05) in gastric juice volume, ulcer index, MDA, IL-6, and cytochrome c, while levels of gastric juice pH, GSH, CAT, GST, SOD, and NO increased. Histopathological investigation of stomach sections revealed architecture preservation of the gastric mucosa after ovothiol A administration. The anti-ulcerogenic activity of ovothiol A includes scavenging free radicals, inhibition of inflammation, regulation of apoptosis, and stabilization of fibroblast growth factors to promote gastric ulcers healing.

Marine microorganisms are an important source of natural polyketides, which have become a significant reservoir of lead structures for drug design due to their diverse biological activities. In this review, we provide a summary of the resources, structures, biological activities, and proposed biosynthetic pathways of the benzyl alcohol/salicylaldehyde-type polyketides. In addition, the total syntheses of these secondary metabolites from their discoveries to the present day are presented. This review could be helpful for researchers in the total synthesis of complex natural products and the use of polyketide bioactive molecules for pharmacological purposes and applications in medicinal chemistry.

The phylum Echinodermata comprising the classes Asteroidea, Ophiuroidea, Echinoidea, Holothuroidea, and Crinodeia, is one of the important invertebrate groups. Members of this phylum live exclusively in marine habitats and are distributed in almost all depths and latitudes. Some of them, such as sea urchins and sea cucumbers, are commercially valuable and constitute a major fishery resource. Echinoderms are increasingly recognized as a unique source of various metabolites with a wide range of biological activities. The importance of dietary polyunsaturated fatty acids, such as eicosapentaenoic acid, in human health has drawn attention to echinoderms as a promising source of essential fatty acids (FAs). Extensive information on the FAs of the phylum has been accumulated to date. The biosynthetic capabilities and feeding habits of echinoderms explain the findings of the unusual FAs in them. Certain common and unusual FAs may serve as chemotaxonomic markers of the classes. The main goal of the review was to gather the relevant information on the distribution of FAs among the echinoderm classes, describe the structures, distribution, biosynthetic pathways, and bioactivity, with an emphasis on the FAs specific for echinoderms. A large part of the review is devoted to the FAs derived from echinoderms that exhibit various biological activities promising for potential therapeutic applications.

Five new compounds, including two cyclopiane diterpenes conidiogenones J and K (1-2), a steroid andrastin H (5), an alkaloid (Z)-4-(5-acetoxy-N-hydroxy-3-methylpent-2-enamido) butanoate (6), and an aliphatic acid (Z)-5-acetoxy-3-methylpent-2-enoic acid (7), together with ten known compounds (3-4 and 8-15) were isolated from the EtOAc extract of the fermentation broth of the Lumnitzera littorea-derived fungus Penicillium oxalicum HLLG-13. Their structures were elucidated by 1D, 2D NMR, and HR-ESI-MS spectral analyses. The absolute configurations of 1, 2, 5, and 8 were determined by quantum chemical electronic circular dichroism (ECD) calculations, and the absolute configuration of 8 was determined for the first time. Compound 15 was a new natural product, and its NMR data were reported for the first time. Compounds 5 and 9-14 exhibited antibacterial activities against Staphylococcus epidermidis and Candida albicans, with MIC values ranging from 6.25 to 25 μg/ mL. Compounds 1-6 and 9-14 showed significant growth inhibition activities against newly hatched Helicoverpa armigera Hubner larvae, with IC50 values ranging from 50 to 200 μg/mL.

Cancer still poses a global threat, since a lot of tumors remain untreatable despite all the available chemotherapeutic drugs, whose side effects, it must also be noted, still raise concerns. The antitumoral properties of marine seaweeds make them a potential source of new, less toxic, and more active antitumoral agents. Furthermore, these natural extracts can be combined with nanotechnology to increase their efficacy and improve targeting. In this work, a Codium tomentosum (CT) aqueous extract was employed for the green synthesis of gold nanoparticles (Au@CT). The complete characterization of Au@CT was performed by UV-Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Zeta potential, electron microscopy, X-ray powder diffraction (XRD), high-performance steric exclusion chromatography (HPSEC), and by the determination of their antioxidant capacity. The antiproliferative activity of Au@CT was then tested in hepatic (HEPG-2) and pancreatic (BxPC-3) cell lines. Their potential capacity as enhancers of gemcitabine, a drug frequently used to treat both types of tumors, was also tested. The activity of Au@CT was compared to the activity of the CT extract alone. A synergistic effect with gemcitabine was proven for HEPG-2. Our results showed that gold nanoparticles synthesized from seaweed extracts with antitumoral activity could be a good gemcitabine enhancer.

Fucoidan is a sulfated algal polyanionic polysaccharide that possesses many biological activities. In this paper, a fucoidan (SHF) polysaccharide was extracted from Sargassum hemiphyllum collected in the South China Sea. The SHF, with a molecular weight of 1166.48 kDa (44.06%, w/w), consisted of glucose (32.68%, w/w), galactose (24.81%, w/w), fucose (20.75%, w/w), xylose (6.98%, w/w), mannose (2.76%, w/w), other neutral monosaccharides, and three uronic acids, including glucuronic acid (5.39%, w/w), mannuronic acid (1.76%, w/w), and guronuronic acid (1.76%, w/w). The SHF exhibited excellent immunostimulatory activity. An immunostimulating assay showed that SHF could significantly increase NO secretion in macrophage RAW 264.7 cells via upregulation of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) levels based on both gene expression and protein abundance. These results suggest that SHF isolated from Sargassum hemiphyllum has great potential to act as a health-boosting ingredient in the pharmaceutical and functional-food fields.

Docosahexaenoic acid (DHA) is an important omega-3 polyunsaturated fatty acid (PUFA) that plays a critical physiological role in human health. Schizochytrium sp. is considered an excellent strain for DHA production, but the synthesis of DHA is limited by the availability of nicotinamide adenine dinucleotide phosphate (NADPH). In this study, the endogenous glucose-6-phosphate dehydrogenase (G6PD) gene was overexpressed in Schizochytrium sp. H016. Results demonstrated that G6PD overexpression increased the availability of NADPH, which ultimately altered the fatty acid profile, resulting in a 1.91-fold increase in DHA yield (8.81 g/L) and increased carbon flux by shifting it from carbohydrate and protein synthesis to lipid production. Thus, G6PD played a vital role in primary metabolism. In addition, G6PD significantly increased DHA content and lipid accumulation by 31.47% and 40.29%, respectively. The fed-batch fermentation experiment results showed that DHA production reached 17.01 g/L in the overexpressing G6PD strain. These results elucidated the beneficial effects of NADPH on the synthesis of PUFA in Schizochytrium sp. H016, which may be a potential target for metabolic engineering. Furthermore, this study provides a promising regulatory strategy for the large-scale production of DHA in Schizochytrium sp.

The psychrophilic marine microorganism Thraustochytrium sp. RT2316-16 can produce carotenoids as well as lipids containing the omega-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid and docosahexaenoic acid. This work reports on the effects of the composition of the culture medium, including certain amino acids, on growth and lipid synthesis by RT2316-16. Compared with the culture on glutamate, the use of lysine, alanine, or serine, increased the content of the omega-3 PUFA in total lipids. In the media that contained yeast extract, glutamate, and glucose, lipid accumulation occurred when organic ammonium was exhausted earlier than glucose. In contrast, lipid mobilization was promoted if glucose was exhausted while organic ammonium (supplied by yeast extract and glutamate) remained in the medium. The total content of carotenoids in the lipid-free biomass decreased during the first 12 to 24 h of culture, simultaneously with a decrease in the total lipid content of the biomass. The experimental data suggested a possible interrelationship between the metabolism of carotenoids and lipids. A high content of omega-3 PUFA in the total lipids could be obtained by growing the thraustochytrid in a medium with a low glucose concentration (6 g L-1) and a high concentration of organic nitrogen (yeast extract 12 g L-1; glutamate 1.06 g L-1), after glucose was exhausted. These observations may guide the development of a strategy to enhance omega-3 PUFA in the biomass.

SCOPE: The dysbiosis of intestinal microecology plays an important pathogenic role in the development of inflammatory bowel disease. METHODS AND RESULTS: A polysaccharide named Fuc-S, with a molecular weight of 156 kDa, was prepared by the ultrasonic degradation of fucoidan. Monosaccharide composition, FTIR, methylation, and NMR spectral analysis indicated that Fuc-S may have a backbone consisting of →3)-α-L-Fucp-(1→, →4)-α-L-Fucp-(1→ and →3, 4)-α-D-Glcp-(1→. Moreover, male C57BL/6 mice were fed three cycles of 1.8% dextran sulfate sodium (DSS) for 5 days and then water for 7 days to induce colitis. The longitudinal microbiome alterations were evaluated using 16S amplicon sequencing. In vivo assays showed that Fuc-S significantly improved clinical manifestations, colon shortening, colon injury, and colonic inflammatory cell infiltration associated with DSS-induced chronic colitis in mice. Further studies revealed that these beneficial effects were associated with the inhibition of Akt, p-38, ERK, and JNK phosphorylation in the colon tissues, regulating the structure and abundance of the gut microbiota, and modulating the host-microbe tryptophan metabolism of the mice with chronic colitis. CONCLUSION: Our data confirmed the presence of glucose in the backbone of fucoidan and provided useful information that Fuc-S can be applied as an effective functional food and pharmaceutical candidate for IBD treatment.

In this review, we aim to provide a summary of recent research advancements and applications of algin (i.e., alginic acid) and alginate-hybrid materials (AHMs) in medical fields. Algin/alginate are abundant natural products that are chemically inert and biocompatible, and they have superior gelation properties, good mechanical strengths, and biodegradability. The AHMs have been widely applied in wound dressing, cell culture, tissue engineering, and drug delivery. However, medical applications in different fields require different properties in the AHMs. The drug delivery application requires AHMs to provide optimal drug loading, controlled and targeted drug-releasing, and/or visually guided drug delivery. AHMs for wound dressing application need to have improved mechanical properties, hydrophilicity, cell adhesion, and antibacterial properties. AHMs for tissue engineering need improved mechanical properties that match the target organs, superior cell affinity, and cell loading capacity. Various methods to produce AHMs that meet different needs were summarized. Formulations to form AHMs with improved stability, drug/cell-loading capacity, cell adhesion, and mechanical properties are active research areas. This review serves as a road map to provide insights into the strategies to develop AHMs in medical applications.

The aim of this study is to investigate the differences in the accumulation capacity of chrysolaminarin among six Tribonema species and to isolate this polysaccharide for immunomodulatory activity evaluation. The results showed that T. aequale was the most productive strain with the highest content and productivity of chrysolaminarin, which were 17.20% (% of dry weight) and 50.91 mg/L/d, respectively. Chrysolaminarin was then extracted and isolated from this alga, and its monosaccharide composition was mainly composed of a glucose (61.39%), linked by β-D-(1→3) (main chain) and β-D-(1→6) (branch chain) glycosidic bonds, with a molecular weight of less than 6 kDa. In vitro immunomodulatory assays showed that it could activate RAW264.7 cells at a certain concentration (1000 μg/mL), as evidenced by the increased phagocytic activity and upregulated mRNA expression levels of IL-1β, IL6, TNF-α and Nos2. Moreover, Western blot revealed that this polysaccharide stimulated the phosphorylation of p-65, p-38 and JNK in NF-κB and MAPK signaling pathways. Overall, these findings provide a reference for the further development and utilization of algae-based chrysolaminarin, while also offering an in-depth understanding of the immunoregulatory mechanism.

Alginates (ALG) have been used in biomedical and pharmaceutical technologies for decades. ALG are natural polymers occurring in brown algae and feature multiple advantages, including biocompatibility, low toxicity and mucoadhesiveness. Moreover, ALG demonstrate biological activities per se, including anti-hyperlipidemic, antimicrobial, anti-reflux, immunomodulatory or anti-inflammatory activities. ALG are characterized by gelling ability, one of the most frequently utilized properties in the drug form design. ALG have numerous applications in pharmaceutical technology that include micro- and nanoparticles, tablets, mucoadhesive dosage forms, wound dressings and films. However, there are some shortcomings, which impede the development of modified-release dosage forms or formulations with adequate mechanical strength based on pure ALG. Other natural polymers combined with ALG create great potential as drug carriers, improving limitations of ALG matrices. Therefore, in this paper, ALG blends with pectins, chitosan, gelatin, and carrageenans were critically reviewed.

Although several antibiotics are already widely used against a large number of pathogens, the discovery of new antimicrobial compounds with new mechanisms of action is critical today in order to overcome the spreading of antimicrobial resistance among pathogen bacteria. In this regard, marine organisms represent a potential source of a wide diversity of unique secondary metabolites produced as an adaptation strategy to survive in competitive and hostile environments. Among the multidrug-resistant Gram-negative bacteria, Pseudomonas aeruginosa is undoubtedly one of the most important species due to its high intrinsic resistance to different classes of antibiotics on the market and its ability to cause serious therapeutic problems. In the present review, we first discuss the general mechanisms involved in the antibiotic resistance of P. aeruginosa. Subsequently, we list the marine molecules identified up until now showing activity against P. aeruginosa, dividing them according to whether they act as antimicrobial or anti-virulence compounds.

Prolonged exposure to fine dust (FD) increases the risk of skin inflammation. Stimulated epidermal cells release growth factors into their extracellular environment, which can induce inflammation in dermal cells. Algae are considered rich sources of bioactive materials. The present study emphasized the effect of low-molecular-weight fucoidan isolated from Sargassum confusum (LMF) against FD-induced inflammation in HaCaT keratinocytes and underneath fibroblasts (HDFs) in an integrated culture model. HDFs were treated with media from FD-stimulated HaCaT with LMF treatments (preconditioned media). The results suggested that FD increased the oxidative stress in HaCaT, thereby increasing the sub-G1 phase of the cell cycle up to 587%, as revealed via flow cytometric analysis. With preconditioned media, HDFs also displayed oxidative stress; however, the increase in the sub-G1 phase was insignificant compared with HaCaT. LMF dose-dependently regulated the NF-κB/MAPK signaling in HaCaT. Furthermore, significant downregulation in NF-κB/MAPK signaling, as well as inflammatory cytokines, tissue inhibitors of metalloproteinases, matrix metalloproteinases, and reduction in relative elastase and collagenase activities related to the extracellular matrix degeneration were observed in HDFs with a preconditioned media treatment. Therefore, we concluded that HDFs were protected from inflammation by preconditioned media. Continued research on tissue culture and in vivo studies may reveal the therapeutic potential of LMF.

Most proteins have the ability to self-associate into homooligomeric protein complexes, which consist of two or more identical subunits. Today, modern methods of molecular modeling are an integral part of the study of many biologically active molecules. In silico methods are widely used in structure establishing and function and activity prediction of lectins - carbohydrate-binding proteins. Here, we described by computer simulation the spatial organization of lectin isolated from the mantle of the mussel Mytilus trossulus (MTL). It was shown that the dimerization of MTL gives a total of six ligand binding sites that may be important for the manifestation its biological properties. The ability of MTL to form a dimeric and oligomeric structure was confirmed by dynamic light scattering and SDS-PAGE methods.

Six new sesquiterpene aminoglycosides, trichaspside F (2) and cyclonerosides A-E (5-9), two new diterpene aminoglycosides, harzianosides A and B (10, 11), and three known sesquiterpenes, trichodermoside (1), cycloneran-3,7,10,11-tetraol (3), and cyclonerodiol (4), have been isolated from the n-butanol extract of Trichoderma sp. SCSIOW21 (Hypocreaceae), a deep-sea-sediment-derived fungus. The structures and relative configurations of the new compounds were determined using spectroscopic techniques and comparisons with those reported in the literature. The absolute configurations of the aglycone part of cyclonerosides A-E (5-9) were tentatively proposed based on optical rotation and biogenic considerations. Cyclonerosides A-E (5-9) represent the first glycosides of cyclonelane-type sesquiterpenes generated from Trichoderma. The NO-production-inhibitory activities were evaluated using macrophage RAW264.7 cells. Among the isolated compounds, trichaspside F (2) and cyclonerosides B-E (6-9) exhibited the strongest NO-production-inhibitory activities with IC50 values of 54.8, 50.7, 57.1, 42.0, and 48.0 µM, respectively, compared to the IC50 value of 30.8 µM for the positive control (quercetin). When tested for anti-fungal activities against several pathogenic fungi, none of the compounds exhibited significant activities at a concentration of 100 µM.

Tetrodotoxins (TTXs), the pufferfish venom traditionally associated with Indo-Pacific area, has been reported during last decades in ever wider range of marine organisms and ever more geographical areas, including shellfish in Europe. Wild mussels (Mytilus galloprovincialis) grown in the Marche Region (N Adriatic Sea, Italy) were shown to be prone to TTX contamination during the warm season, with a suspected role of Vibrio alginolyticus characterized by non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS)-encoding genes. This work aimed to deepen the knowledge about the toxin's origin and the way through which it accumulates in mussels. A two-year study (spring-summer 2020-2021) confirmed the recurrent presence of TTX (11-68 µg kg-1) in the official monitored natural mussel beds of the Conero Riviera. During 2021, a supplementary nonroutine monitoring of a natural mussel bed in the same area was carried out weekly from June until August for TTXs and/or the presence of V. alginolyticus. Biotic (mussels, mesozooplankton, worms and phytoplankton); abiotic (water and sediment) matrices and phytoplankton assemblage characterizations were studied. Mussels showed relevant TTX contamination levels (9-296 µg kg-1) with extremely rapid TTX accumulation/depletion rates. The toxin presence in phytoplankton and its distribution in the different mussel tissues supports its possible exogenous origin. The V. alginolyticus count trend overlaps that of TTX contamination in mussels, and similar trends were reported also for some phytoplankton species. The role of V. alginolyticus carrying NRPS or PKS genes as a possible TTX source and of phytoplankton as a "potential vector" should therefore be further investigated.

Alginate oligosaccharides (AOS) and their derivatives become popular due to their favorable biological activity, and the key to producing functional AOS is to find efficient alginate lyases. This study showed one alginate lyase TsAly7A found in Thalassomonas sp. LD5, which was predicted to have excellent industrial properties. Bioinformatics analysis and enzymatic properties of recombinant TsAly7A (rTsAly7A) were investigated. TsAly7A belonged to the fifth subfamily of polysaccharide lyase family 7 (PL7). The optimal temperature and pH of rTsAly7A was 30 °C and 9.1 in Glycine-NaOH buffer, respectively. The pH stability of rTsAly7A under alkaline conditions was pretty good and it can remain at above 90% of the initial activity at pH 8.9 in Glycine-NaOH buffer for 12 h. In the presence of 100 mM NaCl, rTsAly7A showed the highest activity, while in the absence of NaCl, 50% of the highest activity was observed. The rTsAly7A was an endo-type alginate lyase, and its end-products of alginate degradation were unsaturated oligosaccharides (degree of polymerization 2-6). Collectively, the rTsAly7A may be a good industrial production tool for producing AOS with high degree of polymerization.

The biochemical composition, molecular diversity, and two different bioactivities of Asparagopsis armata and Rugulopteryx okamurae (two alien species with different invasive patterns in the southern Iberian Peninsula) were analyzed through spectrophotometric methods and Fourier transform ion cyclotron mass spectroscopy (FT-ICR-MS). A total of 3042 molecular formulas were identified from the different extracts. The dH2O extracts were the most molecularly different. A. armata presented the highest content of nitrogenous compounds (proteins, CHON) and sulphur content, whereas R. okamurae was rich in carbonated compounds (total carbon, lipids, CHO, and CHOP). Antioxidant capacity and phenolic content were higher in R. okamurae than in A. armata. Antimicrobial activity was detected from both species. A. armata showed capacity to inhibit human and fish pathogens (e.g., Staphylococcus aureus or Vibrio anguillarum), whereas R. okamurae only showed inhibition against human bacteria (Staphylococcus aureus and Cutibacterium acnes). In R. okamurae, molecules with a great number of pharmaceutical activities (e.g., anti-inflammatory or antitumoral), antibacterial, biomaterial, and other utilities were found. The main molecules of A. armata had also pharmaceutical applications (e.g., antimalarian, antithrombotic, anti-inflammatory, or antiarthritis). The valorization of these species can help to counteract the environmental effects of the bioinvasions.

Τhis mini-review summarizes the hematopoietic and immunostimulating properties of alkyl glycerol ethers (AGs) reported earlier in the literature available to us. The role of AGs in the nervous system and aging of the body are also briefly described. We made an attempt to consider the data in terms of adaptation. The hematopoietic, immunostimulating and antioxidant properties of AGs in a variety of experimental situations, including stress, as well as the protective action of AGs against some adaptation diseases, allow us to consider them as substances that prevent some negative effects of stress and promote adaptation. The new approach to AGs as adaptogens seems promising and opens good opportunities for their new application.

The benthic dinoflagellate genus Gambierdiscus is the primary producer of toxins responsible for ciguatera poisoning (CP), a food intoxication endemic in tropical and subtropical areas of the world. We used high-performance liquid chromatography tandem high-resolution mass spectrometry (HPLC-HRMS) to investigate the toxin profile of Gambierdiscus balechii 1123M1M10, which was obtained from Marakei Island (2°01'N, 173°15'E), Republic of Kiribati, located in the central Pacific Ocean. Four new gambierone analogues including 12,13-dihydro-44-methylgambierone, 38-dehydroxy-12,13-dihydro-44-methylgambierone, 38-dehydroxy-44-methylgambierone, and desulfo-hydroxyl gambierone, and two known compounds, gambierone and 44-methylgambierone, were proposed by analyzing their fragmentation behaviors and pathways. Our findings provide new insights into the toxin profile of Gambierdiscus balechii 1123M1M10, which can be used as a biomarker for species identification, and lay the foundation for further toxin isolation and bioactivity studies of gambierones.

Bacterial symbionts of marine invertebrates are rich sources of novel, pharmaceutically relevant natural products that could become leads in combatting multidrug-resistant pathogens and treating disease. In this study, the bioactive potential of the marine invertebrate symbiont Thalassomonas actiniarum was investigated. Bioactivity screening of the strain revealed Gram-positive specific antibacterial activity as well as cytotoxic activity against a human melanoma cell line (A2058). The dereplication of the active fraction using HPLC-MS led to the isolation and structural elucidation of cholic acid and 3-oxo cholic acid. T. actiniarum is one of three type species belonging to the genus Thalassomonas. The ability to generate cholic acid was assessed for all three species using thin-layer chromatography and was confirmed by LC-MS. The re-sequencing of all three Thalassomonas type species using long-read Oxford Nanopore Technology (ONT) and Illumina data produced complete genomes, enabling the bioinformatic assessment of the ability of the strains to produce cholic acid. Although a complete biosynthetic pathway for cholic acid synthesis in this genus could not be determined based on sequence-based homology searches, the identification of putative penicillin or homoserine lactone acylases in all three species suggests a mechanism for the hydrolysis of conjugated bile acids present in the growth medium, resulting in the generation of cholic acid and 3-oxo cholic acid. With little known currently about the bioactivities of this genus, this study serves as the foundation for future investigations into their bioactive potential as well as the potential ecological role of bile acid transformation, sterol modification and quorum quenching by Thalassomonas sp. in the marine environment.

The antioxidant effect of probiotics has been widely recognized across the world, which is of great significance in food, medicine, and aquaculture. There are abundant marine microbial resources in the ocean, which provide a new space for humans to explore new probiotics. Previously, we reported on the anti-infective effects of Planococcus maritimu ML1206, a potential marine probiotic. The antioxidant activity of ML1206 in C. elegans was studied in this paper. The study showed that ML1206 could improve the ability of nematodes to resist oxidative stress and effectively prolong their lifespan. The results confirmed that ML1206 could significantly increase the activities of CAT and GSH-PX, and reduce the accumulation of reactive oxygen species (ROS) in nematodes under oxidative stress conditions. In addition, ML1206 promoted DAF-16 transfer to the nucleus and upregulated the expression of sod-3, hsp-16.2, and ctl-2, which are downstream antioxidant-related genes of DAF-16. Furthermore, the expression of the SOD-3::GFP and HSP-16.2::GFP was significantly higher in the transgenic strains fed with ML1206 than that in the control group fed with OP50, with or without stress. In summary, these findings suggest that ML1206 is a novel marine probiotic with an antioxidant function that stimulates nematodes to improve their defense abilities against oxidative stress and prolong the lifespan by regulating the translocation of FOXO/DAF-16. Therefore, ML1206 may be explored as a potential dietary supplement in aquaculture and for anti-aging and antioxidant purposes.

Nature-based and sustainably sourced cosmetics have been dominating the area of skincare products worldwide. Due to their antioxidant and antiaging properties, compounds from cyanobacteria, such as carotenoids and phycobiliproteins, may replace synthetic ingredients in cosmetic formulations and may be used in products such as sunscreens, skincare creams, and makeup. In this study, we evaluated the potential of acetonic and aqueous extracts from cyanobacteria strains of the genera Cyanobium and Leptothoe and from strains within Synechococcales and Oscillatoriales orders, for use in cosmetics. Extractions were sequentially performed with acetone and water. Extracts were firstly analyzed for their toxicity to keratinocytes, fibroblasts, and endothelial cells (HaCAT, 3T3L1 and hCMEC/D3, respectively). The non-cytotoxic extracts were characterized in terms of total proteins, carotenoids, chlorophyll, phenols, phycobiliproteins, and analyzed for their antioxidant potential against the superoxide anion radical (O2•-), and for their ability to inhibit key enzymes associated with the skin aging process. Aqueous extracts were richer in total proteins and phycobiliproteins. The aqueous extracts of Synechococcales cyanobacterium LEGE 181157 and Synechococcales cyanobacterium LEGE 181150 showed the highest value for total proteins (760.81 and 695.25 μg BSA mL-1dry extract, respectively) and the best values regarding O2•- scavenging (IC50 = 63.24 and 112.18 μg mL-1dry extract, respectively) with a significant negative correlation observed (p < 0.01). Moreover, aqueous extracts of Synechococcales cyanobacterium LEGE 181150 and Synechococcales cyanobacterium LEGE 181157 inhibited hyaluronidase, (IC50 of 483.86 and 645.06 μg mL-1dry extract, respectively), with a significant negative correlation with total proteins (p < 0.05), pointing out the contribution of these compounds to the biological activities observed. Acetonic extracts were richer in carotenoids and phenols. Zeaxanthin and β-carotene were predominant among all strains, being present in higher amount in Cyanobium sp. LEGE 07175 (53.08 μg mg-1) and Leptothoe sp. LEGE 181156 (47.89 μg mg-1), respectively. The same strains also showed the highest values for collagenase inhibition at 750 μg mL-1dry extract (32.88 and 36.61%, respectively). Furthermore, Leptothoe sp. LEGE 181156 exhibited the lowest IC50 value for tyrosinase inhibition (465.92 μg mL-1dry extract) and Synechococcales cyanobacterium LEGE 181157 presented the best values for elastase inhibition (IC50 of 380.50 and IC25 of 51.43 μg mL-1dry extract). In general, cyanobacteria extracts demonstrated potential for being used for antiaging purposes, with aqueous extracts being more efficient at free radicals scavenging and acetonic ones at avoiding degradation of dermal matrix components.

Inflammation is an organism's response to chemical or physical injury. It is split into acute and chronic inflammation and is the last, most significant cause of death worldwide. Nowadays, according to the World Health Organization (WHO), the greatest threat to human health is chronic disease. Worldwide, three out of five people die from chronic inflammatory diseases such as stroke, chronic respiratory diseases, heart disorders, and cancer. Nowadays, anti-inflammatory drugs (steroidal and non-steroidal, enzyme inhibitors that are essential in the inflammatory process, and receptor antagonists, among others) have been considered as promising treatments to be explored. However, there remains a significant proportion of patients who show poor or incomplete responses to these treatments or experience associated severe side effects. Seaweeds represent a valuable resource of bioactive compounds associated with anti-inflammatory effects and offer great potential for the development of new anti-inflammatory drugs. This review presents an overview of specialized metabolites isolated from seaweeds with in situ and in vivo anti-inflammatory properties. Phlorotannins, carotenoids, sterols, alkaloids, and polyunsaturated fatty acids present significant anti-inflammatory effects given that some of them are involved directly or indirectly in several inflammatory pathways. The majority of the isolated compounds inhibit the pro-inflammatory mediators/cytokines. Studies have suggested an excellent selectivity of chromene nucleus towards inducible pro-inflammatory COX-2 than its constitutive isoform COX-1. Additional research is needed to understand the mechanisms of action of seaweed's compounds in inflammation, given the production of sustainable and healthier anti-inflammatory agents.

Tetrodotoxin (TTX) is a potent marine neurotoxin that occurs in several Australian phyla, including pufferfish, toadfish, gobies, and the blue-ringed octopus. These animals are partially immune, and TTX is known to bioaccumulate and subject to trophic transfer. As such, it could be more ubiquitously distributed in animals than is currently known. Flatworms of the order Polycladida are commonly occurring invertebrates in intertidal ecosystems and are especially diverse in Australian waters. While TTX has been identified in polyclads from Japan and New Zealand, Australian species have yet to be tested. In this study, several eastern Australian polyclad flatworm species from the suborders Cotylea and Acotylea were tested for TTX and analogs by HILIC-HRMS to understand the distribution of this toxin within these suborders. Herein, we report the detection of TTX and some known analogs in polyclad species, one of which is a pest to shellfish aquaculture. We also report, for the first time, the application of MALDI mass spectrometry imaging utilized to map TTX spatially within the intestinal system of polyclads. The identification of TTX and its analogs in Australian flatworms illustrates a broader range of toxic flatworms and highlights that analogs are important to consider when studying the distributions of toxins in animals.

Metal-polysaccharides have recently raised significant interest due to their multifunctional bioactivities. The antimicrobial activity of a complex of Cu2O with the sulfated polysaccharide (PS) of the marine red microalga Porphyridium sp. was previously attributed to spikes formed on the complex surface (roughness). This hypothesis was further examined here using other Cu-PS complexes (i.e., monovalent-Cu2O, CuCl and divalent-CuO, CuCl2). The nanostructure parameters of the monovalent complexes, namely, longer spikes (1000 nm) and greater density (2000-5000 spikes/µm2) were found to be related to the superior inhibition of microbial growth and viability and biofilm formation. When Escherichia coli TV1061, used as a bioluminescent test organism, was exposed to the monovalent Cu-PS complexes, enhanced bioluminescence accumulation was observed, probably due to membrane perforation by the spikes on the surface of the complexes and consequent cytoplasmic leakage. In addition, differences were found in the surface chemistry of the monovalent and divalent Cu-PS complexes, with the monovalent Cu-PS complexes exhibiting greater stability (ζ-potential, FTIR spectra, and leaching out), which could be related to spike formation. This study thus supports our hypothesis that the spikes protruding from the monovalent Cu-PS surfaces, as characterized by their aspect ratio, are responsible for the antimicrobial and antibiofilm activities of the complexes.

A global health concern has emerged as a response to the recent SARS-CoV-2 pandemic. The identification and inhibition of drug targets of SARS-CoV-2 is a decisive obligation of scientists. In addition to the cell entry mechanism, SARS-CoV-2 expresses a complicated replication mechanism that provides excellent drug targets. Papain-like protease (PLpro) and 3-chymotrypsin-like protease (3CLpro) play a vital role in polyprotein processing, producing functional non-structural proteins essential for viral replication and survival in the host cell. Moreover, PLpro is employed by SARS-CoV-2 for reversing host immune responses. Therefore, if some particular compound has the potential to interfere with the proteolytic activities of 3CLpro and PLpro of SARS-CoV-2, it may be effective as a treatment or prophylaxis for COVID-19, reducing viral load, and reinstating innate immune responses. Thus, the present study aims to inhibit SARS-CoV-2 through 3CLpro and PLpro using marine natural products isolated from marine algae that contain numerous beneficial biological activities. Molecular docking analysis was utilized in the present study for the initial screening of selected natural products depending on their 3CLpro and PLpro structures. Based on this approach, Ishophloroglucin A (IPA), Dieckol, Eckmaxol, and Diphlorethohydroxycarmalol (DPHC) were isolated and used to perform in vitro evaluations. IPA presented remarkable inhibitory activity against interesting drug targets. Moreover, Dieckol, Eckmaxol, and DPHC also expressed significant potential as inhibitors. Finally, the results of the present study confirm the potential of IPA, Dieckol, Eckmaxol, and DPHC as inhibitors of SARS-CoV-2. To the best of our knowledge, this is the first study that assesses the use of marine natural products as a multifactorial approach against 3CLpro and PLpro of SARS-CoV-2.

Diabetes mellitus is a chronic metabolic disorder. In addition to taking medication, adjusting the composition of the diet is also considered one of the effective methods to control the levels of blood glucose. Chitosan and its derivatives are natural and versatile biomaterials with health benefits. Chitosan has the potential to alleviate diabetic hyperglycemia by reducing hepatic gluconeogenesis and increasing skeletal muscle glucose uptake and utility. Scientists also focus on the glucose-lowering effect of chitosan oligosaccharide (COS). COS supplementation has the potential to alleviate abnormal glucose metabolism in diabetic rats by inhibiting gluconeogenesis and lipid peroxidation in the liver. Both high and low molecular weight chitosan feeding reduced insulin resistance by inhibiting lipid accumulation in the liver and adipose tissue and ameliorating chronic inflammation in diabetic rats. COS can reduce insulin resistance but has less ability to reduce hepatic lipids in diabetic rats. A clinical trial showed that a 3-month administration of chitosan increased insulin sensitivity and decreased body weight and triglycerides in obese patients. Chitosan and COS are considered Generally Recognized as Safe; however, they are still considered to be of safety concerns. This review highlights recent advances of chitosan and its derivatives in the glucose-lowering/antidiabetic effects and the safety.

With respect to the potential natural resources in the marine environment, marine macroalgae or seaweeds are recognized to have health impacts. Two marine algae that are found in the Red Sea, Codium tomentosum (Green algae) and Actinotrichia fragilis (Red algae), were collected. Antibacterial and antioxidant activities of aqueous extracts of these algae were evaluated in vitro. Polyphenols from the extracts were determined using HPLC. Fillet fish was fortified with these algal extracts in an attempt to improve its nutritional value, and sensory evaluation was performed. The antibacterial effect of C. tomentosum extract was found to be superior to that of A. fragilis extract. Total phenolic contents of C. tomentosum and A. fragilis aqueous extract were 32.28 ± 1.63 mg/g and 19.96 ± 1.28 mg/g, respectively, while total flavonoid contents were 4.54 ± 1.48 mg/g and 3.86 ± 1.02 mg/g, respectively. Extract of C. tomentosum demonstrates the highest antioxidant activity, with an IC50 value of 75.32 ± 0.07 μg/mL. The IC50 of L-ascorbic acid as a positive control was 22.71 ± 0.03 μg/mL. The IC50 values for inhibiting proliferation on normal PBMC cells were 33.7 ± 1.02 µg/mL and 51.0 ± 1.14 µg/mL for C. tomentosum and A. fragilis, respectively. The results indicated that both algal aqueous extracts were safe, with low toxicity to normal cells. Interestingly, fillet fish fortified with C. tomentosum extract demonstrated the greatest overall acceptance score. These findings highlight the potential of these seaweed species for cultivation as a sustainable and safe source of therapeutic compounds for treating human and fish diseases, as well as effective food supplements and preservatives instead of chemical ones after performing in vivo assays.

Carbon dots (CDs) have attracted significant research attention worldwide due to their unique properties and advantageous attributes, such as superior optical properties, biocompatibility, easy surface functionalization, and more. Moreover, biomass-derived CDs have attracted much attention because of their additional advantages related to more environmentally friendly and lower-cost synthesis. In this respect, chitosan has been recently explored for the preparation of CDs, which in comparison to other natural precursors exhibited additional advantages. Beyond the benefits related to the eco-friendly and abundant nature of chitosan, using it as a nanomaterial precursor offers additional benefits in terms of structure, morphology, and dopant elements. Furthermore, the high content of nitrogen in chitosan allows it to be used as a single carbon and nitrogen precursor for the preparation of N-doped CDs, significantly improving their fluorescent properties and, therefore, their performances. This review addresses the most recent advances in chitosan-based CDs with a special focus on synthesis methods, enhanced properties, and their applications in different fields, including biomedicine, the environment, and food packaging. Finally, this work also addresses the key challenges to be overcome to propose future perspectives and research to unlock their great potential for practical applications.

κ-carrageenases are members of the glycoside hydrolase family 16 (GH16) that hydrolyze sulfated galactans in red algae, known as κ-carrageenans. In this study, a novel κ-carrageenase gene from the marine bacterium Rhodopirellula sallentina SM41 (RsCgk) was discovered via the genome mining approach. There are currently no reports on κ-carrageenase from the Rhodopirellula genus, and RsCgk shares a low identity (less than 65%) with κ- carrageenase from other genera. The RsCgk was heterologously overexpressed in Escherichia coli BL21 and characterized for its enzymatic properties. RsCgk exhibited maximum activity at pH 7.0 and 40 °C, and 50% of its initial activity was retained after incubating at 30 °C for 2 h. More than 70% of its activity was maintained after incubation at pH 6.0-8.0 and 4 °C for 24 h. As a marine derived enzyme, RsCgk showed excellent salt tolerance, retaining full activity in 1.2 M NaCl, and the addition of NaCl greatly enhanced its thermal stability. Mass spectrometry analysis of the RsCgk hydrolysis products revealed that the enzyme had high degradation specificity and mainly produced κ-carrageenan disaccharide. Comparative molecular dynamics simulations revealed that the conformational changes of tunnel-forming loops under salt environments may cause the deactivation or stabilization of RsCgk. Our results demonstrated that RsCgk could be utilized as a potential tool enzyme for efficient production of κ-carrageenan oligosaccharides under high salt conditions.

The unicellular green microalga Dunaliella is a potential source of a wide range of nutritionally important compounds applicable to the food industry. The aim of this study was to assess the effect of Dunaliella salina dried biomass on the growth and adherence of 10 strains of Lactobacillus, Lacticaseibacillus, and Bifidobacterium. The immunomodulatory, antioxidant, and cytotoxic effects of D. salina on human peripheral mononuclear cells and simulated intestinal epithelial cell lines Caco-2 and HT-29 were evaluated. Furthermore, the hypocholesterolemic effects of the microalgae on lipid metabolism in rats fed a high-fat diet were analyzed. The addition of D. salina biomass had a positive effect on the growth of nine out of 10 probiotics and promoted the adherence of three bifidobacteria strains to human cell lines. The antioxidant and immunomodulatory properties of D. salina were concentration-dependent. The inflammatory cytokines (TNF-α and IL-6) were significantly increased following Dunaliella stimulation at the lowest concentration (0.5% w/v). Eight week supplementation of D. salina to the diet of hypercholesteromic rats significantly decreased the serum concentrations of LDL-C, VLDL, IDL-B, and IDL-C. D. salina is not cytotoxic in intestinal cell models; it promotes adherence of selected bifidobacteria, it affords immunomodulatory and antioxidant effects, and its addition to diets may help decrease atherosclerosis risk factors.

Three new dibenzo-α-pyrone derivatives, alternolides A-C (1-3), and seven known congeners (4-10) were isolated from the marine-derived fungus of Alternaria alternata LW37 assisted by the one strain-many compounds (OSMAC) strategy. The structures of 1-3 were established by extensive spectroscopic analyses, and their absolute configurations were determined by modified Snatzke's method and electronic circular dichroism (ECD) calculations. Compounds 6 and 7 showed good 1,1-diphenyl-2-picrylhydrazyl (DPPH) antioxidant scavenging activities with IC50 values of 83.94 ± 4.14 and 23.60 ± 1.23 µM, respectively. Additionally, 2, 3 and 7 exhibited inhibitory effects against α-glucosidase with IC50 values of 725.85 ± 4.75, 451.25 ± 6.95 and 6.27 ± 0.68 µM, respectively. The enzyme kinetics study indicated 2 and 3 were mixed-type inhibitors of α-glucosidase with Ki values of 347.0 and 108.5 µM, respectively. Furthermore, the interactions of 2, 3 and 7 with α-glucosidase were investigated by molecular docking.

Aurantiochytrium is a heterotrophic marine microalga that has potential industrial applications. The main objectives of this study were to isolate an Aurantiochytrium strain from Sand Cay (Son Ca) Island, Vietnam, optimize its culture conditions, determine its nutritional composition, extract polyunsaturated fatty acids (PUFAs) in the free (FFA) and the alkyl ester (FAAE) forms, and evaluate the antioxidation and neuroprotection properties of the PUFAs. Aurantiochytrium sp. SC145 can be grown stably under laboratory conditions. Its culture conditions were optimized for a dry cell weight (DCW) of 31.18 g/L, with total lipids comprising 25.29%, proteins 7.93%, carbohydrates 15.21%, and carotenoid at 143.67 µg/L of DCW. The FAAEs and FFAs extracted from Aurantiochytrium sp. SC145 were rich in omega 3-6-9 fatty acids (40.73% and 44.00% of total fatty acids, respectively). No acute or subchronic oral toxicity was determined in mice fed with the PUFAs in FFA or FAAE forms at different doses over 90 days. Furthermore, the PUFAs in the FFA or FAAE forms and their main constituents of EPA, DHA, and ALA showed antioxidant and AChE inhibitory properties and neuroprotective activities against damage caused by H2O2- and amyloid-ß protein fragment 25-35 (Aβ25-35)-induced C6 cells. These data suggest that PUFAs extracted from Aurantiochytrium sp. SC145 may be a potential therapeutic target for the treatment of neurodegenerative disorders.

Repetitive exposure to ultraviolet B (UVB) is one of the main causes of skin photoaging. We previously reported that dieckol isolated from Eisenia bicyclis extract has potential anti-photoaging effects in UVB-irradiated Hs68 cells. Here, we aimed to evaluate the anti-photoaging activity of dieckol in a UVB-irradiated hairless mouse model. In this study, hairless mice were exposed to UVB for eight weeks. At the same time, dieckol at two doses (5 or 10 mg/kg) was administered orally three times a week. We found that dieckol suppressed UVB-induced collagen degradation and matrix metalloproteinases (MMPs)-1, -3, and -9 expression by regulating transforming growth factor beta (TGF-β)/Smad2/3 and mitogen-activated protein kinases (MAPKs)/activator protein-1 (AP-1) signaling. In addition, dieckol rescued the production of hyaluronic acid (HA) and effectively restored the mRNA expression of hyaluronan synthase (HAS)-1/-2 and hyaluronidase (HYAL)-1/-2 in UVB-irradiated hairless mice. We observed a significant reduction in transepidermal water loss (TEWL), epidermal/dermal thickness, and wrinkle formation in hairless mice administered dieckol. Based on these results, we suggest that dieckol, due to its anti-photoaging role, may be used as a nutricosmetic ingredient for improving skin health.

Lectin is a carbohydrate-binding protein that recognizes specific cells by binding to cell-surface polysaccharides. Tumor cells generally show various glycosylation patterns, making them distinguishable from non-cancerous cells. Consequently, lectin has been suggested as a good anticancer agent. Herein, the anticancer activity of Bryopsis plumosa lectins (BPL1, BPL2, and BPL3) was screened and tested against lung cancer cell lines (A549, H460, and H1299). BPL2 showed high anticancer activity compared to BPL1 and BPL3. Cell viability was dependent on BPL2 concentration and incubation time. The IC50 value for lung cancer cells was 50 μg/mL after 24 h of incubation in BPL2 containing medium; however, BPL2 (50 μg/mL) showed weak toxicity in non-cancerous cells (MRC5). BPL2 affected cancer cell growth while non-cancerous cells were less affected. Further, BPL2 (20 μg/mL) inhibited cancer cell invasion and migration (rates were ˂20%). BPL2 induced the downregulation of epithelial-to-mesenchymal transition-related genes (Zeb1, vimentin, and Twist). Co-treatment with BPL2 and gefitinib (10 μg/mL and 10 μM, respectively) showed a synergistic effect compared with monotherapy. BPL2 or gefitinib monotherapy resulted in approximately 90% and 70% cell viability, respectively, with concomitant treatment showing 40% cell viability. Overall, BPL2 can be considered a good candidate for development into an anticancer agent.

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by elevated levels of blood glucose due to insulin resistance or insulin-secretion defects. The development of diabetes is mainly attributed to the interaction of several complex pathogenic, genetic, environmental and metabolic processes. Dipeptidyl peptidase-4 (DPP-4) is a serine protease that cleaves X-proline dipeptides from the N-terminus of several polypeptides, including natural hypoglycemic incretin hormones. Inhibition of this enzyme restores and maintains glucose homeostasis, making it an attractive drug target for the management of T2DM. Natural products are important sources of bioactive agents for anti-T2DM drug discovery. Marine ecosystems are a rich source of bioactive products and have inspired the development of drugs for various human disorders, including diabetes. Here, structure-based virtual screening and molecular docking were performed to identify antidiabetic compounds from the Comprehensive Marine Natural Products Database (CMNPD). The binding characteristics of two shortlisted compounds, CMNPD13046 and CMNPD17868, were assessed using molecular dynamics simulations. Thus, this study provides insights into the potential antidiabetic activity and the underlying molecular mechanism of two compounds of marine origin. These compounds could be investigated further for the development of potent DPP-4 inhibitors.

The search for new sources of antimicrobial compounds has become an urgent need, due to the threat that the spread of bacterial resistance represents for global health and food safety. Brown macroalgae have been proposed as a great reservoir in the search for novel antimicrobial compounds. In this study, mid-polarity extracts were performed with a selection of 20 brown macroalgae species from northern Spain. The total polyphenol, carbohydrate and protein contents were quantified by spectrophotometry. The volatile organic compounds (VOCs) of whole macroalgae were also studied as a biomarker of their metabolic state in the representative species of the tested families by gas chromatography-mass spectrometry (GC-MS). The antimicrobial potential of the extracts was assessed by a disk diffusion assay against 20 target bacteria and further determinations of the minimum inhibitory (MIC) and minimum bactericidal concentrations (MBC) were performed by a microdilution assay for the active extracts. Ericaria selaginoides, Bifurcaria bifurcata and Dictyota dichotoma showed an antimicrobial effect against six Gram-positive strains: Bacillus cereus, Bacillus subtilis, Geobacillus stearothermophilus, Listeria monocytogenes, Staphylococcus aureus and Staphylococcus haemolyticus. The phenolic content was generally higher in the extracts that showed antimicrobial activity, followed by carbohydrates and low contents of proteins. The results obtained in this study reveal the potential of brown macroalgae as a promising alternative source of antimicrobial compounds as functional ingredients for the application in industrial fields.

Conus regius is a marine venomous mollusk of the Conus genus that captures its prey by injecting a rich cocktail of bioactive disulfide bond rich peptides called conotoxins. These peptides selectively target a broad range of ion channels, membrane receptors, transporters, and enzymes, making them valuable pharmacological tools and potential drug leads. C. regius-derived conotoxins are particularly attractive due to their marked potency and selectivity against specific nicotinic acetylcholine receptor subtypes, whose signalling is involved in pain, cognitive disorders, drug addiction, and cancer. However, the species-specific differences in sensitivity and the low stability and bioavailability of these conotoxins limit their clinical development as novel therapeutic agents for these disorders. Here, we give an overview of the main pharmacological features of the C. regius-derived conotoxins described so far, focusing on the molecular mechanisms underlying their potential therapeutic effects. Additionally, we describe adoptable chemical engineering solutions to improve their pharmacological properties for future potential clinical translation.

Marine algal species comprise of a large portion of polysaccharides which have shown multifunctional properties and health benefits for treating and preventing human diseases. Laminarin, or β-glucan, a storage polysaccharide from brown algae, has been reported to have potential pharmacological properties such as antioxidant, anti-tumor, anti-coagulant, anticancer, immunomodulatory, anti-obesity, anti-diabetic, anti-inflammatory, wound healing, and neuroprotective potential. It has been widely investigated as a functional material in biomedical applications as it is biodegradable, biocompatible, and is low toxic substances. The reported preclinical and clinical studies demonstrate the potential of laminarin as natural alternative agents in biomedical and industrial applications such as nutraceuticals, pharmaceuticals, functional food, drug development/delivery, and cosmeceuticals. This review summarizes the biological activities of laminarin, including mechanisms of action, impacts on human health, and reported health benefits. Additionally, this review also provides an overview of recent advances and identifies gaps and opportunities for further research in this field. It further emphasizes the molecular characteristics and biological activities of laminarin in both preclinical and clinical settings for the prevention of the diseases and as potential therapeutic interventions.

Insomnia is a common sleep disorder. Natural sleep aids are gaining worldwide popularity as alternatives to prescription drugs for improving sleep. Recently, numerous studies have investigated the sedative-hypnotic effects of the polyphenols of terrestrial plants. The hypnotic effects of marine polyphenols have also been studied in recent years. Phlorotannins are marine polyphenols that are found only in brown algae. Phlorotannins exert sedative-hypnotic effects via the gamma-aminobutyric acid type A-benzodiazepine receptor. In addition, the brown seaweed Ecklonia cava supplement containing phlorotannins has been approved by the Ministry of Food and Drug Safety as a health-functional ingredient that helps improve sleep quality. Currently, it is meaningful to deal with the sedative-hypnotic effects of phlorotannins as natural sleep aids. The current review comprehensively presents the sedative-hypnotic effects in animal models and human clinical trials as well as their mechanism of action, extraction, purification, and safety.

The field of marine bioactive compounds (marine drugs) has evolved significantly in recent years [...].

Plastics are present in the majority of daily-use products worldwide. Due to society's production and consumption patterns, plastics are accumulating in the environment, causing global pollution issues and intergenerational impacts. Our work aims to contribute to the development of solutions and sustainable methods to mitigate this pressing problem, focusing on the ability of marine-derived actinomycetes to accelerate plastics biodegradation and produce polyhydroxyalkanoates (PHAs), which are biodegradable bioplastics. The thin plastic films' biodegradation was monitored by weight loss, changes in the surface chemical structure (Infra-Red spectroscopy FTIR-ATR), and by mechanical properties (tensile strength tests). Thirty-six marine-derived actinomycete strains were screened for their plastic biodegradability potential. Among these, Streptomyces gougerotti, Micromonospora matsumotoense, and Nocardiopsis prasina revealed ability to degrade plastic films-low-density polyethylene (LDPE), polystyrene (PS) and polylactic acid (PLA) in varying conditions, namely upon the addition of yeast extract to the culture media and the use of UV pre-treated thin plastic films. Enhanced biodegradation by these bacteria was observed in both cases. S. gougerotti degraded 0.56% of LDPE films treated with UV radiation and 0.67% of PS films when inoculated with yeast extract. Additionally, N. prasina degraded 1.27% of PLA films when these were treated with UV radiation, and yeast extract was added to the culture medium. The main and most frequent differences observed in FTIR-ATR spectra during biodegradation occurred at 1740 cm-1, indicating the formation of carbonyl groups and an increase in the intensity of the bands, which indicates oxidation. Young Modulus decreased by 30% on average. In addition, S. gougerotti and M. matsumotoense, besides biodegrading conventional plastics (LDPE and PS), were also able to use these as a carbon source to produce degradable PHA bioplastics in a circular economy concept.