Search Results (80)

The marine seaweed Undaria pinnatifida belongs to the large group of brown macroalgae (Ochrophyta) and is valued both as a nutritious food and a source of pharmaceutical compounds. It has been widely consumed in East Asia as part of the traditional diet and is generally regarded as a “healthy longevity food.” Consequently, it represents one of the most promising natural sources of biomedicinal and bioactive products. This review aims to synthesize current scientific evidence on the pharmacologically active compounds of U. pinnatifida, emphasizing their mechanisms of action and therapeutic potential in neurodegenerative and chronic diseases. This narrative review is based on a comprehensive literature search of peer-reviewed articles from scientific databases, focusing on studies addressing the pharmacological properties of U. pinnatifida and its major bioactive constituents. Recent research highlights that compounds such as fucoxanthin (a carotenoid), fucosterol (a sterol), fucoidan (a polysaccharide), alginate, and dietary fiber found in U. pinnatifida possess significant potential for developing treatments for conditions including goitre, urinary diseases, scrofula, dropsy, stomach ailments, and hemorrhoids. Moreover, these compounds exhibit remarkable pharmacological properties, including immunomodulation, antitumor, antiviral, antioxidant, antidiabetic, anti-inflammatory, anticoagulant, antithrombotic, and antibacterial activities, all with low toxicity and minimal side effects. Additionally, U. pinnatifida shows promise in the treatment or prevention of neurodegenerative diseases such as Alzheimer’s and Parkinson’s, as well as neuropsychiatric conditions like depression, supported by its antioxidant effects against oxidative stress and neuroprotective activities. Numerous in vitro and in vivo studies have confirmed that U. pinnatifida polysaccharides (UPPs), particularly fucoidans, exhibit significant biological activities. Thus, accumulating evidence positions UPPs as promising therapeutic agents for a variety of diseases. Full article

Immunotherapy is a transformative strategy in oncology, yet the development of novel immunomodulatory agents remains essential. This study explores the anti-tumor potential of a structurally unique polysaccharide isolated from an Aspergillus ochraceus (AOP), sourced from the Antarctic Weddell Sea. Using alkaline-assisted extraction and chromatographic purification, we obtained a homogeneous polysaccharide predominantly composed of galactose and mannose, with an average molecular weight of 39.67 kDa. The structure was characterized by an integrated nuclear magnetic resonance spectroscopy and mass spectrometry analysis, revealing that the AOP is composed of β (1→5)-linked galactofuranose units, with a minor substitution by α-D-mannopyranose residues via (1→2) glycosidic bonds at the C2 of the galactofuranose. Functional assays, including CCK8 and wound-healing tests, demonstrated that this polysaccharide, referred to as AOP, inhibited melanoma cell proliferation and migration in a dose-dependent manner. Additionally, the AOP activated RAW264.7 and bone marrow-derived macrophage (BMDM) cells without exhibiting significant cytotoxicity, leading to the release of inflammatory factors such as TNF-α, IL-1β, and IL-6. Mechanistically, the AOP was found to upregulate the expression of CD86 and IFN-γ, while downregulating genes like IL-4 and Arg1. These findings position the AOP as the first documented Antarctic fungal polysaccharide with macrophage-reprogramming capabilities against melanoma, offering novel molecular insights for marine-derived immunotherapeutics. Full article

Galaxamide, an N-methylated cyclo-pentapeptide containing five D-leucines isolated from Galaxaura filamentosa, has shown significant antitumor activity. This unique cyclo-pentapeptide offered a fresh skeleton for structural modifications. Herein, galaxamide and its 23 analogs (Gala01~Gala24) were designed and synthesized by substituting D-leucine with various proteinogenic amino acids or altering the amino acid configuration using the “3 + 2” strategy, and the in vitro antitumor activity of these cyclopeptides was studied utilizing the CCK-8 assay against two human tumor cell lines (A549 and K562) and one human normal cell line (293T). The total yields of galaxamide and its analogs reached 9.7% and 9.1–16.0%, respectively. CCK-8 assays demonstrated that these compounds showed broad-spectrum antitumor activity, with Gala04 exhibiting outstanding activity against K562 cells (IC₅₀ = 4.2 µM). The anticancer efficacy of galaxamide analogs against tumor cell lines was significantly influenced by the quantity of D-leucines and the D-leucine position. Full article

Polysaccharides (PSs) are the most abundant carbohydrates in nature, performing essential biological functions such as immune system regulation, structural support, and cell communication. PSs from marine microalgae have gained increasing attention due to their diverse biological activities and potential applications in various fields, including the human health sector. These natural macromolecules, primarily composed of glucose, xylose, galactose, rhamnose, and fucose, exhibit bioactive properties influenced by their molecular weight, sulfation degree, and structural complexity. Microalgal PSs can function as antiviral, antimicrobial, antioxidant, immunomodulatory, and antitumor agents, making them promising candidates for pharmaceutical and nutraceutical applications. Additionally, their physicochemical properties make them valuable as bioactive ingredients in cosmetics, serving as hydrating agents, UV protectants, and anti-ageing compounds. The production of PSs from microalgae presents a sustainable alternative to terrestrial plants, as microalgae can be cultivated under controlled conditions, ensuring high yield and purity while minimizing environmental impact. Despite their potential, challenges remain in optimizing extraction techniques, enhancing structural characterization, and scaling up production for commercial applications. This review provides an overview of the principal biological activities of PSs from eukaryotic microalgae and their possible use as ingredients for cosmetic applications. Challenges to address to implement their use as products to improve human health and wellbeing are also discussed. Full article

Diterpenoids from marine-derived organisms represent a prolific source of secondary metabolites, characterized by their exceptionally promising chemical structures and pronounced pharmacological properties. In recent years, marine diterpenoids have garnered considerable attention and are regarded as a prominent area of scientific research. As a vital class of metabolites, diterpenoids show diverse biological activities, encompassing antibacterial, antifungal, antiviral, anti-inflammatory, inhibitory, and cytotoxic activities, among others. With the rapid advancement of equipment and identified technology, there has been a tremendous surge in the discovery rate of novel diterpenoid skeletons and bioactivities derived from marine fungi over the past decade. The present review compiles the reported diterpenoids from marine fungal sources mainly generated from January 2000 to December 2024. In this paper, 515 diterpenoids from marine organisms are summarized. Among them, a total of 281 structures from various fungal species are included, comprising 55 from sediment, 39 from marine animals (predominantly invertebrates, including 17 from coral and 22 from sponges), and 53 from marine plants (including 34 from algae and 19 from mangrove). Diverse biological activities are exhibited in 244 compounds, and among these, 112 compounds showed great anti-tumor activity (45.90%) and 110 metabolites showed remarkable cytotoxicity (45.08%). Furthermore, these compounds displayed a range of diverse bioactivities, including potent anti-oxidant activity (2.87%), promising anti-inflammatory activity (1.64%), great anti-bacterial activity (1.64%), notable anti-thrombotic activity (1.23%), etc. Moreover, the diterpenoids’ structural characterization and biological activities are additionally elaborated upon. The present critical summary provides a comprehensive overview of the reported knowledge regarding diterpenoids derived from marine fungi, invertebrates, and aquatic plants. The systematic review presented herein offers medical researchers an extensive range of promising lead compounds for the development of marine drugs, thereby furnishing novel and valuable pharmaceutical agents. Full article

L-asparaginase (ASNase) hydrolyzes L-asparagine to L-aspartic acid and ammonia and has been used as an antitumor agent for the treatment of acute lymphoblastic leukemia. ASNase has also been used to mitigate the suspected carcinogenic effects of acrylamide in foods. Commercial ASNases currently used in the pharmaceutical and food industries are produced by microorganisms, such as bacteria and fungi. However, their toxicity and poor thermal stability limit their application. Therefore, identifying novel sources of ASNase is critical. In the present study, we identified an asparaginase-producing marine bacterial strain, GH-W2b, as a Pseudomonas species. Based on the plate assay results, GH-W2b produced ASNase with marginal L-glutaminase (GLNase) activity, which has been reported to cause adverse effects in clinical ASNases. The ASNase activity of GH-W2b was maximized at 50–65 °C and pH 7.0–8.5. Notably, the activities were consistent at a wide range of NaCl concentrations (0–15%) at 37 °C. In addition, compared to the control (no pre-incubation), ASNase activities were retained (>87%) by 2 h pre-incubation at 4–37 °C. Overall, our results suggest that GH-W2b ASNase has the potential to serve as a candidate for the development of salt-tolerant and/or alternative ASNases in pharmaceutical and food products. Full article

In recent years, research on active polysaccharides has progressed significantly, particularly regarding their anticancer and immunomodulatory properties. Among these, clam polysaccharides, a type of marine-derived polysaccharide, exhibit notable biological activities, including both anticancer effects and immune modulation. The aims of this study are to investigate the anticancer and immunomodulatory effects of microwave-extracted clam polysaccharide (MCP) in vitro. Cell experiments demonstrated that MCP significantly inhibited both colony formation and migration of HT-29 cells. Furthermore, treatment with MCP led to the downregulation of Bcl-2 gene expression, a reduction in mitochondrial membrane potential, activation of cytochrome C gene and caspase-3 gene, and, finally, the induction of apoptosis in HT-29 cells, implying the involvement of the mitochondrial pathway. Additionally, MCP was found to prompt a phenotypic shift in macrophages from M2 to M1 subtype and from M0 to M1 subtype. MCP also decreased reactive oxygen species (ROS) levels within the cancer cells, thereby augmenting anticancer efficacy through a dual mechanism of immune activation and antioxidant enhancement. These findings suggest that MCPs present significant potential as natural antitumor agents and immunomodulators, especially in the development of functional foods or drugs. Full article

Macroalgae are known as abundant sources of phytochemicals, which offer a plethora of beneficial biological properties. Besides being the most notable classes of compounds found in macroalgae, phlorotannins, bromophenols, and terpenoids comprise some of the most relevant for their biological properties. Phlorotannins, mainly prevalent in brown algae and structurally characterized as complex polyphenolic compounds derived from phloroglucinol units, possess robust antioxidant, anti-inflammatory, antitumor, and cytotoxic activities, modulated by factors such as the degree of polymerization and environmental conditions. Bromophenols, halogenated compounds found in algae and other marine organisms, exhibit significant antioxidant and antiviral properties. Their diverse structures and bromination patterns contribute to their potential as therapeutic and chemical defense agents. Pigments (chemically described as primary terpenoids) play a critical role in light absorption and energy transfer in macroalgae and are divided into three main groups: (i) carotenoids, which are primarily found in brown algae and provide photoprotective and antioxidant benefits; (ii) chlorophylls, known for facilitating the conversion of light into biological energy; and (iii) phycobilins, which are mostly found in red algae and play important roles in light absorption and energy transfer, besides providing remarkable health benefits. Finally, secondary terpenoids, which are particularly abundant in red algae (e.g., the Rhodomelaceae family) are central to cellular interactions and exhibit significant antioxidant, antimicrobial, antidiabetic, and anti-inflammatory properties. This study represents a detailed analysis of the biosynthesis, structural diversity, and biological activities of these macroalgae metabolites, emphasizing their potential biological properties. Full article

The development of antitumor drugs and therapy requires new approaches and molecules, and products of natural origin provide intriguing alternatives for antitumor research. Gastropodan hemocyanins-multimeric copper-containing glycoproteins have been used in therapeutic vaccines and antitumor agents in many cancer models. Materials and Methods: We established a murine model of melanoma by challenging C57BL/6 mice with a B16F10 cell line for solid tumor formation in experimental animals. The anticancer properties of hemocyanins isolated from the marine snail Rapana thomasiana (RtH) and the terrestrial snail Helix aspersa (HaH) were evaluated in this melanoma model using various schemes of therapy. Flow cytometry, ELISA, proliferation, and cytotoxicity assays, as well as histology investigations, were also performed. Results: Beneficial effects on tumor growth, tumor incidence, and survival of tumor-bearing C57BL/6 mice after administration of the RtH or HaH were observed. The generation of high titers of melanoma-specific IgM antibodies, pro-inflammatory cytokines, and tumor-specific CTLs, and high levels of tumor-infiltrated M1 macrophages enhanced the immune reaction and tumor suppression. Discussion: Both RtH and HaH exhibited promising properties for applications as antitumor therapeutic agents and future experiments with humans. Full article

Recently, we re-isolated the glycosylated angucycline antibiotics P-1894B (1) and grincamycin (1′) from the marine-derived Streptomyces lusitanus SCSIO LR32 as potent antitumor agents and identified their biosynthesis gene cluster gcn. Both P-1894B (1) and grincamycin (1′) possess a trisaccharide and a disaccharide moiety comprised of five deoxysugars. In this work, three genes encoding glycosyltransferases (GcnG1, GcnG2, and GcnG3) responsible for the assembly of deoxysugars into angucycline aglycone were identified from the biosynthesis gene cluster gcn. Gene inactivations of gcnG1, gcnG2, gcnG3, and gcnG1G2 by lambda-RED-mediated gene replacements led to the construction of four mutants, in which the glycosyltransferase genes were disrupted, respectively. The metabolites from the mutants were purified and identified, including two new analogues designated as grincamycin U (3a) and V (3′). The sequential glycosylation steps in the biosynthesis of P-1894B (1) and grincamycin (1′) catalyzed by GcnG3, GcnG1, and GcnG2 were elucidated. Full article

Anticancer peptides are short and structurally heterogeneous aminoacidic chains, which display selective cytotoxicity mostly against tumor cells, but not healthy cells, based on their different cell surface properties. Their anti-tumoral activity is carried out through interference with intracellular homeostasis, such as plasmalemma integrity, cell cycle control, enzymatic activities and mitochondrial functions, ultimately acting as angiogenesis-, drug resistance- and metastasis-inhibiting agents, immune stimulators, differentiation inducers and necrosis or extrinsic/intrinsic apoptosis promoters. The marine environment features an ever-growing level of biodiversity, and seas and oceans are poorly exploited mines in terms of natural products of biomedical interest. Adaptation processes to extreme and competitive environmental conditions led marine species to produce unique metabolites as a chemical strategy to allow inter-individual signalization and ensure survival against predators, infectious agents or UV radiation. These natural metabolites have found broad use in various applications in healthcare management, due to their anticancer, anti-angiogenic, anti-inflammatory and regeneration abilities. The aim of this review is to pick selected studies that report on the isolation of marine animal-derived peptides and the identification of their anticancer activity in in vitro cultures of cancer cells, and list them with respect to the taxonomical hierarchy of the source organism. Full article

Globally, prostate cancer is among the most threatening and leading causes of death in men. This study, therefore, aimed to search for an ideal antitumor strategy with high efficacy, low drug resistance, and no or few adverse effects. Resistomycin is a natural antibiotic derived from marine actinomycetes, and it possesses various biological activities. Prostate cancer cells (PC3) were treated with resistomycin (IC₁₂.₅: 0.65 or IC₂₅: 1.3 µg/mL) or 5-fluorouracil (5-FU; IC₂₅: 7 µg/mL) for 24 h. MTT assay and flow cytometry were utilized to assess cell viability and apoptosis. Oxidative stress, apoptotic-related markers, and cell cycle were also assessed. The results revealed that the IC₅₀ of resistomycin and 5-FU on PC3 cells were 2.63 µg/mL and 14.44 µg/mL, respectively. Furthermore, treated cells with the high dose of resistomycin showed an increased number of apoptotic cells compared to those treated with the lower dose. Remarkable induction of reactive oxygen species generation and lactate dehydrogenase (LDH) leakage with high malondialdehyde (MDA), carbonyl protein (CP), and 8-hydroxyguanosine (8-OHdG) contents were observed in resistomycin-treated cells. In addition, marked declines in glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in PC3 cells subjected to resistomycin therapy were observed. Resistomycin triggered observable cell apoptosis by increasing Bax, caspase-3, and cytosolic cytochrome c levels and decreasing Bcl-2 levels. In addition, notable downregulation of proliferating cell nuclear antigen (PCNA) and cyclin D1 was observed in resistomycin-treated cancerous cells. According to this evaluation, the antitumor potential of resistomycin, in a concentration-dependent manner, in prostate cancer cells was achieved by triggering oxidative stress, mitochondrial apoptosis, and cell cycle arrest in cancer cells. In conclusion, our investigation suggests that resistomycin can be considered a starting point for developing new chemotherapeutic agents for human prostate cancer. Full article

The marine environment is a promising source of natural products with possible pharmacological applications. In this sense, marine microorganisms, especially marine fungi, can produce bioactive compounds with various therapeutic properties. Colorectal cancer (CRC) represents a major health problem worldwide, since the treatments used to date are not capable of improving patient survival; that is why natural compounds from marine fungi offer a promising alternative. This study focused on evaluating the antitumor and antioxidant activity of fractions derived from the marine fungi E. maritima and P. lilacinum in two CRC cell lines T84 and SW480. Fractions Fr-EM6, Fr-EM7, Fr-EM8 and Fr-PLMOH-3 demonstrated potent cytotoxic activity in tested CRC cell lines with no activity in the non-tumor line. In particular, the Fr-PLMOH-3 fraction from P. lilacinum showed significant antiproliferative effects on T84 and SW480 cell lines and exhibited a greater cytotoxic effect on cancer stem cells compared to tumor cells. Furthermore, the Fr-EM8 fraction from E. maritima demonstrated a strong antioxidant capacity. These findings highlight the potential of compounds of marine origin as effective and selective antitumor agents for the treatment of CRC. Further studies are needed to explore the underlying mechanisms and potential clinical applications of these bioactive fractions and compounds. Full article

Ascidians are marine invertebrates that synthesize sulfated glycosaminoglycans (GAGs) within their viscera. Ascidian GAGs are considered analogues of mammalian GAGs and possess great potential as bioactive compounds, presenting antitumoral and anticoagulant activity. Due to its worldwide occurrence and, therefore, being a suitable organism for large-scale mariculture in many marine environments, our main objectives are to study Microcosmus exasperatus GAGs regarding composition, structure, and biological activity. We also aim to develop efficient protocols for sulfated polysaccharides extraction and purification for large-scale production and clinical applications. GAGs derived from M. exasperatus viscera were extracted by proteolytic digestion, purified by ion-exchange liquid chromatography, and characterized by agarose gel electrophoresis and enzymatic treatments. Anticoagulant activity was evaluated by APTT assays. Antitumoral activity was assessed in an in vitro model of tumor cell culture using MTT, clonogenic, and wound healing assays, respectively. Our results show that M. exasperatus presents three distinct polysaccharides; among them, two were identified: a dermatan sulfate and a fucosylated dermatan sulfate. Antitumoral activity was confirmed for the total polysaccharides (TP). While short-term incubation does not affect tumor cell viability at low concentrations, long-term TP incubation decreases LLC tumor cell growth/proliferation at different concentrations. In addition, TP decreased tumor cell migration at different concentrations. In conclusion, we state that M. exasperatus presents great potential as an alternative GAG source, producing compounds with antitumoral properties at low concentrations that do not possess anticoagulant activity and do not enhance other aspects of malignancy, such as tumor cell migration. Our perspectives are to apply these molecules in future preclinical studies for cancer treatment as antitumoral agents to be combined with current treatments to potentiate therapeutic efficacy. Full article

R-phycoerythrin (R-PE) can be enzymatically extracted from red seaweeds such as Palmaria palmata. This pigment has numerous applications and is notably known as an antioxidant, antitumoral or anti-inflammatory agent. Enzymes secreted by P. palmata associated fungal strains were assumed to be efficient and adapted for R-PE extraction from this macroalga. The aim of the present study was to quantify both xylanolytic and cellulolytic activities of enzymatic extracts obtained from six Palmaria palmata derived fungal strains. Degradation of P. palmata biomass by fungal enzymatic extracts was also investigated, focused on soluble protein and R-PE extraction. Enzymatic extracts were obtained by solid state fermentation. Macroalgal degradation abilities were evaluated by measuring reducing sugar release using DNS assays. Soluble proteins and R-PE recovery yields were evaluated through bicinchoninic acid and spectrophotometric assays, respectively. Various enzymatic activities were obtained according to fungal isolates up to 978 U/mL for xylanase and 50 U/mL for cellulase. Enzymatic extract allowed high degrading abilities, with four of the six fungal strains assessed exhibiting at least equal results as the commercial enzymes for the reducing sugar release. Similarly, all six strains allowed the same soluble protein extraction yield and four of them led to an improvement of R-PE extraction. R-PE extraction from P. palamata using marine fungal enzymes appeared particularly promising. To the best of our knowledge, this study is the first on the use of enzymes of P. palmata associated fungi in the degradation of its own biomass for biomolecules recovery. Full article