Search Results (287)

Natural bioactive peptides have emerged as pivotal candidates in modern science due to their multifaceted biological activities and versatile applications across biomedicine, biotechnology, and nutraceuticals. These molecules exhibit a broad pharmacological spectrum including antimicrobial, antiplatelet, antioxidant, antihypertensive, and antitumor properties, positioning them as potent therapeutic agents and essential functional food constituents. Compared to synthetic alternatives, their inherent structural diversity, biocompatibility, and biodegradability offer a superior safety profile by minimizing systemic toxicity and adverse effects. This review provides a comprehensive analysis of the primary natural reservoirs of these peptides, which encompass terrestrial flora and fauna as well as marine organisms and microorganisms, while elucidating their complex mechanisms of action and structure–function relationships. Furthermore, we evaluate contemporary methodologies for peptide identification and optimization, such as high-throughput proteomics, computational modeling, and strategic chemical modifications aimed at enhancing metabolic stability and bioavailability. Although bottlenecks in extraction, scalable production, and proteolytic susceptibility persist, recent breakthroughs in recombinant technology and rational design are facilitating their industrial translation. Finally, we discuss future perspectives focused on the synergy between artificial intelligence, nanotechnology, and sustainable circular economy strategies to maximize the therapeutic accessibility and functional efficacy of natural peptides. Full article

Marine plants are a rich source of bioactive compounds with unique properties. The Mediterranean seagrass Posidonia oceanica is particularly abundant in phenolics and flavonoids, which exhibit antioxidant and anti-inflammatory activities. In this study, a phenolic-rich extract (POS) was obtained from beach-cast P. oceanica leaves using supercritical fluid extraction (SFE), an eco-friendly technique that preserves thermolabile compounds and avoids organic solvents. POS was incorporated into a base cream (POS-enriched cream) to evaluate its bioactive potential in topical applications. The antioxidant capacity of POS and the cream formulation was firstly evaluated using the DPPH radical scavenging assay, confirming strong radical scavenging activity for the POS (IC₅₀ = 2.32 ± 0.33 mg/mL) and significant activity for the POS-enriched cream (IC₅₀ = 16.76 ± 0.58 mg/mL) compared to a base cream as control (IC₅₀ = 37.62 ± 1.27 mg/mL). The antioxidant and photoprotective effects of POS were investigated in human skin fibroblasts (HS-68) exposed to oxidative stress and UV-induced damage, while anti-melanogenic activity was assessed in human epidermal melanocytes (HEM) by measuring tyrosinase activity and melanin content. POS significantly reduced ROS accumulation and modulated key molecular pathways involved in apoptosis (p-JNK), inflammation (NF-κB), energy balance (p-AMPK), and collagen synthesis (Col1A1) in fibroblasts. In melanocytes, both POS pure extract and POS-enriched cream effectively inhibited tyrosinase activity while maintaining unaltered basal melanin levels, indicating a modulatory rather than fully suppressive effect. These findings highlight the potential of P. oceanica SFE extracts as sustainable natural marine-derived products for photoprotection and anti-melanogenesis, thereby bridging the gap between marine waste stream management and applications in skin health and anti-aging strategies. Full article

The study evaluated the potential of Thymus mastichina, Lavandula luisiery, and Origanum virens hydrolates—essential oil-rich species found in the Dehesa ecosystem—as natural agents for pork preservation through marination. Hydrolates, the main by-products of essential oil distillation, were characterized by their volatile composition, total phenolic content, antioxidant capacity, and antimicrobial activity against Escherichia coli and Listeria innocua. Pork fillets were marinated (24 h) with increasing hydrolate concentrations (1:1, 1:1.5, 1:2 w/w) and then stored for eight days under refrigeration to assess microbial growth, oxidation, and color changes. All hydrolates exhibited similar antimicrobial effects, though Origanum showed the highest phenolic content and antioxidant activity. Marination had limited antimicrobial impact. Marination with Origanum and Thymus provided significant protection against lipid oxidation during storage, while Lavandula displayed limited or even pro-oxidative behavior at certain doses. Marination did not affect carbonyl formation although it caused slight changes in instrumental color. Overall, the study highlights the potential of Lavandula, Thymus, and Origanum hydrolates as sustainable alternatives to synthetic antioxidants in meat products, emphasizing their antioxidant—rather than antimicrobial—effect. Full article

Phlorotannins, a unique group of polyphenolic compounds derived exclusively from brown macroalgae (Phaeophyceae), have gained substantial scientific and industrial interest due to their structural diversity and multifaceted bioactivities. These marine metabolites, composed of phloroglucinol units linked through various C–C and C–O–C bonds, exhibit broad-spectrum antioxidant, anti-inflammatory, antimicrobial, antidiabetic, anticancer, and neuroprotective effects. Despite their promising in vitro efficacy, large-scale application remains hindered by three critical translational barriers: (i) extreme natural variability in phlorotannin content driven by ecological and seasonal factors, complicating raw material standardization; (ii) physicochemical instability and poor aqueous solubility resulting in limited oral bioavailability; and (iii) insufficient development of advanced delivery systems to ensure controlled release and targeted bioactivity. This comprehensive review integrates ecological, biochemical, and technological perspectives to establish a unified framework for translating phlorotannin research toward clinical and commercial realization. It systematically examines biosynthetic regulation, structural classification, extraction and purification methods, bioactivity mechanisms, pharmacokinetic barriers, and toxicological safety considerations. The review concludes by highlighting future research priorities essential for achieving industrial scalability, formulation reproducibility, and regulatory acceptance in marine bioactive development. Full article

Background: Ultraviolet B (UVB) radiation induces oxidative stress, inflammation, and collagen degradation in skin, leading to photodamage. Ergosterol (ERG)—a sterol widely distributed in fungi and algae, including numerous marine species—possesses antioxidant and anti-inflammatory activities, but its photoprotective mechanisms remain unclear. Methods: Using integrated in vitro (UVB-irradiated human keratinocytes) and in vivo (topical ERG in a murine UVB model) approaches, combined with transcriptomic and network pharmacology analyses, we evaluated ERG’s effects on oxidative stress, inflammation, and extracellular matrix integrity. Results: ERG treatment preserved keratinocyte viability, reduced reactive oxygen species, and suppressed pro-inflammatory mediators after UVB exposure. In mice, topical ERG significantly attenuated epidermal hyperplasia, maintained tight-junction integrity, and inhibited collagen matrix degradation. Mechanistically, ERG exerted dual inhibition of the nuclear factor kappa B (NF-κB) pathway, which mediates inflammation, and the mitogen-activated protein kinase (MAPK) pathway, which regulates collagen degradation. Conclusions: These findings identify ERG as a marine-derived sterol with potent photoprotective activity that simultaneously targets oxidative stress, inflammation, and extracellular matrix damage, highlighting its promise as a natural compound for dermatological applications and aligning with ongoing efforts to explore marine-derived agents against skin oxidative stress and inflammation. Full article

Background/Objectives: Natural products derived from marine algae serve as promising reservoirs of bioactive compounds for preventing and managing inflammation-associated diseases. This study systematically investigated the regional variations in antioxidant and anti-inflammatory activities of the brown alga Sargassum thunbergii collected from seven coastal regions of Korea and elucidated the underlying mechanisms of action. Methods: Among all samples, the extract from Haeundae-gu exhibited the highest total polyphenol (47.3 ± 2.1 mg GAE/g) and flavonoid (19.8 ± 1.7 mg QE/g) contents, showing superior antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl (DPPH) (RC₅₀ = 44.54 µg/mL), 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (RC₅₀ = 36.42 µg/mL), and ferric reducing antioxidant power (FRAP) (0.56 mM FeSO₄ eq/mg) assays. In lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages, the Haeundae-gu extract markedly suppressed nitric oxide (NO) production and downregulated inducible nitric oxide synthase (iNOS) expression in a dose-dependent manner without cytotoxic effects. High-performance liquid chromatography (HPLC) identified fucosterol (10.23 ± 0.17 mg/g extract) as a predominant sterol component, and molecular docking analysis revealed specific hydrogen bonding of fucosterol with TYR489 in the active site of iNOS (GlideScore = −4.774 kcal/mol). Results: These findings indicate that both phenolic compounds and sterols such as fucosterol act synergistically to enhance the antioxidant and anti-inflammatory effects of S. thunbergii. Conclusions: In summary, the mechanistic and functional insights obtained in this study highlight S. thunbergii, particularly from Haeundae-gu, as a promising marine-derived bioresource for developing nutraceuticals and therapeutic interventions against oxidative stress and inflammation-related disorders. Full article

Metabolic Syndrome (MetS), a cluster of interconnected metabolic abnormalities, poses a growing global health burden. A well-established therapeutic target for the diseases is the incretin hormone glucagon-like peptide-1 (GLP-1); however, synthetic agonists have drawbacks such as expense, injectable administration, and side effects. Concurrently, one of the main pathogenic characteristics of MetS is oxidative stress, in which the Thioredoxin-Interacting Protein (TXNIP)/thioredoxin system is a critical player. The strong evidence that natural compounds derived from plant, marine, and microbiological sources can simultaneously target the TXNIP–thioredoxin antioxidant axis and GLP-1 signaling is examined in this study. These substances can limit TXNIP expression and increase thioredoxin activity while also stimulating GLP-1 secretion, inhibiting dipeptidyl peptidase-4 (DPP-4), or acting as GLP-1 receptor agonists. A cycle of reinforcement is created by these two actions: Pancreatic β-cell activity and incretin responsiveness are improved by GLP-1-mediated TXNIP downregulation, which also strengthens antioxidant defense. However, translational development must overcome major pharmacological obstacles, especially those related to bioavailability, metabolic stability, and standardization, despite encouraging preclinical effectiveness. To speed up this translational process, integrative computational techniques (such as molecular docking, network pharmacology, and artificial intelligence) are strong tools for lead optimization and creation of hypothesis. Thus, natural products can provide a special chance to discover multi-target treatments that comprehensively address the oxidative and hormonal causes of MetS. Full article

Fucoxanthin (Fx), a marine xanthophyll carotenoid, has attracted considerable scientific attention due to its wide-ranging biological activities, including antioxidant, anti-inflammatory, anti-obesity, and anticancer effects. Despite its substantial therapeutic potential, the clinical application of Fx and its derivatives remains constrained by their structural complexity, low chemical stability, and limited bioavailability. This review offers a thorough and up-to-date overview of Fx, encompassing its primary natural sources, the metabolic biotransformation to fucoxanthinol (FxOH) and amarouciaxanthin A—metabolites whose bioactive properties significantly contribute to the observed in vivo effects—and the molecular mechanisms underlying the biological activities of Fx and its metabolites, with emphasis on their modulation of key intracellular signalling pathways involved in inflammation, lipid metabolism, and cell proliferation. Furthermore, it explores how targeted structural modifications may enhance the pharmacokinetic profiles and expand the therapeutic potential of Fx-based compounds, while highlighting promising strategies for their optimisation. By integrating insights from pharmacology, biochemistry, and synthetic chemistry, this work aims to guide future efforts in the rational design of marine-derived bioactive agents and underscores the value of marine biodiversity in therapeutic innovation. Full article

Alzheimer’s disease continues to be one of the most urgent neurodegenerative conditions, with acetylcholinesterase (AChE) inhibitors serving as a fundamental component of contemporary treatment approaches. Growing evidence underscores that marine ecosystems are a rich source of structurally varied and biologically active natural products exhibiting anticholinesterase properties. This review presents a thorough synthesis of marine-derived metabolites—including those sourced from bacteria, fungi, sponges, algae, and other marine life—that demonstrate inhibitory effects against AChE and butyrylcholinesterase (BuChE). Numerous compounds, such as meroterpenoids, alkaloids, peptides, and phlorotannins, not only show nanomolar to micromolar inhibitory activity but also reveal additional neuroprotective characteristics, including antioxidant effects, anti-amyloid properties, and modulation of neuronal survival pathways. Despite these encouraging findings, the transition to clinical applications is hindered by a lack of comprehensive pharmacokinetic, toxicity, and long-term efficacy studies. The structural variety of marine metabolites provides valuable frameworks for the development of next-generation cholinesterase inhibitors. Further interdisciplinary research is essential to enhance their therapeutic potential and facilitate their incorporation into strategies for addressing Alzheimer’s disease and related conditions. Full article

Background: Alginate is a naturally occurring anionic polysaccharide extracted from brown marine algae and widely explored for biomedical applications due to its biocompatibility and functional versatility. This study aims to extract and compare alginates from two Red Sea brown algae, Turbinaria ornata (TA) and Hormophysa cuneiformis (HA), and to evaluate how structural differences influence their therapeutic properties. Methods: Alginate was isolated by sequential acid–alkaline extraction and characterized using FTIR, XRD, TGA, elemental analysis, and HPLC. Biological activities were assessed through antioxidant, anti-inflammatory, antidiabetic, neuroprotective, and hepatoprotective assays, supported by molecular docking and gene ontology interaction analysis. Results: Distinct physicochemical variations were observed between HA and TA. TA exhibited stronger antioxidant (IC₅₀ = 25.89 µg/mL), anti-inflammatory (COX-1 IC₅₀ = 69.61 µg/mL), antidiabetic (α-amylase IC₅₀ = 45.14 µg/mL), and hepatoprotective activities (IC₅₀ = 118.21 µg/mL), whereas HA displayed superior neuroprotective potential through butyrylcholinesterase inhibition (IC₅₀ = 39.01 µg/mL). Molecular docking supported the in vitro findings by confirming interactions with key protein targets associated with oxidative stress and metabolic pathways. Conclusions: Structural variation between species-derived alginates directly impacts their biological activities. TA represents a promising candidate for metabolic and anti-inflammatory therapies, while HA may be more suitable for neuroprotective interventions. These results emphasize the importance of source-specific alginate selection for developing targeted pharmaceutical applications. Full article

Marine algae are a sustainable and eco-friendly resource, growing rapidly without freshwater or arable land while aiding carbon sequestration. Their extract is rich in biodegradable polysaccharides like alginate, fucoidan, carrageenan, agar, and Ulvan which can be used further in wound healing thanks to their unique characteristics such as ensuring moisture balance and tissue regeneration by forming biocompatible hydrogels with antimicrobial, anti-inflammatory, and antioxidant properties, key requirements in wound healing. The present study explored the utilization of local grown marine algae (i.e., Aegean seashores from Türkiye) and transforming the waste into useful end-products for dermatocosmetics and healing systems. The extracted polyssacharide, e.g., Ulvan which was characterized by means of FT-IR spectroscopy, DSC, and antioxidant activity, was included inside a semi-solid formulation and combined with other polysaccharides from other natural sources such a chitosan, alginate, and hyaluronic acid to form bioactive hydrogels with wound closure activity. The formulated hydrogels exhibited significant swelling capacity, antioxidant activity, and the selected optimal formulation exhibited enhanced wound closure rates in vitro, demonstrating potential for wound-healing applications. Full article

Background: The extensive use of antibiotics in aquaculture has raised serious concerns, emphasizing the need for sustainable and natural alternatives. This study evaluated the potential of red dragon fruit (Hylocereus polyrhizus) juice by-products (RJB) as a functional feed additive for juvenile red seabream (Pagrus major). Materials and Methods: The bioactive composition and antioxidant capacity of RJB were analyzed, and five experimental diets containing 0, 0.2, 0.4, 0.8, and 1% RJB were fed to fish for 56 days. Results: Growth performance, feed utilization, body composition, antioxidant enzyme activities, and lysozyme activity were evaluated. RJB contained substantial levels of phenolic and flavonoid compounds and exhibited strong radical-scavenging activity. Dietary inclusion of up to 1% RJB did not significantly affect growth, feed efficiency, or plasma biochemistry. However, fish fed the 1% RJB diet showed increased catalase and glutathione levels, significantly enhanced lysozyme activity, and improved survival following Edwardsiella tarda infection. Conclusion: These results demonstrate that RJB can be safely incorporated into marine fish diets to enhance antioxidant capacity and innate immune defense. The valorization of fruit-processing by-products such as RJB offers a promising strategy for developing antibiotic-free and sustainable aquaculture practices. Full article

Mycosporine-like amino acids (MAAs) are multifunctional, UV-absorbing and antioxidant metabolites produced by marine algae, offering promising applications in biotechnology and dermocosmetic sciences. In this study, MAAs were sustainably extracted from nori seaweed (Porphyra spp.) using an ultrasound-assisted aqueous method, an eco-friendly approach that ensures efficiency and industrial scalability. Chromatographic enrichment followed by MALDI-TOF mass spectrometry confirmed the presence of bioactive compounds, including porphyra-334, palythine, and myc-ornithine. The enriched fraction exhibited potent antioxidant activity (low IC₅₀ in DPPH and ABTS assays) and significant anti-elastase effects, highlighting its potential as a natural anti-aging agent. To optimize delivery, MAAs were incorporated into a stable water-in-oil nanoemulsion, which maintained droplet sizes below 400 nm and a low polydispersity index (PDI < 0.2) for up to four months. A randomized, double-blind clinical study in 20 volunteers further demonstrated that the MAA-based nanoemulsion significantly improved skin hydration (+53.6%) and reduced transepidermal water loss (TEWL), confirming its humectant and barrier-strengthening efficacy. These findings position Porphyra spp. as a sustainable marine resource for producing MAAs, and demonstrate their practical potential as natural, multifunctional ingredients in eco-conscious cosmetic and pharmaceutical formulations. Full article

Natural bioactive chemicals sourced from marine species have attracted growing interest due to their immunomodulatory, antioxidant, and gut microbiota-regulating characteristics. These chemicals, especially peptides, offer therapeutic approaches for addressing inflammation, immunological dysfunction, and intestinal barrier disturbance, which are frequently observed in conditions such as inflammatory bowel disease (IBD). This review centers on current discoveries about marine-derived peptides from octopus, sea conch, and scallop. These substances have demonstrated a considerable ability to restore intestinal integrity, regulate immune cell function, reduce pro-inflammatory cytokines, and rebalance dysbiotic gut microbiota. We consider several in vivo scenarios, encompassing dextran sulphate sodium (DDS)-induced colitis and cyclophosphamide-induced immunosuppression. These compounds raise the expression of tight junction proteins (including ZO-1 and occludin), boost the production of mucin, and encourage the growth of good bacteria such as Lactobacillus and Lachnospiraceae. Their effects are mechanistically associated with the inhibition of critical inflammatory pathways (e.g., Nuclear factor-κB (NF-κB), Toll-like receptor 4 (TLR-4)) and the modulation of both innate and adaptive immune responses. These versatile bioactives can serve as dietary supplements or complementary therapies for gastrointestinal and cancer-related issues. This review emphasizes the therapeutic potential of marine peptides, concentrating on gut–immune–microbiota interactions, as well as exploring future avenues for clinical translation and drug development Full article

Marine-derived bioactive peptides (MBPs) are emerging as promising natural agents for regulating inflammatory responses. MBPs, typically obtained through enzymatic hydrolysis of proteins from various marine organisms such as fish, mollusks, and algae, exhibit diverse biological activities, including antioxidant, immunomodulatory, and anti-inflammatory effects. The ability of MBPs to modulate key inflammatory mediators such as TNF-α, IL-6, and COX-2, primarily through pathways like NF-κB and MAPK, highlights the therapeutic potential of MBPs in managing chronic inflammatory diseases. However, most existing studies are confined to in vitro assays or animal models, with limited translation to human clinical applications. This review explores the stability, bioavailability, and metabolic rate of MBPs under physiological conditions, which remain poorly understood. In addition, a lack of standardized protocols for peptide extraction, purification, and efficacy evaluation hinders comparative analysis across studies and also different proteomics approaches for separation, purification, identification, and quantification of marine-derived peptides with therapeutic properties. The structure–function relationship of MBPs is also underexplored, limiting rational design and targeted applications in functional foods or therapeutic products. These limitations are largely due to a lack of consolidated information and integrated research efforts. To address these challenges, this review summarizes recent progress in identifying MBPs with anti-inflammatory potentials, outlines key mechanisms, and highlights current limitations. Additionally, this review also emphasizes the need to enhance mechanistic understanding, optimize delivery strategies, and advance clinical validation to fully realize the therapeutic potential of MBPs. Full article