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Mar. Drugs, Volume 22, Issue 2 (February 2024) – 45 articles

Cover Story (view full-size image): Marine invertebrates are a rich source of bioactive natural products. Chemical investigation of the tunicate Cystodytes dellechiajei, selected during a biological screening for ligands of the innate immune receptor TREM2, involved in immunomodulatory processes and neurodegenerative diseases, led us to isolate two known pyridoacridine alkaloids, shermilamine B and N-deacetylshermilamine B, and a family of methyl-branched cerebrosides. The latter class of molecules showed selective binding to TREM2 in a dose-dependent manner, whereas the pyridoacridine alkaloids were strongly cytotoxic against multiple myeloma cell lines. N-deacetylshermilamine B was also the first example of a polycyclic alkaloid to show an affinity for this receptor. View this paper
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13 pages, 934 KiB  
Article
Influence of Nutrient Deprivation on the Antioxidant Capacity and Chemical Profile of Two Diatoms from Genus Chaetoceros
by Roberta Frleta Matas, Sanja Radman, Martina Čagalj and Vida Šimat
Mar. Drugs 2024, 22(2), 96; https://doi.org/10.3390/md22020096 - 19 Feb 2024
Viewed by 1912
Abstract
The limited availability of phosphate, nitrogen and silicon in the growth media affects the growth, cellular processes, and metabolism of diatoms. Silicon deficiency primarily affects diatom morphology, while phosphate deficiency reduces the production of nucleic acids and phospholipids. Differences in pigment and protein [...] Read more.
The limited availability of phosphate, nitrogen and silicon in the growth media affects the growth, cellular processes, and metabolism of diatoms. Silicon deficiency primarily affects diatom morphology, while phosphate deficiency reduces the production of nucleic acids and phospholipids. Differences in pigment and protein composition are mainly due to nitrogen deficiency. In this study, Chaetoceros socialis and Chaetoceros costatus were cultured under phosphate, nitrogen, and silicon deprivation conditions. The diatom biomass was collected during the stationary growth phase and extracted with 70% ethanol under ultrasonication. The chemical profiles of the extracts were analyzed by high-performance liquid chromatography with high-resolution mass spectrometry with electrospray ionisation (UHPLC-ESI-HRMS), while the antioxidant capacity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and oxygen radical absorbance capacity (ORAC) assays. Pigments, fatty acids, sterols, and derivatives were detected in both species. The total phenolic content in the extracts ranged from 46.25 ± 1.08 to 89.38 ± 6.21 mg of gallic acid equivalent (GAE)/L and from 29.58 ± 1.08 to 54.17 ± 1.18 mg GAE/L. for C. costatus and C. socialis, respectively. Antioxidant activity was higher in C. costatus extracts, especially those obtained from nitrogen-deprived media. The results of this study contribute to the existing knowledge and the ongoing efforts to overcome application and commercialization barriers of microalgae for wide-ranging potential in different industries. Full article
(This article belongs to the Special Issue Metabolites in Marine Planktonic Organisms)
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16 pages, 4884 KiB  
Article
In Vitro Insights into the Role of 7,8-Epoxy-11-Sinulariolide Acetate Isolated from Soft Coral Sinularia siaesensis in the Potential Attenuation of Inflammation and Osteoclastogenesis
by Lin-Mao Ke, Dan-Dan Yu, Ming-Zhi Su, Liao Cui and Yue-Wei Guo
Mar. Drugs 2024, 22(2), 95; https://doi.org/10.3390/md22020095 - 19 Feb 2024
Cited by 1 | Viewed by 2084
Abstract
The balance between bone-resorbing osteoclasts and bone-forming osteoblasts is essential for the process of bone remodeling. Excessive osteoclast differentiation plays a pivotal role in the pathogenesis of bone diseases such as rheumatoid arthritis and osteoporosis. In the present study, we examined whether 7,8-epoxy-11-sinulariolide [...] Read more.
The balance between bone-resorbing osteoclasts and bone-forming osteoblasts is essential for the process of bone remodeling. Excessive osteoclast differentiation plays a pivotal role in the pathogenesis of bone diseases such as rheumatoid arthritis and osteoporosis. In the present study, we examined whether 7,8-epoxy-11-sinulariolide acetate (Esa), a marine natural product present in soft coral Sinularia siaesensis, attenuates inflammation and osteoclastogenesis in vitro. The results indicated that Esa significantly inhibited lipopolysaccharide (LPS)-induced inflammation model of RAW264.7 cells and suppressed receptor activator for nuclear factor-κB ligand (RANKL)-triggered osteoclastogenesis. Esa significantly down-regulated the protein expression of iNOS, COX-2, and TNF-α by inhibiting the NF-κB/MAPK/PI3K pathways and reducing the release of reactive oxygen species (ROS) in RAW264.7 macrophages. Besides, Esa treatment significantly inhibited osteoclast differentiation and suppressed the expression of osteoclast-specific markers such as NFATC1, MMP-9, and CTSK proteins. These findings suggest that Esa may be a potential agent for the maintenance of bone homeostasis associated with inflammation. Full article
(This article belongs to the Special Issue Bioactive Compounds from Soft Corals and Their Derived Microorganisms)
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12 pages, 1930 KiB  
Article
Development of Integrated Vectors with Strong Constitutive Promoters for High-Yield Antibiotic Production in Mangrove-Derived Streptomyces
by Mingxia Zhao, Zhiqiang Yang, Xinyue Li, Yaqi Liu, Yingying Zhang, Mengqian Zhang, Yangli Li, Xincheng Wang, Zixin Deng, Kui Hong and Dongqing Zhu
Mar. Drugs 2024, 22(2), 94; https://doi.org/10.3390/md22020094 - 18 Feb 2024
Viewed by 2248
Abstract
It is important to improve the production of bioactive secondary products for drug development. The Escherichia coli—Streptomyces shuttle vector pSET152 and its derived vector pIB139 containing a strong constitutive promoter ermEp* are commonly used as integrative vectors in actinomycetes. Four new integrative [...] Read more.
It is important to improve the production of bioactive secondary products for drug development. The Escherichia coli—Streptomyces shuttle vector pSET152 and its derived vector pIB139 containing a strong constitutive promoter ermEp* are commonly used as integrative vectors in actinomycetes. Four new integrative vectors carrying the strong constitutive promoter kasOp*, hrdBp, SCO5768p, and SP44, respectively, were constructed and proven to be functional in different mangrove-derived Streptomyces host strains by using kanamycin resistance gene neo as a reporter. Some biosynthetic genes of elaiophylins, azalomycin Fs, and armeniaspirols were selected and inserted into these vectors to overexpress in their producers including Streptomyces sp. 219807, Streptomyces sp. 211726, and S. armeniacus DSM 43125, resulting in an approximately 1.1–1.4-fold enhancement of the antibiotic yields. Full article
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21 pages, 3770 KiB  
Article
Understanding the Impact of Nitrogen Availability: A Limiting Factor for Enhancing Fucoxanthin Productivity in Microalgae Cultivation
by To Quyen Truong, Yun Ji Park, Jessica Winarto, Phuong Kim Huynh, Jinyoung Moon, Yeong Bin Choi, Dae-Geun Song, Song Yi Koo and Sang Min Kim
Mar. Drugs 2024, 22(2), 93; https://doi.org/10.3390/md22020093 - 18 Feb 2024
Cited by 2 | Viewed by 2373
Abstract
This study aimed to investigate the regulation of fucoxanthin (FX) biosynthesis under various nitrogen conditions to optimize FX productivity in Phaeodactylum tricornutum. Apart from light, nitrogen availability significantly affects the FX production of microalgae; however, the underlying mechanism remains unclear. In batch [...] Read more.
This study aimed to investigate the regulation of fucoxanthin (FX) biosynthesis under various nitrogen conditions to optimize FX productivity in Phaeodactylum tricornutum. Apart from light, nitrogen availability significantly affects the FX production of microalgae; however, the underlying mechanism remains unclear. In batch culture, P. tricornutum was cultivated with normal (NN, 0.882 mM sodium nitrate), limited (LN, 0.22 mM), and high (HN, 8.82 mM) initial nitrogen concentrations in f/2 medium. Microalgal growth and photosynthetic pigment production were examined, and day 5 samples were subjected to fucoxanthin–chlorophyll a/c-binding protein (FCP) proteomic and transcriptomic analyses. The result demonstrated that HN promoted FX productivity by extending the exponential growth phase for higher biomass and FX accumulation stage (P1), showing a continuous increase in FX accumulation on day 6. Augmented FX biosynthesis via the upregulation of carotenogenesis could be primarily attributed to enhanced FCP formation in the thylakoid membrane. Key proteins, such as LHC3/4, LHCF8, LHCF5, and LHCF10, and key genes, such as PtPSY, PtPDS, and PtVDE, were upregulated under nitrogen repletion. Finally, the combination of low light and HN prolonged the P1 stage to day 10, resulting in maximal FX productivity to 9.82 ± 0.56 mg/L/day, demonstrating an effective strategy for enhancing FX production in microalgae cultivation. Full article
(This article belongs to the Special Issue Advances in Marine-Derived Fucoxanthin Studies)
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16 pages, 5945 KiB  
Article
Marine Brown Algae-Derived Compounds as Potential Inhibitors of Japanese Encephalitis Virus RNA-Dependent RNA Polymerase
by Saud O. Alshammari
Mar. Drugs 2024, 22(2), 92; https://doi.org/10.3390/md22020092 - 17 Feb 2024
Cited by 2 | Viewed by 2086
Abstract
The Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that primarily affects people in Asia and seriously threatens public health. Considering the rising occurrence rates and lack of targeted antiviral treatments, it is essential to comprehend and tackle obstacles related to JEV in [...] Read more.
The Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that primarily affects people in Asia and seriously threatens public health. Considering the rising occurrence rates and lack of targeted antiviral treatments, it is essential to comprehend and tackle obstacles related to JEV in order to lessen its influence on world health. This investigation explores compounds derived from marine brown algae (Phaeophyceae) as potential inhibitors of JEV RNA-dependent RNA polymerase (RdRp), a critical enzyme in the virus’s replication cycle. Employing the computational virtual screen approach, four compounds, i.e., CMNPD16749, CMNPD2606, CMNPD27817, and CMNPD23662, with favorable binding energies ranging from −15.7 Kcal/mol to −13.9 kcal/mol were identified. Subsequently, through molecular docking analysis, the interactions responsible for the binding stability between the target protein and hit molecules compared to the reference molecule Galidesvir were studied. Further, through extensive molecular dynamic (MD) simulation studies at 200 ns, it was confirmed that each docked complex showed acceptable dynamic stability compared to the reference molecule. These findings were further validated using MM/PBSA free binding energy calculations, PCA analysis and free energy landscape construction. These computational findings suggested that the brown algae-derived compounds may act as an antiviral drug against JEV infection and lay a crucial foundation for future experimental studies against JEV. Full article
(This article belongs to the Special Issue Marine Compounds and Research of the Middle East 2nd Edition)
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17 pages, 3483 KiB  
Article
Brown Algae Dictyopteris divaricata Attenuates Adipogenesis by Modulating Adipocyte Differentiation and Promoting Lipolysis through Heme Oxygenase-1 Activation in 3T3-L1 Cells
by Lakshi A. Dayarathne, Seok-Chun Ko, Mi-Jin Yim, Jeong Min Lee, Ji-Yul Kim, Gun-Woo Oh, Chul Hwan Kim, Kyung Woo Kim, Dae-Sung Lee and Jae-Young Je
Mar. Drugs 2024, 22(2), 91; https://doi.org/10.3390/md22020091 - 16 Feb 2024
Cited by 4 | Viewed by 2285
Abstract
The present study aims to explore the probable anti-adipogenesis effect of Dictyopteris divaricata (D. divaricata) in 3T3-L1 preadipocytes by regulating heme oxygenase-1 (HO-1). The extract of D. divaricata retarded lipid accretion and decreased triglyceride (TG) content in 3T3-L1 adipocytes but increased [...] Read more.
The present study aims to explore the probable anti-adipogenesis effect of Dictyopteris divaricata (D. divaricata) in 3T3-L1 preadipocytes by regulating heme oxygenase-1 (HO-1). The extract of D. divaricata retarded lipid accretion and decreased triglyceride (TG) content in 3T3-L1 adipocytes but increased free glycerol levels. Treatment with the extract inhibited lipogenesis by inhibiting protein expressions of fatty acid synthase (FAS) and lipoprotein lipase (LPL), whereas lipolysis increased by activating phosphorylation of hormone-sensitive lipase (p-HSL) and AMP-activated protein kinase (p-AMPK). The extract inhibited adipocyte differentiation of 3T3-L1 preadipocytes through down-regulating adipogenic transcription factors, including peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα), and sterol regulatory element-binding protein 1 (SREBP1). This is attributed to the triggering of Wnt/β-catenin signaling. In addition, this study found that treatment with the extract activated HO-1 expression. Pharmacological approaches revealed that treatment with Zinc Protoporphyrin (ZnPP), an HO-1 inhibitor, resulted in an increase in lipid accumulation and a decrease in free glycerol levels. Finally, three adipogenic transcription factors, such as PPARγ, C/EBPα, and SREBP1, restored their expression in the presence of ZnPP. Analysis of chemical constituents revealed that the extract of D. divaricata is rich in 1,4-benzenediol, 7-tetradecenal, fucosterol, and n-hexadecanoic acid, which are known to have multiple pharmacological properties. Full article
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19 pages, 4367 KiB  
Article
Targeted Affinity Purification and Mechanism of Action of Angiotensin-Converting Enzyme (ACE) Inhibitory Peptides from Sea Cucumber Gonads
by Yangduo Wang, Shicheng Chen, Wenzheng Shi, Shuji Liu, Xiaoting Chen, Nan Pan, Xiaoyan Wang, Yongchang Su and Zhiyu Liu
Mar. Drugs 2024, 22(2), 90; https://doi.org/10.3390/md22020090 - 16 Feb 2024
Cited by 3 | Viewed by 2433
Abstract
Protein hydrolysates from sea cucumber (Apostichopus japonicus) gonads are rich in active materials with remarkable angiotensin-converting enzyme (ACE) inhibitory activity. Alcalase was used to hydrolyze sea cucumber gonads, and the hydrolysate was separated by the ultrafiltration membrane to produce a low-molecular-weight [...] Read more.
Protein hydrolysates from sea cucumber (Apostichopus japonicus) gonads are rich in active materials with remarkable angiotensin-converting enzyme (ACE) inhibitory activity. Alcalase was used to hydrolyze sea cucumber gonads, and the hydrolysate was separated by the ultrafiltration membrane to produce a low-molecular-weight peptide component (less than 3 kDa) with good ACE inhibitory activity. The peptide component (less than 3 kDa) was isolated and purified using a combination method of ACE gel affinity chromatography and reverse high-performance liquid chromatography. The purified fractions were identified by liquid chromatography–tandem mass spectrometry (LC–MS/MS), and the resulting products were filtered using structure-based virtual screening (SBVS) to obtain 20 peptides. Of those, three noncompetitive inhibitory peptides (DDQIHIF with an IC50 value of 333.5 μmol·L−1, HDWWKER with an IC50 value of 583.6 μmol·L−1, and THDWWKER with an IC50 value of 1291.8 μmol·L−1) were further investigated based on their favorable pharmacochemical properties and ACE inhibitory activity. Molecular docking studies indicated that the three peptides were entirely enclosed within the ACE protein cavity, improving the overall stability of the complex through interaction forces with the ACE active site. The total free binding energies (ΔGtotal) for DDQIHIF, HDWWKER, and THDWWKER were −21.9 Kcal·mol−1, −71.6 Kcal·mol−1, and −69.1 Kcal·mol−1, respectively. Furthermore, a short-term assay of antihypertensive activity in spontaneously hypertensive rats (SHRs) revealed that HDWWKER could significantly decrease the systolic blood pressure (SBP) of SHRs after intravenous administration. The results showed that based on the better antihypertensive activity of the peptide in SHRs, the feasibility of targeted affinity purification and computer-aided drug discovery (CADD) for the efficient screening and preparation of ACE inhibitory peptide was verified, which provided a new idea of modern drug development method for clinical use. Full article
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12 pages, 2872 KiB  
Article
Synthesis of Bioactive Nickel Nanoparticles Using Bacterial Strains from an Antarctic Consortium
by Joseph Amruthraj Nagoth, Maria Sindhura John, Kesava Priyan Ramasamy, Alessio Mancini, Marco Zannotti, Sara Piras, Rita Giovannetti, Lydia Rathnam, Cristina Miceli, Maria Chiara Biondini and Sandra Pucciarelli
Mar. Drugs 2024, 22(2), 89; https://doi.org/10.3390/md22020089 - 14 Feb 2024
Cited by 1 | Viewed by 2271
Abstract
Marine microorganisms have been demonstrated to be an important source for bioactive molecules. In this paper we report the synthesis of Ni nanoparticles (NiSNPs) used as reducing and capping agents for five bacterial strains isolated from an Antarctic marine consortium: Marinomonas sp. ef1, [...] Read more.
Marine microorganisms have been demonstrated to be an important source for bioactive molecules. In this paper we report the synthesis of Ni nanoparticles (NiSNPs) used as reducing and capping agents for five bacterial strains isolated from an Antarctic marine consortium: Marinomonas sp. ef1, Rhodococcus sp. ef1, Pseudomonas sp. ef1, Brevundimonas sp. ef1, and Bacillus sp. ef1. The NiSNPs were characterized by Ultraviolet–visible (UV–vis) spectroscopy, Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM), X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopic analysis. The maximum absorbances in the UV–Vis spectra were in the range of 374 nm to 422 nm, corresponding to the Surface plasmon resonance (SPR) of Nickel. DLS revealed NiSNPs with sizes between 40 and 45 nm. All NiSNPs were polycrystalline with a face-centered cubic lattice, as revealed by XRD analyses. The NiSNPs zeta potential values were highly negative. TEM analysis showed that the NiSNPs were either spherical or rod shaped, well segregated, and with a size between 20 and 50 nm. The FTIR spectra revealed peaks of amino acid and protein binding to the NiSNPs. Finally, all the NiSNPs possess significant antimicrobial activity, which may play an important role in the management of infectious diseases affecting human health. Full article
(This article belongs to the Special Issue Bioactive Molecules from Extreme Environments III)
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13 pages, 4201 KiB  
Article
Anithiactin D, a Phenylthiazole Natural Product from Mudflat-Derived Streptomyces sp., Suppresses Motility of Cancer Cells
by Sultan Pulat, Inho Yang, Jihye Lee, Sunghoon Hwang, Rui Zhou, Chathurika D. B. Gamage, Mücahit Varlı, İsa Taş, Yi Yang, So-Yeon Park, Ahreum Hong, Jeong-Hyeon Kim, Dong-Chan Oh, Hangun Kim, Sang-Jip Nam and Heonjoong Kang
Mar. Drugs 2024, 22(2), 88; https://doi.org/10.3390/md22020088 - 14 Feb 2024
Cited by 1 | Viewed by 2385
Abstract
Anithiactin D (1), a 2-phenylthiazole class of natural products, was isolated from marine mudflat-derived actinomycetes Streptomyces sp. 10A085. The chemical structure of 1 was elucidated based on the interpretation of NMR and MS data. The absolute configuration of 1 was determined [...] Read more.
Anithiactin D (1), a 2-phenylthiazole class of natural products, was isolated from marine mudflat-derived actinomycetes Streptomyces sp. 10A085. The chemical structure of 1 was elucidated based on the interpretation of NMR and MS data. The absolute configuration of 1 was determined by comparing the experimental and calculated electronic circular dichroism (ECD) spectral data. Anithiactin D (1) significantly decreased cancer cell migration and invasion activities at a concentration of 5 μM via downregulation of the epithelial-to-mesenchymal transition (EMT) markers in A549, AGS, and Caco-2 cell lines. Moreover, 1 inhibited the activity of Rho GTPases, including Rac1 and RhoA in the A549 cell line, suppressed RhoA in AGS and Caco-2 cell lines, and decreased the mRNA expression levels of some matrix metalloproteinases (MMPs) in AGS and Caco-2 cell lines. Thus 1, which is a new entity of the 2-phenylthiazole class of natural products with a unique aniline-indole fused moiety, is a potent inhibitor of the motility of cancer cells. Full article
(This article belongs to the Special Issue Marine Streptomyces-Derived Natural Products 2024)
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10 pages, 966 KiB  
Article
Meirols A–C: Bioactive Catecholic Compounds from the Marine-Derived Fungus Meira sp. 1210CH-42
by Min Ah Lee, Jong Soon Kang, Jeong-Wook Yang, Hwa-Sun Lee, Chang-Su Heo, Sun Joo Park and Hee Jae Shin
Mar. Drugs 2024, 22(2), 87; https://doi.org/10.3390/md22020087 - 14 Feb 2024
Viewed by 2014
Abstract
Three new catecholic compounds, named meirols A–C (24), and one known analog, argovin (1), were isolated from the marine-derived fungus Meira sp. 1210CH-42. Their structures were determined by extensive analysis of 1D, 2D NMR, and HR-ESIMS spectroscopic [...] Read more.
Three new catecholic compounds, named meirols A–C (24), and one known analog, argovin (1), were isolated from the marine-derived fungus Meira sp. 1210CH-42. Their structures were determined by extensive analysis of 1D, 2D NMR, and HR-ESIMS spectroscopic data. Their absolute configurations were elucidated based on ECD calculations. All the compounds exhibited strong antioxidant capabilities with EC50 values ranging from 6.01 to 7.47 μM (ascorbic acid, EC50 = 7.81 μM), as demonstrated by DPPH radical scavenging activity assays. In the α-glucosidase inhibition assay, 1 and 2 showed potent in vitro inhibitory activity with IC50 values of 184.50 and 199.70 μM, respectively (acarbose, IC50 = 301.93 μM). Although none of the isolated compounds exhibited cytotoxicity against one normal and six solid cancer cell lines, 1 exhibited moderate cytotoxicity against the NALM6 and RPMI-8402 blood cancer cell lines with GI50 values of 9.48 and 21.00 μM, respectively. Compound 2 also demonstrated weak cytotoxicity against the NALM6 blood cancer cell line with a GI50 value of 29.40 μM. Full article
(This article belongs to the Special Issue Bioactive Secondary Metabolites of Marine Fungi 2.0)
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16 pages, 2818 KiB  
Article
Synthetic Antimicrobial Peptides Fail to Induce Leucocyte Innate Immune Functions but Elicit Opposing Transcriptomic Profiles in European Sea Bass and Gilthead Seabream
by Laura Cervera, Elena Chaves-Pozo and Alberto Cuesta
Mar. Drugs 2024, 22(2), 86; https://doi.org/10.3390/md22020086 - 14 Feb 2024
Cited by 1 | Viewed by 1900
Abstract
Antimicrobial peptides (AMPs) are promising molecules in diverse fields, including aquaculture. AMPs possess lytic effects on a wide range of pathogens, resulting in a potential replacement for traditional antimicrobials in aquaculture. In addition, they also have modulatory effects on host immune responses. Thus, [...] Read more.
Antimicrobial peptides (AMPs) are promising molecules in diverse fields, including aquaculture. AMPs possess lytic effects on a wide range of pathogens, resulting in a potential replacement for traditional antimicrobials in aquaculture. In addition, they also have modulatory effects on host immune responses. Thus, the objective of this work was to evaluate the immunomodulatory capability of three known synthetic AMPs derived from European sea bass, NK-lysin (Nkl), hepcidin (Hamp), and dicentracin (Dic), in head-kidney cell suspensions from European sea bass and gilthead seabream. The tested peptides were neither cytotoxic for European sea bass nor gilthead seabream cells and failed to modulate the respiratory burst and phagocytosis activities. However, they modified the pattern of transcription of immune-related genes differently in both species. Peptides were able to promote the expression of marker genes for anti-inflammatory (il10), antiviral (mx, irf3), cell-mediated cytotoxicity (nccrp1, gzmb), and antibody responses (ighm) in European sea bass, with the Nkl peptide being the most effective. Contrary to this, the effects of those peptides on gilthead seabream mainly resulted in the suppression of immune responses. To conclude, European sea bass-derived peptides can be postulated as potential tools for immunostimulation in European sea bass fish farms, but more efforts are required for their universal use in other species. Full article
(This article belongs to the Special Issue Marine Drugs Research in Spain 2nd Edition)
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28 pages, 4576 KiB  
Article
Anti-Inflammatory and Immunomodulatory Properties of a Crude Polysaccharide Derived from Green Seaweed Halimeda tuna: Computational and Experimental Evidences
by Marwa Kraiem, Sonia Ben Hamouda, Malek Eleroui, Marwa Ajala, Amal Feki, Amel Dghim, Zakaria Boujhoud, Marwa Bouhamed, Riadh Badraoui, Jean Marc Pujo, Khadija Essafi-Benkhadir, Hatem Kallel and Ibtissem Ben Amara
Mar. Drugs 2024, 22(2), 85; https://doi.org/10.3390/md22020085 - 11 Feb 2024
Cited by 14 | Viewed by 2817
Abstract
In this study, we investigated for the first time the anti-inflammatory and immunomodulatory properties of crude polysaccharide (PSHT) extracted from green marine algae Halimeda tuna. PSHT exhibited anti-oxidant activity in vitro through scavenging 1, 1-diphenyl-2-picryl hydroxyl free radical, reducing Fe3+/ferricyanide [...] Read more.
In this study, we investigated for the first time the anti-inflammatory and immunomodulatory properties of crude polysaccharide (PSHT) extracted from green marine algae Halimeda tuna. PSHT exhibited anti-oxidant activity in vitro through scavenging 1, 1-diphenyl-2-picryl hydroxyl free radical, reducing Fe3+/ferricyanide complex, and inhibiting nitric oxide. PSHT maintained the erythrocyte membrane integrity and prevented hemolysis. Our results also showed that PSHT exerted a significant anti-edematic effect in vivo by decreasing advanced oxidation protein products and malondialdehyde levels and increasing the superoxide dismutase and glutathione peroxidase activities in rat’s paw model and erythrocytes. Interestingly, PSHT increased the viability of murine RAW264.7 macrophages and exerted an anti-inflammatory effect on lipopolysaccharide-stimulated cells by decreasing pro-inflammatory molecule levels, including nitric oxide, granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor-alpha (TNF-α). Our findings indicate that PSHT could be used as a potential immunomodulatory, anti-inflammatory, anti-hemolytic, and anti-oxidant agent. These results could be explained by the computational findings showing that polysaccharide building blocks bound both cyclooxygenase-2 (COX-2) and TNF-α with acceptable affinities. Full article
(This article belongs to the Special Issue Bioactive Polysaccharides from Seaweeds)
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12 pages, 1820 KiB  
Article
Effects of Ultrasonic Power on the Structure and Rheological Properties of Skin Collagen from Albacore (Thunnus alalunga)
by Hao Pan, Xuehua Zhang, Jianbo Ni, Qianqian Liang, Xin Jiang, Zihui Zhou and Wenzheng Shi
Mar. Drugs 2024, 22(2), 84; https://doi.org/10.3390/md22020084 - 10 Feb 2024
Cited by 5 | Viewed by 2002
Abstract
The effects of ultrasonic power (0, 150, 300, 450, and 600 W) on the extraction yield and the structure and rheological properties of pepsin-soluble collagen (PSC) from albacore skin were investigated. Compared with the conventional pepsin extraction method, ultrasonic treatment (UPSC) significantly increased [...] Read more.
The effects of ultrasonic power (0, 150, 300, 450, and 600 W) on the extraction yield and the structure and rheological properties of pepsin-soluble collagen (PSC) from albacore skin were investigated. Compared with the conventional pepsin extraction method, ultrasonic treatment (UPSC) significantly increased the extraction yield of collagen from albacore skin, with a maximum increase of 8.56%. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that peptides of low molecular weight were produced when the ultrasonic power exceeded 300 W. Meanwhile, secondary structure, tertiary structure, and X-ray diffraction analyses showed that the original triple helix structure of collagen was intact after the ultrasonic treatment. The collagen solutions extracted under different ultrasonic powers had significant effects on the dynamic frequency sweep, but a steady shear test suggested that the collagen extracted at 150 W had the best viscosity. These results indicate that an ultrasonic power between 150 and 300 W can improve not only the extraction yield of natural collagen, but also the rheological properties of the collagen solution without compromising the triple helix structure. Full article
(This article belongs to the Special Issue Bioactive Compounds from Marine Fish)
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19 pages, 9574 KiB  
Article
Identification of PLK1-PBD Inhibitors from the Library of Marine Natural Products: 3D QSAR Pharmacophore, ADMET, Scaffold Hopping, Molecular Docking, and Molecular Dynamics Study
by Nan Zhou, Chuangze Zheng, Huiting Tan and Lianxiang Luo
Mar. Drugs 2024, 22(2), 83; https://doi.org/10.3390/md22020083 - 10 Feb 2024
Cited by 6 | Viewed by 2302
Abstract
PLK1 is found to be highly expressed in various types of cancers, but the development of inhibitors for it has been slow. Most inhibitors are still in clinical stages, and many lack the necessary selectivity and anti-tumor effects. This study aimed to create [...] Read more.
PLK1 is found to be highly expressed in various types of cancers, but the development of inhibitors for it has been slow. Most inhibitors are still in clinical stages, and many lack the necessary selectivity and anti-tumor effects. This study aimed to create new inhibitors for the PLK1-PBD by focusing on the PBD binding domain, which has the potential for greater selectivity. A 3D QSAR model was developed using a dataset of 112 compounds to evaluate 500 molecules. ADMET prediction was then used to select three molecules with strong drug-like characteristics. Scaffold hopping was employed to reconstruct 98 new compounds with improved drug-like properties and increased activity. Molecular docking was used to compare the efficient compound abbapolin, confirming the high-activity status of [(14S)-14-hydroxy-14-(pyridin-2-yl)tetradecyl]ammonium,[(14S)-15-(2-furyl)-14-hydroxypentadecyl]ammonium and [(14S)-14-hydroxy-14-phenyltetradecyl]ammonium. Molecular dynamics simulations and MMPBSA were conducted to evaluate the stability of the compounds in the presence of proteins. An in-depth analysis of [(14S)-15-(2-furyl)-14-hydroxypentadecyl]ammonium and [(14S)-14-hydroxy-14-phenyltetradecyl]ammonium identified them as potential candidates for PLK1 inhibitors. Full article
(This article belongs to the Special Issue Marine Drug Discovery through Molecular Docking)
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17 pages, 3164 KiB  
Article
Reconstruction of Long-Chain Polyunsaturated Acid Synthesis Pathways in Marine Red Microalga Porphyridium cruentum Using Lipidomics and Transcriptomics
by Tao Li, Chulin Li, Weinan Wang, Hualian Wu, Houbo Wu, Jin Xu and Wenzhou Xiang
Mar. Drugs 2024, 22(2), 82; https://doi.org/10.3390/md22020082 - 9 Feb 2024
Cited by 1 | Viewed by 2135
Abstract
The marine red microalga Porphyridium can simultaneously synthesize long-chain polyunsaturated fatty acids, including eicosapentaenoic acid (C20:5, EPA) and arachidonic acid (C20:4, ARA). However, the distribution and synthesis pathways of EPA and ARA in Porphyridium are not clearly understood. In this study, Porphyridium cruentum [...] Read more.
The marine red microalga Porphyridium can simultaneously synthesize long-chain polyunsaturated fatty acids, including eicosapentaenoic acid (C20:5, EPA) and arachidonic acid (C20:4, ARA). However, the distribution and synthesis pathways of EPA and ARA in Porphyridium are not clearly understood. In this study, Porphyridium cruentum CCALA 415 was cultured in nitrogen-replete and nitrogen-limited conditions. Fatty acid content determination, transcriptomic, and lipidomic analyses were used to investigate the synthesis of ARA and EPA. The results show that membrane lipids were the main components of lipids, while storage lipids were present in a small proportion in CCALA 415. Nitrogen limitation enhanced the synthesis of storage lipids and ω6 fatty acids while inhibiting the synthesis of membrane lipids and ω3 fatty acids. A total of 217 glycerolipid molecular species were identified, and the most abundant species included monogalactosyldiglyceride (C16:0/C20:5) (MGDG) and phosphatidylcholine (C16:0/C20:4) (PC). ARA was mainly distributed in PC, and EPA was mainly distributed in MGDG. Among all the fatty acid desaturases (FADs), the expressions of Δ5FAD, Δ6FAD, Δ9FAD, and Δ12FAD were up-regulated, whereas those of Δ15FAD and Δ17FAD were down-regulated. Based on these results, only a small proportion of EPA was synthesized through the ω3 pathway, while the majority of EPA was synthesized through the ω6 pathway. ARA synthesized in the ER was likely shuttled into the chloroplast by DAG and was converted into EPA by Δ17FAD. Full article
(This article belongs to the Special Issue Marine Lipids 2023)
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15 pages, 2159 KiB  
Article
Structure and Binding Properties to Blood Co-Factors of the Least Sulfated Galactan Found in the Cell Wall of the Red Alga Botryocladia occidentalis
by Antim K. Maurya, Hoda Al. Ahmed, Anderson DeWitt, Anter A. Shami, Sandeep K. Misra and Vitor H. Pomin
Mar. Drugs 2024, 22(2), 81; https://doi.org/10.3390/md22020081 - 9 Feb 2024
Viewed by 3104
Abstract
Three different populations of sulfated polysaccharides can be found in the cell wall of the red alga Botryocladia occidentalis. In a previous work, the structures of the two more sulfated polysaccharides were revised. In this work, NMR-based structural analysis was performed on [...] Read more.
Three different populations of sulfated polysaccharides can be found in the cell wall of the red alga Botryocladia occidentalis. In a previous work, the structures of the two more sulfated polysaccharides were revised. In this work, NMR-based structural analysis was performed on the least sulfated polysaccharide and its chemically modified derivatives. Results have revealed the presence of both 4-linked α- and 3-linked β-galactose units having the following chemical features: more than half of the total galactose units are not sulfated, the α-units occur primarily as 3,6-anhydrogalactose units either 2-O-methylated or 2-O-sulfated, and the β-galactose units can be 4-O-sulfated or 2,4-O-disulfated. SPR-based results indicated weaker binding of the least sulfated galactan to thrombin, factor Xa, and antithrombin, but stronger binding to heparin cofactor II than unfractionated heparin. This report together with our previous publication completes the structural characterization of the three polysaccharides found in the cell wall of the red alga B. occidentalis and correlates the impact of their composing chemical groups with the levels of interaction with the blood co-factors. Full article
(This article belongs to the Special Issue Characterization of Bioactive Components in Edible Algae 3rd Edition)
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19 pages, 662 KiB  
Review
Oleaginous Microbial Lipids’ Potential in the Prevention and Treatment of Neurological Disorders
by Mariam Alhattab, Lakshana S. Moorthy, Durva Patel, Christopher M. M. Franco and Munish Puri
Mar. Drugs 2024, 22(2), 80; https://doi.org/10.3390/md22020080 - 6 Feb 2024
Cited by 4 | Viewed by 2594
Abstract
The products of oleaginous microbes, primarily lipids, have gained tremendous attention for their health benefits in food-based applications as supplements. However, this emerging biotechnology also offers a neuroprotective treatment/management potential for various diseases that are seldom discussed. Essential fatty acids, such as DHA, [...] Read more.
The products of oleaginous microbes, primarily lipids, have gained tremendous attention for their health benefits in food-based applications as supplements. However, this emerging biotechnology also offers a neuroprotective treatment/management potential for various diseases that are seldom discussed. Essential fatty acids, such as DHA, are known to make up the majority of brain phospholipid membranes and are integral to cognitive function, which forms an important defense against Alzheimer’s disease. Omega-3 polyunsaturated fatty acids have also been shown to reduce recurrent epilepsy seizures and have been used in brain cancer therapies. The ratio of omega-3 to omega-6 PUFAs is essential in maintaining physiological function. Furthermore, lipids have also been employed as an effective vehicle to deliver drugs for the treatment of diseases. Lipid nanoparticle technology, used in pharmaceuticals and cosmeceuticals, has recently emerged as a biocompatible, biodegradable, low-toxicity, and high-stability means for drug delivery to address the drawbacks associated with traditional medicine delivery methods. This review aims to highlight the dual benefit that lipids offer in maintaining good health for disease prevention and in the treatment of neurological diseases. Full article
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17 pages, 1422 KiB  
Review
Current Research Status of Azaspiracids
by Jiaping Yang, Weiqin Sun, Mingjuan Sun, Yunyi Cui and Lianghua Wang
Mar. Drugs 2024, 22(2), 79; https://doi.org/10.3390/md22020079 - 4 Feb 2024
Cited by 1 | Viewed by 2447
Abstract
The presence and impact of toxins have been detected in various regions worldwide ever since the discovery of azaspiracids (AZAs) in 1995. These toxins have had detrimental effects on marine resource utilization, marine environmental protection, and fishery production. Over the course of more [...] Read more.
The presence and impact of toxins have been detected in various regions worldwide ever since the discovery of azaspiracids (AZAs) in 1995. These toxins have had detrimental effects on marine resource utilization, marine environmental protection, and fishery production. Over the course of more than two decades of research and development, scientists from all over the world have conducted comprehensive studies on the in vivo metabolism, in vitro synthesis methods, pathogenic mechanisms, and toxicology of these toxins. This paper aims to provide a systematic introduction to the discovery, distribution, pathogenic mechanism, in vivo biosynthesis, and in vitro artificial synthesis of AZA toxins. Additionally, it will summarize various detection methods employed over the past 20 years, along with their advantages and disadvantages. This effort will contribute to the future development of rapid detection technologies and the invention of detection devices for AZAs in marine environmental samples. Full article
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10 pages, 678 KiB  
Article
Brominated Depsidones with Antibacterial Effects from a Deep-Sea-Derived Fungus Spiromastix sp.
by Zequan Huang, Dong Liu, Shang Chen, Jinwei Ren, Chenghai Gao, Zhiyong Li, Aili Fan and Wenhan Lin
Mar. Drugs 2024, 22(2), 78; https://doi.org/10.3390/md22020078 - 3 Feb 2024
Viewed by 2114
Abstract
Eleven new brominated depsidones, namely spiromastixones U-Z5 (111) along with five known analogues (1216), were isolated from a deep-sea-derived fungus Spiromastix sp. through the addition of sodium bromide during fermentation. Their structures were elucidated by [...] Read more.
Eleven new brominated depsidones, namely spiromastixones U-Z5 (111) along with five known analogues (1216), were isolated from a deep-sea-derived fungus Spiromastix sp. through the addition of sodium bromide during fermentation. Their structures were elucidated by extensive analysis of the spectroscopic data including high-resolution MS and 1D and 2D NMR data. Compounds 610 and 16 exhibited significant inhibition against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE) with MIC values ranging from 0.5 to 2.0 μM. Particularly, tribrominated 7 displayed the strongest activity against MRSA and VRE with a MIC of 0.5 and 1.0 μM, respectively, suggesting its potential for further development as a new antibacterial agent. Full article
(This article belongs to the Special Issue Marine Bioactive Compound Discovery through OSMAC Approach)
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17 pages, 3679 KiB  
Review
The Role of Natural and Synthetic Flavonoids in the Prevention of Marine Biofouling
by Daniela Pereira, Madalena Pinto, Joana R. Almeida, Marta Correia-da-Silva and Honorina Cidade
Mar. Drugs 2024, 22(2), 77; https://doi.org/10.3390/md22020077 - 2 Feb 2024
Cited by 2 | Viewed by 2247
Abstract
Marine biofouling is a major concern for the maritime industry, environment, and human health. Biocides which are currently used in marine coatings to prevent this phenomenon are toxic to the marine environment, and therefore a search for antifoulants with environmentally safe properties is [...] Read more.
Marine biofouling is a major concern for the maritime industry, environment, and human health. Biocides which are currently used in marine coatings to prevent this phenomenon are toxic to the marine environment, and therefore a search for antifoulants with environmentally safe properties is needed. A large number of scientific papers have been published showing natural and synthetic compounds with potential to prevent the attachment of macro- and microfouling marine organisms on submerged surfaces. Flavonoids are a class of compounds which are highly present in nature, including in marine organisms, and have been found in a wide range of biological activities. Some natural and synthetic flavonoids have been evaluated over the last few years for their potential to prevent the settlement and/or the growth of marine organisms on submerged structures, thereby preventing marine biofouling. This review compiles, for the first-time, natural flavonoids as well as their synthetic analogues with attributed antifouling activity against macrofouling and microfouling marine organisms. Full article
(This article belongs to the Section Marine Chemoecology for Drug Discovery)
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16 pages, 6761 KiB  
Article
EPA and DHA Alleviated Chronic Dextran Sulfate Sodium Exposure-Induced Depressive-like Behaviors in Mice and Potential Mechanisms Involved
by Xi-Yu Wang, Shu-Sen He, Miao-Miao Zhou, Xiao-Ran Li, Cheng-Cheng Wang, Ying-Cai Zhao, Chang-Hu Xue and Hong-Xia Che
Mar. Drugs 2024, 22(2), 76; https://doi.org/10.3390/md22020076 - 31 Jan 2024
Cited by 2 | Viewed by 2339
Abstract
Patients with ulcerative colitis (UC) have higher rates of depression. However, the mechanism of depression development remains unclear. The improvements of EPA and DHA on dextran sulfate sodium (DSS)-induced UC have been verified. Therefore, the present study mainly focused on the effects of [...] Read more.
Patients with ulcerative colitis (UC) have higher rates of depression. However, the mechanism of depression development remains unclear. The improvements of EPA and DHA on dextran sulfate sodium (DSS)-induced UC have been verified. Therefore, the present study mainly focused on the effects of EPA and DHA on UC-induced depression in C57BL/6 mice and the possible mechanisms involved. A forced swimming test and tail suspension experiment showed that EPA and DHA significantly improved DSS-induced depressive-like behavior. Further analysis demonstrated that EPA and DHA could significantly suppress the inflammation response of the gut and brain by regulating the NLRP3/ASC signal pathway. Moreover, intestine and brain barriers were maintained by enhancing ZO-1 and occludin expression. In addition, EPA and DHA also increased the serotonin (5-HT) concentration and synaptic proteins. Interestingly, EPA and DHA treatments increased the proportion of dominant bacteria, alpha diversity, and beta diversity. In conclusion, oral administration of EPA and DHA alleviated UC-induced depressive-like behavior in mice by modulating the inflammation, maintaining the mucosal and brain barriers, suppressing neuronal damage and reverting microbiota changes. Full article
(This article belongs to the Special Issue Marine Fish Oils as Functional Foods)
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15 pages, 2178 KiB  
Article
Chemical and Pharmacological Prospection of the Ascidian Cystodytes dellechiajei
by Pedro Jatai Batista, Genoveffa Nuzzo, Carmela Gallo, Dalila Carbone, Mario dell’Isola, Mario Affuso, Giusi Barra, Federica Albiani, Fabio Crocetta, Riccardo Virgili, Valerio Mazzella, Daniela Castiglia, Giuliana d’Ippolito, Emiliano Manzo and Angelo Fontana
Mar. Drugs 2024, 22(2), 75; https://doi.org/10.3390/md22020075 - 31 Jan 2024
Cited by 1 | Viewed by 2185
Abstract
Marine invertebrates are a traditional source of natural products with relevant biological properties. Tunicates are soft-bodied, solitary or colonial, sessile organisms that provide compounds unique in their structure and activity. The aim of this work was to investigate the chemical composition of the [...] Read more.
Marine invertebrates are a traditional source of natural products with relevant biological properties. Tunicates are soft-bodied, solitary or colonial, sessile organisms that provide compounds unique in their structure and activity. The aim of this work was to investigate the chemical composition of the ascidian Cystodytes dellechiajei, selected on the basis of a positive result in biological screening for ligands of relevant receptors of the innate immune system, including TLR2, TLR4, dectin-1b, and TREM2. Bioassay-guided screening of this tunicate extract yielded two known pyridoacridine alkaloids, shermilamine B (1) and N-deacetylshermilamine B (2), and a family of methyl-branched cerebrosides (3). Compounds 2 and 3 showed selective binding to TREM2 in a dose-dependent manner. N-deacetylshermilamine B (2), together with its acetylated analogue, shermilamine B (1), was also strongly cytotoxic against multiple myeloma cell lines. TREM2 is involved in immunomodulatory processes and neurodegenerative diseases. N-deacetylshermilamine B (2) is the first example of a polycyclic alkaloid to show an affinity for this receptor. Full article
(This article belongs to the Special Issue Marine Drug Research in Italy)
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10 pages, 1663 KiB  
Communication
Origin of the 6/5/6/5 Tetracyclic Cyclopiazonic Acids
by Wenyuan Zhang, Xuejian Jiang, Minjun Wang, Zhizhen Zhang and Nan Wang
Mar. Drugs 2024, 22(2), 74; https://doi.org/10.3390/md22020074 - 31 Jan 2024
Viewed by 1869
Abstract
The natural product α-cyclopiazonic acid (α-CPA) is a very potent Ca2+-ATPase inhibitor. The CPA family of compounds comprise over 80 chemical entities with at least five distinct skeletons. While α-CPA features a canonical 6/5/6/5/5 skeleton, the 6/5/6/5 skeleton is the most [...] Read more.
The natural product α-cyclopiazonic acid (α-CPA) is a very potent Ca2+-ATPase inhibitor. The CPA family of compounds comprise over 80 chemical entities with at least five distinct skeletons. While α-CPA features a canonical 6/5/6/5/5 skeleton, the 6/5/6/5 skeleton is the most prevalent among the CPA family. However, the origin of the unique tetracyclic skeleton remains unknown. The 6/5/6/5-type CPAs may derive from a precursor of acetoacetyl-l-tryptophan (AATrp) generated from a hypothetic thioesterase-like pathway. Alternatively, cleavage of the tetramic acid ring would also result in the formation of the 6/5/6/5 scaffold. Aspergillus oryzae HMP-F28 is a marine sponge-associated filamentous fungus known to produce CPAs that act as primary neurotoxins. To elucidate the origin of this subfamily of CPAs, we performed homologous recombination and genetic engineering experiments on strain HMP-F28. Our results are supportive of the ring cleavage pathway through which the tetracyclic 6/5/6/5-type CPAs are generated from 6/5/6/5/5-type pentacyclic CPAs. Full article
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40 pages, 2956 KiB  
Review
Marine Animal Co-Products—How Improving Their Use as Rich Sources of Health-Promoting Lipids Can Foster Sustainability
by João Pedro Monteiro, M. Rosário Domingues and Ricardo Calado
Mar. Drugs 2024, 22(2), 73; https://doi.org/10.3390/md22020073 - 30 Jan 2024
Cited by 4 | Viewed by 5279
Abstract
Marine lipids are recognized for their-health promoting features, mainly for being the primary sources of omega-3 fatty acids, and are therefore critical for human nutrition in an age when the global supply for these nutrients is experiencing an unprecedent pressure due to an [...] Read more.
Marine lipids are recognized for their-health promoting features, mainly for being the primary sources of omega-3 fatty acids, and are therefore critical for human nutrition in an age when the global supply for these nutrients is experiencing an unprecedent pressure due to an ever-increasing demand. The seafood industry originates a considerable yield of co-products worldwide that, while already explored for other purposes, remain mostly undervalued as sustainable sources of healthy lipids, often being explored for low-value oil production. These co-products are especially appealing as lipid sources since, besides the well-known nutritional upside of marine animal fat, which is particularly rich in omega-3 polyunsaturated fatty acids, they also have interesting bioactive properties, which may garner them further interest, not only as food, but also for other high-end applications. Besides the added value that these co-products may represent as valuable lipid sources, there is also the obvious ecological upside of reducing seafood industry waste. In this sense, repurposing these bioresources will contribute to a more sustainable use of marine animal food, reducing the strain on already heavily depleted seafood stocks. Therefore, untapping the potential of marine animal co-products as valuable lipid sources aligns with both health and environmental goals by guaranteeing additional sources of healthy lipids and promoting more eco-conscious practices. Full article
(This article belongs to the Section Marine Biotechnology Related to Drug Discovery or Production)
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14 pages, 3572 KiB  
Article
2,4,6-Triphenyl-1-hexene, an Anti-Melanogenic Compound from Marine-Derived Bacillus sp. APmarine135
by Hye Yeon Kim, Hye-Yeon Do, Saitbyul Park, Keon Woo Kim, Daejin Min, Eun-Young Lee, Dabin Shim, Sung Yeon Cho, Jin Oh Park, Chang Seok Lee, Sang-Jip Nam and Jaeyoung Ko
Mar. Drugs 2024, 22(2), 72; https://doi.org/10.3390/md22020072 - 30 Jan 2024
Viewed by 2420
Abstract
Although melanin protects against ultraviolet radiation, its overproduction causes freckles and senile lentigines. Recently, various biological effects of metabolites derived from marine microorganisms have been highlighted due to their potential for biological and pharmacological applications. In this study, we discovered the anti-melanogenic effect [...] Read more.
Although melanin protects against ultraviolet radiation, its overproduction causes freckles and senile lentigines. Recently, various biological effects of metabolites derived from marine microorganisms have been highlighted due to their potential for biological and pharmacological applications. In this study, we discovered the anti-melanogenic effect of Bacillus sp. APmarine135 and verified the skin-whitening effect. Fractions of APmarine135 showed the melanin synthesis inhibition effect in B16 melanoma cells, and 2,4,6-triphenyl-1-hexene was identified as an active compound. The melanogenic capacity of 2,4,6-triphenyl-1-hexene (1) was investigated by assessing the intracellular melanin content in B16 cells. Treatment with 5 ppm of 2,4,6-triphenyl-1-hexene (1) for 72 h suppressed the α-melanocyte-stimulating hormone (α-MSH)-induced intracellular melanin increase to the same level as in the untreated control group. Additionally, 2,4,6-triphenyl-1-hexene (1) treatment suppressed the activity of tyrosinase, the rate-limiting enzyme for melanogenesis. Moreover, 2,4,6-triphenyl-1-hexene (1) treatment downregulated tyrosinase, Tyrp-1, and Tyrp-2 expression by inhibiting the microphthalmia-associated transcription factor (MITF). Furthermore, 2,4,6-triphenyl-1-hexene (1) treatment decreased the melanin content in the three-dimensional (3D) human-pigmented epidermis model MelanoDerm and exerted skin-whitening effects. Mechanistically, 2,4,6-triphenyl-1-hexene (1) exerted anti-melanogenic effects by suppressing tyrosinase, Tyrp-1, and Tyrp-2 expression and activities via inhibition of the MITF. Collectively, these findings suggest that 2,4,6-triphenyl-1-hexene (1) is a promising anti-melanogenic agent in the cosmetic industry. Full article
(This article belongs to the Section Marine Pharmacology)
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19 pages, 7385 KiB  
Article
Venomics Reveals the Venom Complexity of Sea Anemone Heteractis magnifica
by Ming Li, Kailin Mao, Meiling Huang, Yanling Liao, Jinxing Fu, Kun Pan, Qiong Shi and Bingmiao Gao
Mar. Drugs 2024, 22(2), 71; https://doi.org/10.3390/md22020071 - 28 Jan 2024
Cited by 3 | Viewed by 2664
Abstract
The venoms of various sea anemones are rich in diverse toxins, which usually play a dual role in capturing prey and deterring predators. However, the complex components of such venoms have not been well known yet. Here, venomics of integrating transcriptomic and proteomic [...] Read more.
The venoms of various sea anemones are rich in diverse toxins, which usually play a dual role in capturing prey and deterring predators. However, the complex components of such venoms have not been well known yet. Here, venomics of integrating transcriptomic and proteomic technologies was applied for the first time to identify putative protein and peptide toxins from different tissues of the representative sea anemone, Heteractis magnifica. The transcriptomic analysis of H. magnifica identified 728 putative toxin sequences, including 442 and 381 from the tentacles and the column, respectively, and they were assigned to 68 gene superfamilies. The proteomic analysis confirmed 101 protein and peptide toxins in the venom, including 91 in the tentacles and 39 in the column. The integrated venomics also confirmed that some toxins such as the ShK-like peptides and defensins are co-expressed in both the tentacles and the column. Meanwhile, a homology analysis was conducted to predict the three-dimensional structures and potential activity of seven representative toxins. Altogether, this venomics study revealed the venom complexity of H. magnifica, which will help deepen our understanding of cnidarian toxins, thereby supporting the in-depth development of valuable marine drugs. Full article
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54 pages, 5279 KiB  
Review
Cytotoxic Compounds from Marine Fungi: Sources, Structures, and Bioactivity
by Yukang Gao, Jianjian Wang, Pornphimon Meesakul, Jiamin Zhou, Jinyan Liu, Shuo Liu, Cong Wang and Shugeng Cao
Mar. Drugs 2024, 22(2), 70; https://doi.org/10.3390/md22020070 - 28 Jan 2024
Cited by 3 | Viewed by 2948
Abstract
Marine fungi, such as species from the Penicillium and Aspergillus genera, are prolific producers of a diversity of natural products with cytotoxic properties. These fungi have been successfully isolated and identified from various marine sources, including sponges, coral, algae, mangroves, sediment, and seawater. [...] Read more.
Marine fungi, such as species from the Penicillium and Aspergillus genera, are prolific producers of a diversity of natural products with cytotoxic properties. These fungi have been successfully isolated and identified from various marine sources, including sponges, coral, algae, mangroves, sediment, and seawater. The cytotoxic compounds derived from marine fungi can be categorized into five distinct classes: polyketides, peptides, terpenoids and sterols, hybrids, and other miscellaneous compounds. Notably, the pre-eminent group among these compounds comprises polyketides, accounting for 307 out of 642 identified compounds. Particularly, within this collection, 23 out of the 642 compounds exhibit remarkable cytotoxic potency, with IC50 values measured at the nanomolar (nM) or nanogram per milliliter (ng/mL) levels. This review elucidates the originating fungal strains, the sources of isolation, chemical structures, and the noteworthy antitumor activity of the 642 novel natural products isolated from marine fungi. The scope of this review encompasses the period from 1991 to 2023. Full article
(This article belongs to the Special Issue Natural Products from the Beibu Gulf of the South China Sea)
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15 pages, 6280 KiB  
Article
The Screening and Identification of a Dextranase-Secreting Marine Actinmycete Saccharomonospora sp. K1 and Study of Its Enzymatic Characteristics
by Boyan Wang, Yizhuo Wu, Qiang Li, Xudong Wu, Xinxin Kang, Lei Zhang, Mingsheng Lyu and Shujun Wang
Mar. Drugs 2024, 22(2), 69; https://doi.org/10.3390/md22020069 - 28 Jan 2024
Viewed by 1821
Abstract
In this study, an actinomycete was isolated from sea mud. The strain K1 was identified as Saccharomonospora sp. by 16S rDNA. The optimal enzyme production temperature, initial pH, time, and concentration of the inducer of this actinomycete strain K1 were 37 °C, pH [...] Read more.
In this study, an actinomycete was isolated from sea mud. The strain K1 was identified as Saccharomonospora sp. by 16S rDNA. The optimal enzyme production temperature, initial pH, time, and concentration of the inducer of this actinomycete strain K1 were 37 °C, pH 8.5, 72 h, and 2% dextran T20 of medium, respectively. Dextranase from strain K1 exhibited maximum activity at 8.5 pH and 50 °C. The molecular weight of the enzyme was <10 kDa. The metal ions Sr2+ and K+ enhanced its activity, whereas Fe3+ and Co2+ had an opposite effect. In addition, high-performance liquid chromatography showed that dextran was mainly hydrolyzed to isomaltoheptose and isomaltopentaose. Also, it could effectively remove biofilms of Streptococcus mutans. Furthermore, it could be used to prepare porous sweet potato starch. This is the first time a dextranase-producing actinomycete strain was screened from marine samples. Full article
(This article belongs to the Section Marine Biotechnology Related to Drug Discovery or Production)
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16 pages, 4537 KiB  
Article
Purification and Properties of a Plasmin-like Marine Protease from Clamworm (Perinereis aibuhitensis)
by Tingting Jiang, Bing Zhang, Haixing Zhang, Mingjun Wei, Yue Su, Tuo Song, Shijia Ye, Yuping Zhu and Wenhui Wu
Mar. Drugs 2024, 22(2), 68; https://doi.org/10.3390/md22020068 - 27 Jan 2024
Viewed by 2420
Abstract
Marine organisms are a rich source of enzymes that exhibit excellent biological activity and a wide range of applications. However, there has been limited research on the proteases found in marine mudflat organisms. Based on this background, the marine fibrinolytic enzyme FELP, which [...] Read more.
Marine organisms are a rich source of enzymes that exhibit excellent biological activity and a wide range of applications. However, there has been limited research on the proteases found in marine mudflat organisms. Based on this background, the marine fibrinolytic enzyme FELP, which was isolated and purified from clamworm (Perinereis aibuhitensis), has exhibited excellent fibrinolytic activity. We demonstrated the FELP with a purification of 10.61-fold by precipitation with ammonium sulfate, ion-exchange chromatography, and gel-filtration chromatography. SDS-PAGE, fibrin plate method, and LC–MS/MS indicated that the molecular weight of FELP is 28.9 kDa and identified FELP as a fibrinolytic enzyme-like protease. FELP displayed the maximum fibrinolytic activity at pH 9 (407 ± 16 mm2) and 50 °C (724 ± 27 mm2) and had excellent stability at pH 7–11 (50%) or 30–60 °C (60%), respectively. The three-dimensional structure of some amino acid residues of FELP was predicted with the SWISS-MODEL. The fibrinolytic and fibrinogenolytic assays showed that the enzyme possessed direct fibrinolytic activity and indirect fibrinolysis via the activation of plasminogen; it could preferentially degrade Aα-chains of fibrinogen, followed by Bβ- and γ-chains. Overall, the fibrinolytic enzyme was successfully purified from Perinereis aibuhitensis, a marine Annelida (phylum), with favorable stability that has strong fibrinolysis activity in vitro. Therefore, FELP appears to be a potent fibrinolytic enzyme with an application that deserves further investigation. Full article
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19 pages, 4583 KiB  
Article
Lipidome Plasticity Enables Unusual Photosynthetic Flexibility in Arctic vs. Temperate Diatoms
by Jon Brage Svenning, Terje Vasskog, Karley Campbell, Agnethe Hansen Bæverud, Torbjørn Norberg Myhre, Lars Dalheim, Zoé Lulu Forgereau, Janina Emilia Osanen, Espen Holst Hansen and Hans C. Bernstein
Mar. Drugs 2024, 22(2), 67; https://doi.org/10.3390/md22020067 - 27 Jan 2024
Cited by 2 | Viewed by 2198
Abstract
The diatom lipidome actively regulates photosynthesis and displays a high degree of plasticity in response to a light environment, either directly as structural modifications of thylakoid membranes and protein–pigment complexes, or indirectly via photoprotection mechanisms that dissipate excess light energy. This acclimation is [...] Read more.
The diatom lipidome actively regulates photosynthesis and displays a high degree of plasticity in response to a light environment, either directly as structural modifications of thylakoid membranes and protein–pigment complexes, or indirectly via photoprotection mechanisms that dissipate excess light energy. This acclimation is crucial to maintaining primary production in marine systems, particularly in polar environments, due to the large temporal variations in both the intensity and wavelength distributions of downwelling solar irradiance. This study investigated the hypothesis that Arctic marine diatoms uniquely modify their lipidome, including their concentration and type of pigments, in response to wavelength-specific light quality in their environment. We postulate that Arctic-adapted diatoms can adapt to regulate their lipidome to maintain growth in response to the extreme variability in photosynthetically active radiation. This was tested by comparing the untargeted lipidomic profiles, pigmentation, specific growth rates and carbon assimilation of the Arctic diatom Porosira glacialis vs. the temperate species Coscinodiscus radiatus during exponential growth under red, blue and white light. Here, we found that the chromatic wavelength influenced lipidome remodeling and growth in each strain, with P. glacialis showing effective utilization of red light coupled with increased inclusion of primary light-harvesting pigments and polar lipid classes. These results indicate a unique photoadaptation strategy that enables Arctic diatoms like P. glacialis to capitalize on a wide chromatic growth range and demonstrates the importance of active lipid regulation in the Arctic light environment. Full article
(This article belongs to the Special Issue Ecology, Diversity and Evolution of Diatoms)
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