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Marine Drugs
Volume 13
Issue 6
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Mar. Drugs, Volume 13, Issue 6 (June 2015) – 39 articles , Pages 3259-3991

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457 KiB  
Review
Can Some Marine-Derived Fungal Metabolites Become Actual Anticancer Agents?
by Nelson G. M. Gomes, Florence Lefranc, Anake Kijjoa and Robert Kiss
Mar. Drugs 2015, 13(6), 3950-3991; https://doi.org/10.3390/md13063950 - 19 Jun 2015
Cited by 103 | Viewed by 15032
Abstract
Marine fungi are known to produce structurally unique secondary metabolites, and more than 1000 marine fungal-derived metabolites have already been reported. Despite the absence of marine fungal-derived metabolites in the current clinical pipeline, dozens of them have been classified as potential chemotherapy candidates [...] Read more.
Marine fungi are known to produce structurally unique secondary metabolites, and more than 1000 marine fungal-derived metabolites have already been reported. Despite the absence of marine fungal-derived metabolites in the current clinical pipeline, dozens of them have been classified as potential chemotherapy candidates because of their anticancer activity. Over the last decade, several comprehensive reviews have covered the potential anticancer activity of marine fungal-derived metabolites. However, these reviews consider the term “cytotoxicity” to be synonymous with “anticancer agent”, which is not actually true. Indeed, a cytotoxic compound is by definition a poisonous compound. To become a potential anticancer agent, a cytotoxic compound must at least display (i) selectivity between normal and cancer cells (ii) activity against multidrug-resistant (MDR) cancer cells; and (iii) a preferentially non-apoptotic cell death mechanism, as it is now well known that a high proportion of cancer cells that resist chemotherapy are in fact apoptosis-resistant cancer cells against which pro-apoptotic drugs have more than limited efficacy. The present review thus focuses on the cytotoxic marine fungal-derived metabolites whose ability to kill cancer cells has been reported in the literature. Particular attention is paid to the compounds that kill cancer cells through non-apoptotic cell death mechanisms. Full article
(This article belongs to the Special Issue Bioactive Compounds from Marine Fungi)
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1627 KiB  
Article
Induction of Apoptosis and Antitumor Activity of Eel Skin Mucus, Containing Lactose-Binding Molecules, on Human Leukemic K562 Cells
by Choong-Hwan Kwak, Sook-Hyun Lee, Sung-Kyun Lee, Sun-Hyung Ha, Seok-Jong Suh, Kyung-Min Kwon, Tae-Wook Chung, Ki-Tae Ha, Young-Chae Chang, Young-Choon Lee, Dong-Soo Kim, Hyeun-Wook Chang and Cheorl-Ho Kim
Mar. Drugs 2015, 13(6), 3936-3949; https://doi.org/10.3390/md13063936 - 19 Jun 2015
Cited by 17 | Viewed by 7868
Abstract
For innate immune defense, lower animals such as fish and amphibian are covered with skin mucus, which acts as both a mechanical and biochemical barrier. Although several mucus sources have been isolated and studied for their biochemical and immunological functions, the precise mechanism(s) [...] Read more.
For innate immune defense, lower animals such as fish and amphibian are covered with skin mucus, which acts as both a mechanical and biochemical barrier. Although several mucus sources have been isolated and studied for their biochemical and immunological functions, the precise mechanism(s) of action remains unknown. In the present study, we additionally found the eel skin mucus (ESM) to be a promising candidate for use in anti-tumor therapy. Our results showed that the viability of K562 cells was decreased in a dose-dependent manner by treatment with the isolated ESM. The cleaved forms of caspase-9, caspase-3 and poly adenosine diphosphate-ribose polymerase were increased by ESM. The levels of Bax expression and released cytochrome C were also increased after treatment with ESM. Furthermore, during the ESM mediated-apoptosis, phosphorylation levels of ERK1/2 and p38 but not JNK were increased and cell viabilities of the co-treated cells with ESM and inhibitors of ERK 1/2 or p38 were also increased. In addition, treatment with lactose rescued the ESM-mediated decrease in cell viability, indicating lactose-containing glycans in the leukemia cells acted as a counterpart of the ESM for interaction. Taken together, these results suggest that ESM could induce mitochondria-mediated apoptosis through membrane interaction of the K562 human leukemia cells. To the best of our knowledge, this is the first observation that ESM has anti-tumor activity in human cells. Full article
(This article belongs to the Special Issue Marine Glycoconjugates)
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Article
Persistent Contamination of Octopuses and Mussels with Lipophilic Shellfish Toxins during Spring Dinophysis Blooms in a Subtropical Estuary
by Luiz L. Mafra, Jr., Daiana Lopes, Vanessa C. Bonilauri, Hajime Uchida and Toshiyuki Suzuki
Mar. Drugs 2015, 13(6), 3920-3935; https://doi.org/10.3390/md13063920 - 18 Jun 2015
Cited by 21 | Viewed by 6052
Abstract
This study investigates the occurrence of diarrhetic shellfish toxins (DSTs) and their producing phytoplankton species in southern Brazil, as well as the potential for toxin accumulation in co-occurring mussels (Perna perna) and octopuses (Octopus vulgaris). During the spring in [...] Read more.
This study investigates the occurrence of diarrhetic shellfish toxins (DSTs) and their producing phytoplankton species in southern Brazil, as well as the potential for toxin accumulation in co-occurring mussels (Perna perna) and octopuses (Octopus vulgaris). During the spring in 2012 and 2013, cells of Dinophysis acuminata complex were always present, sometimes at relatively high abundances (max. 1143 cells L−1), likely the main source of okadaic acid (OA) in the plankton (max. 34 ng L−1). Dinophysis caudata occurred at lower cell densities in 2013 when the lipophilic toxins pectenotoxin-2 (PTX-2) and PTX-2 seco acid were detected in plankton and mussel samples. Here, we report for the first time the accumulation of DSTs in octopuses, probably linked to the consumption of contaminated bivalves. Perna perna mussels were consistently contaminated with different DSTs (max. 42 µg kg−1), and all octopuses analyzed (n = 5) accumulated OA in different organs/tissues: digestive glands (DGs) > arms > gills > kidneys > stomach + intestine. Additionally, similar concentrations of 7-O-palmytoyl OA and 7-O-palmytoly dinophysistoxin-1 (DTX-1) were frequently detected in the hepatopancreas of P. perna and DGs of O. vulgaris. Therefore, octopuses can be considered a potential vector of DSTs to both humans and top predators such as marine mammals. Full article
(This article belongs to the Special Issue Okadaic Acid and Dinophysis Toxins)
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Article
Structural Characterization of New Peptide Variants Produced by Cyanobacteria from the Brazilian Atlantic Coastal Forest Using Liquid Chromatography Coupled to Quadrupole Time-of-Flight Tandem Mass Spectrometry
by Miriam Sanz, Ana Paula Dini Andreote, Marli Fatima Fiore, Felipe Augusto Dörr and Ernani Pinto
Mar. Drugs 2015, 13(6), 3892-3919; https://doi.org/10.3390/md13063892 - 18 Jun 2015
Cited by 36 | Viewed by 7745
Abstract
Cyanobacteria from underexplored and extreme habitats are attracting increasing attention in the search for new bioactive substances. However, cyanobacterial communities from tropical and subtropical regions are still largely unknown, especially with respect to metabolite production. Among the structurally diverse secondary metabolites produced by [...] Read more.
Cyanobacteria from underexplored and extreme habitats are attracting increasing attention in the search for new bioactive substances. However, cyanobacterial communities from tropical and subtropical regions are still largely unknown, especially with respect to metabolite production. Among the structurally diverse secondary metabolites produced by these organisms, peptides are by far the most frequently described structures. In this work, liquid chromatography/electrospray ionization coupled to high resolution quadrupole time-of-flight tandem mass spectrometry with positive ion detection was applied to study the peptide profile of a group of cyanobacteria isolated from the Southeastern Brazilian coastal forest. A total of 38 peptides belonging to three different families (anabaenopeptins, aeruginosins, and cyanopeptolins) were detected in the extracts. Of the 38 peptides, 37 were detected here for the first time. New structural features were proposed based on mass accuracy data and isotopic patterns derived from full scan and MS/MS spectra. Interestingly, of the 40 surveyed strains only nine were confirmed to be peptide producers; all of these strains belonged to the order Nostocales (three Nostoc sp., two Desmonostoc sp. and four Brasilonema sp.). Full article
(This article belongs to the Special Issue Compounds from Cyanobacteria)
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Article
Ecklonia cava Polyphenol Has a Protective Effect against Ethanol-Induced Liver Injury in a Cyclic AMP-Dependent Manner
by Haruka Yamashita, Mayu Goto, Isao Matsui-Yuasa and Akiko Kojima-Yuasa
Mar. Drugs 2015, 13(6), 3877-3891; https://doi.org/10.3390/md13063877 - 18 Jun 2015
Cited by 25 | Viewed by 6561
Abstract
Previously, we showed that Ecklonia cava polyphenol (ECP) treatment suppressed ethanol-induced increases in hepatocyte death by scavenging intracellular reactive oxygen species (ROS) and maintaining intracellular glutathione levels. Here, we examined the effects of ECP on the activities of alcohol-metabolizing enzymes and their regulating [...] Read more.
Previously, we showed that Ecklonia cava polyphenol (ECP) treatment suppressed ethanol-induced increases in hepatocyte death by scavenging intracellular reactive oxygen species (ROS) and maintaining intracellular glutathione levels. Here, we examined the effects of ECP on the activities of alcohol-metabolizing enzymes and their regulating mechanisms in ethanol-treated hepatocytes. Isolated hepatocytes were incubated with or without 100 mM ethanol. ECP was dissolved in dimethylsulfoxide. ECP was added to cultured cells that had been incubated with or without ethanol. The cells were incubated for 0–24 h. In cultured hepatocytes, the ECP treatment with ethanol inhibited cytochrome P450 2E1 (CYP2E1) expression and activity, which is related to the production of ROS when large quantities of ethanol are oxidized. On the other hand, ECP treatment with ethanol increased the activity of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase. These changes in activities of CYP2E1 and ADH were suppressed by treatment with H89, an inhibitor of protein kinase A. ECP treatment with ethanol enhanced cyclic AMP concentrations compared with those of control cells. ECP may be a candidate for preventing ethanol-induced liver injury via regulating alcohol metabolic enzymes in a cyclic AMP-dependent manner. Full article
(This article belongs to the Special Issue Marine Functional Food)
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Article
Characterization of Shrimp Oil from Pandalus borealis by High Performance Liquid Chromatography and High Resolution Mass Spectrometry
by Guangling Jiao, Joseph P. M. Hui, Ian W. Burton, Marie-Hélène Thibault, Claude Pelletier, Josée Boudreau, Nadia Tchoukanova, Balaji Subramanian, Yahia Djaoued, Stephen Ewart, Jacques Gagnon, Kathryn Vanya Ewart and Junzeng Zhang
Mar. Drugs 2015, 13(6), 3849-3876; https://doi.org/10.3390/md13063849 - 18 Jun 2015
Cited by 28 | Viewed by 9982
Abstract
Northern shrimp (Pandalus borealis) oil, which is rich in omega-3 fatty acids, was recovered from the cooking water of shrimp processing facilities. The oil contains significant amounts of omega-3 fatty acids in triglyceride form, along with substantial long-chain monounsaturated fatty acids [...] Read more.
Northern shrimp (Pandalus borealis) oil, which is rich in omega-3 fatty acids, was recovered from the cooking water of shrimp processing facilities. The oil contains significant amounts of omega-3 fatty acids in triglyceride form, along with substantial long-chain monounsaturated fatty acids (MUFAs). It also features natural isomeric forms of astaxanthin, a nutritional carotenoid, which gives the oil a brilliant red color. As part of our efforts in developing value added products from waste streams of the seafood processing industry, we present in this paper a comprehensive characterization of the triacylglycerols (TAGs) and astaxanthin esters that predominate in the shrimp oil by using HPLC-HRMS and MS/MS, as well as 13C-NMR. This approach, in combination with FAME analysis, offers direct characterization of fatty acid molecules in their intact forms, including the distribution of regioisomers in TAGs. The information is important for the standardization and quality control, as well as for differentiation of composition features of shrimp oil, which could be sold as an ingredient in health supplements and functional foods. Full article
(This article belongs to the Special Issue Marine Functional Food)
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349 KiB  
Article
Amino Acid-Derived Metabolites from the Ascidian Aplidium sp.
by Tae Hyung Won, Chang-Kwon Kim, So-Hyoung Lee, Boon Jo Rho, Sang Kook Lee, Dong-Chan Oh, Ki-Bong Oh and Jongheon Shin
Mar. Drugs 2015, 13(6), 3836-3848; https://doi.org/10.3390/md13063836 - 16 Jun 2015
Cited by 13 | Viewed by 5756
Abstract
Four new iodobenzene-containing dipeptides (1–4), a related bromotryptophan-containing dipeptide (5), and an iodophenethylamine (6) were isolated from the ascidian Aplidium sp. collected off the coast of Chuja-do, Korea. The structures of these novel compounds, designated [...] Read more.
Four new iodobenzene-containing dipeptides (1–4), a related bromotryptophan-containing dipeptide (5), and an iodophenethylamine (6) were isolated from the ascidian Aplidium sp. collected off the coast of Chuja-do, Korea. The structures of these novel compounds, designated as apliamides A–E (1–5) and apliamine A (6) were determined via combined spectroscopic analyses. The absolute configuration of the amino acid residue in 1 was determined by advanced Marfey’s analysis. Several of these compounds exhibited moderate cytotoxicity and significant inhibition against Na+/K+-ATPase (4). Full article
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Article
Dangerous Relations in the Arctic Marine Food Web: Interactions between Toxin Producing Pseudo-nitzschia Diatoms and Calanus Copepodites
by Sara Harðardóttir, Marina Pančić, Anna Tammilehto, Bernd Krock, Eva Friis Møller, Torkel Gissel Nielsen and Nina Lundholm
Mar. Drugs 2015, 13(6), 3809-3835; https://doi.org/10.3390/md13063809 - 16 Jun 2015
Cited by 70 | Viewed by 9631
Abstract
Diatoms of the genus Pseudo-nitzschia produce domoic acid (DA), a toxin that is vectored in the marine food web, thus causing serious problems for marine organisms and humans. In spite of this, knowledge of interactions between grazing zooplankton and diatoms is restricted. In [...] Read more.
Diatoms of the genus Pseudo-nitzschia produce domoic acid (DA), a toxin that is vectored in the marine food web, thus causing serious problems for marine organisms and humans. In spite of this, knowledge of interactions between grazing zooplankton and diatoms is restricted. In this study, we examined the interactions between Calanus copepodites and toxin producing Pseudo-nitzschia. The copepodites were fed with different concentrations of toxic P. seriata and a strain of P. obtusa that previously was tested to be non-toxic. The ingestion rates did not differ among the diets (P. seriata, P. obtusa, a mixture of both species), and they accumulated 6%–16% of ingested DA (up to 420 µg per dry weight copepodite). When P. seriata was exposed to the copepodites, either through physical contact with the grazers or separated by a membrane, the toxicity of P. seriata increased (up to 3300%) suggesting the response to be chemically mediated. The induced response was also triggered when copepodites grazed on another diatom, supporting the hypothesis that the cues originate from the copepodite. Neither pH nor nutrient concentrations explained the induced DA production. Unexpectedly, P. obtusa also produced DA when exposed to grazing copepodites, thus representing the second reported toxic polar diatom. Full article
(This article belongs to the Special Issue Metabolites in Diatoms)
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Article
Functional Genomics of the Aeromonas salmonicida Lipopolysaccharide O-Antigen and A-Layer from Typical and Atypical Strains
by Susana Merino, Elena De Mendoza, Rocío Canals and Juan M. Tomás
Mar. Drugs 2015, 13(6), 3791-3808; https://doi.org/10.3390/md13063791 - 15 Jun 2015
Cited by 18 | Viewed by 6297
Abstract
The A. salmonicida A450 LPS O-antigen, encoded by the wbsalmo gene cluster, is exported through an ABC-2 transporter-dependent pathway. It represents the first example of an O-antigen LPS polysaccharide with three different monosaccharides in their repeating unit assembled by this pathway. Until [...] Read more.
The A. salmonicida A450 LPS O-antigen, encoded by the wbsalmo gene cluster, is exported through an ABC-2 transporter-dependent pathway. It represents the first example of an O-antigen LPS polysaccharide with three different monosaccharides in their repeating unit assembled by this pathway. Until now, only repeating units with one or two different monosaccharides have been described. Functional genomic analysis of this wbsalmo region is mostly in agreement with the LPS O-antigen structure of acetylated l-rhamnose (Rha), d-glucose (Glc), and 2-amino-2-deoxy-d-mannose (ManN). Between genes of the wbsalmo we found the genes responsible for the biosynthesis and assembly of the S-layer (named A-layer in these strains). Through comparative genomic analysis and in-frame deletions of some of the genes, we concluded that all the A. salmonicida typical and atypical strains, other than A. salmonicida subsp. pectinolytica strains, shared the same wbsalmo and presence of A-layer. A. salmonicida subsp. pectinolytica strains lack wbsalmo and A-layer, two major virulence factors, and this could be the reason they are the only ones not found as fish pathogens. Full article
(This article belongs to the Special Issue Marine Lipopolysaccharides)
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367 KiB  
Article
A New Meroditerpene and a New Tryptoquivaline Analog from the Algicolous Fungus Neosartorya takakii KUFC 7898
by War War May Zin, Suradet Buttachon, Jamrearn Buaruang, Luís Gales, José A. Pereira, Madalena M. M. Pinto, Artur M. S. Silva and Anake Kijjoa
Mar. Drugs 2015, 13(6), 3776-3790; https://doi.org/10.3390/md13063776 - 15 Jun 2015
Cited by 35 | Viewed by 7490
Abstract
A new meroditerpene sartorenol (1), a new natural product takakiamide (2) and a new tryptoquivaline analog (3) were isolated, together with nine known compounds, including aszonapyrone A, chevalone B, aszonalenin, acetylaszonalenin, 3′-(4-oxoquinazolin-3-yl) spiro[1H-indole-3,5′-oxolane]-2,2′-dione, tryptoquivalines L, [...] Read more.
A new meroditerpene sartorenol (1), a new natural product takakiamide (2) and a new tryptoquivaline analog (3) were isolated, together with nine known compounds, including aszonapyrone A, chevalone B, aszonalenin, acetylaszonalenin, 3′-(4-oxoquinazolin-3-yl) spiro[1H-indole-3,5′-oxolane]-2,2′-dione, tryptoquivalines L, F and H, and the isocoumarin derivative, 6-hydroxymellein, from the ethyl acetate extract of the culture of the algicolous fungus Neosartorya takakii KUFC 7898. The structures of the new compounds were established based on 1D and 2D NMR spectral analysis, and, in the case of sartorenol (1) and tryptoquivaline U (3), X-ray analysis was used to confirm their structures and to determine the absolute configuration of their stereogenic carbons. Compounds 1, 2 and 3 were evaluated for their antimicrobial activity against Gram-positive and Gram-negative bacteria, and multidrug-resistant isolates from the environment; however, none exhibited antibacterial activity (MIC ˃ 256 mg/mL). The three new compounds did not show any quorum sensing inhibition in the screening protocol based on the pigment production by Chromobacterium violaceum (ATCC 31532). Full article
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Article
Sulfated Galactan from Palisada flagellifera Inhibits Toxic Effects of Lachesis muta Snake Venom
by Ana Cláudia Rodrigues Da Silva, Luciana Garcia Ferreira, Maria Eugênia Rabello Duarte, Miguel Daniel Noseda, Eladio Flores Sanchez and André Lopes Fuly
Mar. Drugs 2015, 13(6), 3761-3775; https://doi.org/10.3390/md13063761 - 11 Jun 2015
Cited by 9 | Viewed by 6366
Abstract
In Brazil, snakebites are a public health problem and accidents caused by Lachesis muta have the highest mortality index. Envenomation by L. muta is characterized by systemic (hypotension, bleeding and renal failure) and local effects (necrosis, pain and edema). The treatment to reverse [...] Read more.
In Brazil, snakebites are a public health problem and accidents caused by Lachesis muta have the highest mortality index. Envenomation by L. muta is characterized by systemic (hypotension, bleeding and renal failure) and local effects (necrosis, pain and edema). The treatment to reverse the evolution of all the toxic effects is performed by injection of antivenom. However, such therapy does not effectively neutralize tissue damage or any other local effect, since in most cases victims delay seeking appropriate medical care. In this way, alternative therapies are in demand, and molecules from natural sources have been exhaustively tested. In this paper, we analyzed the inhibitory effect of a sulfated galactan obtained from the red seaweed Palisada flagellifera against some toxic activities of L. muta venom. Incubation of sulfated galactan with venom resulted in inhibition of hemolysis, coagulation, proteolysis, edema and hemorrhage. Neutralization of hemorrhage was also observed when the galactan was administered after or before the venom injection; thus mimicking a real in vivo situation. Moreover, the galactan blocked the edema caused by a phospholipase A2 isolated from the same venom. Therefore, the galactan from P. flagellifera may represent a promising tool to treat envenomation by L. muta as a coadjuvant for the conventional antivenom. Full article
(This article belongs to the Special Issue Marine Secondary Metabolites)
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Article
Valorization of Sargassum muticum Biomass According to the Biorefinery Concept
by Elena M. Balboa, Andrés Moure and Herminia Domínguez
Mar. Drugs 2015, 13(6), 3745-3760; https://doi.org/10.3390/md13063745 - 11 Jun 2015
Cited by 81 | Viewed by 11551
Abstract
The biorefinery concept integrates processes and technologies for an efficient biomass conversion using all components of a feedstock. Sargassum muticum is an invasive brown algae which could be regarded as a renewable resource susceptible of individual valorization of the constituent fractions into high [...] Read more.
The biorefinery concept integrates processes and technologies for an efficient biomass conversion using all components of a feedstock. Sargassum muticum is an invasive brown algae which could be regarded as a renewable resource susceptible of individual valorization of the constituent fractions into high added-value compounds. Microwave drying technology can be proposed before conventional ethanol extraction of algal biomass, and supercritical fluid extraction with CO2 was useful to extract fucoxanthin and for the fractionation of crude ethanol extracts. Hydrothermal processing is proposed to fractionate the algal biomass and to solubilize the fucoidan and phlorotannin fractions. Membrane technology was proposed to concentrate these fractions and obtain salt- and arsenic-free saccharidic fractions. Based on these technologies, this study presents a multipurpose process to obtain six different products with potential applications for nutraceutical, cosmetic and pharmaceutical industries. Full article
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Article
Use of Natural Antimicrobial Peptides and Bacterial Biopolymers for Cultured Pearl Production
by Christelle Simon-Colin, Yannick Gueguen, Evelyne Bachere, Achraf Kouzayha, Denis Saulnier, Nicolas Gayet and Jean Guezennec
Mar. Drugs 2015, 13(6), 3732-3744; https://doi.org/10.3390/md13063732 - 11 Jun 2015
Cited by 16 | Viewed by 12231
Abstract
Cultured pearls are the product of grafting and rearing of Pinctada margaritifera pearl oysters in their natural environment. Nucleus rejections and oyster mortality appear to result from bacterial infections or from an inappropriate grafting practice. To reduce the impact of bacterial infections, synthetic [...] Read more.
Cultured pearls are the product of grafting and rearing of Pinctada margaritifera pearl oysters in their natural environment. Nucleus rejections and oyster mortality appear to result from bacterial infections or from an inappropriate grafting practice. To reduce the impact of bacterial infections, synthetic antibiotics have been applied during the grafting practice. However, the use of such antibiotics presents a number of problems associated with their incomplete biodegradability, limited efficacy in some cases, and an increased risk of selecting for antimicrobial resistant bacteria. We investigated the application of a marine antimicrobial peptide, tachyplesin, which is present in the Japanese horseshoe crab Tachypleus tridentatus, in combination with two marine bacterial exopolymers as alternative treatment agents. In field studies, the combination treatment resulted in a significant reduction in graft failures vs. untreated controls. The combination of tachyplesin (73 mg/L) with two bacterial exopolysaccharides (0.5% w/w) acting as filming agents, reduces graft-associated bacterial contamination. The survival data were similar to that reported for antibiotic treatments. These data suggest that non-antibiotic treatments of pearl oysters may provide an effective means of improving oyster survival following grafting procedures. Full article
(This article belongs to the Special Issue Marine Peptides and Their Mimetics)
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Article
Extraction, Isolation, Structural Characterization and Anti-Tumor Properties of an Apigalacturonan-Rich Polysaccharide from the Sea Grass Zostera caespitosa Miki
by Youjing Lv, Xindi Shan, Xia Zhao, Chao Cai, Xiaoliang Zhao, Yinzhi Lang, He Zhu and Guangli Yu
Mar. Drugs 2015, 13(6), 3710-3731; https://doi.org/10.3390/md13063710 - 11 Jun 2015
Cited by 25 | Viewed by 8129
Abstract
An apigalacturonan (AGA)-rich polysaccharide, ZCMP, was isolated from the sea grass Zostera caespitosa Miki. The depolymerized fragments derived from ZCMP were obtained by either acidic degradation or pectinase degradation, and their structures were characterized by electrospray ionization collision-induced-dissociation mass spectrometry (ESI-CID-MS2) and nuclear [...] Read more.
An apigalacturonan (AGA)-rich polysaccharide, ZCMP, was isolated from the sea grass Zostera caespitosa Miki. The depolymerized fragments derived from ZCMP were obtained by either acidic degradation or pectinase degradation, and their structures were characterized by electrospray ionization collision-induced-dissociation mass spectrometry (ESI-CID-MS2) and nuclear magnetic resonance (NMR) spectroscopy. The average molecular weight of ZCMP was 77.2 kD and it consisted of galacturonic acid (GalA), apiosefuranose (Api), galactose (Gal), rhamnose (Rha), arabinose (Ara), xylose (Xyl), and mannose (Man), at a molar ratio of 51.4꞉15.5꞉6.0꞉11.8꞉4.2꞉4.4꞉4.2. There were two regions of AGA (70%) and rhamnogalacturonan-I (RG-Ι, 30%) in ZCMP. AGA was composed of an α-1,4-D-galactopyranosyluronan backbone mainly substituted at the O-3 position by single Api residues. RG-Ι possessed a backbone of repeating disaccharide units of →4GalAα1,2Rhaα1→, with a few α-L-arabinose and β-D-galactose residues as side chains. The anti-angiogenesis assay showed that ZCMP inhibited the migratory activity of human umbilical vein endothelial cell (HUVECs), with no influence on endothelial cells growth. ZCMP also promoted macrophage phagocytosis. These findings of the present study demonstrated the potential anti-tumor activity of ZCMP through anti-angiogenic and immunoregulatory pathways. Full article
(This article belongs to the Special Issue Marine Glycoconjugates)
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Review
Low-Molecular-Weight Metabolites from Diatoms: Structures, Biological Roles and Biosynthesis
by Valentin Stonik and Inna Stonik
Mar. Drugs 2015, 13(6), 3672-3709; https://doi.org/10.3390/md13063672 - 9 Jun 2015
Cited by 75 | Viewed by 11675
Abstract
Diatoms are abundant and important biological components of the marine environment that biosynthesize diverse natural products. These microalgae are rich in various lipids, carotenoids, sterols and isoprenoids, some of them containing toxins and other metabolites. Several groups of diatom natural products have attracted [...] Read more.
Diatoms are abundant and important biological components of the marine environment that biosynthesize diverse natural products. These microalgae are rich in various lipids, carotenoids, sterols and isoprenoids, some of them containing toxins and other metabolites. Several groups of diatom natural products have attracted great interest due to their potential practical application as energy sources (biofuel), valuable food constituents, and prospective materials for nanotechnology. In addition, hydrocarbons, which are used in climate reconstruction, polyamines which participate in biomineralization, new apoptotic agents against tumor cells, attractants and deterrents that regulate the biochemical communications between marine species in seawaters have also been isolated from diatoms. However, chemical studies on these microalgae are complicated by difficulties, connected with obtaining their biomass, and the influence of nutrients and contaminators in their environment as well as by seasonal and climatic factors on the biosynthesis of the corresponding natural products. Overall, the number of chemically studied diatoms is lower than that of other algae, but further studies, particularly those connected with improvements in the isolation and structure elucidation technique as well as the genomics of diatoms, promise both to increase the number of studied species with isolated biologically active natural products and to provide a clearer perception of their biosynthesis. Full article
(This article belongs to the Special Issue Metabolites in Diatoms)
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Article
Effect of Marine Collagen Peptides on Physiological and Neurobehavioral Development of Male Rats with Perinatal Asphyxia
by Linlin Xu, Wenhong Dong, Jie Zhao and Yajun Xu
Mar. Drugs 2015, 13(6), 3653-3671; https://doi.org/10.3390/md13063653 - 5 Jun 2015
Cited by 32 | Viewed by 7182
Abstract
Asphyxia during delivery produces long-term deficits in brain development. We investigated the neuroprotective effects of marine collagen peptides (MCPs), isolated from Chum Salmon skin by enzymatic hydrolysis, on male rats with perinatal asphyxia (PA). PA was performed by immersing rat fetuses with uterine [...] Read more.
Asphyxia during delivery produces long-term deficits in brain development. We investigated the neuroprotective effects of marine collagen peptides (MCPs), isolated from Chum Salmon skin by enzymatic hydrolysis, on male rats with perinatal asphyxia (PA). PA was performed by immersing rat fetuses with uterine horns removed from ready-to-deliver rats into a water bath for 15 min. Caesarean-delivered pups were used as controls. PA rats were intragastrically administered with 0.33 g/kg, 1.0 g/kg and 3.0 g/kg body weight MCPs from postnatal day 0 (PND 0) till the age of 90-days. Behavioral tests were carried out at PND21, PND 28 and PND 90. The results indicated that MCPs facilitated early body weight gain of the PA pups, however had little effects on early physiological development. Behavioral tests revealed that MCPs facilitated long-term learning and memory of the pups with PA through reducing oxidative damage and acetylcholinesterase (AChE) activity in the brain, and increasing hippocampus phosphorylated cAMP-response element binding protein (p-CREB) and brain derived neurotrophic factor (BDNF) expression. Full article
(This article belongs to the Special Issue Marine Functional Food)
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Article
Peniciadametizine A, a Dithiodiketopiperazine with a Unique Spiro[furan-2,7'-pyrazino[1,2-b][1,2]oxazine] Skeleton, and a Related Analogue, Peniciadametizine B, from the Marine Sponge-Derived Fungus Penicillium adametzioides
by Yang Liu, Attila Mándi, Xiao-Ming Li, Ling-Hong Meng, Tibor Kurtán and Bin-Gui Wang
Mar. Drugs 2015, 13(6), 3640-3652; https://doi.org/10.3390/md13063640 - 5 Jun 2015
Cited by 58 | Viewed by 8283
Abstract
Peniciadametizine A (1); a new dithiodiketopiperazine derivative possessing a unique spiro[furan-2,7'-pyrazino[1,2-b][1,2]oxazine] skeleton, together with a highly oxygenated new analogue, peniciadametizine B (2); as well as two known compounds, brasiliamide A (3); and viridicatumtoxin (4), were isolated and identified from [...] Read more.
Peniciadametizine A (1); a new dithiodiketopiperazine derivative possessing a unique spiro[furan-2,7'-pyrazino[1,2-b][1,2]oxazine] skeleton, together with a highly oxygenated new analogue, peniciadametizine B (2); as well as two known compounds, brasiliamide A (3); and viridicatumtoxin (4), were isolated and identified from Penicillium adametzioides AS-53, a fungus obtained from an unidentified marine sponge. The unambiguous assignment of the relative and absolute configuration for the spiro center C-2 of compound 1 was solved by the combination of NMR and ECD measurements with Density-Functional Theory (DFT) conformational analysis and Time-Dependent Density-Functional Theory-Electronic Circular Dichroism (TDDFT-ECD) calculations. The spiro[furan-2,7'-pyrazino[1,2-b][1,2]oxazine] skeleton of 1 has not been reported yet among natural products and the biosynthetic pathway for 1 and 2 was discussed. Compounds 1 and 2 showed inhibitory activity against the pathogenic fungus Alternaria brassicae. Full article
(This article belongs to the Special Issue Bioactive Compounds from Marine Fungi)
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Article
Activation of RAF1 (c-RAF) by the Marine Alkaloid Lasonolide A Induces Rapid Premature Chromosome Condensation
by Rozenn Jossé, Yong-Wei Zhang, Valentin Giroux, Arun K. Ghosh, Ji Luo and Yves Pommier
Mar. Drugs 2015, 13(6), 3625-3639; https://doi.org/10.3390/md13063625 - 5 Jun 2015
Cited by 14 | Viewed by 7000
Abstract
Lasonolide A (LSA), a potent antitumor polyketide from the marine sponge, Forcepia sp., induces rapid and reversible protein hyperphosphorylation and premature chromosome condensation (PCC) at nanomolar concentrations independent of cyclin-dependent kinases. To identify cellular targets of LSA, we screened 2951 shRNAs targeting a [...] Read more.
Lasonolide A (LSA), a potent antitumor polyketide from the marine sponge, Forcepia sp., induces rapid and reversible protein hyperphosphorylation and premature chromosome condensation (PCC) at nanomolar concentrations independent of cyclin-dependent kinases. To identify cellular targets of LSA, we screened 2951 shRNAs targeting a pool of human kinases and phosphatases (1140 RefSeqs) to identify genes that modulate PCC in response to LSA. This led to the identification of RAF1 (C-RAF) as a mediator of LSA-induced PCC, as shRNAs against RAF1 conferred resistance to LSA. We found that LSA induced RAF1 phosphorylation on Serine 338 within minutes in human colorectal carcinoma HCT-116, ovarian carcinoma OVCAR-8, and Burkitt’s lymphoma CA46 cell lines. RAF1 depletion by siRNAs attenuated LSA-induced PCC in HCT-116 and OVCAR-8 cells. Furthermore, mouse embryonic fibroblasts (MEF) with homozygous deletion in Raf1, but not deletion in the related kinase Braf, were resistant to LSA-induced PCC. Complementation of Raf1−/− MEFs with wild-type human RAF1, but not with kinase-dead RAF1 mutant, restored LSA-induced PCC. Finally, the Raf inhibitor sorafenib, but not the MEK inhibitor AZD6244, effectively suppressed LSA-induced PCC. Our findings implicate a previously unknown, MAPK-independent role of RAF1 in chromatin condensation and potent activation of this pathway by LSA. Full article
(This article belongs to the Special Issue Okadaic Acid and Dinophysis Toxins)
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Article
White Shrimp Litopenaeus vannamei That Have Received Gracilaria tenuistipitata Extract Show Early Recovery of Immune Parameters after Ammonia Stressing
by Yu-Yuan Chen, Jiann-Chu Chen, Yong-Chin Lin, Su-Tuen Yeh and Chien-Lun Huang
Mar. Drugs 2015, 13(6), 3606-3624; https://doi.org/10.3390/md13063606 - 5 Jun 2015
Cited by 33 | Viewed by 7637
Abstract
White shrimp Litopenaeus vannamei immersed in seawater (35‰) containing Gracilaria tenuistipitata extract (GTE) at 0 (control), 400, and 600 mg/L for 3 h were exposed to 5 mg/L ammonia-N (ammonia as nitrogen), and immune parameters including hyaline cells (HCs), granular cells (GCs, including [...] Read more.
White shrimp Litopenaeus vannamei immersed in seawater (35‰) containing Gracilaria tenuistipitata extract (GTE) at 0 (control), 400, and 600 mg/L for 3 h were exposed to 5 mg/L ammonia-N (ammonia as nitrogen), and immune parameters including hyaline cells (HCs), granular cells (GCs, including semi-granular cells), total hemocyte count (THC), phenoloxidase (PO) activity, respiratory bursts (RBs), superoxide dismutase (SOD) activity, lysozyme activity, and hemolymph protein level were examined 24~120 h post-stress. The immune parameters of shrimp immersed in 600 mg/L GTE returned to original values earlier, at 96~120 h post-stress, whereas in control shrimp they did not. In another experiment, shrimp were immersed in seawater containing GTE at 0 and 600 mg/L for 3 h and examined for transcript levels of immune-related genes at 24 h post-stress. Transcript levels of lipopolysaccharide and β-1,3-glucan binding protein (LGBP), peroxinectin (PX), cytMnSOD, mtMnSOD, and HSP70 were up-regulated at 24 h post-stress in GTE receiving shrimp. We concluded that white shrimp immersed in seawater containing GTE exhibited a capability for maintaining homeostasis by regulating cellular and humoral immunity against ammonia stress as evidenced by up-regulated gene expression and earlier recovery of immune parameters. Full article
(This article belongs to the Special Issue Marine Functional Food)
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Article
Antibiofilm Activity of the Brown Alga Halidrys siliquosa against Clinically Relevant Human Pathogens
by Alessandro Busetti, Thomas P. Thompson, Diana Tegazzini, Julianne Megaw, Christine A. Maggs and Brendan F. Gilmore
Mar. Drugs 2015, 13(6), 3581-3605; https://doi.org/10.3390/md13063581 - 5 Jun 2015
Cited by 18 | Viewed by 8927
Abstract
The marine brown alga Halidrys siliquosa is known to produce compounds with antifouling activity against several marine bacteria. The aim of this study was to evaluate the antimicrobial and antibiofilm activity of organic extracts obtained from the marine brown alga H. siliquosa against [...] Read more.
The marine brown alga Halidrys siliquosa is known to produce compounds with antifouling activity against several marine bacteria. The aim of this study was to evaluate the antimicrobial and antibiofilm activity of organic extracts obtained from the marine brown alga H. siliquosa against a focused panel of clinically relevant human pathogens commonly associated with biofilm-related infections. The partially fractionated methanolic extract obtained from H. siliquosa collected along the shores of Co. Donegal; Ireland; displayed antimicrobial activity against bacteria of the genus Staphylococcus; Streptococcus; Enterococcus; Pseudomonas; Stenotrophomonas; and Chromobacterium with MIC and MBC values ranging from 0.0391 to 5 mg/mL. Biofilms of S. aureus MRSA were found to be susceptible to the algal methanolic extract with MBEC values ranging from 1.25 mg/mL to 5 mg/mL respectively. Confocal laser scanning microscopy using LIVE/DEAD staining confirmed the antimicrobial nature of the antibiofilm activity observed using the MBEC assay. A bioassay-guided fractionation method was developed yielding 10 active fractions from which to perform purification and structural elucidation of clinically-relevant antibiofilm compounds. Full article
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Article
Drimane Sesquiterpene-Conjugated Amino Acids from a Marine Isolate of the Fungus Talaromyces minioluteus (Penicillium Minioluteum)
by Suthatip Ngokpol, Wittaya Suwakulsiri, Sanya Sureram, Kriengsak Lirdprapamongkol, Thammarat Aree, Suthep Wiyakrutta, Chulabhorn Mahidol, Somsak Ruchirawat and Prasat Kittakoop
Mar. Drugs 2015, 13(6), 3567-3580; https://doi.org/10.3390/md13063567 - 5 Jun 2015
Cited by 37 | Viewed by 7621
Abstract
Four new sesquiterpene lactones (3, 4, 6 and 7) and three known compounds, purpuride (1), berkedrimane B (2) and purpuride B (5), were isolated from the marine fungus, Talaromyces minioluteus (Penicillium minioluteum [...] Read more.
Four new sesquiterpene lactones (3, 4, 6 and 7) and three known compounds, purpuride (1), berkedrimane B (2) and purpuride B (5), were isolated from the marine fungus, Talaromyces minioluteus (Penicillium minioluteum). New compounds were drimane sesquiterpenes conjugated with N-acetyl-l-valine, and their structures were elucidated by analysis of spectroscopic data, as well as by single crystal X-ray analysis. The isolated compounds could not inhibit the apoptosis-regulating enzyme, caspase-3, while three of the compounds (2, 3 and 7) exhibited weak cytotoxic activity. Full article
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Article
1H NMR Spectroscopy and MVA Analysis of Diplodus sargus Eating the Exotic Pest Caulerpa cylindracea
by Sandra A. De Pascali, Laura Del Coco, Serena Felline, Ernesto Mollo, Antonio Terlizzi and Francesco P. Fanizzi
Mar. Drugs 2015, 13(6), 3550-3566; https://doi.org/10.3390/md13063550 - 5 Jun 2015
Cited by 13 | Viewed by 7373
Abstract
The green alga Caulerpa cylindracea is a non-autochthonous and invasive species that is severely affecting the native communities in the Mediterranean Sea. Recent researches show that the native edible fish Diplodus sargus actively feeds on this alga and cellular and physiological alterations have [...] Read more.
The green alga Caulerpa cylindracea is a non-autochthonous and invasive species that is severely affecting the native communities in the Mediterranean Sea. Recent researches show that the native edible fish Diplodus sargus actively feeds on this alga and cellular and physiological alterations have been related to the novel alimentary habits. The complex effects of such a trophic exposure to the invasive pest are still poorly understood. Here we report on the metabolic profiles of plasma from D. sargus individuals exposed to C. cylindracea along the southern Italian coast, using 1H NMR spectroscopy and multivariate analysis (Principal Component Analysis, PCA, Orthogonal Partial Least Square, PLS, and Orthogonal Partial Least Square Discriminant Analysis, OPLS-DA). Fish were sampled in two seasonal periods from three different locations, each characterized by a different degree of algal abundance. The levels of the algal bisindole alkaloid caulerpin, which is accumulated in the fish tissues, was used as an indicator of the trophic exposure to the seaweed and related to the plasma metabolic profiles. The profiles appeared clearly influenced by the sampling period beside the content of caulerpin, while the analyses also supported a moderate alteration of lipid and choline metabolism related to the Caulerpa-based diet. Full article
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Article
Biological Activities and Chemical Composition of Methanolic Extracts of Selected Autochthonous Microalgae Strains from the Red Sea
by Hugo Pereira, Luísa Custódio, Maria João Rodrigues, Carolina Bruno De Sousa, Marta Oliveira, Luísa Barreira, Nuno Da Rosa Neng, José Manuel Florêncio Nogueira, Salman A. Alrokayan, Fouzi Mouffouk, Khalid M. Abu-Salah, Radhouan Ben-Hamadou and João Varela
Mar. Drugs 2015, 13(6), 3531-3549; https://doi.org/10.3390/md13063531 - 3 Jun 2015
Cited by 47 | Viewed by 8958
Abstract
Four lipid-rich microalgal species from the Red Sea belonging to three different genera (Nannochloris, Picochlorum and Desmochloris), previously isolated as novel biodiesel feedstocks, were bioprospected for high-value, bioactive molecules. Methanol extracts were thus prepared from freeze-dried biomass and screened for [...] Read more.
Four lipid-rich microalgal species from the Red Sea belonging to three different genera (Nannochloris, Picochlorum and Desmochloris), previously isolated as novel biodiesel feedstocks, were bioprospected for high-value, bioactive molecules. Methanol extracts were thus prepared from freeze-dried biomass and screened for different biological activities. Nannochloris sp. SBL1 and Desmochloris sp. SBL3 had the highest radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl, and the best copper and iron chelating activities. All species had potent butyrylcholinesterase inhibitory activity (>50%) and mildly inhibited tyrosinase. Picochlorum sp. SBL2 and Nannochloris sp. SBL4 extracts significantly reduced the viability of tumoral (HepG2 and HeLa) cells with lower toxicity against the non-tumoral murine stromal (S17) cells. Nannochloris sp. SBL1 significantly reduced the viability of Leishmania infantum down to 62% (250 µg/mL). Picochlorum sp. SBL2 had the highest total phenolic content, the major phenolic compounds identified being salicylic, coumaric and gallic acids. Neoxanthin, violaxanthin, zeaxanthin, lutein and β-carotene were identified in the extracts of all strains, while canthaxanthin was only identified in Picochlorum sp. SBL2. Taken together, these results strongly suggest that the microalgae included in this work could be used as sources of added-value products that could be used to upgrade the final biomass value. Full article
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Article
Fucoidan Suppresses Hypoxia-Induced Lymphangiogenesis and Lymphatic Metastasis in Mouse Hepatocarcinoma
by Hongming Teng, Yazong Yang, Hengyun Wei, Zundong Liu, Zhichao Liu, Yanhong Ma, Zixiang Gao, Lin Hou and Xiangyang Zou
Mar. Drugs 2015, 13(6), 3514-3530; https://doi.org/10.3390/md13063514 - 3 Jun 2015
Cited by 57 | Viewed by 7186
Abstract
Metastasis, the greatest clinical challenge associated with cancer, is closely connected to multiple biological processes, including invasion and adhesion. The hypoxic environment in tumors is an important factor that causes tumor metastasis by activating HIF-1α. Fucoidan, extracted from brown algae, is a sulfated [...] Read more.
Metastasis, the greatest clinical challenge associated with cancer, is closely connected to multiple biological processes, including invasion and adhesion. The hypoxic environment in tumors is an important factor that causes tumor metastasis by activating HIF-1α. Fucoidan, extracted from brown algae, is a sulfated polysaccharide and, as a novel marine biological material, has been used to treat various disorders in China, Korea, Japan and other countries. In the present study, we demonstrated that fucoidan derived from Undaria pinnatifida sporophylls significantly inhibits the hypoxia-induced expression, nuclear translocation and activity of HIF-1α, the synthesis and secretion of VEGF-C and HGF, cell invasion and lymphatic metastasis in a mouse hepatocarcinoma Hca-F cell line. Fucoidan also suppressed lymphangiogenesis in vitro and in vivo. In addition, accompanied by a reduction in the HIF-1α nuclear translocation and activity, fucoidan significantly reduced the levels of p-PI3K, p-Akt, p-mTOR, p-ERK, NF-κB, MMP-2 and MMP-9, but increased TIMP-1 levels. These results indicate strongly that the anti-metastasis and anti-lymphangiogenesis activities of fucoidan are mediated by suppressing HIF-1α/VEGF-C, which attenuates the PI3K/Akt/mTOR signaling pathways. Full article
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Review
Antibacterial and Antifungal Compounds from Marine Fungi
by Lijian Xu, Wei Meng, Cong Cao, Jian Wang, Wenjun Shan and Qinggui Wang
Mar. Drugs 2015, 13(6), 3479-3513; https://doi.org/10.3390/md13063479 - 2 Jun 2015
Cited by 114 | Viewed by 14314
Abstract
This paper reviews 116 new compounds with antifungal or antibacterial activities as well as 169 other known antimicrobial compounds, with a specific focus on January 2010 through March 2015. Furthermore, the phylogeny of the fungi producing these antibacterial or antifungal compounds was analyzed. [...] Read more.
This paper reviews 116 new compounds with antifungal or antibacterial activities as well as 169 other known antimicrobial compounds, with a specific focus on January 2010 through March 2015. Furthermore, the phylogeny of the fungi producing these antibacterial or antifungal compounds was analyzed. The new methods used to isolate marine fungi that possess antibacterial or antifungal activities as well as the relationship between structure and activity are shown in this review. Full article
(This article belongs to the Special Issue Bioactive Compounds from Marine Fungi)
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Review
Ciguatera Fish Poisoning in East Asia and Southeast Asia
by Thomas Y. K. Chan
Mar. Drugs 2015, 13(6), 3466-3478; https://doi.org/10.3390/md13063466 - 2 Jun 2015
Cited by 42 | Viewed by 11703
Abstract
In the coastal countries of East Asia and Southeast Asia, ciguatera should be common because of the extensive tropical and subtropical coral reefs along the coasts and in the neighboring seas with ciguatoxic fishes. An extensive search of journal databases, the Internet and [...] Read more.
In the coastal countries of East Asia and Southeast Asia, ciguatera should be common because of the extensive tropical and subtropical coral reefs along the coasts and in the neighboring seas with ciguatoxic fishes. An extensive search of journal databases, the Internet and the government websites was performed to identify all reports of ciguatera from the regions. Based on the official data and large published case series, the incidence of ciguatera was higher in the coastal cities (Hong Kong, Foshan, Zhongshan) of southern China than in Japan (Okinawa Prefecture). In Singapore, ciguatera appeared to be almost unknown. In other countries, only isolated cases or small case series were reported, but under-reporting was assumed to be common. Ciguatera may cause severe acute illness and prolonged neurological symptoms. Ciguatera represents an important public health issue for endemic regions, with significant socio-economic impact. Coordinated strategies to improve risk assessment, risk management and risk communication are required. The systematic collection of accurate data on the incidence and epidemiology of ciguatera should enable better assessment and management of its risk. Much more work needs to be done to define the size threshold for important coral reef fish species from different regions, above which the risk of ciguatera significantly increases. Full article
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Article
Entry Inhibition of Influenza Viruses with High Mannose Binding Lectin ESA-2 from the Red Alga Eucheuma serra through the Recognition of Viral Hemagglutinin
by Yuichiro Sato, Kinjiro Morimoto, Takanori Kubo, Takemasa Sakaguchi, Akira Nishizono, Makoto Hirayama and Kanji Hori
Mar. Drugs 2015, 13(6), 3454-3465; https://doi.org/10.3390/md13063454 - 29 May 2015
Cited by 37 | Viewed by 7670
Abstract
Lectin sensitivity of the recent pandemic influenza A virus (H1N1-2009) was screened for 12 lectins with various carbohydrate specificity by a neutral red dye uptake assay with MDCK cells. Among them, a high mannose (HM)-binding anti-HIV lectin, ESA-2 from the red alga Eucheuma [...] Read more.
Lectin sensitivity of the recent pandemic influenza A virus (H1N1-2009) was screened for 12 lectins with various carbohydrate specificity by a neutral red dye uptake assay with MDCK cells. Among them, a high mannose (HM)-binding anti-HIV lectin, ESA-2 from the red alga Eucheuma serra, showed the highest inhibition against infection with an EC50 of 12.4 nM. Moreover, ESA-2 exhibited a wide range of antiviral spectrum against various influenza strains with EC50s of pico molar to low nanomolar levels. Besides ESA-2, HM-binding plant lectin ConA, fucose-binding lectins such as fungal AOL from Aspergillus oryzae and AAL from Aleuria aurantia were active against H1N1-2009, but the potency of inhibition was of less magnitude compared with ESA-2. Direct interaction between ESA-2 and a viral envelope glycoprotein, hemagglutinin (HA), was demonstrated by ELISA assay. This interaction was effectively suppressed by glycoproteins bearing HM-glycans, indicating that ESA-2 binds to the HA of influenza virus through HM-glycans. Upon treatment with ESA-2, no viral antigens were detected in the host cells, indicating that ESA-2 inhibited the initial steps of virus entry into the cells. ESA-2 would thus be useful as a novel microbicide to prevent penetration of viruses such as HIV and influenza viruses to the host cells. Full article
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Article
New Anti-Inflammatory Cembranes from the Cultured Soft Coral Nephthea columnaris
by Ting-Hsi Hsiao, Chun-Sung Sung, Yu-Hsuan Lan, Yi-Chen Wang, Mei-Chin Lu, Zhi-Hong Wen, Yang-Chang Wu and Ping-Jyun Sung
Mar. Drugs 2015, 13(6), 3443-3453; https://doi.org/10.3390/md13063443 - 29 May 2015
Cited by 29 | Viewed by 6166
Abstract
Two new cembranes, columnariols A (1) and B (2), were isolated from the cultured soft coral Nephthea columnaris. The structures of cembranes 1 and 2 were elucidated by spectroscopic methods. In the anti-inflammatory effects test, cembranes 1 and [...] Read more.
Two new cembranes, columnariols A (1) and B (2), were isolated from the cultured soft coral Nephthea columnaris. The structures of cembranes 1 and 2 were elucidated by spectroscopic methods. In the anti-inflammatory effects test, cembranes 1 and 2 were found to significantly inhibit the accumulation of the pro-inflammatory iNOS and COX-2 protein of the lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. Compound 1 exhibited moderate cytotoxicity toward LNCaP cells with an IC50 value of 9.80 μg/mL. Full article
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Article
Biological Properties of Fucoxanthin in Oil Recovered from Two Brown Seaweeds Using Supercritical CO2 Extraction
by Saravana Periaswamy Sivagnanam, Shipeng Yin, Jae Hyung Choi, Yong Beom Park, Hee Chul Woo and Byung Soo Chun
Mar. Drugs 2015, 13(6), 3422-3442; https://doi.org/10.3390/md13063422 - 29 May 2015
Cited by 137 | Viewed by 10966
Abstract
The bioactive materials in brown seaweeds hold great interest for developing new drugs and healthy foods. The oil content in brown seaweeds (Saccharina japonica and Sargassum horneri) was extracted by using environmentally friendly supercritical CO2 (SC-CO2) with ethanol [...] Read more.
The bioactive materials in brown seaweeds hold great interest for developing new drugs and healthy foods. The oil content in brown seaweeds (Saccharina japonica and Sargassum horneri) was extracted by using environmentally friendly supercritical CO2 (SC-CO2) with ethanol as a co-solvent in a semi-batch flow extraction process and compared the results with a conventional extraction process using hexane, ethanol, and acetone mixed with methanol (1:1, v/v). The SC-CO2 method was used at a temperature of 45 °C and pressure of 250 bar. The flow rate of CO2 (27 g/min) was constant for the entire extraction period of 2 h. The obtained oil from the brown seaweeds was analyzed to determine their valuable compounds such as fatty acids, phenolic compounds, fucoxanthin and biological properties including antioxidant, antimicrobial, and antihypertension effects. The amounts of fucoxanthin extracted from the SC-CO2 oils of S. japonica and S. horneri were 0.41 ± 0.05 and 0.77 ± 0.07 mg/g, respectively. High antihypertensive activity was detected when using mixed acetone and methanol, whereas the phenolic content and antioxidant property were higher in the oil extracted by SC-CO2. The acetone–methanol mix extracts exhibited better antimicrobial activities than those obtained by other means. Thus, the SC-CO2 extraction process appears to be a good method for obtaining valuable compounds from both brown seaweeds, and showed stronger biological activity than that obtained by the conventional extraction process. Full article
(This article belongs to the Special Issue Marine Functional Food)
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258 KiB  
Article
The Antihyperlipidemic Mechanism of High Sulfate Content Ulvan in Rats
by Huimin Qi and Jiwen Sheng
Mar. Drugs 2015, 13(6), 3407-3421; https://doi.org/10.3390/md13063407 - 29 May 2015
Cited by 42 | Viewed by 6179
Abstract
Numerous studies have suggested that hyperlipidemia is closely linked to cardiovascular disease. The aim of this study was to investigate the possible antihyperlipidemia mechanism of HU (high sulfate content of ulvan) in high-cholesterol fed rats. Wistar rats were made hyperlipidemic by feeding with [...] Read more.
Numerous studies have suggested that hyperlipidemia is closely linked to cardiovascular disease. The aim of this study was to investigate the possible antihyperlipidemia mechanism of HU (high sulfate content of ulvan) in high-cholesterol fed rats. Wistar rats were made hyperlipidemic by feeding with a high-cholesterol diet. HU was administered to these hyperlipidemia rats for 30 days. Lipid levels and the mRNA expressions of FXR, LXR and PPARγ in liver were measured after 30 days of treatment. In the HU-treated groups, the middle dosage group of male rats (total cholesterol (TC): p < 0.01) and the low-dosage group of female rats (TC, LDL-C: p < 0.01) showed stronger activity with respect to antihyperlipidemia. Moreover, some HU groups could upregulate the mRNA expression of FXR and PPARγ and downregulate the expression of LXR. For the male rats, compared with the hyperlipidemia group, the middle dosage HU had the most pronounced effect on increasing the mRNA levels of FXR (p < 0.01); low- and high-dosage HU showed a significant inhibition of the mRNA levels of LXR (p < 0.01). All HU female groups could upregulate the mRNA expression of PPARγ in a concentration-dependent manner. In summary, HU could improve lipid profiles through upregulation of FXR and PPARγ and downregulation of LXR. Full article
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