Next Issue
Previous Issue

E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Table of Contents

Mar. Drugs, Volume 9, Issue 11 (November 2011), Pages 2164-2487

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
View options order results:
result details:
Displaying articles 1-19
Export citation of selected articles as:

Research

Jump to: Review, Other

Open AccessArticle Sulfated-Polysaccharide Fraction from Red Algae Gracilaria caudata Protects Mice Gut Against Ethanol-Induced Damage
Mar. Drugs 2011, 9(11), 2188-2200; doi:10.3390/md9112188
Received: 14 September 2011 / Revised: 17 October 2011 / Accepted: 24 October 2011 / Published: 2 November 2011
Cited by 15 | PDF Full-text (499 KB) | HTML Full-text | XML Full-text
Abstract
The aim of the present study was to investigate the gastroprotective activity of a sulfated-polysaccharide (PLS) fraction extracted from the marine red algae Gracilaria caudata and the mechanism underlying the gastroprotective activity. Male Swiss mice were treated with PLS (3, 10, 30 and
[...] Read more.
The aim of the present study was to investigate the gastroprotective activity of a sulfated-polysaccharide (PLS) fraction extracted from the marine red algae Gracilaria caudata and the mechanism underlying the gastroprotective activity. Male Swiss mice were treated with PLS (3, 10, 30 and 90 mg·kg−1, p.o.), and after 30 min, they were administered 50% ethanol (0.5 mL/25 g−1, p.o.). One hour later, gastric damage was measured using a planimeter. Samples of the stomach tissue were also obtained for histopathological assessment and for assays of glutathione (GSH) and malondialdehyde (MDA). Other groups were pretreated with l-NAME (10 mg·kg−1, i.p.), dl-propargylglycine (PAG, 50 mg·kg−1, p.o.) or glibenclamide (5 mg·kg−1, i.p.). After 1 h, PLS (30 mg·kg−1, p.o.) was administered. After 30 min, ethanol 50% was administered (0.5 mL/25g−1, p.o.), followed by sacrifice after 60 min. PLS prevented-ethanol-induced macroscopic and microscopic gastric injury in a dose-dependent manner. However, treatment with l-NAME or glibenclamide reversed this gastroprotective effect. Administration of propargylglycine did not influence the effect of PLS. Our results suggest that PLS has a protective effect against ethanol-induced gastric damage in mice via activation of the NO/KATP pathway. Full article
(This article belongs to the collection Marine Polysaccharides)
Figures

Open AccessArticle Examination of Marine-Based Cultivation of Three Demosponges for Acquiring Bioactive Marine Natural Products
Mar. Drugs 2011, 9(11), 2201-2219; doi:10.3390/md9112201
Received: 15 September 2011 / Revised: 8 October 2011 / Accepted: 21 October 2011 / Published: 7 November 2011
Cited by 11 | PDF Full-text (737 KB) | HTML Full-text | XML Full-text
Abstract
Marine sponges are an extremely rich and important source of natural products. Mariculture is one solution to the so-called “supply problem” that often hampers further studies and development of novel compounds from sponges. We report the extended culture (767 days) at sea in
[...] Read more.
Marine sponges are an extremely rich and important source of natural products. Mariculture is one solution to the so-called “supply problem” that often hampers further studies and development of novel compounds from sponges. We report the extended culture (767 days) at sea in depths of 10 and 20 m of three sponge species: Negombata magnifica, Amphimedon chloros and Theonella swinhoei that produce latrunculin-B, halitoxin and swinholide-A, respectively. Since sponge-associated microorganisms may be the true producers of many of the natural products found in sponges and also be linked to the health of the sponges, we examined the stability of the bacterial communities in cultured versus wild sponges. Growth rate of the sponges (ranging from 308 to 61 and −19 (%)(year−1) in N. magnifica, A. chloros and T. swinhoei, respectively) differed significantly between species but not between the two depths at which the species were cultivated. Survivorship varied from 96% to 57%. During culture all species maintained the content of the desired natural product. Denaturing gradient gel electrophoresis analysis of the sponge-associated bacterial consortia revealed that differences existed between cultured and wild sponges in T. swinhoei and A. chloros but the communities remained quite stable in N. magnifica. The cultivation technique for production of natural products was found to be most appropriate for N. magnifica, while for T. swinhoei and A. chloros it was less successful, because of poorer growth and survival rates and shifts in their bacterial consortia. Full article
(This article belongs to the Special Issue Bioactive Compounds from Marine Sponges)
Open AccessArticle New Polyether Triterpenoids from Laurencia viridis and Their Biological Evaluation
Mar. Drugs 2011, 9(11), 2220-2235; doi:10.3390/md9112220
Received: 22 August 2011 / Revised: 24 October 2011 / Accepted: 27 October 2011 / Published: 7 November 2011
Cited by 18 | PDF Full-text (3136 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The red seaweed Laurencia viridis is a rich source of secondary metabolites derived from squalene. New polyethers, such as iubol (2), 22-hydroxy-15(28)-dehydrovenustatriol (3), 1,2-dehydropseudodehydrothyrsiferol (4), and secodehydrothyrsiferol (5) have been isolated and characterized from this alga. The structures were determined through the interpretation
[...] Read more.
The red seaweed Laurencia viridis is a rich source of secondary metabolites derived from squalene. New polyethers, such as iubol (2), 22-hydroxy-15(28)-dehydrovenustatriol (3), 1,2-dehydropseudodehydrothyrsiferol (4), and secodehydrothyrsiferol (5) have been isolated and characterized from this alga. The structures were determined through the interpretation of NMR spectroscopic data and the relative configuration was proposed on the basis of NOESY spectrum and biogenetic considerations. All new compounds exhibited significant cytotoxic activity against a panel of cancer cell lines. Full article
Open AccessArticle Bacteriophages with Potential for Inactivation of Fish Pathogenic Bacteria: Survival, Host Specificity and Effect on Bacterial Community Structure
Mar. Drugs 2011, 9(11), 2236-2255; doi:10.3390/md9112236
Received: 22 September 2011 / Revised: 21 October 2011 / Accepted: 28 October 2011 / Published: 7 November 2011
Cited by 18 | PDF Full-text (1227 KB) | HTML Full-text | XML Full-text
Abstract
Phage therapy may represent a viable alternative to antibiotics to inactivate fish pathogenic bacteria. Its use, however, requires the awareness of novel kinetics phenomena not applied to conventional drug treatments. The main objective of this work was to isolate bacteriophages with potential to
[...] Read more.
Phage therapy may represent a viable alternative to antibiotics to inactivate fish pathogenic bacteria. Its use, however, requires the awareness of novel kinetics phenomena not applied to conventional drug treatments. The main objective of this work was to isolate bacteriophages with potential to inactivate fish pathogenic bacteria, without major effects on the structure of natural bacterial communities of aquaculture waters. The survival was determined in marine water, through quantification by the soft agar overlay technique. The host specificity was evaluated by cross infection. The ecological impact of phage addition on the structure of the bacterial community was evaluated by DGGE of PCR amplified 16S rRNA gene fragments. The survival period varied between 12 and 91 days, with a higher viability for Aeromonas salmonicida phages. The phages of Vibrio parahaemolyticus and of A. salmonicida infected bacteria of different families with a high efficacy of plating. The specific phages of pathogenic bacteria had no detectable impact on the structure of the bacterial community. In conclusion, V. parahaemolyticus and A. salmonicida phages show good survival time in marine water, have only a moderated impact on the overall bacterial community structure and the desired specificity for host pathogenic bacteria, being potential candidates for therapy of fish infectious diseases in marine aquaculture systems. Full article
(This article belongs to the Special Issue Marine Anti-infective Agents)
Figures

Open AccessArticle Tasco®, a Product of Ascophyllum nodosum, Imparts Thermal Stress Tolerance in Caenorhabditis elegans
Mar. Drugs 2011, 9(11), 2256-2282; doi:10.3390/md9112256
Received: 30 August 2011 / Revised: 9 October 2011 / Accepted: 24 October 2011 / Published: 8 November 2011
Cited by 8 | PDF Full-text (931 KB) | HTML Full-text | XML Full-text
Abstract
Tasco®, a commercial product manufactured from the brown alga Ascophyllum nodosum, has been shown to impart thermal stress tolerance in animals. We investigated the physiological, biochemical and molecular bases of this induced thermal stress tolerance using the invertebrate animal model,
[...] Read more.
Tasco®, a commercial product manufactured from the brown alga Ascophyllum nodosum, has been shown to impart thermal stress tolerance in animals. We investigated the physiological, biochemical and molecular bases of this induced thermal stress tolerance using the invertebrate animal model, Caenorhabiditis elegans. Tasco® water extract (TWE) at 300 µg/mL significantly enhanced thermal stress tolerance as well as extended the life span of C. elegans. The mean survival rate of the model animals under thermal stress (35 °C) treated with 300 µg/mL and 600 µg/mL TWE, respectively, was 68% and 71% higher than the control animals. However, the TWE treatments did not affect the nematode body length, fertility or the cellular localization of daf-16. On the contrary, TWE under thermal stress significantly increased the pharyngeal pumping rate in treated animals compared to the control. Treatment with TWE also showed differential protein expression profiles over control following 2D gel-electrophoresis analysis. Furthermore, TWE significantly altered the expression of at least 40 proteins under thermal stress; among these proteins 34 were up-regulated while six were down-regulated. Mass spectroscopy analysis of the proteins altered by TWE treatment revealed that these proteins were related to heat stress tolerance, energy metabolism and a muscle structure related protein. Among them heat shock proteins, superoxide dismutase, glutathione peroxidase, aldehyde dehydrogenase, saposin-like proteins 20, myosin regulatory light chain 1, cytochrome c oxidase RAS-like, GTP-binding protein RHO A, OS were significantly up-regulated, while eukaryotic translation initiation factor 5A-1 OS, 60S ribosomal protein L18 OS, peroxiredoxin protein 2 were down regulated by TWE treatment. These results were further validated by gene expression and reporter gene expression analyses. Overall results indicate that the water soluble components of Tasco® imparted thermal stress tolerance in the C. elegans by altering stress related biochemical pathways. Full article
Open AccessArticle Antioxidant Effect of a Marine Oligopeptide Preparation from Chum Salmon (Oncorhynchus keta) by Enzymatic Hydrolysis in Radiation Injured Mice
Mar. Drugs 2011, 9(11), 2304-2315; doi:10.3390/md9112304
Received: 27 September 2011 / Revised: 2 November 2011 / Accepted: 3 November 2011 / Published: 10 November 2011
Cited by 8 | PDF Full-text (717 KB) | HTML Full-text | XML Full-text
Abstract
Marine oligopeptide preparation (MOP) obtained from Chum Salmon (Oncorhynchus keta) by the method of enzymatic hydrolysis, has been found to possess a radioprotective property through stimulation of the radiation-induced immunosuppression. The current study aimed to further investigate the free radicals scavenging
[...] Read more.
Marine oligopeptide preparation (MOP) obtained from Chum Salmon (Oncorhynchus keta) by the method of enzymatic hydrolysis, has been found to possess a radioprotective property through stimulation of the radiation-induced immunosuppression. The current study aimed to further investigate the free radicals scavenging and antioxidant effects of MOP in radiation injured mice. Female ICR mice (6–8 weeks old) were randomly divided into 5 groups, i.e., blank control, irradiation control and MOP (0.225, 0.450 and 1.350 g/kg body weight) plus an irradiation-treated group. The result revealed that MOP significantly increased the white blood cell counts after irradiation, and lessened the radiation-induced oxidative damage. These effects may be caused by augmentation of the activities of antioxidant enzymes, such as SOD and GSH-Px, reduction of the lipid peroxidation (MDA level) in liver, and protection against radiation-induced apoptosis. Therefore, we propose that MOP be used as an ideal antioxidant to alleviate radiation-induced oxidation damage in cancer patients. Full article
(This article belongs to the Special Issue Marine Functional Food)
Open AccessArticle 4-Acetoxydolastane Diterpene from the Brazilian Brown Alga Canistrocarpus cervicornis as Antileishmanial Agent
Mar. Drugs 2011, 9(11), 2369-2383; doi:10.3390/md9112369
Received: 14 September 2011 / Revised: 1 October 2011 / Accepted: 18 October 2011 / Published: 11 November 2011
Cited by 18 | PDF Full-text (2495 KB) | HTML Full-text | XML Full-text
Abstract
Natural marine products have shown an interesting array of diverse and novel chemical structures with potent biological activities. Our study reports the antiproliferative assays of crude extracts, fraction and pure compound (4R,9S,14S)-4α-acetoxy-9β,14α-dihydroxydolast-1(15),7-diene (1) obtained from
[...] Read more.
Natural marine products have shown an interesting array of diverse and novel chemical structures with potent biological activities. Our study reports the antiproliferative assays of crude extracts, fraction and pure compound (4R,9S,14S)-4α-acetoxy-9β,14α-dihydroxydolast-1(15),7-diene (1) obtained from brown alga Canistrocarpus cervicornis showing the antileishmanial activity. We showed that 1 had a dose-dependent activity during 72 h of treatment, exhibiting IC50 of 2.0 µg/mL, 12.0 µg/mL, and 4.0 µg/mL for promastigote, axenic amastigote and intracellular amastigote forms of Leishmania amazonensis, respectively. A cytotoxicity assay showed that the action of the isolated compound 1 was 93.0 times less toxic to the macrophage than to the protozoan. Additionally, compound 1 induced ultrastructural changes, including extensive mitochondrial damage; decrease in Rh123 fluorescence, suggesting interference with the mitochondrial membrane potential; and lipid peroxidation in parasite cells. The use of 1 from C. cervicornis against L. amazonensis parasites might be of great interest as a future alternative to the development of new antileishmanial drugs. Full article
Open AccessArticle Isolation and Identification of a New Tetrodotoxin-Producing Bacterial Species, Raoultella terrigena, from Hong Kong Marine Puffer Fish Takifugu niphobles
Mar. Drugs 2011, 9(11), 2384-2396; doi:10.3390/md9112384
Received: 24 September 2011 / Revised: 3 November 2011 / Accepted: 4 November 2011 / Published: 14 November 2011
Cited by 14 | PDF Full-text (651 KB) | HTML Full-text | XML Full-text
Abstract
Puffer fish, Takifugu niphobles, collected from the Hong Kong coastal waters were screened for tetrodotoxin-producing bacteria. A Gram-negative, non-acid-fast, non-sporing and rod shaped bacterial strain (designated as gutB01) was isolated from the intestine of the puffer fish and was shown to produce
[...] Read more.
Puffer fish, Takifugu niphobles, collected from the Hong Kong coastal waters were screened for tetrodotoxin-producing bacteria. A Gram-negative, non-acid-fast, non-sporing and rod shaped bacterial strain (designated as gutB01) was isolated from the intestine of the puffer fish and was shown to produce tetrodotoxin (TTX). Based on the Microbial Identification (MIDI) and 16S-23S rDNA internal transcribed spacer (ITS) phylogenetic analysis, the strain was identified as Raoultella terrigena. The TTX production ability of the strain was confirmed by mouse bioassay, ELISA and mass spectrometry (MALDI-TOF). Our results reiterate that the TTX found in puffer fish was likely produced by the associated bacteria and TTX are widely produced amongst a diversity of bacterial species. Full article
(This article belongs to the Special Issue Tetrodotoxin)
Open AccessArticle Neoamphimedine Circumvents Metnase-Enhanced DNA Topoisomerase IIα Activity Through ATP-Competitive Inhibition
Mar. Drugs 2011, 9(11), 2397-2408; doi:10.3390/md9112397
Received: 6 September 2011 / Revised: 8 November 2011 / Accepted: 9 November 2011 / Published: 18 November 2011
Cited by 10 | PDF Full-text (904 KB) | HTML Full-text | XML Full-text
Abstract
Type IIα DNA topoisomerase (TopoIIα) is among the most important clinical drug targets for the treatment of cancer. Recently, the DNA repair protein Metnase was shown to enhance TopoIIα activity and increase resistance to TopoIIα poisons. Using in vitro DNA decatenation assays we
[...] Read more.
Type IIα DNA topoisomerase (TopoIIα) is among the most important clinical drug targets for the treatment of cancer. Recently, the DNA repair protein Metnase was shown to enhance TopoIIα activity and increase resistance to TopoIIα poisons. Using in vitro DNA decatenation assays we show that neoamphimedine potently inhibits TopoIIα-dependent DNA decatenation in the presence of Metnase. Cell proliferation assays demonstrate that neoamphimedine can inhibit Metnase-enhanced cell growth with an IC50 of 0.5 µM. Additionally, we find that the apparent Km of TopoIIα for ATP increases linearly with higher concentrations of neoamphimedine, indicating ATP-competitive inhibition, which is substantiated by molecular modeling. These findings support the continued development of neoamphimedine as an anticancer agent, particularly in solid tumors that over-express Metnase. Full article
(This article belongs to the Special Issue Bioactive Compounds from Marine Sponges)
Figures

Open AccessArticle Tetrodotoxin Sensitivity of the Vertebrate Cardiac Na+ Current
Mar. Drugs 2011, 9(11), 2409-2422; doi:10.3390/md9112409
Received: 20 September 2011 / Revised: 2 November 2011 / Accepted: 10 November 2011 / Published: 21 November 2011
Cited by 12 | PDF Full-text (833 KB) | HTML Full-text | XML Full-text
Abstract
Evolutionary origin and physiological significance of the tetrodotoxin (TTX) resistance of the vertebrate cardiac Na+ current (INa) is still unresolved. To this end, TTX sensitivity of the cardiac INa was examined in cardiac myocytes of a cyclostome (lamprey), three
[...] Read more.
Evolutionary origin and physiological significance of the tetrodotoxin (TTX) resistance of the vertebrate cardiac Na+ current (INa) is still unresolved. To this end, TTX sensitivity of the cardiac INa was examined in cardiac myocytes of a cyclostome (lamprey), three teleost fishes (crucian carp, burbot and rainbow trout), a clawed frog, a snake (viper) and a bird (quail). In lamprey, teleost fishes, frog and bird the cardiac INa was highly TTX-sensitive with EC50-values between 1.4 and 6.6 nmol·L−1. In the snake heart, about 80% of the INa was TTX-resistant with EC50 value of 0.65 μmol·L−1, the rest being TTX-sensitive (EC50 = 0.5 nmol·L−1). Although TTX-resistance of the cardiac INa appears to be limited to mammals and reptiles, the presence of TTX-resistant isoform of Na+ channel in the lamprey heart suggest an early evolutionary origin of the TTX-resistance, perhaps in the common ancestor of all vertebrates. Full article
(This article belongs to the Special Issue Tetrodotoxin)
Figures

Open AccessArticle Variability of Non-Polar Secondary Metabolites in the Red Alga Portieria
Mar. Drugs 2011, 9(11), 2438-2468; doi:10.3390/md9112438
Received: 17 August 2011 / Revised: 1 November 2011 / Accepted: 8 November 2011 / Published: 21 November 2011
Cited by 8 | PDF Full-text (1181 KB) | HTML Full-text | XML Full-text
Abstract
Possible sources of variation in non-polar secondary metabolites of Portieria hornemannii, sampled from two distinct regions in the Philippines (Batanes and Visayas), resulting from different life-history stages, presence of cryptic species, and/or spatiotemporal factors, were investigated. PCA analyses demonstrated secondary metabolite variation
[...] Read more.
Possible sources of variation in non-polar secondary metabolites of Portieria hornemannii, sampled from two distinct regions in the Philippines (Batanes and Visayas), resulting from different life-history stages, presence of cryptic species, and/or spatiotemporal factors, were investigated. PCA analyses demonstrated secondary metabolite variation between, as well as within, five cryptic Batanes species. Intraspecific variation was even more pronounced in the three cryptic Visayas species, which included samples from six sites. Neither species groupings, nor spatial or temporal based patterns, were observed in the PCA analysis, however, intraspecific variation in secondary metabolites was detected between life-history stages. Male gametophytes (102 metabolites detected) were strongly discriminated from the two other stages, whilst female gametophyte (202 metabolites detected) and tetrasporophyte (106 metabolites detected) samples were partially discriminated. These results suggest that life-history driven variations, and possibly other microscale factors, may influence the variation within Portieria species. Full article
(This article belongs to the Special Issue Metabolomic Approaches to Marine Organisms)
Open AccessArticle Alkaloids and Sesquiterpenes from the South China Sea Gorgonian Echinogorgia pseudossapo
Mar. Drugs 2011, 9(11), 2479-2487; doi:10.3390/md9112479
Received: 13 October 2011 / Revised: 14 November 2011 / Accepted: 15 November 2011 / Published: 24 November 2011
Cited by 8 | PDF Full-text (307 KB) | HTML Full-text | XML Full-text
Abstract
Five zoanthoxanthin alkaloids (15) and four sesquiterpenes (69) were isolated from the South China Sea gorgonian Echinogorgia pseudossapo. Their structures were determined on the bases of extensive spectroscopic analyses, including 1D and 2D NMR
[...] Read more.
Five zoanthoxanthin alkaloids (15) and four sesquiterpenes (69) were isolated from the South China Sea gorgonian Echinogorgia pseudossapo. Their structures were determined on the bases of extensive spectroscopic analyses, including 1D and 2D NMR data. Among them, pseudozoanthoxanthins III and IV (12), 8-hydroxy-6β-methoxy-14-oxooplop-6,12-olide (6) and 3β-methoxyguaian-10(14)-en-2β-ol (7) were new, 1 and 3 showed mild anti-HSV-1 activity, and 7 showed significant antilarval activity towards Balanus amphitrite larvae. Full article

Review

Jump to: Research, Other

Open AccessReview Pectenotoxin-2 from Marine Sponges: A Potential Anti-Cancer Agent—A Review
Mar. Drugs 2011, 9(11), 2176-2187; doi:10.3390/md9112176
Received: 2 September 2011 / Revised: 9 October 2011 / Accepted: 19 October 2011 / Published: 2 November 2011
Cited by 14 | PDF Full-text (312 KB) | HTML Full-text | XML Full-text | Correction | Supplementary Files
Abstract
Pectenotoxin-2 (PTX-2), which was first identified as a cytotoxic entity in marine sponges, has been reported to display significant cytotoxicity to human cancer cells where it inhibits mitotic separation and cytokinesis through the depolymerization of actin filaments. In the late stage of endoreduplication,
[...] Read more.
Pectenotoxin-2 (PTX-2), which was first identified as a cytotoxic entity in marine sponges, has been reported to display significant cytotoxicity to human cancer cells where it inhibits mitotic separation and cytokinesis through the depolymerization of actin filaments. In the late stage of endoreduplication, the effects of PTX-2 on different cancer cells involves: (i) down-regulation of anti-apoptotic Bcl-2 members and IAP family proteins; (ii) up-regulation of pro-apoptotic Bax protein and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-receptor 1/receptor 2 (DR4/DR5); and (iii) mitochondrial dysfunction. In addition, PTX-2 induces apoptotic effects through suppression of the nuclear factor κB (NF-κB) signaling pathway in several cancer cells. Analysis of cell cycle regulatory proteins showed that PTX-2 increases phosphorylation of Cdc25c and decreases protein levels of Cdc2 and cyclin B1. Cyclin-dependent kinase (Cdk) inhibitor p21 and Cdk2, which are associated with the induction of endoreduplication, were upregulated. Furthermore, it was found that PTX-2 suppressed telomerase activity through the transcriptional and post-translational suppression of hTERT. The purpose of this review was to provide an update regarding the anti-cancer mechanism of PTX-2, with a special focus on its effects on different cellular signaling cascades. Full article
(This article belongs to the Special Issue Bioactive Compounds from Marine Sponges)
Open AccessReview Gustatory Detection of Tetrodotoxin and Saxitoxin, and Its Competitive Inhibition by Quinine and Strychnine in Freshwater Fishes
Mar. Drugs 2011, 9(11), 2283-2290; doi:10.3390/md9112283
Received: 19 September 2011 / Revised: 31 October 2011 / Accepted: 1 November 2011 / Published: 8 November 2011
Cited by 3 | PDF Full-text (563 KB) | HTML Full-text | XML Full-text
Abstract
Fish detect extremely low levels of marine toxins tetrodotoxin (TTX) and saxitoxin (STX) via the specialized gustatory receptor(s). Physiological and pharmacological studies show that receptor(s) for TTX and STX are distinct from those which detect feeding stimulant amino acids and bile acids, and
[...] Read more.
Fish detect extremely low levels of marine toxins tetrodotoxin (TTX) and saxitoxin (STX) via the specialized gustatory receptor(s). Physiological and pharmacological studies show that receptor(s) for TTX and STX are distinct from those which detect feeding stimulant amino acids and bile acids, and that TTX and STX do not share the same receptor populations, while interacting with quinine and strychnine in a competitive fashion suggestive of an antidotal relationship. Full article
(This article belongs to the Special Issue Tetrodotoxin)
Open AccessReview Analytical Challenges: Determination of Tetrodotoxin in Human Urine and Plasma by LC-MS/MS
Mar. Drugs 2011, 9(11), 2291-2303; doi:10.3390/md9112291
Received: 20 September 2011 / Revised: 27 October 2011 / Accepted: 28 October 2011 / Published: 8 November 2011
Cited by 15 | PDF Full-text (272 KB) | HTML Full-text | XML Full-text
Abstract
Tetrodotoxin (TTX) is a powerful sodium channel blocker found in puffer fish and some marine animals. Cases of TTX poisoning most often result from puffer fish ingestion. Diagnosis is mainly from patient’s signs and symptoms or the detection of TTX in the leftover
[...] Read more.
Tetrodotoxin (TTX) is a powerful sodium channel blocker found in puffer fish and some marine animals. Cases of TTX poisoning most often result from puffer fish ingestion. Diagnosis is mainly from patient’s signs and symptoms or the detection of TTX in the leftover food. If leftover food is unavailable, the determination of TTX in the patient’s urine and/or plasma is essential to confirm the diagnosis. Although various methods for the determination of TTX have been published, most of them are for food tissue samples. Dealing with human urine and blood samples is much more challenging. Unlike in food, the amount of toxin in the urine and blood of a patient is generally extremely low; therefore a very sensitive method is required to detect it. In this regard, mass spectrometry (MS) methods are the best choice. Since TTX is a very polar compound, there will be lack of retention on conventional reverse-phase columns; use of ion pair reagent or hydrophilic interaction liquid chromatography (HILIC) can help solve this problem. The problem of ion suppression is another challenge in analyzing polar compound in biological samples. This review will discuss different MS methods and their pros and cons. Full article
(This article belongs to the Special Issue Tetrodotoxin)
Open AccessReview Brominated Compounds from Marine Sponges of the Genus Aplysina and a Compilation of Their 13C NMR Spectral Data
Mar. Drugs 2011, 9(11), 2316-2368; doi:10.3390/md9112316
Received: 18 August 2011 / Revised: 24 October 2011 / Accepted: 31 October 2011 / Published: 10 November 2011
Cited by 22 | PDF Full-text (729 KB) | HTML Full-text | XML Full-text
Abstract
Aplysina is the best representative genus of the family Aplysinidae. Halogenated substances are its main class of metabolites. These substances contribute greatly to the chemotaxonomy and characterization of the sponges belonging to this genus. Due to their pharmacological activities, these alkaloids are of
[...] Read more.
Aplysina is the best representative genus of the family Aplysinidae. Halogenated substances are its main class of metabolites. These substances contribute greatly to the chemotaxonomy and characterization of the sponges belonging to this genus. Due to their pharmacological activities, these alkaloids are of special interest. The chemistry of halogenated substances and of the alkaloids has long been extensively studied in terrestrial organisms, while the number of marine organisms studied has just started to increase in the last decades. This review describes 101 halogenated substances from 14 species of Aplysina from different parts of the world. These substances can be divided into the following classes: bromotyramines (A), cavernicolins (B), hydroverongiaquinols (C), bromotyrosineketals (D), bromotyrosine lactone derivatives (E), oxazolidones (F), spiroisoxazolines (G), verongiabenzenoids (H), verongiaquinols (I), and dibromocyclohexadienes (J). A compilation of their 13C NMR data is also part of the review. For this purpose 138 references were consulted. Full article
Open AccessReview Advancement into the Arctic Region for Bioactive Sponge Secondary Metabolites
Mar. Drugs 2011, 9(11), 2423-2437; doi:10.3390/md9112423
Received: 22 September 2011 / Revised: 9 November 2011 / Accepted: 11 November 2011 / Published: 21 November 2011
Cited by 18 | PDF Full-text (511 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Porifera have long been a reservoir for the discovery of bioactive compounds and drug discovery. Most research in the area has focused on sponges from tropical and temperate waters, but more recently the focus has shifted to the less accessible colder waters of
[...] Read more.
Porifera have long been a reservoir for the discovery of bioactive compounds and drug discovery. Most research in the area has focused on sponges from tropical and temperate waters, but more recently the focus has shifted to the less accessible colder waters of the Antarctic and, to a lesser extent, the Arctic. The Antarctic region in particular has been a more popular location for natural products discovery and has provided promising candidates for drug development. This article reviews groups of bioactive compounds that have been isolated and reported from the southern reaches of the Arctic Circle, surveys the known sponge diversity present in the Arctic waters, and details a recent sponge collection by our group in the Aleutian Islands, Alaska. The collection has yielded previously undescribed sponge species along with primary activity against opportunistic infectious diseases, malaria, and HCV. The discovery of new sponge species and bioactive crude extracts gives optimism for the isolation of new bioactive compounds from a relatively unexplored source. Full article
(This article belongs to the Special Issue Bioactive Compounds from Marine Sponges)

Other

Jump to: Research, Review

Open AccessCase Report An Acute Case of Intoxication with Cyanobacteria and Cyanotoxins in Recreational Water in Salto Grande Dam, Argentina
Mar. Drugs 2011, 9(11), 2164-2175; doi:10.3390/md9112164
Received: 7 September 2011 / Revised: 19 October 2011 / Accepted: 20 October 2011 / Published: 31 October 2011
Cited by 33 | PDF Full-text (261 KB) | HTML Full-text | XML Full-text
Abstract
Cyanobacterial blooms and hepatotoxic microcystins (MCs) usually occur in summer, constituting a sanitary and environmental problem in Salto Grande Dam, Argentina. Water sports and recreational activities take place in summer in this lake. We reported an acute case of cyanobacterial poisoning in Salto
[...] Read more.
Cyanobacterial blooms and hepatotoxic microcystins (MCs) usually occur in summer, constituting a sanitary and environmental problem in Salto Grande Dam, Argentina. Water sports and recreational activities take place in summer in this lake. We reported an acute case of cyanobacterial poisoning in Salto Grande dam, Argentina, which occurred in January 2007. Accidentally, a young man was immersed in an intense bloom of Microcystis spp. A level of 48.6 µg·L−1 of microcystin-LR was detected in water samples. Four hours after exposure, the patient showed nausea, abdominal pain and fever. Three days later, dyspnea and respiratory distress were reported. The patient was hospitalized in intensive care and diagnosed with an atypical pneumonia. Finally, a week after the exposure, the patient developed a hepatotoxicosis with a significant increase of hepatic damage biomarkers (ALT, AST and γGT). Complete recovery took place within 20 days. This is the first study to show an acute intoxication with microcystin-producing cyanobacteria blooms in recreational water. Full article
(This article belongs to the Special Issue Algal Toxins)
Open AccessShort Note A New Diketopiperazine, Cyclo-(4-S-hydroxy-R-proline-R-isoleucine), from an Australian Specimen of the Sponge Stelletta sp.
Mar. Drugs 2011, 9(11), 2469-2478; doi:10.3390/md9112469
Received: 29 August 2011 / Revised: 11 November 2011 / Accepted: 16 November 2011 / Published: 22 November 2011
Cited by 4 | PDF Full-text (315 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
While investigating the cytotoxic activity of the methanol extract of an Australian marine sponge Stelletta sp. (Demospongiae), a new diketopiperazine, cyclo-(4-S-hydroxy-R-proline-R-isoleucine) (1), was isolated together with the known bengamides; A (2), F (
[...] Read more.
While investigating the cytotoxic activity of the methanol extract of an Australian marine sponge Stelletta sp. (Demospongiae), a new diketopiperazine, cyclo-(4-S-hydroxy-R-proline-R-isoleucine) (1), was isolated together with the known bengamides; A (2), F (3), N (4), Y (5), and bengazoles; Z (6), C4 (7) and C6 (8). The isolation and structure elucidation of the diketopiperazine (1), together with the activity of 18 against a panel of human and mammalian cell lines are discussed. Full article
(This article belongs to the Special Issue Bioactive Compounds from Marine Sponges)

Journal Contact

MDPI AG
Marine Drugs Editorial Office
St. Alban-Anlage 66, 4052 Basel, Switzerland
marinedrugs@mdpi.com
Tel. +41 61 683 77 34
Fax: +41 61 302 89 18
Editorial Board
Contact Details Submit to Marine Drugs
Back to Top