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Mar. Drugs, Volume 10, Issue 8 (August 2012) – 15 articles , Pages 1619-1898

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Research

Jump to: Review

327 KiB  
Article
A Great Barrier Reef Sinularia sp. Yields Two New Cytotoxic Diterpenes
by Anthony D. Wright, Jonathan L. Nielson, Dianne M. Tapiolas, Catherine H. Liptrot and Cherie A. Motti
Mar. Drugs 2012, 10(8), 1619-1630; https://doi.org/10.3390/md10081619 - 31 Jul 2012
Cited by 21 | Viewed by 6603
Abstract
The methanol extract of a Sinularia sp., collected from Bowden Reef, Queensland, Australia, yielded ten natural products. These included the new nitrogenous diterpene (4R*,5R*,9S*,10R*,11Z)-4-methoxy-9-((dimethylamino)-methyl)-12,15-epoxy-11(13)-en-decahydronaphthalen-16-ol (1), and the new lobane, (1R* [...] Read more.
The methanol extract of a Sinularia sp., collected from Bowden Reef, Queensland, Australia, yielded ten natural products. These included the new nitrogenous diterpene (4R*,5R*,9S*,10R*,11Z)-4-methoxy-9-((dimethylamino)-methyl)-12,15-epoxy-11(13)-en-decahydronaphthalen-16-ol (1), and the new lobane, (1R*,2R*,4S*,15E)-loba-8,10,13(14),15(16)-tetraen-17,18-diol-17-acetate (2). Also isolated were two known cembranes, sarcophytol-B and (1E,3E,7E)-11,12-epoxycembratrien-15-ol, and six known lobanes, loba-8,10,13(15)-triene-16,17,18-triol, 14,18-epoxyloba-8,10,13(15)-trien-17-ol, lobatrientriol, lobatrienolide, 14,17-epoxyloba-8,10,13(15)-trien-18-ol-18-acetate and (17R)-loba-8,10,13(15)-trien-17,18-diol. Structures of the new compounds were elucidated through interpretation of spectra obtained after extensive NMR and MS investigations and comparison with literature values. The tumour cell growth inhibition potential of 1 and 2 along with loba-8,10,13(15)-triene-16,17,18-triol, 14,17-epoxyloba-8,10,13(15)-trien-18-ol-18-acetate, lobatrienolide, (1E,3E,7E)-11,12-epoxycembratrien-15-ol and sarcophytol-B were assessed against three human tumour cell lines (SF-268, MCF-7 and H460). The lobanes and cembranes tested demonstrated 50% growth inhibition in the range 6.8–18.5 µM, with no selectivity, whilst 1 was less active (GI50 70–175 µM). Full article
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10059 KiB  
Article
Trypanocidal Action of (−)-Elatol Involves an Oxidative Stress Triggered by Mitochondria Dysfunction
by Vânia Cristina Desoti, Danielle Lazarin-Bidóia, Daniela Bueno Sudatti, Renato Crespo Pereira, Antonio Alonso, Tania Ueda-Nakamura, Benedito Prado Dias Filho, Celso Vataru Nakamura and Sueli De Oliveira Silva
Mar. Drugs 2012, 10(8), 1631-1646; https://doi.org/10.3390/md10081631 - 03 Aug 2012
Cited by 50 | Viewed by 8388
Abstract
Natural compounds have shown good potential for the discovery of new chemotherapeutics for the treatment of Chagas’ disease. Recently, our group reported the effective trypanocidal activity of (−)-elatol, extracted from the red macroalgae Laurencia dendroidea present in the Brazilian coast against Trypanosoma cruzi [...] Read more.
Natural compounds have shown good potential for the discovery of new chemotherapeutics for the treatment of Chagas’ disease. Recently, our group reported the effective trypanocidal activity of (−)-elatol, extracted from the red macroalgae Laurencia dendroidea present in the Brazilian coast against Trypanosoma cruzi. However, the mechanism of action of this compound has remained unclear. There are only hypotheses concerning its action on mitochondrial function. Here, we further investigated the mechanisms of action of (−)-elatol on trypomastigotes of T. cruzi. For this, we evaluated some biochemical alterations in trypomastigotes treated with (−)-elatol. Our results show that (−)-elatol induced depolarization of the mitochondrial membrane, an increase in the formation of mitochondrial superoxide anion and loss of cell membrane and DNA integrity. Additionally, (−)-elatol induced formation of autophagic vacuoles and a decrease in cell volume. All together, these results suggest that the trypanocidal action of (−)-elatol involves multiple events and mitochondria might be the initial target organelle. Our hypothesis is that the mitochondrial dysfunction leads to an increase of ROS production through the electron transport chain, which affects cell membrane and DNA integrity leading to different types of parasite death. Full article
(This article belongs to the Special Issue Marine Algae)
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1048 KiB  
Article
Preparation and Characterization of O-Acylated Fucosylated Chondroitin Sulfate from Sea Cucumber
by Na Gao, Mingyi Wu, Shao Liu, Wu Lian, Zi Li and Jinhua Zhao
Mar. Drugs 2012, 10(8), 1647-1661; https://doi.org/10.3390/md10081647 - 10 Aug 2012
Cited by 31 | Viewed by 11532
Abstract
Fucosylated chondroitin sulfate (FuCS), a kind of complex glycosaminoglycan from sea cucumber, has potent anticoagulant activity. In order to understand the relationship between structures and activity, the depolymerized FuCS (dFuCS) was chosen to prepare its derivates by selective substitution at OH groups. Its [...] Read more.
Fucosylated chondroitin sulfate (FuCS), a kind of complex glycosaminoglycan from sea cucumber, has potent anticoagulant activity. In order to understand the relationship between structures and activity, the depolymerized FuCS (dFuCS) was chosen to prepare its derivates by selective substitution at OH groups. Its O-acylation was carried out in a homogeneous way using carboxylic acid anhydrides. The structures of O-acylated derivatives were characterized by NMR. The results indicated that the 4-O-sulfated fucose residues may be easier to be acylated than the other ones in the sulfated fucose branches. But the O-acylation was always accompanied by the β-elimination, and the degree of elimination was higher as that of acylation was higher. The results of clotting assay indicated that the effect of partial O-acylation of the dFuCS on their anticoagulant potency was not significant and the O-acylation of 2-OH groups of 4-O-sulfated fucose units did not affect the anticoagulant activity. Full article
(This article belongs to the Special Issue Marine Glycoconjugates)
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1385 KiB  
Article
Briareolate Esters from the Gorgonian Briareum asbestinum
by Rian J. Meginley, Prasoon Gupta, Thomas C. Schulz, Amanda B. McLean, Allan J. Robins and Lyndon M. West
Mar. Drugs 2012, 10(8), 1662-1670; https://doi.org/10.3390/md10081662 - 10 Aug 2012
Cited by 7 | Viewed by 6659
Abstract
Two new briarane diterpenoids briareolate esters J (1) and K (2) were isolated from the methanolic extract of the octocoral Briareum asbestinum collected off the coast of Boca Raton, Florida. The structures of briaranes 1 and 2 were elucidated [...] Read more.
Two new briarane diterpenoids briareolate esters J (1) and K (2) were isolated from the methanolic extract of the octocoral Briareum asbestinum collected off the coast of Boca Raton, Florida. The structures of briaranes 1 and 2 were elucidated by interpretation of spectroscopic data. Briareolate ester K (2) showed weak growth inhibition activity against human embryonic stem cells (BG02). Full article
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327 KiB  
Article
Evaluation of Pseudopteroxazole and Pseudopterosin Derivatives against Mycobacterium tuberculosis and Other Pathogens
by Malcolm W. B. McCulloch, Brad Haltli, Douglas H. Marchbank and Russell G. Kerr
Mar. Drugs 2012, 10(8), 1711-1728; https://doi.org/10.3390/md10081711 - 15 Aug 2012
Cited by 25 | Viewed by 11011
Abstract
Pseudopterosins and pseudopteroxazole are intriguing marine natural products that possess notable antimicrobial activity with a commensurate lack of cytotoxicity. New semi-synthetic pseudopteroxazoles, pseudopteroquinoxalines and pseudopterosin congeners along with simple synthetic mimics of the terpene skeleton were synthesized. In order to build structure-activity relationships, [...] Read more.
Pseudopterosins and pseudopteroxazole are intriguing marine natural products that possess notable antimicrobial activity with a commensurate lack of cytotoxicity. New semi-synthetic pseudopteroxazoles, pseudopteroquinoxalines and pseudopterosin congeners along with simple synthetic mimics of the terpene skeleton were synthesized. In order to build structure-activity relationships, a set of 29 new and previously reported compounds was assessed for in vitro antimicrobial and cytotoxic activities. A number of congeners exhibited antimicrobial activity against a range of Gram-positive bacteria including Mycobacterium tuberculosis H37Rv, with four displaying notable antitubercular activity against both replicating and non-replicating persistent forms of M. tuberculosis. One new semi-synthetic compound, 21-((1H-imidazol-5-yl)methyl)-pseudopteroxazole (7a), was more potent than the natural products pseudopterosin and pseudopteroxazole and exhibited equipotent activity against both replicating and non-replicating persistent forms of M. tuberculosis with a near absence of in vitro cytotoxicity. Pseudopteroxazole also exhibited activity against strains of M. tuberculosis H37Rv resistant to six clinically used antibiotics. Full article
(This article belongs to the Special Issue Marine Antibiotics)
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384 KiB  
Article
Gene Sequence Based Clustering Assists in Dereplication of Pseudoalteromonas luteoviolacea Strains with Identical Inhibitory Activity and Antibiotic Production
by Nikolaj G. Vynne, Maria Mansson and Lone Gram
Mar. Drugs 2012, 10(8), 1729-1740; https://doi.org/10.3390/md10081729 - 15 Aug 2012
Cited by 17 | Viewed by 7389
Abstract
Some microbial species are chemically homogenous, and the same secondary metabolites are found in all strains. In contrast, we previously found that five strains of P. luteoviolacea were closely related by 16S rRNA gene sequence but produced two different antibiotic profiles. The purpose [...] Read more.
Some microbial species are chemically homogenous, and the same secondary metabolites are found in all strains. In contrast, we previously found that five strains of P. luteoviolacea were closely related by 16S rRNA gene sequence but produced two different antibiotic profiles. The purpose of the present study was to determine whether such bioactivity differences could be linked to genotypes allowing methods from phylogenetic analysis to aid in selection of strains for biodiscovery. Thirteen P. luteoviolacea strains divided into three chemotypes based on production of known antibiotics and four antibacterial profiles based on inhibition assays against Vibrio anguillarum and Staphylococcus aureus. To determine whether chemotype and inhibition profile are reflected by phylogenetic clustering we sequenced 16S rRNA, gyrB and recA genes. Clustering based on 16S rRNA gene sequences alone showed little correlation to chemotypes and inhibition profiles, while clustering based on concatenated 16S rRNA, gyrB, and recA gene sequences resulted in three clusters, two of which uniformly consisted of strains of identical chemotype and inhibition profile. A major time sink in natural products discovery is the effort spent rediscovering known compounds, and this study indicates that phylogeny clustering of bioactive species has the potential to be a useful dereplication tool in biodiscovery efforts. Full article
(This article belongs to the Special Issue Marine Antibiotics)
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997 KiB  
Article
Natural Products from Antarctic Colonial Ascidians of the Genera Aplidium and Synoicum: Variability and Defensive Role
by Laura Núñez-Pons, Marianna Carbone, Jennifer Vázquez, Jaime Rodríguez, Rosa María Nieto, María Mercedes Varela, Margherita Gavagnin and Conxita Avila
Mar. Drugs 2012, 10(8), 1741-1764; https://doi.org/10.3390/md10081741 - 20 Aug 2012
Cited by 44 | Viewed by 9055
Abstract
Ascidians have developed multiple defensive strategies mostly related to physical, nutritional or chemical properties of the tunic. One of such is chemical defense based on secondary metabolites. We analyzed a series of colonial Antarctic ascidians from deep-water collections belonging to the genera Aplidium [...] Read more.
Ascidians have developed multiple defensive strategies mostly related to physical, nutritional or chemical properties of the tunic. One of such is chemical defense based on secondary metabolites. We analyzed a series of colonial Antarctic ascidians from deep-water collections belonging to the genera Aplidium and Synoicum to evaluate the incidence of organic deterrents and their variability. The ether fractions from 15 samples including specimens of the species A. falklandicum, A. fuegiense, A. meridianum, A. millari and S. adareanum were subjected to feeding assays towards two relevant sympatric predators: the starfish Odontaster validus, and the amphipod Cheirimedon femoratus. All samples revealed repellency. Nonetheless, some colonies concentrated defensive chemicals in internal body-regions rather than in the tunic. Four ascidian-derived meroterpenoids, rossinones B and the three derivatives 2,3-epoxy-rossinone B, 3-epi-rossinone B, 5,6-epoxy-rossinone B, and the indole alkaloids meridianins A–G, along with other minoritary meridianin compounds were isolated from several samples. Some purified metabolites were tested in feeding assays exhibiting potent unpalatabilities, thus revealing their role in predation avoidance. Ascidian extracts and purified compound-fractions were further assessed in antibacterial tests against a marine Antarctic bacterium. Only the meridianins showed inhibition activity, demonstrating a multifunctional defensive role. According to their occurrence in nature and within our colonial specimens, the possible origin of both types of metabolites is discussed. Full article
(This article belongs to the Special Issue Deep-Sea Natural Products)
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784 KiB  
Article
The Transcriptome of Bathymodiolus azoricus Gill Reveals Expression of Genes from Endosymbionts and Free-Living Deep-Sea Bacteria
by Conceição Egas, Miguel Pinheiro, Paula Gomes, Cristina Barroso and Raul Bettencourt
Mar. Drugs 2012, 10(8), 1765-1783; https://doi.org/10.3390/md10081765 - 20 Aug 2012
Cited by 19 | Viewed by 8335
Abstract
Deep-sea environments are largely unexplored habitats where a surprising number of species may be found in large communities, thriving regardless of the darkness, extreme cold, and high pressure. Their unique geochemical features result in reducing environments rich in methane and sulfides, sustaining complex [...] Read more.
Deep-sea environments are largely unexplored habitats where a surprising number of species may be found in large communities, thriving regardless of the darkness, extreme cold, and high pressure. Their unique geochemical features result in reducing environments rich in methane and sulfides, sustaining complex chemosynthetic ecosystems that represent one of the most surprising findings in oceans in the last 40 years. The deep-sea Lucky Strike hydrothermal vent field, located in the Mid Atlantic Ridge, is home to large vent mussel communities where Bathymodiolus azoricus represents the dominant faunal biomass, owing its survival to symbiotic associations with methylotrophic or methanotrophic and thiotrophic bacteria. The recent transcriptome sequencing and analysis of gill tissues from B. azoricus revealed a number of genes of bacterial origin, hereby analyzed to provide a functional insight into the gill microbial community. The transcripts supported a metabolically active microbiome and a variety of mechanisms and pathways, evidencing also the sulfur and methane metabolisms. Taxonomic affiliation of transcripts and 16S rRNA community profiling revealed a microbial community dominated by thiotrophic and methanotrophic endosymbionts of B. azoricus and the presence of a Sulfurovum-like epsilonbacterium. Full article
(This article belongs to the Special Issue Metagenomics in Biodiscovery from Oceans)
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445 KiB  
Article
Scavenging Capacity of Marine Carotenoids against Reactive Oxygen and Nitrogen Species in a Membrane-Mimicking System
by Eliseu Rodrigues, Lilian R. B. Mariutti and Adriana Z. Mercadante
Mar. Drugs 2012, 10(8), 1784-1798; https://doi.org/10.3390/md10081784 - 20 Aug 2012
Cited by 97 | Viewed by 9171
Abstract
Carotenoid intake has been associated with the decrease of the incidence of some chronic diseases by minimizing the in vivo oxidative damages induced by reactive oxygen (ROS) and nitrogen species (RNS). The carotenoids are well-known singlet oxygen quenchers; however, their capacity to scavenge [...] Read more.
Carotenoid intake has been associated with the decrease of the incidence of some chronic diseases by minimizing the in vivo oxidative damages induced by reactive oxygen (ROS) and nitrogen species (RNS). The carotenoids are well-known singlet oxygen quenchers; however, their capacity to scavenge other reactive species, such as peroxyl radical (ROO), hydroxyl radical (HO), hypochlorous acid (HOCl) and anion peroxynitrite (ONOO), still needs to be more extensively studied, especially using membrane-mimicking systems, such as liposomes. Moreover, the identification of carotenoids possessing high antioxidant capacity can lead to new alternatives of drugs or nutritional supplements for prophylaxis or therapy of pathological conditions related to oxidative damages, such as cardiovascular diseases. The capacity to scavenge ROO, HO, HOCl and ONOO of seven carotenoids found in marine organisms was determined in liposomes based on the fluorescence loss of a fluorescent lipid (C11-BODIPY581/591) due to its oxidation by these reactive species. The carotenoid-bearing hydroxyl groups were generally more potent ROS scavengers than the carotenes, whilst β-carotene was the most efficient ONOO scavenger. The role of astaxanthin as an antioxidant should be highlighted, since it was a more potent scavenger of ROO, HOCl and ONOO than α-tocopherol. Full article
(This article belongs to the Special Issue Marine Carotenoids and Oxidative Stress)
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515 KiB  
Article
Chemistry of the Nudibranch Aldisa andersoni: Structure and Biological Activity of Phorbazole Metabolites
by Genoveffa Nuzzo, Maria Letizia Ciavatta, Robert Kiss, Véronique Mathieu, Helene Leclercqz, Emiliano Manzo, Guido Villani, Ernesto Mollo, Florence Lefranc, Lisette D’Souza, Margherita Gavagnin and Guido Cimino
Mar. Drugs 2012, 10(8), 1799-1811; https://doi.org/10.3390/md10081799 - 20 Aug 2012
Cited by 25 | Viewed by 7967
Abstract
The first chemical study of the Indo-Pacific dorid nudibranch Aldisa andersoni resulted in the isolation of five chlorinated phenyl-pyrrolyloxazoles belonging to the phorbazole series. Two new molecules, 9-chloro-phorbazole D and N1-methyl-phorbazole A, co-occurring with known phorbazoles A, B and D, have been [...] Read more.
The first chemical study of the Indo-Pacific dorid nudibranch Aldisa andersoni resulted in the isolation of five chlorinated phenyl-pyrrolyloxazoles belonging to the phorbazole series. Two new molecules, 9-chloro-phorbazole D and N1-methyl-phorbazole A, co-occurring with known phorbazoles A, B and D, have been characterized. Phorbazoles were found to be present mainly in the external part of the mollusc. The structures of the new compounds were determined by interpretation of spectroscopic data, mainly NMR and mass spectrometry and by comparison with the literature data. Evaluation of feeding-deterrence activity as well as in vitro growth inhibitory properties in human cancer cells was also carried out. Full article
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1440 KiB  
Article
Pardaxin, a Fish Antimicrobial Peptide, Exhibits Antitumor Activity toward Murine Fibrosarcoma in Vitro and in Vivo
by Shu-Ping Wu, Tsui-Chin Huang, Ching-Chun Lin, Cho-Fat Hui, Cheng-Hui Lin and Jyh-Yih Chen
Mar. Drugs 2012, 10(8), 1852-1872; https://doi.org/10.3390/md10081852 - 22 Aug 2012
Cited by 37 | Viewed by 7503
Abstract
The antitumor activity of pardaxin, a fish antimicrobial peptide, has not been previously examined in in vitro and in vivo systems for treating murine fibrosarcoma. In this study, the antitumor activity of synthetic pardaxin was tested using murine MN-11 tumor cells as the [...] Read more.
The antitumor activity of pardaxin, a fish antimicrobial peptide, has not been previously examined in in vitro and in vivo systems for treating murine fibrosarcoma. In this study, the antitumor activity of synthetic pardaxin was tested using murine MN-11 tumor cells as the study model. We show that pardaxin inhibits the proliferation of MN-11 cells and reduces colony formation in a soft agar assay. Transmission electron microscopy (TEM) showed that pardaxin altered the membrane structure similar to what a lytic peptide does, and also produced apoptotic features, such as hollow mitochondria, nuclear condensation, and disrupted cell membranes. A qRT-PCR and ELISA showed that pardaxin induced apoptosis, activated caspase-7 and interleukin (IL)-7r, and downregulated caspase-9, ATF 3, SOCS3, STAT3, cathelicidin, p65, and interferon (IFN)-γ suggesting that pardaxin induces apoptosis through the death receptor/nuclear factor (NF)-κB signaling pathway after 14 days of treatment in tumor-bearing mice. An antitumor effect was observed when pardaxin (25 mg/kg; 0.5 mg/day) was used to treat mice for 14 days, which caused significant inhibition of MN-11 cell growth in mice. Overall, these results indicate that pardaxin has the potential to be a novel therapeutic agent to treat fibrosarcomas. Full article
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369 KiB  
Article
Metabolomic Analyses of Blood Plasma after Oral Administration of D-Glucosamine Hydrochloride to Dogs
by Tomohiro Osaki, Kazuo Azuma, Seiji Kurozumi, Yoshimori Takamori, Takeshi Tsuka, Tomohiro Imagawa, Yoshiharu Okamoto and Saburo Minami
Mar. Drugs 2012, 10(8), 1873-1882; https://doi.org/10.3390/md10081873 - 22 Aug 2012
Cited by 14 | Viewed by 6943
Abstract
D-Glucosamine hydrochloride (GlcN∙HCl) is an endogenous amino monosaccharide synthesized from glucose that is useful in the treatment of joint diseases in both humans and animals. The aim of this study was to examine amino acid metabolism in dogs after oral administration of GlcN∙HCl. [...] Read more.
D-Glucosamine hydrochloride (GlcN∙HCl) is an endogenous amino monosaccharide synthesized from glucose that is useful in the treatment of joint diseases in both humans and animals. The aim of this study was to examine amino acid metabolism in dogs after oral administration of GlcN∙HCl. Accelerated fumarate respiration and elevated plasma levels of lactic acid and alanine were observed after administration. These results suggest that oral administration of GlcN∙HCl induces anaerobic respiration and starvation in cells, and we hypothesize that these conditions promote cartilage regeneration. Further studies are required to evaluate the expression of transforming growth factor-beta (TGF-β). Full article
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950 KiB  
Article
Induction of Apoptosis by 11-Dehydrosinulariolide via Mitochondrial Dysregulation and ER Stress Pathways in Human Melanoma Cells
by Tzu-Rong Su, Feng-Jen Tsai, Jen-Jie Lin, Han Hsiang Huang, Chien-Chih Chiu, Jui-Hsin Su, Ya-Ting Yang, Jeff Yi-Fu Chen, Bing-Sang Wong and Yu-Jen Wu
Mar. Drugs 2012, 10(8), 1883-1898; https://doi.org/10.3390/md10081883 - 22 Aug 2012
Cited by 37 | Viewed by 7670
Abstract
In this study the isolated compound 11-dehydrosinulariolide from soft coral Sinularia leptoclados possessed anti-proliferative, anti-migratory and apoptosis-inducing activities against A2058 melanoma cells. Anti-tumor effects of 11-dehydrosinulariolide were determined by MTT assay, cell migration assay and flow cytometry. Growth and migration of melanoma cells [...] Read more.
In this study the isolated compound 11-dehydrosinulariolide from soft coral Sinularia leptoclados possessed anti-proliferative, anti-migratory and apoptosis-inducing activities against A2058 melanoma cells. Anti-tumor effects of 11-dehydrosinulariolide were determined by MTT assay, cell migration assay and flow cytometry. Growth and migration of melanoma cells were dose-dependently inhibited by 2–8 μg/mL 11-dehydrosinulariolide. Flow cytometric data indicated that 11-dehydrosinulariolide induces both early and late apoptosis in melanoma cells. It was found that the apoptosis induced by 11-dehydrosinulariolide is relevant to mitochondrial-mediated apoptosis via caspase-dependent pathways, elucidated by loss of mitochondrial membrane potential (∆Ym), release of cytochrome C, activation of caspase-3/-9 and Bax as well as suppression of Bcl-2/Bcl-xL. The cleavage of PARP-1 suggested partial involvement of caspase-independent pathways. Immunoblotting data displayed up-regulations of PERK/eIF2α/ATF4/CHOP and ATF6/CHOP coupling with elevation of ER stress chaperones GRP78, GRP94, calnexin, calreticulin and PDI, implicating the involvement of these factors in ER stress-mediated apoptosis induced by 11-dehydrosinulariolide. The abolishment of apoptotic events after pre-treatment with salubrinal indicated that ER stress-mediated apoptosis is also induced by 11-dehydrosinulariolide against melanoma cells. The data in this study suggest that 11-dehydrosinulariolide potentially induces apoptosis against melanoma cells via mitochondrial dysregulation and ER stress pathways. Full article
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Review

Jump to: Research

435 KiB  
Review
Glycosides from Marine Sponges (Porifera, Demospongiae): Structures, Taxonomical Distribution, Biological Activities and Biological Roles
by Vladimir I. Kalinin, Natalia V. Ivanchina, Vladimir B. Krasokhin, Tatyana N. Makarieva and Valentin A. Stonik
Mar. Drugs 2012, 10(8), 1671-1710; https://doi.org/10.3390/md10081671 - 10 Aug 2012
Cited by 46 | Viewed by 9172
Abstract
Literature data about glycosides from sponges (Porifera, Demospongiae) are reviewed. Structural diversity, biological activities, taxonomic distribution and biological functions of these natural products are discussed. Full article
(This article belongs to the Special Issue Marine Glycoconjugates)
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16456 KiB  
Review
Sea Anemone (Cnidaria, Anthozoa, Actiniaria) Toxins: An Overview
by Bárbara Frazão, Vitor Vasconcelos and Agostinho Antunes
Mar. Drugs 2012, 10(8), 1812-1851; https://doi.org/10.3390/md10081812 - 22 Aug 2012
Cited by 173 | Viewed by 29312
Abstract
The Cnidaria phylum includes organisms that are among the most venomous animals. The Anthozoa class includes sea anemones, hard corals, soft corals and sea pens. The composition of cnidarian venoms is not known in detail, but they appear to contain a variety of [...] Read more.
The Cnidaria phylum includes organisms that are among the most venomous animals. The Anthozoa class includes sea anemones, hard corals, soft corals and sea pens. The composition of cnidarian venoms is not known in detail, but they appear to contain a variety of compounds. Currently around 250 of those compounds have been identified (peptides, proteins, enzymes and proteinase inhibitors) and non-proteinaceous substances (purines, quaternary ammonium compounds, biogenic amines and betaines), but very few genes encoding toxins were described and only a few related protein three-dimensional structures are available. Toxins are used for prey acquisition, but also to deter potential predators (with neurotoxicity and cardiotoxicity effects) and even to fight territorial disputes. Cnidaria toxins have been identified on the nematocysts located on the tentacles, acrorhagi and acontia, and in the mucous coat that covers the animal body. Sea anemone toxins comprise mainly proteins and peptides that are cytolytic or neurotoxic with its potency varying with the structure and site of action and are efficient in targeting different animals, such as insects, crustaceans and vertebrates. Sea anemones toxins include voltage-gated Na+ and K+ channels toxins, acid-sensing ion channel toxins, Cytolysins, toxins with Kunitz-type protease inhibitors activity and toxins with Phospholipase A2 activity. In this review we assessed the phylogentic relationships of sea anemone toxins, characterized such toxins, the genes encoding them and the toxins three-dimensional structures, further providing a state-of-the-art description of the procedures involved in the isolation and purification of bioactive toxins. Full article
(This article belongs to the Special Issue Sea Anemone Toxins)
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