Marine Drugs

16 pages, 3410 KiB

Open AccessArticle

In Vitro Vascular-Protective Effects of a Tilapia By-Product Oligopeptide on Angiotensin II-Induced Hypertensive Endothelial Injury in HUVEC by Nrf2/NF-κB Pathways

by Jiali Chen, Fang Gong, Mei-Fang Chen, Chengyong Li, Pengzhi Hong, Shengli Sun, Chunxia Zhou and Zhong-Ji Qian

Mar. Drugs 2019, 17(7), 431; https://doi.org/10.3390/md17070431 - 23 Jul 2019

Cited by 20 | Viewed by 5075

Abstract

Angiotensin II (Ang II) is closely involved in endothelial injury during the development of hypertension. In this study, the protective effects of the tilapia by-product oligopeptide Leu-Ser-Gly-Tyr-Gly-Pro (LSGYGP) on oxidative stress and endothelial injury in Angiotensin II (Ang II)-stimulated human umbilical vein endothelial [...] Read more.

Angiotensin II (Ang II) is closely involved in endothelial injury during the development of hypertension. In this study, the protective effects of the tilapia by-product oligopeptide Leu-Ser-Gly-Tyr-Gly-Pro (LSGYGP) on oxidative stress and endothelial injury in Angiotensin II (Ang II)-stimulated human umbilical vein endothelial cells (HUVEC) were evaluated. LSGYGP dose-dependently suppressed the fluorescence intensities of nitric oxide (NO) and reactive oxygen species (ROS), inhibited the nuclear factor-kappa B (NF-κB) pathway, and reduced inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and endothelin-1 (ET-1) expression, as shown by western blot. In addition, it attenuated the expression of gamma-glutamyltransferase (GGT) and heme oxygenase 1 (HO-1), as well as increasing superoxide dismutase (SOD) and glutathione (GSH) expression through the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Other experiments revealed that LSGYGP increased the apoptotic inhibition ratio between cleaved-caspase-3/procaspase-3, reduced expressions of pro-apoptotic ratio between Bcl-2/Bax, inhibited phosphorylation of mitogen-activated protein kinases (MAPK), and increased phosphorylation of the serine/threonine kinase (Akt) pathway. Furthermore, LSGYGP significantly decreased Ang II-induced DNA damage in a comet assay, and molecular docking results showed that the steady interaction between LSGYGP with NF-κB may be attributed to hydrogen bonds. These results suggest that this oligopeptide is effective in protecting against Ang II-induced HUVEC injury through the reduction of oxidative stress and alleviating endothelial damage. Thus, it has the potential for the therapeutic treatment of hypertension-associated diseases. Full article

(This article belongs to the Special Issue Marine Bioactive Peptides: Structure, Function, and Therapeutic Potential)

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10 pages, 1340 KiB

Open AccessArticle

Syntheses of Benzo[d]Thiazol-2(3H)-One Derivatives and Their Antidepressant and Anticonvulsant Effects

by Qinghao Jin, Zhiyang Fu, Liping Guan and Haiying Jiang

Mar. Drugs 2019, 17(7), 430; https://doi.org/10.3390/md17070430 - 23 Jul 2019

Cited by 16 | Viewed by 3734

Abstract

Thirty-four new benzo[d]thiazol derivatives 2a–2i, 3a–3r, and 4a–4g were synthesized and investigated for their potential antidepressant and anticonvulsant effects. In a forced swimming test, 2c and 2d showed the highest antidepressant and anticonvulsant [...] Read more.

Thirty-four new benzo[d]thiazol derivatives 2a–2i, 3a–3r, and 4a–4g were synthesized and investigated for their potential antidepressant and anticonvulsant effects. In a forced swimming test, 2c and 2d showed the highest antidepressant and anticonvulsant effects. 2c and 2d displayed a higher percentage decrease in immobility duration (89.96% and 89.62%, respectively) than that of fluoxetine (83.62%). In the maximal electroshock seizure test, 3n and 3q showed the highest anticonvulsant effect, with ED₅₀ values of 46.1 and 64.3 mg kg⁻¹, and protective indices of 6.34 and 4.11, respectively, which were similar to those of phenobarbital or valproate. We also found that the mechanism for the antidepressant activity of 2c and 2d may be via increasing the concentrations of serotonin and norepinephrine. Full article

(This article belongs to the Special Issue Synthetic and Biosynthetic Approaches to Marine Natural Products)

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24 pages, 3892 KiB

Open AccessArticle

Novel Insights on the Toxicity of Phycotoxins on the Gut through the Targeting of Enteric Glial Cells

by Océane Reale, Antoine Huguet and Valérie Fessard

Mar. Drugs 2019, 17(7), 429; https://doi.org/10.3390/md17070429 - 23 Jul 2019

Cited by 10 | Viewed by 4351

Abstract

In vitro and in vivo studies have shown that phycotoxins can impact intestinal epithelial cells and can cross the intestinal barrier to some extent. Therefore, phycotoxins can reach cells underlying the epithelium, such as enteric glial cells (EGCs), which are involved in gut [...] Read more.

In vitro and in vivo studies have shown that phycotoxins can impact intestinal epithelial cells and can cross the intestinal barrier to some extent. Therefore, phycotoxins can reach cells underlying the epithelium, such as enteric glial cells (EGCs), which are involved in gut homeostasis, motility, and barrier integrity. This study compared the toxicological effects of pectenotoxin-2 (PTX2), yessotoxin (YTX), okadaic acid (OA), azaspiracid-1 (AZA1), 13-desmethyl-spirolide C (SPX), and palytoxin (PlTX) on the rat EGC cell line CRL2690. Cell viability, morphology, oxidative stress, inflammation, cell cycle, and specific glial markers were evaluated using RT-qPCR and high content analysis (HCA) approaches. PTX2, YTX, OA, AZA1, and PlTX induced neurite alterations, oxidative stress, cell cycle disturbance, and increase of specific EGC markers. An inflammatory response for YTX, OA, and AZA1 was suggested by the nuclear translocation of NF-κB. Caspase-3-dependent apoptosis and induction of DNA double strand breaks (γH2AX) were also observed with PTX2, YTX, OA, and AZA1. These findings suggest that PTX2, YTX, OA, AZA1, and PlTX may affect intestinal barrier integrity through alterations of the human enteric glial system. Our results provide novel insight into the toxicological effects of phycotoxins on the gut. Full article

(This article belongs to the Special Issue High-Throughput Screening of Marine Resources)

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23 pages, 2265 KiB

Open AccessFeature PaperReview

Prostaglandins in Marine Organisms: A Review

by Federica Di Costanzo, Valeria Di Dato, Adrianna Ianora and Giovanna Romano

Mar. Drugs 2019, 17(7), 428; https://doi.org/10.3390/md17070428 - 23 Jul 2019

Cited by 61 | Viewed by 10142

Abstract

Prostaglandins (PGs) are lipid mediators belonging to the eicosanoid family. PGs were first discovered in mammals where they are key players in a great variety of physiological and pathological processes, for instance muscle and blood vessel tone regulation, inflammation, signaling, hemostasis, reproduction, and [...] Read more.

Prostaglandins (PGs) are lipid mediators belonging to the eicosanoid family. PGs were first discovered in mammals where they are key players in a great variety of physiological and pathological processes, for instance muscle and blood vessel tone regulation, inflammation, signaling, hemostasis, reproduction, and sleep-wake regulation. These molecules have successively been discovered in lower organisms, including marine invertebrates in which they play similar roles to those in mammals, being involved in the control of oogenesis and spermatogenesis, ion transport, and defense. Prostaglandins have also been found in some marine macroalgae of the genera Gracilaria and Laminaria and very recently the PGs pathway has been identified for the first time in some species of marine microalgae. In this review we report on the occurrence of prostaglandins in the marine environment and discuss the anti-inflammatory role of these molecules. Full article

(This article belongs to the Special Issue Marine Anti-inflammatory Agents)

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25 pages, 2448 KiB

Open AccessReview

Quorum Sensing Inhibition by Marine Bacteria

by Anabela Borges and Manuel Simões

Mar. Drugs 2019, 17(7), 427; https://doi.org/10.3390/md17070427 - 23 Jul 2019

Cited by 64 | Viewed by 9652

Abstract

Antibiotic resistance has been increasingly reported for a wide variety of bacteria of clinical significance. This widespread problem constitutes one of the greatest challenges of the twenty-first century. Faced with this issue, clinicians and researchers have been persuaded to design novel strategies in [...] Read more.

Antibiotic resistance has been increasingly reported for a wide variety of bacteria of clinical significance. This widespread problem constitutes one of the greatest challenges of the twenty-first century. Faced with this issue, clinicians and researchers have been persuaded to design novel strategies in order to try to control pathogenic bacteria. Therefore, the discovery and elucidation of the mechanisms underlying bacterial pathogenesis and intercellular communication have opened new perspectives for the development of alternative approaches. Antipathogenic and/or antivirulence therapies based on the interruption of quorum sensing pathways are one of several such promising strategies aimed at disarming rather than at eradicating bacterial pathogens during the course of colonization and infection. This review describes mechanisms of bacterial communication involved in biofilm formation. An overview of the potential of marine bacteria and their bioactive components as QS inhibitors is further provided. Full article

(This article belongs to the Special Issue Quorum Quenching Agents: Exploring Quorum Sensing Interfering Strategies in Marine Bacteria for the Development of Novel Therapeutics)

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17 pages, 5182 KiB

Open AccessArticle

Genome Sequencing of the Japanese Eel (Anguilla japonica) for Comparative Genomic Studies on tbx4 and a tbx4 Gene Cluster in Teleost Fishes

by Weiwei Chen, Chao Bian, Xinxin You, Jia Li, Lizhen Ye, Zhengyong Wen, Yunyun Lv, Xinhui Zhang, Junmin Xu, Shaosen Yang, Ruobo Gu, Xueqiang Lin and Qiong Shi

Mar. Drugs 2019, 17(7), 426; https://doi.org/10.3390/md17070426 - 20 Jul 2019

Cited by 10 | Viewed by 14662

Abstract

Limbs originated from paired fish fins are an important innovation in Gnathostomata. Many studies have focused on limb development-related genes, of which the T-box transcription factor 4 gene (tbx4) has been considered as one of the most essential factors in the [...] Read more.

Limbs originated from paired fish fins are an important innovation in Gnathostomata. Many studies have focused on limb development-related genes, of which the T-box transcription factor 4 gene (tbx4) has been considered as one of the most essential factors in the regulation of the hindlimb development. We previously confirmed pelvic fin loss in tbx4-knockout zebrafish. Here, we report a high-quality genome assembly of the Japanese eel (Anguilla japonica), which is an economically important fish without pelvic fins. The assembled genome is 1.13 Gb in size, with a scaffold N50 of 1.03 Mb. In addition, we collected 24 tbx4 sequences from 22 teleost fishes to explore the correlation between tbx4 and pelvic fin evolution. However, we observed complete exon structures of tbx4 in several pelvic-fin-loss species such as Ocean sunfish (Mola mola) and ricefield eel (Monopterus albus). More interestingly, an inversion of a special tbx4 gene cluster (brip1-tbx4-tbx2b- bcas3) occurred twice independently, which coincides with the presence of fin spines. A nonsynonymous mutation (M82L) was identified in the nuclear localization sequence (NLS) of the Japanese eel tbx4. We also examined variation and loss of hindlimb enhancer B (HLEB), which may account for pelvic fin loss in Tetraodontidae and Diodontidae. In summary, we generated a genome assembly of the Japanese eel, which provides a valuable genomic resource to study the evolution of fish tbx4 and helps elucidate the mechanism of pelvic fin loss in teleost fishes. Our comparative genomic studies, revealed for the first time a potential correlation between the tbx4 gene cluster and the evolutionary development of toxic fin spines. Because fin spines in teleosts are usually venoms, this tbx4 gene cluster may facilitate the genetic engineering of toxin-related marine drugs. Full article

(This article belongs to the Special Issue Genetics of Marine Organisms Associated with Human Health)

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13 pages, 1156 KiB

Open AccessReview

Pinnatoxins’ Deleterious Effects on Cholinergic Networks: From Experimental Models to Human Health

by Nicolas Delcourt, Emmeline Lagrange, Eric Abadie, Valérie Fessard, Jean-Marc Frémy, Jean-Paul Vernoux, Marie-Bénédicte Peyrat, Thomas Maignien, Nathalie Arnich, Jordi Molgó and César Mattei

Mar. Drugs 2019, 17(7), 425; https://doi.org/10.3390/md17070425 - 20 Jul 2019

Cited by 13 | Viewed by 4412

Abstract

Pinnatoxins (PnTXs) are emerging neurotoxins that were discovered about 30 years ago. They are solely produced by the marine dinoflagellate Vulcanodinium rugosum, and may be transferred into the food chain, as they have been found in various marine invertebrates, including bivalves. No [...] Read more.

Pinnatoxins (PnTXs) are emerging neurotoxins that were discovered about 30 years ago. They are solely produced by the marine dinoflagellate Vulcanodinium rugosum, and may be transferred into the food chain, as they have been found in various marine invertebrates, including bivalves. No human intoxication has been reported to date although acute toxicity was induced by PnTxs in rodents. LD₅₀ values have been estimated for the different PnTXs through the oral route. At sublethal doses, all symptoms are reversible, and no neurological sequelae are visible. These symptoms are consistent with impairment of central and peripheral cholinergic network functions. In fact, PnTXs are high-affinity competitive antagonists of nicotinic acetylcholine receptors (nAChRs). Moreover, their lethal effects are consistent with the inhibition of muscle nAChRs, inducing respiratory distress and paralysis. Human intoxication by ingestion of PnTXs could result in various symptoms observed in episodes of poisoning with natural nAChR antagonists. This review updates the available data on PnTX toxicity with a focus on their mode of action on cholinergic networks and suggests the effects that could be extrapolated on human physiology. Full article

(This article belongs to the Special Issue Marine Toxins Affecting Cholinergic System)

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12 pages, 1497 KiB

Open AccessArticle

Abalone Collagen Extracts Potentiate Stem Cell Properties of Human Epidermal Keratinocytes

by Sajee Thaweekitphathanaphakdee, Pithi Chanvorachote, Sagaw Prateepchinda, Mattaka Khongkow and Apirada Sucontphunt

Mar. Drugs 2019, 17(7), 424; https://doi.org/10.3390/md17070424 - 20 Jul 2019

Cited by 6 | Viewed by 5273

Abstract

Stem cell activities in human tissues are critical for tissue integrity and function. Maintaining keratinocyte stem cells (KSCs) stemness helps sustain healthy skin by supporting keratinocyte renewal, involving the formation of epidermal barriers. In this study, abalone collagen (AC) extracts with molecular weights [...] Read more.

Stem cell activities in human tissues are critical for tissue integrity and function. Maintaining keratinocyte stem cells (KSCs) stemness helps sustain healthy skin by supporting keratinocyte renewal, involving the formation of epidermal barriers. In this study, abalone collagen (AC) extracts with molecular weights of 3 kDa (AC 1) and 300 kDa (AC 2) were compared to the epidermal growth factor (EGF) for their effects on cell proliferation, cell migration (wound healing), spheroid formation, and the expression level of stem cell markers on human keratinocytes (HaCaT cells). Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and cell proliferation was quantified by ATP and DNA content analysis and Sulforhodamine B (SRB) assays. Cell migration assay was determined using the scratch wound healing test. Spheroid formation was evaluated and the expression level of stem cell markers was investigated by western blot analysis. The results showed that AC 1 at the concentration of 100 µg/mL could stimulate HaCaT cell proliferation, migration, spheroid formation, and the expression level of stem cell markers (keratin 19, β-catenin, ALDH1A1) compared to the control. In conclusion, a smaller molecular weight of abalone collagen extract exhibits a better effect on keratinocytes proliferation, migration, and stemness, which could be a potential active ingredient in cosmeceutical products. Full article

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12 pages, 922 KiB

Open AccessArticle

Cytotoxic Sesquiterpenoid Quinones and Quinols, and an 11-Membered Heterocycle, Kauamide, from the Hawaiian Marine Sponge Dactylospongia elegans

by Ram P. Neupane, Stephen M. Parrish, Jayanti Bhandari Neupane, Wesley Y. Yoshida, M. L. Richard Yip, James Turkson, Mary Kay Harper, John D. Head and Philip G. Williams

Mar. Drugs 2019, 17(7), 423; https://doi.org/10.3390/md17070423 - 19 Jul 2019

Cited by 14 | Viewed by 3671

Abstract

Several known sesquiterpenoid quinones and quinols (1–9), and kauamide (10), a new polyketide-peptide containing an 11-membered heterocycle, were isolated from the extracts of the Hawaiian marine sponge Dactylospongia elegans. The planar structure of 10 was determined [...] Read more.

Several known sesquiterpenoid quinones and quinols (1–9), and kauamide (10), a new polyketide-peptide containing an 11-membered heterocycle, were isolated from the extracts of the Hawaiian marine sponge Dactylospongia elegans. The planar structure of 10 was determined from spectroscopic analyses, and its relative and absolute configurations were established from density functional theory (DFT) calculations of the GIAO NMR shielding tensors, and advanced Marfey’s analysis of the N-MeLeu residue, respectively. Compounds 1 and 3 showed moderate inhibition of β-secretase 1 (BACE1), whereas 1–9 exhibited moderate to potent inhibition of growth of human glioma (U251) cells. Compounds 1–2 and 4–7 were also active against human pancreatic carcinoma (Panc-1) cells. Full article

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7 pages, 1151 KiB

Open AccessArticle

Mycousfurans A and B, Antibacterial Usnic Acid Congeners from the Fungus Mycosphaerella sp., Isolated from a Marine Sediment

by Jihye Lee, Jusung Lee, Geum Jin Kim, Inho Yang, Weihong Wang, Joo-Won Nam, Hyukjae Choi, Sang-Jip Nam and Heonjoong Kang

Mar. Drugs 2019, 17(7), 422; https://doi.org/10.3390/md17070422 - 19 Jul 2019

Cited by 14 | Viewed by 4615

Abstract

Mycousfurans (1 and 2), two new usnic acid congeners, along with (−)-mycousnine (3), (−)-placodiolic acid (4), and (+)-usnic acid (5), were isolated using high-performance liquid chromatography-ultraviolet (HPLC-UV)-guided fractionation of extracts of Mycosphaerella sp. isolated from [...] Read more.

Mycousfurans (1 and 2), two new usnic acid congeners, along with (−)-mycousnine (3), (−)-placodiolic acid (4), and (+)-usnic acid (5), were isolated using high-performance liquid chromatography-ultraviolet (HPLC-UV)-guided fractionation of extracts of Mycosphaerella sp. isolated from a marine sediment. The planar structures of 1 and 2 were elucidated using 1D and 2D NMR spectra. The relative configurations of the stereogenic carbons of 1 and 2 were established via analysis of their nuclear Overhauser spectroscopy (NOESY) spectra, and their absolute configurations were determined using a comparison of experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1 and 2 were found to have antibacterial activity, showing moderate activity against Kocuria rhizophila and Staphylococcus aureus. Full article

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24 pages, 3555 KiB

Open AccessArticle

Selective Suppression of Cell Growth and Programmed Cell Death-Ligand 1 Expression in HT1080 Fibrosarcoma Cells by Low Molecular Weight Fucoidan Extract

by Kiichiro Teruya, Yoshihiro Kusumoto, Hiroshi Eto, Noboru Nakamichi and Sanetaka Shirahata

Mar. Drugs 2019, 17(7), 421; https://doi.org/10.3390/md17070421 - 19 Jul 2019

Cited by 14 | Viewed by 5173

Abstract

Low molecular weight fucoidan extract (LMF), prepared by an abalone glycosidase digestion of a crude fucoidan extracted from Cladosiphon novae-caledoniae Kylin, exhibits various biological activities, including anticancer effect. Various cancers express programmed cell death-ligand 1 (PD-L1), which is known to play a significant [...] Read more.

Low molecular weight fucoidan extract (LMF), prepared by an abalone glycosidase digestion of a crude fucoidan extracted from Cladosiphon novae-caledoniae Kylin, exhibits various biological activities, including anticancer effect. Various cancers express programmed cell death-ligand 1 (PD-L1), which is known to play a significant role in evasion of the host immune surveillance system. PD-L1 is also expressed in many types of normal cells for self-protection. Previous research has revealed that selective inhibition of PD-L1 expressed in cancer cells is critical for successful cancer eradication. In the present study, we analyzed whether LMF could regulate PD-L1 expression in HT1080 fibrosarcoma cells. Our results demonstrated that LMF suppressed PD-L1/PD-L2 expression and the growth of HT1080 cancer cells and had no effect on the growth of normal TIG-1 cells. Thus, LMF differentially regulates PD-L1 expression in normal and cancer cells and could serve as an alternative complementary agent for treatment of cancers with high PD-L1 expression. Full article

(This article belongs to the Collection Marine Compounds and Cancer)

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15 pages, 3625 KiB

Open AccessArticle

Evaluation of Oxasqualenoids from the Red Alga Laurencia viridis against Acanthamoeba

by Jacob Lorenzo-Morales, Ana R. Díaz-Marrero, Francisco Cen-Pacheco, Ines Sifaoui, María Reyes-Batlle, María L. Souto, Antonio Hernández Daranas, José E. Piñero and José J. Fernández

Mar. Drugs 2019, 17(7), 420; https://doi.org/10.3390/md17070420 - 19 Jul 2019

Cited by 27 | Viewed by 4388

Abstract

Acanthamoeba genus is a widely distributed and opportunistic parasite with increasing importance worldwide as an emerging pathogen in the past decades. This protozoan has an active trophozoite stage, a cyst stage, and is dormant and very resistant. It can cause Acanthamoeba keratitis, an [...] Read more.

Acanthamoeba genus is a widely distributed and opportunistic parasite with increasing importance worldwide as an emerging pathogen in the past decades. This protozoan has an active trophozoite stage, a cyst stage, and is dormant and very resistant. It can cause Acanthamoeba keratitis, an ocular sight-threatening disease, and granulomatous amoebic encephalitis, a chronic, very fatal brain pathology. In this study, the amoebicidal activity of sixteen Laurencia oxasqualenoid metabolites and semisynthetic derivatives were tested against Acanthamoeba castellanii Neff. The results obtained point out that iubol (3) and dehydrothyrsiferol (1) possess potent activities, with IC₅₀ values of 5.30 and 12.83 µM, respectively. The hydroxylated congeners thyrsiferol (2) and 22-hydroxydehydrothyrsiferol (4), active in the same value range at IC₅₀ 13.97 and 17.00 µM, are not toxic against murine macrophages; thus, they are solid candidates for the development of new amoebicidal therapies. Full article

(This article belongs to the Special Issue Marine Natural Products with Antiprotozoal Activity)

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24 pages, 4433 KiB

Open AccessFeature PaperArticle

Rapid Metabolome and Bioactivity Profiling of Fungi Associated with the Leaf and Rhizosphere of the Baltic Seagrass Zostera marina

by Lars-Erik Petersen, Michael Marner, Antje Labes and Deniz Tasdemir

Mar. Drugs 2019, 17(7), 419; https://doi.org/10.3390/md17070419 - 19 Jul 2019

Cited by 19 | Viewed by 6046

Abstract

Zostera marina (eelgrass) is a marine foundation species with key ecological roles in coastal habitats. Its bacterial microbiota has been well studied, but very little is known about its mycobiome. In this study, we have isolated and identified 13 fungal strains, dominated by [...] Read more.

Zostera marina (eelgrass) is a marine foundation species with key ecological roles in coastal habitats. Its bacterial microbiota has been well studied, but very little is known about its mycobiome. In this study, we have isolated and identified 13 fungal strains, dominated by Penicillium species (10 strains), from the leaf and the root rhizosphere of Baltic Z. marina. The organic extracts of the fungi that were cultured by an OSMAC (One-Strain–Many-Compounds) regime using five liquid culture media under both static and shaking conditions were investigated for their chemical and bioactivity profiles. All extracts showed strong anti-quorum sensing activity, and the majority of the Penicillium extracts displayed antimicrobial or anti-biofilm activity against Gram-negative environmental marine and human pathogens. HPLC-DAD-MS-based rapid metabolome analyses of the extracts indicated the high influence of culture conditions on the secondary metabolite (SM) profiles. Among 69 compounds detected in all Penicillium sp. extracts, 46 were successfully dereplicated. Analysis of SM relatedness in culture conditions by Hierarchical Cluster Analysis (HCA) revealed generally low similarity and showed a strong effect of medium selection on chemical profiles of Penicillium sp. This is the first study assessing both the metabolite and bioactivity profile of the fungi associated with Baltic eelgrass Z. marina. Full article

(This article belongs to the Special Issue Selected Papers from the 2nd International Conference of Marine Fungal Natural Products (MaFNaP_2017))

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11 pages, 1607 KiB

Open AccessArticle

Costatone C—A New Halogenated Monoterpene from the New Zealand Red Alga Plocamium angustum

by Joe Bracegirdle, Zaineb Sohail, Michael J. Fairhurst, Monica L. Gerth, Giuseppe C. Zuccarello, Muhammad Ali Hashmi and Robert A. Keyzers

Mar. Drugs 2019, 17(7), 418; https://doi.org/10.3390/md17070418 - 19 Jul 2019

Cited by 9 | Viewed by 4001

Abstract

Red algae of the genus Plocamium have been a rich source of halogenated monoterpenes. Herein, a new cyclic monoterpene, costatone C (7), was isolated from the extract of P. angustum collected in New Zealand, along with the previously reported (1E [...] Read more.

Red algae of the genus Plocamium have been a rich source of halogenated monoterpenes. Herein, a new cyclic monoterpene, costatone C (7), was isolated from the extract of P. angustum collected in New Zealand, along with the previously reported (1E,5Z)-1,6-dichloro-2-methylhepta-1,5-dien-3-ol (8). Elucidation of the planar structure of 7 was achieved through conventional NMR and (−)-HR-APCI-MS techniques, and the absolute configuration by comparison of experimental and DFT-calculated ECD spectra. The absolute configuration of 8 was determined using Mosher’s method. Compound 7 showed mild antibacterial activity against Staphylococcus aureus and S. epidermidis. The state of Plocamium taxonomy and its implications upon natural product distributions, especially across samples from specimens collected in different countries, is also discussed. Full article

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15 pages, 933 KiB

Open AccessReview

Chitosan Use in Dentistry: A Systematic Review of Recent Clinical Studies

by Marco Cicciù, Luca Fiorillo and Gabriele Cervino

Mar. Drugs 2019, 17(7), 417; https://doi.org/10.3390/md17070417 - 17 Jul 2019

Cited by 70 | Viewed by 8637

Abstract

This study aims to highlight the latest marine-derived technologies in the biomedical field. The dental field, in particular, uses many marine-derived biomaterials, including chitosan. Chitosan that is used in different fields of medicine, is analyzed in this review with the aim of highlighting [...] Read more.

This study aims to highlight the latest marine-derived technologies in the biomedical field. The dental field, in particular, uses many marine-derived biomaterials, including chitosan. Chitosan that is used in different fields of medicine, is analyzed in this review with the aim of highlighting its uses and advantages in the dental field. A literature search was conducted in scientific search engines, using keywords in order to achieve the highest possible number of results. A review of randomized controlled trials (RCT) was conducted to evaluate and process all the relevant results for chitosan and oral health. After a screening and a careful analysis of the literature, there were only 12 results highlighted. Chitosan performs different functions and it is used in different fields of dentistry in a safe and effective way. Among the uses of chitosan, we report on the remineralizing property of chitosan which hardens tissues of the tooth, and therefore its role as a desensibilizer used in toothpastes. According to our systematic review, the use of chitosan has shown better surgical healing of post-extraction oral wounds. Furthermore, some studies show a reduction in bacterial biofilm when used in dental cements. In addition, it has antibacterial, antifungal, hemostatic and other systemic properties which aid its use for drug delivering. Full article

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10 pages, 1016 KiB

Open AccessArticle

Cytotoxic Furanoditerpenes from the Sponge Spongia tubulifera Collected in the Mexican Caribbean

by Dawrin Pech-Puch, Jaime Rodríguez, Bastien Cautain, Carlos Alfredo Sandoval-Castro and Carlos Jiménez

Mar. Drugs 2019, 17(7), 416; https://doi.org/10.3390/md17070416 - 16 Jul 2019

Cited by 16 | Viewed by 3675

Abstract

Two new spongian furanoditerpenes, 3β-hydroxyspongia-13(16),14-dien-2-one (1) and 19-dehydroxy-spongian diterpene 17 (2), along with five known terpenes, the spongian furanoditerpenes 9-nor-3-hydroxyspongia-3,13(16),14-trien-2-one (3), 3β,19 dihydroxyspongia-13(16),14-dien-2-one (epispongiadiol) (4) and spongian diterpene 17 (5), the furanoditerpene ambliol [...] Read more.

Two new spongian furanoditerpenes, 3β-hydroxyspongia-13(16),14-dien-2-one (1) and 19-dehydroxy-spongian diterpene 17 (2), along with five known terpenes, the spongian furanoditerpenes 9-nor-3-hydroxyspongia-3,13(16),14-trien-2-one (3), 3β,19 dihydroxyspongia-13(16),14-dien-2-one (epispongiadiol) (4) and spongian diterpene 17 (5), the furanoditerpene ambliol C (6), and the sesterterpene scalarin (7), were isolated from the methanolic extract of the sponge Spongia tubulifera, collected in the Mexican Caribbean. The planar structures of the new compounds were elucidated by 1D/2D NMR and IR spectroscopic analysis, high resolution electrospray mass spectrometry (HRESIMS), and comparison of their spectral data with those reported in the literature. Absolute configurations were determined by comparison of the experimental electronic circular dichroism (ECD) spectrum with those calculated by time-dependent density functional theory (TDDFT). Compounds 1, 4, and 6 displayed weak cytotoxic activity against different human tumour cell lines. Full article

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13 pages, 2992 KiB

Open AccessArticle

Inhibition of Liver Tumor Cell Metastasis by Partially Acetylated Chitosan Oligosaccharide on A Tumor-Vessel Microsystem

by Bolin Jing, Gong Cheng, Jianjun Li, Zhuo A. Wang and Yuguang Du

Mar. Drugs 2019, 17(7), 415; https://doi.org/10.3390/md17070415 - 13 Jul 2019

Cited by 24 | Viewed by 3807

Abstract

Chitooligosaccharides (COS), the only cationic oligosaccharide in nature, have been demonstrated to have anti-tumor activity. However, the inhibitory effects of COS on different stages of tumor metastasis are still unknown, and it is not clear what stage(s) of tumor metastasis COS targeted. To [...] Read more.

Chitooligosaccharides (COS), the only cationic oligosaccharide in nature, have been demonstrated to have anti-tumor activity. However, the inhibitory effects of COS on different stages of tumor metastasis are still unknown, and it is not clear what stage(s) of tumor metastasis COS targeted. To study the inhibitory effects of a new partially acetylated chitooligosaccharide (paCOS) with fraction of acetylation (F_A) 0.46 on each phase of liver cancer cell metastasis, a dynamic tumor-vessel microsystem undergoing physiological flow was leveraged. paCOS (F_A = 0.46) significantly inhibited proliferation of HepG2 cells through vascular absorption on the chip, and inhibited migration of HepG2 cells by inhibiting the formation of pseudopod in liver tumor cells. It was also found that paCOS at 10 μg/mL had a stronger inhibitory effect on liver tumor cells invading blood vessels than that of paCOS at 100 μg/mL, and paCOS at 100 μg/mL, which had a significant destructive effect on tumor vascular growth and barrier function. Moreover, paCOS reduced the number of liver tumor cells adhering onto the surface of HUVECs layer after 3 h of treatment. Therefore, the results revealed that paCOS had considerable potential as drugs for anti-tumor metastasis. Full article

(This article belongs to the Special Issue Antitumor Compounds from Marine Invertebrates)

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12 pages, 1032 KiB

Open AccessArticle

The Purification, Characterization, and Biological Activity of New Polyketides from Mangrove-Derived Endophytic Fungus Epicoccum nigrum SCNU-F0002

by Zhangyuan Yan, Shitong Wen, Meng Ding, Huixian Guo, Cuiying Huang, Xintong Zhu, Junyi Huang, Zhigang She and Yuhua Long

Mar. Drugs 2019, 17(7), 414; https://doi.org/10.3390/md17070414 - 12 Jul 2019

Cited by 25 | Viewed by 4851

Abstract

Six new polyketides, including one coumarin (1), two isocoumarins (2 and 3), dihydroradicinin (4), and two benzofuranone derivatives (7 and 8), together with seven known analogues (5–6 and 9–13) [...] Read more.

Six new polyketides, including one coumarin (1), two isocoumarins (2 and 3), dihydroradicinin (4), and two benzofuranone derivatives (7 and 8), together with seven known analogues (5–6 and 9–13) were isolated from the culture of the mangrove endophytic fungus Epicoccum nigrum SCNU-F0002. The structures were elucidated on the interpretation of spectroscopic data. The absolute configuration of Compounds 2 and 3 were determined by comparison of their ECD spectra with the data of their analogue dihydroisocoumarins described in the literature. The absolute configuration of 4 was determined by single-crystal X-ray diffraction. All the compounds were screened for their antioxidant, antibacterial, anti-phytopathogenic fungi and cytotoxic activities. Using a DPPH radical-scavenging assay, Compounds 10–13 showed potent antioxidant activity with IC₅₀ values of 13.6, 12.1, 18.1, and 11.7 μg/mL, respectively. In addition, Compounds 6 and 7 showed antibacterial effects against Bacillus subtilis (ATCC 6538), Escherichia coli (ATCC 8739), and Staphylococcus aureus (ATCC 6538), with MIC values in the range of 25–50 μg/mL. Full article

(This article belongs to the Special Issue New Challenges in Structure Elucidation of Marine Natural Products: NMR Analyses and Other Advanced Methods)

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15 pages, 1034 KiB

Open AccessArticle

Identification of A Novel Antibacterial Peptide from Atlantic Mackerel belonging to the GAPDH-Related Antimicrobial Family and Its In Vitro Digestibility

by Clément Offret, Ismaïl Fliss, Laurent Bazinet, André Marette and Lucie Beaulieu

Mar. Drugs 2019, 17(7), 413; https://doi.org/10.3390/md17070413 - 12 Jul 2019

Cited by 27 | Viewed by 4521

Abstract

The Atlantic mackerel, Scomber scombrus, is one of the most fished species in the world, but it is still largely used for low-value products, such as bait; mainly for crustacean fishery. This resource could be transformed into products of high value and [...] Read more.

The Atlantic mackerel, Scomber scombrus, is one of the most fished species in the world, but it is still largely used for low-value products, such as bait; mainly for crustacean fishery. This resource could be transformed into products of high value and may offer new opportunities for the discovery of bioactive molecules. Mackerel hydrolysate was investigated to discover antibacterial peptides with biotechnological potential. The proteolytic process generated a hydrolysate composed of 96% proteinaceous compounds with molecular weight lower than 7 kDa. From the whole hydrolysate, antibacterial activity was detected against both Gram-negative and Gram-positive bacteria. After solid phase extraction, purification of the active fraction led to the identification of 4 peptide sequences by mass spectrometry. The peptide sequence N-KVEIVAINDPFIDL-C, called Atlantic Mackerel GAPDH-related peptide (AMGAP), was selected for chemical synthesis to confirm the antibacterial activity and to evaluate its stability through in vitro digestibility. Minimal inhibitory concentrations of AMGAP revealed that Listeria strains were the most sensitive, suggesting potential as food-preservative to prevent bacterial growth. In addition, in vitro digestibility experiments found rapid (after 20 min) and early digestibility (stomach). This study highlights the biotechnological potential of mackerel hydrolysate due to the presence of the antibacterial AMGAP peptide. Full article

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14 pages, 4136 KiB

Open AccessArticle

Gliotoxin Enhances Autophagic Cell Death via the DAPK1-TAp63 Signaling Pathway in Paclitaxel-Resistant Ovarian Cancer Cells

by Ga-Bin Park, Jee-Yeong Jeong and Daejin Kim

Mar. Drugs 2019, 17(7), 412; https://doi.org/10.3390/md17070412 - 12 Jul 2019

Cited by 25 | Viewed by 4149

Abstract

Death-associated protein kinase 1 (DAPK1) expression induced by diverse death stimuli mediates apoptotic activity in various cancers, including ovarian cancer. In addition, mutual interaction between the tumor suppressor p53 and DAPK1 influences survival and death in several cancer cell lines. However, the exact [...] Read more.

Death-associated protein kinase 1 (DAPK1) expression induced by diverse death stimuli mediates apoptotic activity in various cancers, including ovarian cancer. In addition, mutual interaction between the tumor suppressor p53 and DAPK1 influences survival and death in several cancer cell lines. However, the exact role and connection of DAPK1 and p53 family proteins (p53, p63, and p73) in drug-resistant ovarian cancer cells have not been studied previously. In this study, we investigated whether DAPK1 induction by gliotoxin derived from marine fungus regulates the level of transcriptionally active p63 (TAp63) to promote apoptosis in an autophagy-dependent manner. Pre-exposure of paclitaxel-resistant ovarian cancer cells to gliotoxin inhibited the expression of multidrug resistant-associated proteins (MDR1 and MRP1-3), disrupted the mitochondrial membrane potential, and induced caspase-dependent apoptosis through autophagy induction after subsequent treatment with paclitaxel. Gene silencing of DAPK1 prevented TAp63-mediated downregulation of MDR1 and MRP1-3 and autophagic cell death after sequential treatment with gliotoxin and then paclitaxel. However, pretreatment with 3-methyladenine (3-MA), an autophagy inhibitor, had no effect on the levels of DAPK1 and TAp63 or on the inhibition of MDR1 and MRP1-3. These results suggest that DAPK1-mediated TAp63 upregulation is one of the critical pathways that induce apoptosis in chemoresistant cancer cells. Full article

(This article belongs to the Special Issue Selected Papers from the 3rd International Symposium on Life Science)

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10 pages, 1482 KiB

Open AccessArticle

New Antiproliferative Cembrane Diterpenes from the Red Sea Sarcophyton Species

by Hossam M. Hassan, Mostafa E. Rateb, Marwa H. Hassan, Ahmed M. Sayed, Samah Shabana, Mai Raslan, Elham Amin, Fathy A. Behery, Osama M. Ahmed, Abdullatif Bin Muhsinah, Tobias A. M. Gulder and Usama Ramadan Abdelmohsen

Mar. Drugs 2019, 17(7), 411; https://doi.org/10.3390/md17070411 - 11 Jul 2019

Cited by 17 | Viewed by 5921

Abstract

The combination of liquid chromatography coupled to high resolution mass spectrometry (LC-HRESMS)-based dereplication and antiproliferative activity-guided fractionation was applied on the Red Sea-derived soft coral Sarcophyton sp. This approach facilitated the isolation of five new cembrane-type diterpenoids (1–5), along [...] Read more.

The combination of liquid chromatography coupled to high resolution mass spectrometry (LC-HRESMS)-based dereplication and antiproliferative activity-guided fractionation was applied on the Red Sea-derived soft coral Sarcophyton sp. This approach facilitated the isolation of five new cembrane-type diterpenoids (1–5), along with two known analogs (6 and 7), as well as the identification of 19 further, known compounds. The chemical structures of the new compounds were elucidated while using comprehensive spectroscopic analyses, including one-dimensional (1D) and two-dimensional (2D) NMR and HRMS. All of the isolated cembranoids (1–7) showed moderate in vitro antiproliferative activity against a human breast cancer cell line (MCF-7), with IC₅₀ ranging from 22.39–27.12 µg/mL. This class of compounds could thus serve as scaffold for the future design of anticancer leads. Full article

(This article belongs to the Collection Bioactive Compounds from Marine Invertebrates)

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14 pages, 3725 KiB

Open AccessCommunication

Identification and Total Synthesis of Two Previously Unreported Odd-Chain Bis-Methylene-Interrupted Fatty Acids with a Terminal Olefin that Activate Protein Phosphatase, Mg²⁺/Mn²⁺-Dependent 1A (PPM1A) in Ovaries of the Limpet Cellana toreuma

by Hideki Kawashima, Naoki Toyooka, Takuya Okada, Huy Du Nguyen, Yuya Nishikawa, Yuka Miura, Nana Inoue and Ken-ichi Kimura

Mar. Drugs 2019, 17(7), 410; https://doi.org/10.3390/md17070410 - 11 Jul 2019

Cited by 6 | Viewed by 8617

Abstract

Diverse non-methylene-interrupted (NMI) fatty acids (FAs) with odd-chain lengths have been recognized in triacylglycerols and polar lipids from the ovaries of the limpet Cellana toreuma, however their biological properties remain unclear. In this study, two previously unreported odd-chain NMI FAs, (12Z [...] Read more.

Diverse non-methylene-interrupted (NMI) fatty acids (FAs) with odd-chain lengths have been recognized in triacylglycerols and polar lipids from the ovaries of the limpet Cellana toreuma, however their biological properties remain unclear. In this study, two previously unreported odd-chain NMI FAs, (12Z)-12,16-heptadecadienoic (1) and (14Z)-14,18-nonadecadienoic (2) acids, from the ovary lipids of C. toreuma were identified by a combination of equivalent chain length (ECL) values of their methyl esters and capillary gas chromatography-mass spectrometry (GC-MS) of their 3-pyridylcarbinol derivatives. On the basis of the experimental results, both 1 and 2 were synthesized to prove their structural assignments and to test their biological activity. The ECL values and electron impact-mass (EI-MS) spectra of naturally occurring 1 and 2 were in agreement with those of the synthesized 1 and 2. In an in vitro assay, both 1 and 2 activated protein phosphatase, Mg²⁺/Mn²⁺-dependent 1A (PPM1A) up to 100 μM in a dose-dependent manner. Full article

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18 pages, 1998 KiB

Open AccessArticle

In-Depth Characterization of Bioactive Extracts from Posidonia oceanica Waste Biomass

by Isaac Benito-González, Amparo López-Rubio, Antonio Martínez-Abad, Ana-Rosa Ballester, Irene Falcó, Luis González-Candelas, Gloria Sánchez, Jesús Lozano-Sánchez, Isabel Borrás-Linares, Antonio Segura-Carretero and Marta Martínez-Sanz

Mar. Drugs 2019, 17(7), 409; https://doi.org/10.3390/md17070409 - 9 Jul 2019

Cited by 23 | Viewed by 5756

Abstract

Posidonia oceanica waste biomass has been valorised to produce extracts by means of different methodologies and their bioactive properties have been evaluated. Water-based extracts were produced using ultrasound-assisted and hot water methods and classified according to their ethanol-affinity (E1: ethanol soluble; E2: non-soluble). [...] Read more.

Posidonia oceanica waste biomass has been valorised to produce extracts by means of different methodologies and their bioactive properties have been evaluated. Water-based extracts were produced using ultrasound-assisted and hot water methods and classified according to their ethanol-affinity (E1: ethanol soluble; E2: non-soluble). Moreover, a conventional protocol with organic solvents was applied, yielding E3 extracts. Compositional and structural characterization confirmed that while E1 and E3 extracts were mainly composed of minerals and lipids, respectively, E2 extracts were a mixture of minerals, proteins and carbohydrates. All the extracts showed remarkably high antioxidant capacity, which was not only related to phenolic compounds but also to the presence of proteins and polysaccharides. All E2 and E3 extracts inhibited the growth of several foodborne fungi, while only E3 extracts decreased substantially the infectivity of feline calicivirus and murine norovirus. These results show the potential of P. oceanica waste biomass for the production of bioactive extracts. Full article

(This article belongs to the Collection Marine Polysaccharides)

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30 pages, 1697 KiB

Open AccessFeature PaperReview

Marine Biosurfactants: Biosynthesis, Structural Diversity and Biotechnological Applications

by Sonja Kubicki, Alexander Bollinger, Nadine Katzke, Karl-Erich Jaeger, Anita Loeschcke and Stephan Thies

Mar. Drugs 2019, 17(7), 408; https://doi.org/10.3390/md17070408 - 9 Jul 2019

Cited by 114 | Viewed by 9777

Abstract

Biosurfactants are amphiphilic secondary metabolites produced by microorganisms. Marine bacteria have recently emerged as a rich source for these natural products which exhibit surface-active properties, making them useful for diverse applications such as detergents, wetting and foaming agents, solubilisers, emulsifiers and dispersants. Although [...] Read more.

Biosurfactants are amphiphilic secondary metabolites produced by microorganisms. Marine bacteria have recently emerged as a rich source for these natural products which exhibit surface-active properties, making them useful for diverse applications such as detergents, wetting and foaming agents, solubilisers, emulsifiers and dispersants. Although precise structural data are often lacking, the already available information deduced from biochemical analyses and genome sequences of marine microbes indicates a high structural diversity including a broad spectrum of fatty acid derivatives, lipoamino acids, lipopeptides and glycolipids. This review aims to summarise biosyntheses and structures with an emphasis on low molecular weight biosurfactants produced by marine microorganisms and describes various biotechnological applications with special emphasis on their role in the bioremediation of oil-contaminated environments. Furthermore, novel exploitation strategies are suggested in an attempt to extend the existing biosurfactant portfolio. Full article

(This article belongs to the Special Issue Biotechnology Applications of Marine Biosurfactants)

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13 pages, 4677 KiB

Open AccessArticle

Ishige okamurae Extract Ameliorates the Hyperglycemia and Body Weight Gain of db/db Mice through Regulation of the PI3K/Akt Pathway and Thermogenic Factors by FGF21

by Young-Jin Seo, Kippeum Lee, Sungwoo Chei, You-Jin Jeon and Boo-Yong Lee

Mar. Drugs 2019, 17(7), 407; https://doi.org/10.3390/md17070407 - 9 Jul 2019

Cited by 11 | Viewed by 5138

Abstract

Type 2 diabetes mellitus and related metabolic disorders, such as dyslipidemia, present increasing challenges to health worldwide, as a result of urbanization, the increasing prevalence of obesity, poor lifestyle, and other stress-related factors. Ishige okamurae extract (IOE) is known to be effective at [...] Read more.

Type 2 diabetes mellitus and related metabolic disorders, such as dyslipidemia, present increasing challenges to health worldwide, as a result of urbanization, the increasing prevalence of obesity, poor lifestyle, and other stress-related factors. Ishige okamurae extract (IOE) is known to be effective at lowering blood glucose and ameliorating metabolic disease. However, detailed mechanisms for these effects have yet to be elucidated. Here, we show that IOE ameliorates substrate (IRS)/ phosphatidylinositol 3-kinase (PI3K)/Akt pathway and increasing glucose transporter 4 (GLUT4) expression in skeletal muscle and white adipose tissue (WAT). We also demonstrate that IOE increases the expression of fibroblast growth factor (FGF)21, a regulator of glucose and energy metabolism in muscle and WAT. In addition, IOE administration increased peroxisome proliferator-activated receptor γ coactivator 1α expression, which regulates expression of the key thermogenic molecule uncoupling protein 1 in WAT. Thus, the effects of IOE to ameliorate hyperglycemia and adiposity may be mediated through FGF21 activating insulin signaling and increasing the expression of GLUT4 and pro-thermogenic factors. Full article

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13 pages, 3294 KiB

Open AccessArticle

Neurotrophic Effect of Fish-Lecithin Based Nanoliposomes on Cortical Neurons

by Catherine Malaplate, Aurelia Poerio, Marion Huguet, Claire Soligot, Elodie Passeri, Cyril J. F. Kahn, Michel Linder, Elmira Arab-Tehrany and Frances T. Yen

Mar. Drugs 2019, 17(7), 406; https://doi.org/10.3390/md17070406 - 9 Jul 2019

Cited by 15 | Viewed by 3841

Abstract

Lipids play multiple roles in preserving neuronal function and synaptic plasticity, and polyunsaturated fatty acids (PUFAs) have been of particular interest in optimizing synaptic membrane organization and function. We developed a green-based methodology to prepare nanoliposomes (NL) from lecithin that was extracted from [...] Read more.

Lipids play multiple roles in preserving neuronal function and synaptic plasticity, and polyunsaturated fatty acids (PUFAs) have been of particular interest in optimizing synaptic membrane organization and function. We developed a green-based methodology to prepare nanoliposomes (NL) from lecithin that was extracted from fish head by-products. These NL range between 100–120 nm in diameter, with an n-3/n-6 fatty acid ratio of 8.88. The high content of n-3 PUFA (46.3% of total fatty acid content) and docosahexanoic acid (26%) in these NL represented a means for enrichment of neuronal membranes that are potentially beneficial for neuronal growth and synaptogenesis. To test this, the primary cultures of rat embryo cortical neurons were incubated with NL on day 3 post-culture for 24 h, followed by immunoblots or immunofluorescence to evaluate the NL effects on synaptogenesis, axonal growth, and dendrite formation. The results revealed that NL-treated cells displayed a level of neurite outgrowth and arborization on day 4 that was similar to those of untreated cells on day 5 and 6, suggesting accelerated synapse formation and neuronal development in the presence of NL. We propose that fish-derived NL, by virtue of their n-3 PUFA profile and neurotrophic effects, represent a new innovative bioactive vector for developing preventive or curative treatments for neurodegenerative diseases. Full article

(This article belongs to the Special Issue Marine-Derived Products for Biomedicine)

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15 pages, 2145 KiB

Open AccessArticle

Extraction and Characterization of Alginate from an Edible Brown Seaweed (Cystoseira barbata) Harvested in the Romanian Black Sea

by Bogdan Trica, Cédric Delattre, Fabrice Gros, Alina Violeta Ursu, Tanase Dobre, Gholamreza Djelveh, Philippe Michaud and Florin Oancea

Mar. Drugs 2019, 17(7), 405; https://doi.org/10.3390/md17070405 - 8 Jul 2019

Cited by 50 | Viewed by 6343

Abstract

Cystoseira barbata is an edible brown seaweed, traditionally used in the Black Sea area as functional food. Both alginate and brown seaweed biomass are well known for their potential use as adsorbents for heavy metals. Alginate was extracted from C. barbata recovered from [...] Read more.

Cystoseira barbata is an edible brown seaweed, traditionally used in the Black Sea area as functional food. Both alginate and brown seaweed biomass are well known for their potential use as adsorbents for heavy metals. Alginate was extracted from C. barbata recovered from the Romanian coast on the Black Sea with a yield of 19 ± 1.5% (w/w). The structural data for the polysaccharide was obtained by HPSEC-MALS, ¹H-NMR. The M/G ratio was determined to be 0.64 with a molecular weight of 126.6 kDa with an intrinsic viscosity of 406.2 mL/g. Alginate beads were used and their adsorption capacity with respect to Pb²⁺ and Cu²⁺ ions was determined. The adsorption kinetics of C. barbata dry biomass was evaluated and it was shown to have an adsorption capacity of 279.2 ± 7.5 mg/g with respect to Pb²⁺, and 69.3 ± 2 with respect to Cu²⁺. Alginate in the form of beads adsorbs a maximum of 454 ± 4.7 mg/g of Pb²⁺ ions and 107.3 ± 1.7 mg/g of Cu²⁺ ions. Full article

(This article belongs to the Special Issue Characterization of Bioactive Components in Edible Algae)

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17 pages, 4902 KiB

Open AccessArticle

Immunomodulatory Activity of Low Molecular-Weight Peptides from Nibea japonica in RAW264.7 Cells via NF-κB Pathway

by Zhuangwei Zhang, Xuyang Hu, Lin Lin, Guofang Ding and Fangmiao Yu

Mar. Drugs 2019, 17(7), 404; https://doi.org/10.3390/md17070404 - 8 Jul 2019

Cited by 50 | Viewed by 5194

Abstract

In this study, a low molecular-weight (Mw) peptide named NJP (<1 kDa), was purified from a protein hydrolysate of Nibea japonica by ultrafiltration, and its immunomodulatory effect on RAW264.7 cells was evaluated. The lactate dehydrogenase (LDH) and MTT assays were performed to explore [...] Read more.

In this study, a low molecular-weight (Mw) peptide named NJP (<1 kDa), was purified from a protein hydrolysate of Nibea japonica by ultrafiltration, and its immunomodulatory effect on RAW264.7 cells was evaluated. The lactate dehydrogenase (LDH) and MTT assays were performed to explore the cytotoxicity of NJP. The results showed that NJP promoted cell proliferation and had no significant toxic effects on RAW264.7 cells. Moreover, the cells formed multiple pseudopodia indicating that they were in activated state. Further tests showed that NJP significantly promoted phagocytic capacity, and the secretion of proinflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β). It also increased the synthesis of nitric oxide (NO) by upregulating inducible nitric oxide synthase (iNOS) protein level. Flow cytometry revealed that NJP promoted cell cycle progression and increased the percentage of cells in G0/G1 phase. NJP promoted IκBα degradation, p65 and nuclear factor (NF)-κB activation and translocation by up-regulating IKKα/β protein expression. In conclusion, these results indicated that NJP exerts immunomodulatory effects on RAW264.7 cells through the NF-κB signaling pathway. Therefore, NJP can be incorporated in the production of functional foods or nutraceuticals. Full article

(This article belongs to the Special Issue Marine Nutraceuticals and Functional Foods)

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14 pages, 1436 KiB

Open AccessArticle

Evaluation of the Inhibitory Potential of Casuarictin, an Ellagitannin Isolated from White Mangrove (Laguncularia racemosa) Leaves, on Snake Venom Secretory Phospholipase A2

by Caroline Fabri Bittencourt Rodrigues, Marcelo José Pena Ferreira, Mariana Novo Belchor, Caroline R. C. Costa, Danielle P. Novaes, Adeilso Bispo dos Santos Junior, Cinthia I. Tamayose, Marcus Vinícius Terashima Pinho, Marcos Antonio de Oliveira and Marcos Hikari Toyama

Mar. Drugs 2019, 17(7), 403; https://doi.org/10.3390/md17070403 - 8 Jul 2019

Cited by 9 | Viewed by 3954

Abstract

Ellagitannins constitute the largest group of hydrolyzable tannins of plants, and, from this group, casuarictin (Casu) was identified in some plant species. However, to our knowledge, no investigation of secretory phospholipase A2 (sPLA2) inhibition by Casu has been performed yet. Casuarictin was isolated [...] Read more.

Ellagitannins constitute the largest group of hydrolyzable tannins of plants, and, from this group, casuarictin (Casu) was identified in some plant species. However, to our knowledge, no investigation of secretory phospholipase A2 (sPLA2) inhibition by Casu has been performed yet. Casuarictin was isolated by chromatography n-butanol (n-BuOH) partition of Laguncularia racemosa leaves. The pharmacological and biological effects of Casu were evaluated on isolated sPLA2 from the rattlesnake (Crotalus durissus terrificus) and using a plant bacterial strain. The compound was able to form a protein complex consisting of a stable sPLA2 + Casu complex. Analyses carried out with matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF) revealed that the molecular mass of sPLA2 increased from 14,425.62 to 15,362.74 Da. The enzymatic activity of the sPLA2 + Casu complex was significantly lower than that of native sPLA2. Besides, molecular interactions of Casu with sPLA2 were able to virtually abolish the native edematogenic effect as well as myonecrosis induced by the protein when injected 10 min after sPLA2. Therefore, Casu may be considered a potential anti-inflammatory that can be used to treat edema and myonecrosis induced by serine-secreting phospholipase A2. In addition, the compound also showed great antimicrobial potential. Full article

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16 pages, 2582 KiB

Open AccessArticle

Cyanobacteria as Nanogold Factories II: Chemical Reactivity and anti-Myocardial Infraction Properties of Customized Gold Nanoparticles Biosynthesized by Cyanothece sp.

by Nancy S. Younis, Esam M. Bakir, Maged E. Mohamed and Nermin A. El Semary

Mar. Drugs 2019, 17(7), 402; https://doi.org/10.3390/md17070402 - 8 Jul 2019

Cited by 16 | Viewed by 3478

Abstract

Cyanothece sp., a coccoid, unicellular, nitrogen-fixing and hydrogen-producing cyanobacterium, has been used in this study to biosynthesize customized gold nanoparticles under certain chemical conditions. The produced gold nanoparticles had a characteristic absorption band at 525–535 nm. Two types of gold nanoparticle, the purple [...] Read more.

Cyanothece sp., a coccoid, unicellular, nitrogen-fixing and hydrogen-producing cyanobacterium, has been used in this study to biosynthesize customized gold nanoparticles under certain chemical conditions. The produced gold nanoparticles had a characteristic absorption band at 525–535 nm. Two types of gold nanoparticle, the purple and blue, were formed according to the chemical environment in which the cyanobacterium was grown. Dynamic light scattering was implemented to estimate the size of the purple and blue nanoparticles, which ranged from 80 ± 30 nm and 129 ± 40 nm in diameter, respectively. The highest scattering of laser light was recorded for the blue gold nanoparticles, which was possibly due to their larger size and higher concentration. The appearance of anodic and cathodic peaks in cyclic voltammetric scans of the blue gold nanoparticles reflected the oxidation into gold oxide, followed by the subsequent reduction into the nano metal state. The two produced forms of gold nanoparticles were used to treat isoproterenol-induced myocardial infarction in experimental rats. Both forms of nanoparticles ameliorated myocardial infarction injury, with a slight difference in their curative activity with the purple being more effective. Mechanisms that might explain the curative effect of these nanoparticles on the myocardial infarction were proposed. The morphological, physiological, and biochemical attributes of the Cyanothece sp. cyanobacterium were fundamental for the successful production of “tailored” nanoparticles, and complemented the chemical conditions for the differential biosynthesis process. The present research represents a novel approach to manipulate cyanobacterial cells towards the production of different-sized gold nanoparticles whose curative impacts vary accordingly. This is the first report on that type of manipulated gold nanoparticles biosynthesis which will hopefully open doors for further investigations and biotechnological applications. Full article

(This article belongs to the Special Issue Compounds from Cyanobacteria II)

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