Marine Drugs

15 pages, 2491 KiB

Open AccessArticle

Anti-Obesity Effect of Standardized Extract of Microalga Phaeodactylum tricornutum Containing Fucoxanthin

by Song Yi Koo, Ji-Hyun Hwang, Seung-Hoon Yang, Jae-In Um, Kwang Won Hong, Kyungsu Kang, Cheol-Ho Pan, Keum Taek Hwang and Sang Min Kim

Mar. Drugs 2019, 17(5), 311; https://doi.org/10.3390/md17050311 - 27 May 2019

Cited by 61 | Viewed by 7562

Abstract

Fucoxanthin (FX), a marine carotenoid found in macroalgae and microalgae, exhibits several beneficial effects to health. The anti-obesity activity of FX is well documented, but FX has not been mass-produced or applied extensively or commercially because of limited availability of raw materials and [...] Read more.

Fucoxanthin (FX), a marine carotenoid found in macroalgae and microalgae, exhibits several beneficial effects to health. The anti-obesity activity of FX is well documented, but FX has not been mass-produced or applied extensively or commercially because of limited availability of raw materials and complex extraction techniques. In this study, we investigated the anti-obesity effect of standardized FX powder (Phaeodactylum extract (PE)) developed from microalga Phaeodactylum tricornutum as a commercial functional food. The effects of PE on adipogenesis inhibition in 3T3-L1 adipocytes and anti-obesity in high-fat diet (HFD)-fed C57BL/6J mice were evaluated. PE and FX dose-dependently decreased intracellular lipid contents in adipocytes without cytotoxicity. In HFD-fed obese mice, PE supplementation for six weeks decreased body weight, organ weight, and adipocyte size. In the serum parameter analysis, the PE-treated groups showed attenuation of lipid metabolism dysfunction and liver damage induced by HFD. In the liver, uncoupling protein-1 (UCP1) upregulation and peroxisome proliferator activated receptor γ (PPARγ) downregulation were detected in the PE-treated groups. Additionally, micro computed tomography revealed lower fat accumulation in PE-treated groups compared to that in the HFD group. These results indicate that PE exerts anti-obesity effects by inhibiting adipocytic lipogenesis, inducing fat mass reduction and decreasing intracellular lipid content, adipocyte size, and adipose weight. Full article

(This article belongs to the Special Issue Marine Carotenoids)

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Graphical abstract

10 pages, 2713 KiB

Open AccessArticle

Efficient Extraction of Carotenoids from Sargassum muticum Using Aqueous Solutions of Tween 20

by Flávia A. Vieira and Sónia P. M. Ventura

Mar. Drugs 2019, 17(5), 310; https://doi.org/10.3390/md17050310 - 25 May 2019

Cited by 10 | Viewed by 3898

Abstract

The replacement of synthetic compounds by natural products witnesses an increasing demand from the pharmaceutical, cosmetic, food and nutraceutical industries. Included in the set of natural raw materials that are poorly explored are the macroalgae. Despite the detailed characterization and identification of most [...] Read more.

The replacement of synthetic compounds by natural products witnesses an increasing demand from the pharmaceutical, cosmetic, food and nutraceutical industries. Included in the set of natural raw materials that are poorly explored are the macroalgae. Despite the detailed characterization and identification of most relevant biomolecules that are present in the main macroalgae species, there remains a lack of efficient and economically viable processes available to meet the needs of the markets. In this work, an efficient and single-step process, based on aqueous solutions of Tween 20, to recover carotenoids from Sargassum muticum, an invasive brown macroalgae species present in the Portuguese coast, is proposed and optimized allowing an extraction yield of 2.78 ± 0.4 mg_carotenoids.g_{dried mass}⁻¹, which is shown to increase the extraction efficiency by 38% when compared with traditional methods. Full article

(This article belongs to the Special Issue Discovery and Application of Macroalgae-Derived Natural Products)

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Scheme of the conventional method used for the extraction of the carotenoids and the purification of the fucoxanthin. Full article ">Figure 2
Surface response plots (left) and contour plots (right) on the yield of extraction of the carotenoids (mgcarotenoids.gdried mass−1) by combining the effects of (i) Csurf (mol.L−1) and t (minutes), (ii) Csurf (mol.L−1) and R(S/L), and (iii) R(S/L) and t (minutes), using aqueous solutions of Tween 20. Full article ">Figure 3
Pareto chart obtained for the factorial planning 23 obtained for the study of aqueous solutions of Tween 20. Full article ">Figure 4
Second factorial planning 23: surface response plots (left) and contour plots (right) on the yield of extraction of the carotenoids (mgcarotenoids.gdried mass−1) by combining the effects of (i) Csurf (mol.L−1) and t (minutes), (ii) Csurf (mol.L−1) and R(S/L), and (iii) R(S/L) and t (minutes), using aqueous solutions of Tween 20. Full article ">Figure 5
Pareto chart obtained for the second factorial planning 23 using aqueous solutions of Tween 20. Full article ">

13 pages, 383 KiB

Open AccessArticle

Oral Ingestion of Deep Ocean Minerals Increases High-Intensity Intermittent Running Capacity in Soccer Players after Short-Term Post-Exercise Recovery: A Double-Blind, Placebo-Controlled Crossover Trial

by Matthew F. Higgins, Benjamin Rudkin and Chia-Hua Kuo

Mar. Drugs 2019, 17(5), 309; https://doi.org/10.3390/md17050309 - 24 May 2019

Cited by 6 | Viewed by 4954

Abstract

This study examined whether deep ocean mineral (DOM) supplementation improved high-intensity intermittent running capacity after short-term recovery from an initial bout of prolonged high-intensity running in thermoneutral environmental conditions. Nine healthy recreational male soccer players (age: 22 ± 1 y; stature: 181 ± [...] Read more.

This study examined whether deep ocean mineral (DOM) supplementation improved high-intensity intermittent running capacity after short-term recovery from an initial bout of prolonged high-intensity running in thermoneutral environmental conditions. Nine healthy recreational male soccer players (age: 22 ± 1 y; stature: 181 ± 5 cm; and body mass 80 ± 11 kg) completed a graded incremental test to ascertain peak oxygen uptake (V^·O_2PEAK), two familiarisation trials, and two experimental trials following a double-blind, repeated measures, crossover and counterbalanced design. All trials were separated by seven days and at ambient room temperature (i.e., 20 °C). During the 2 h recovery period after the initial ~60 min running at 75% V^·O_2PEAK, participants were provided with 1.38 ± 0.51 L of either deep ocean mineral water (DOM) or a taste-matched placebo (PLA), both mixed with 6% sucrose. DOM increased high-intensity running capacity by ~25% compared to PLA. There were no differences between DOM and PLA for blood lactate concentration, blood glucose concentration, or urine osmolality. The minerals and trace elements within DOM, either individually or synergistically, appear to have augmented high-intensity running capacity in healthy, recreationally active male soccer players after short-term recovery from an initial bout of prolonged, high-intensity running in thermoneutral environmental conditions. Full article

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14 pages, 2051 KiB

Open AccessArticle

Characterization of an Alkaline Alginate Lyase with pH-Stable and Thermo-Tolerance Property

by Yanan Wang, Xuehong Chen, Xiaolin Bi, Yining Ren, Qi Han, Yu Zhou, Yantao Han, Ruyong Yao and Shangyong Li

Mar. Drugs 2019, 17(5), 308; https://doi.org/10.3390/md17050308 - 24 May 2019

Cited by 49 | Viewed by 4555

Abstract

Alginate oligosaccharides (AOS) show versatile bioactivities. Although various alginate lyases have been characterized, enzymes with special characteristics are still rare. In this study, a polysaccharide lyase family 7 (PL7) alginate lyase-encoding gene, aly08, was cloned from the marine bacterium Vibrio sp. SY01 [...] Read more.

Alginate oligosaccharides (AOS) show versatile bioactivities. Although various alginate lyases have been characterized, enzymes with special characteristics are still rare. In this study, a polysaccharide lyase family 7 (PL7) alginate lyase-encoding gene, aly08, was cloned from the marine bacterium Vibrio sp. SY01 and expressed in Escherichia coli. The purified alginate lyase Aly08, with a molecular weight of 35 kDa, showed a specific activity of 841 U/mg at its optimal pH (pH 8.35) and temperature (45 °C). Aly08 showed good pH-stability, as it remained more than 80% of its initial activity in a wide pH range (4.0–10.0). Aly08 was also a thermo-tolerant enzyme that recovered 70.8% of its initial activity following heat shock treatment for 5 min. This study also demonstrated that Aly08 is a polyG-preferred enzyme. Furthermore, Aly08 degraded alginates into disaccharides and trisaccharides in an endo-manner. Its thermo-tolerance and pH-stable properties make Aly08 a good candidate for further applications. Full article

(This article belongs to the Special Issue Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology)

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Phylogenetic analysis of Aly08 with other reported alginate lyases. The reliability of the phylogenetic reconstructions was determained by boot-strapping values (1000 replicates). Branch-related numbers are bootstrap values (confidence limits) representing the substitution frequency of each amino acid residue. A pectate lyase (CAD56882) from Bacillus licheniformis 14A was taken as control. Full article ">Figure 2
Sequence comparison of Aly08 with related alginate lyases from PL family 7: Alg7D (ABD81807) from Saccharophagus degradans 2–40, AlgMsp (BAJ62034) from Microbulbifer sp. 6532A, AlyV4 (AGL7859) from Vibrio sp. QY104, and AlyL2 (AJO61885) from Agarivorans sp. L11. The conserved regions and identical residues are marked with bands and black star, respectively. Full article ">Figure 3
SDS-PAGE analysis of the recombinant enzyme Aly08. Lane M, protein marker; Lane 1, the purified Aly08. Full article ">Figure 4
The biochemical characteristics of Aly08. (A) The optimal temperature of Aly08. (B) The thermal-stability of Aly08. (C) Optimal pH for the relative activity of Aly08 was determined in 20 mM Tris-HCl buffer (solid circle), 20 mM phosphate buffer (solid triangle), 20 mM citic-Na2HPO4 (solid square), or 20 mM glycine-NaOH buffer (hollow circle). (D) pH stability of Aly08 in 20 mM Tris-HCl buffer (solid circle), 20 mM phosphate buffer (solid triangle), 20 mM citic-Na2HPO4 (solid square), or 20 mM glycine-NaOH buffer (hollow circle). Full article ">Figure 5
Thermo-tolerance and heat recovery of Aly08. (A) The difference of thermostability of enzymes incubation at ice-bath for 0 min (black columnar) and 30 min (white columnar). (B) Effects of boiling times on enzyme Aly08. Black and white columns indicate the activity of the heat-inactivated enzyme following ice-bath for 0 min and 30 min, respectively. (C) Effects of different incubation temperatures on the activity recovery of Aly08 under 5 min heat-inactivated conditions. (D) Effects of incubation time at 0 °C on the activity recovery of heat-inactivated Aly08. The enzyme activity without any treatment was 100%. Full article ">Figure 6
Degradation patterns of Aly08 toward sodium alginate. The elution positions of the unsaturated oligosaccharide product fractions with different degrees of polymerization are shown with arrows: DP1 represents unsaturated monosaccharide, DP2 represents unsaturated disaccharide, DP3 represents unsaturated trisaccharide. Full article ">Figure 7
The hydrolytic products of Aly08. (A) TLC analysis of the hydrolytic products of Aly08. Lane M, standard alginate oligosaccharides (DP2-3); Line 0, alginate; Lane 1–9, hydrolytic products of Aly08 for different times (1, 2, 5, 10, 15, 30, 60, 90, and 120 min) toward 0.3% (w/v) high viscosity sodium alginate. DP2 and DP3 indicate alginate disaccharide and trisaccharide, respectively. (B) ESI-MS analysis of the end products of Aly08. Full article ">

19 pages, 1900 KiB

Open AccessArticle

Marine Bacteria, A Source for Alginolytic Enzyme to Disrupt Pseudomonas aeruginosa Biofilms

by Said M. Daboor, Renee Raudonis, Alejandro Cohen, John R. Rohde and Zhenyu Cheng

Mar. Drugs 2019, 17(5), 307; https://doi.org/10.3390/md17050307 - 24 May 2019

Cited by 30 | Viewed by 5181

Abstract

Pseudomonas aeruginosa biofilms are typically associated with the chronic lung infection of cystic fibrosis (CF) patients and represent a major challenge for treatment. This opportunistic bacterial pathogen secretes alginate, a polysaccharide that is one of the main components of its biofilm. Targeting this [...] Read more.

Pseudomonas aeruginosa biofilms are typically associated with the chronic lung infection of cystic fibrosis (CF) patients and represent a major challenge for treatment. This opportunistic bacterial pathogen secretes alginate, a polysaccharide that is one of the main components of its biofilm. Targeting this major biofilm component has emerged as a tempting therapeutic strategy for tackling biofilm-associated bacterial infections. The enormous potential in genetic diversity of the marine microbial community make it a valuable resource for mining activities responsible for a broad range of metabolic processes, including the alginolytic activity responsible for degrading alginate. A collection of 36 bacterial isolates were purified from marine water based on their alginolytic activity. These isolates were identified based on their 16S rRNA gene sequences. Pseudoalteromonas sp. 1400 showed the highest alginolytic activity and was further confirmed to produce the enzyme alginate lyase. The purified alginate lyase (AlyP1400) produced by Pseudoalteromonas sp. 1400 showed a band of 23 KDa on a protein electrophoresis gel and exhibited a bifunctional lyase activity for both poly-mannuronic acid and poly-glucuronic acid degradation. A tryptic digestion of this gel band analyzed by liquid chromatography-tandem mass spectrometry confirmed high similarity to the alginate lyases in polysaccharide lyase family 18. The purified alginate lyase showed a maximum relative activity at 30 °C at a slightly acidic condition. It decreased the sodium alginate viscosity by over 90% and reduced the P. aeruginosa (strain PA14) biofilms by 69% after 24 h of incubation. The combined activity of AlyP1400 with carbenicillin or ciprofloxacin reduced the P. aeruginosa biofilm thickness, biovolume and surface area in a flow cell system. The present data revealed that AlyP1400 combined with conventional antibiotics helped to disrupt the biofilms produced by P. aeruginosa and can be used as a promising combinational therapeutic strategy. Full article

(This article belongs to the Special Issue Marine Bacteria as Sources of Bioactive Compounds)

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Alginate lyase activity produced by different bacterial strains. (a) Total enzyme activity represented as unit per mL, where each one-unit enzyme is defined as the amount of enzyme required to increase the absorbance at 235 nm by 0.01 per minute. (b) Viscosity reduction of selection medium with 1.8% sodium alginate after 24 h incubation measured in centipoise, a unit of absolute viscosity. Error bars represent standard deviation of three independent experiments. The blank is designated as Na-alginate (sodium alginate). Different letters indicate a statistically significant difference between groups (p < 0.05). Full article ">Figure 2
Bifunctional activity of alginate lyase produced by isolated marine bacteria. Enzymes acting against poly-mannuronate (poly-M) show a white halo due to gelation of the degradation products caused by the reaction of lyase with poly-M and enzymes acting against poly-guluronate (poly-G) show a white ring. The lyase activity of the following isolates’ supernatants are shown: 1, Cellulophaga sp. 1423; 2, Pseudoalteromonas sp. 1422; 3, Pseudoalteromonas sp. 1416; 4, Pseudoalteromonas sp. 1400; and 5, well is filled with 1.8% alginate solution in 20 mM Tris-HCl buffer as a blank. Full article ">Figure 3
Biofilm biomass formed after 48 h in 96-well microplates, treated with different cell-free supernatants for 24 h at 37 °C under static conditions. Error bars represent standard deviation (SD) of three independent experiments. Different letters indicate statistically significant differences between groups (p < 0.05). Full article ">Figure 4
The alginate lyase enzyme specific activity (ESA) and total enzyme activity (TEA) produced by Pseudoalteromonas sp. 1400 after 24 h incubation at 150 rpm with (a) different temperatures and (b) different pH values. One-unit enzyme is defined as the amount of enzyme required to increase the absorbance at 235 nm by 0.01 per minute. The error bars for TEA represented the SD values of three independent experiments as means ± SD (n = 3). Full article ">Figure 5
Protein content and specific enzyme activities for AlyP1400 obtained from the Sephadex G100. One-unit enzyme defined as the amount of enzyme required to increase the absorbance at 235 nm by 0.01 per minute. Error bars represented the SD values of three independent experiments as means ± SD (n = 3). Full article ">Figure 6
SDS-PAGE (Coomassie blue staining) and zymogram (active staining for alginate lyase) of the purified alginate lyase (AlyP1400) from Pseudoalteromonas sp. 1400. Lanes are as follows, 1, protein markers; 2, 3 and 4 purified alginate lyase (black arrow show the alginate hydrolysis in 3 and 4), 5 and 6 negative control, 0.1% alginate solution in 20 mM Tis-HCl buffer. Full article ">Figure 7
AlyP1400 biochemical characterization. (a) Thermal enzyme stability and (b) the pH stability of the purified AlyP1400 are illustrated. Error bars represent SD of three independent experiments. Different letters indicate statistically significant differences between groups (p < 0.05). Full article ">Figure 8
Alginate production by P. aeruginosa PA14 grown under biofilm conditions. Fluorescent microscopic images of bacterial cells incubated with MAb F429 and a secondary antibody conjugated with Alexa Fluor 488 are shown. (a) Non-alginate producer E. coli TOP10, (b) P. aeruginosa PA14, (c) P. aeruginosa PA14 control without the primary MAb F429, (d) PA14 with AlyP1400 enzyme. Scale bar, 10 µm. Full article ">

17 pages, 3245 KiB

Open AccessFeature PaperArticle

Synthetic Pinnatoxins A and G Reversibly Block Mouse Skeletal Neuromuscular Transmission In Vivo and In Vitro

by Evelyne Benoit, Aurélie Couesnon, Jiri Lindovsky, Bogdan I. Iorga, Rómulo Aráoz, Denis Servent, Armen Zakarian and Jordi Molgó

Mar. Drugs 2019, 17(5), 306; https://doi.org/10.3390/md17050306 - 24 May 2019

Cited by 12 | Viewed by 3441

Abstract

Pinnatoxins (PnTXs) A-H constitute an emerging family belonging to the cyclic imine group of phycotoxins. Interest has been focused on these fast-acting and highly-potent toxins because they are widely found in contaminated shellfish. Despite their highly complex molecular structure, PnTXs have been chemically [...] Read more.

Pinnatoxins (PnTXs) A-H constitute an emerging family belonging to the cyclic imine group of phycotoxins. Interest has been focused on these fast-acting and highly-potent toxins because they are widely found in contaminated shellfish. Despite their highly complex molecular structure, PnTXs have been chemically synthetized and demonstrated to act on various nicotinic acetylcholine receptor (nAChR) subtypes. In the present work, PnTX-A, PnTX-G and analogue, obtained by chemical synthesis with a high degree of purity (>98%), have been studied in vivo and in vitro on adult mouse and isolated nerve-muscle preparations expressing the mature muscle-type (α1)₂β1δε nAChR. The results show that PnTX-A and G acted on the neuromuscular system of anesthetized mice and blocked the compound muscle action potential (CMAP) in a dose- and time-dependent manner, using a minimally invasive electrophysiological method. The CMAP block produced by both toxins in vivo was reversible within 6–8 h. PnTX-A and G, applied to isolated extensor digitorum longus nerve-muscle preparations, blocked reversibly isometric twitches evoked by nerve stimulation. The action of PnTX-A was reversed by 3,4-diaminopyridine. Both toxins exerted no direct action on muscle fibers, as revealed by direct muscle stimulation. PnTX-A and G blocked synaptic transmission at mouse neuromuscular junctions and PnTX-A amino ketone analogue (containing an open form of the imine ring) had no effect on neuromuscular transmission. These results indicate the importance of the cyclic imine for interacting with the adult mammalian muscle-type nAChR. Modeling and docking studies revealed molecular determinants responsible for the interaction of PnTXs with the muscle-type nAChR. Full article

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

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12 pages, 4342 KiB

Open AccessArticle

Actinomycin V Inhibits Migration and Invasion via Suppressing Snail/Slug-Mediated Epithelial-Mesenchymal Transition Progression in Human Breast Cancer MDA-MB-231 Cells In Vitro

by Shiqi Lin, Caiyun Zhang, Fangyuan Liu, Jiahui Ma, Fujuan Jia, Zhuo Han, Weidong Xie and Xia Li

Mar. Drugs 2019, 17(5), 305; https://doi.org/10.3390/md17050305 - 24 May 2019

Cited by 22 | Viewed by 4720

Abstract

Actinomycin V, an analog of actinomycin D produced by the marine-derived actinomycete Streptomyces sp., possessing a 4-ketoproline instead of a 4-proline in actinomycin D. In this study, the involvement of snail/slug-mediated epithelial-mesenchymal transition (EMT) in the anti-migration and -invasion actions of actinomycin V [...] Read more.

Actinomycin V, an analog of actinomycin D produced by the marine-derived actinomycete Streptomyces sp., possessing a 4-ketoproline instead of a 4-proline in actinomycin D. In this study, the involvement of snail/slug-mediated epithelial-mesenchymal transition (EMT) in the anti-migration and -invasion actions of actinomycin V was investigated in human breast cancer MDA-MB-231 cells in vitro. Cell proliferation effect was evaluated by 3-(4,5-Dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assay. Wound-healing and Transwell assay were performed to investigate the anti-migration and -invasion effects of actinomycin V. Western blotting was used to detect the expression levels of E-cadherin, N-cadherin, vimentin, snail, slug, zinc finger E-box binding homeobox 1 (ZEB1), and twist proteins and the mRNA levels were detected by rt-PCR. Actinomycin V showed stronger cytotoxic activity than that of actinomycin D. Actinomycin V up-regulated both of the protein and mRNA expression levels of E-cadherin and down-regulated that of N-cadherin and vimentin in the same cells. In this connection, actinomycin V decreased the snail and slug protein expression, and consequently inhibited cells EMT procession. Our results suggest that actinomycin V inhibits EMT-mediated migration and invasion via decreasing snail and slug expression, which exhibits therapeutic potential for the treatment of breast cancer and further toxicity investigation in vivo is needed. Full article

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

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29 pages, 707 KiB

Open AccessReview

Microalgae for High-Value Products Towards Human Health and Nutrition

by Ines Barkia, Nazamid Saari and Schonna R. Manning

Mar. Drugs 2019, 17(5), 304; https://doi.org/10.3390/md17050304 - 24 May 2019

Cited by 408 | Viewed by 19953

Abstract

Microalgae represent a potential source of renewable nutrition and there is growing interest in algae-based dietary supplements in the form of whole biomass, e.g., Chlorella and Arthrospira, or purified extracts containing omega-3 fatty acids and carotenoids. The commercial production of bioactive compounds [...] Read more.

Microalgae represent a potential source of renewable nutrition and there is growing interest in algae-based dietary supplements in the form of whole biomass, e.g., Chlorella and Arthrospira, or purified extracts containing omega-3 fatty acids and carotenoids. The commercial production of bioactive compounds from microalgae is currently challenged by the biorefinery process. This review focuses on the biochemical composition of microalgae, the complexities of mass cultivation, as well as potential therapeutic applications. The advantages of open and closed growth systems are discussed, including common problems encountered with large-scale growth systems. Several methods are used for the purification and isolation of bioactive compounds, and many products from microalgae have shown potential as antioxidants and treatments for hypertension, among other health conditions. However, there are many unknown algal metabolites and potential impurities that could cause harm, so more research is needed to characterize strains of interest, improve overall operation, and generate safe, functional products. Full article

(This article belongs to the Special Issue Bioactive Compounds Derived from Marine Microalgae)

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13 pages, 3137 KiB

Open AccessArticle

Blockade of Human α7 Nicotinic Acetylcholine Receptor by α-Conotoxin ImI Dendrimer: Insight from Computational Simulations

by Xiaoxiao Xu, Jiazhen Liang, Zheyu Zhang, Tao Jiang and Rilei Yu

Mar. Drugs 2019, 17(5), 303; https://doi.org/10.3390/md17050303 - 23 May 2019

Cited by 8 | Viewed by 3279

Abstract

Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels that are involved in fast synaptic transmission and mediated physiological activities in the nervous system. α-Conotoxin ImI exhibits subtype-specific blockade towards homomeric α7 and α9 receptors. In this study, we established a method to build [...] Read more.

Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels that are involved in fast synaptic transmission and mediated physiological activities in the nervous system. α-Conotoxin ImI exhibits subtype-specific blockade towards homomeric α7 and α9 receptors. In this study, we established a method to build a 2×ImI-dendrimer/h (human) α7 nAChR model, and based on this model, we systematically investigated the molecular interactions between the 2×ImI-dendrimer and hα7 nAChR. Our results suggest that the 2×ImI-dendrimer possessed much stronger potency towards hα7 nAChR than the α-ImI monomer and demonstrated that the linker between α-ImI contributed to the potency of the 2×ImI-dendrimer by forming a stable hydrogen-bond network with hα7 nAChR. Overall, this study provides novel insights into the binding mechanism of α-ImI dendrimer to hα7 nAChR, and the methodology reported here opens an avenue for the design of more selective dendrimers with potential usage as drug/gene carriers, macromolecular drugs, and molecular probes. Full article

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Structures of a nicotinic acetylcholine receptor (nAChR) and α-ImI. (A) hα7 nAChR bound with α-ImI. nAChRs are ligand-gated ion channels. The structure of nAChR consists of a ligand binding domain (green), a transmembrane domain (yellow), and an intracellular domain (purple). Five α-ImI (light blue) bound to the acetylcholine binding sites. The α-ImI/hα7-nAChR complex structure was built using the crystal structure of α1 subunit (Protein data bank (PDB) code: 2qc1) and AChBP/ImI (PDB code: 2c9t) as templates. (B,C) α-ImI comprises 12 residues and is C-terminal amidated (indicated by *). The structure features a short α-helix and two disulfide bonds that link cysteines I–III and II–IV. The cysteines are highlighted in red. Full article ">Figure 2
Binding mode of the α-ImI monomer and dimer. (A) the binding mode of the α-ImI monomer (light blue). (B) the binding mode of α-ImI of the 2×ImI-dendrimer in the same pocket as (A) (blue). The hα7 nAChR is shown in cartoon, while α-ImI and the residues of the binding site are shown in stick form. Full article ">Figure 3
The conformation of the two α-ImI in the dimer. (A) Evolution of the root mean square deviation (RMSD) for each α-ImI in the dimer in the 50 ns molecular dynamics (MD) simulations. (B) Superposition diagram of the averagely extracted 8 frames (in varied colors) from the last 10 ns and the α-ImI initial frame (in blue). Full article ">Figure 4
The opening of the C-loop in two adjacent binding sites. (A) Side view of the hα7 nAChR subunit. A peripheral loop highlighted in purple represents the C-loop. (B) C-loop opening measurement in the MD simulation. It was measured by calculating the distance between the CA atom of C190 and the CA atom of Y32 in hα7 nAChR over time. Purple and black represent the distance variation of two different binding sites, respectively. Full article ">Figure 5
Conformation and binding modes of the linker. (A) The average extraction frames from 34th ns to 50th ns. Linker was divided into two parts, named UNK8 and UNK9 (<a href="#marinedrugs-17-00303-f007" class="html-fig">Figure 7</a>). (B) Binding mode of the left half of linker (UNK9) at hα7-nAChR; (C) Binding mode of the right half of linker (UNK8) at hα7-nAChR. hα7 nAChR is shown in green, and the two parts of the linkers are colored in orange (UNK9) and purple (UNK8), respectively. Full article ">Figure 6
The 2×ImI-dendrimer/hα7-nAChR model with different lengths of linkers. hα7 nAChR, α-ImI, and the linker are labeled. (A) The 2×ImI-dendrimer model with a linker of reasonable length. Its enthalpy change, entropy change, and binding energy were expressed as ΔH, ΔS, and ΔG. (B) The 2×ImI-dendrimer model with a linker that was too short (2×ImI-dendrimer’). Its enthalpy change, entropy change, and binding energy were expressed as ΔH’, ΔS’, and ΔG’. (C) The 2×ImI-dendrimer model with an overly long linker (2×ImI-dendrimer’’). Its enthalpy change, entropy change, and binding energy were expressed as ΔH’’, ΔS’’, and ΔG’’. Full article ">Figure 7
The structure diagram of the ligand and the linker. (A1) and (A1) represent α-ImI. (B) and (C) are the polyethylene glycol (PEG) spacer units, which were named UNK8 and UNK9 respectively. (D) represents the peptide fraction, and the “X” represents 6 amino acid residues (Gly-Arg-Arg-Arg-Arg-Gly). Full article ">

16 pages, 4498 KiB

Open AccessArticle

Experimental and Computational Study to Reveal the Potential of Non-Polar Constituents from Hizikia fusiformis as Dual Protein Tyrosine Phosphatase 1B and α-Glucosidase Inhibitors

by Su Hui Seong, Duc Hung Nguyen, Aditi Wagle, Mi Hee Woo, Hyun Ah Jung and Jae Sue Choi

Mar. Drugs 2019, 17(5), 302; https://doi.org/10.3390/md17050302 - 22 May 2019

Cited by 24 | Viewed by 3812

Abstract

Hizikia fusiformis (Harvey) Okamura is an edible marine alga that has been widely used in Korea, China, and Japan as a rich source of dietary fiber and essential minerals. In our previous study, we observed that the methanol extract of H. fusiformis and [...] Read more.

Hizikia fusiformis (Harvey) Okamura is an edible marine alga that has been widely used in Korea, China, and Japan as a rich source of dietary fiber and essential minerals. In our previous study, we observed that the methanol extract of H. fusiformis and its non-polar fractions showed potent protein tyrosine phosphatase 1B (PTP1B) and α-glucosidase inhibition. Therefore, the aim of the present study was to identify the active ingredient in the methanol extract of H. fusiformis. We isolated a new glycerol fatty acid (13) and 20 known compounds including 9 fatty acids (1–3, 7–12), mixture of 24R and 24S-saringosterol (4), fucosterol (5), mixture of 24R,28R and 24S,28R-epoxy-24-ethylcholesterol (6), cedrusin (14), 1-(4-hydroxy-3-methoxyphenyl)-2-[2-hydroxy -4-(3-hydroxypropyl)phenoxy]-1,3-propanediol (15), benzyl alcohol alloside (16), madhusic acid A (17), glycyrrhizin (18), glycyrrhizin-6’-methyl ester (19), apo-9′-fucoxanthinone (20) and tyramine (21) from the non-polar fraction of H. fusiformis. New glycerol fatty acid 13 was identified as 2-(7′- (2″-hydroxy-3″-((5Z,8Z,11Z)-icosatrienoyloxy)propoxy)-7′-oxoheptanoyl)oxymethylpropenoic acid by spectroscopic analysis using NMR, IR, and HR-ESI-MS. We investigated the effect of the 21 isolated compounds and metabolites (22 and 23) of 18 against the inhibition of PTP1B and α-glucosidase enzymes. All fatty acids showed potent PTP1B inhibition at low concentrations. In particular, new compound 13 and fucosterol epoxide (6) showed noncompetitive inhibitory activity against PTP1B. Metabolites of glycyrrhizin, 22 and 23, exhibited competitive inhibition against PTP1B. These findings suggest that H. fusiformis, a widely consumed seafood, may be effective as a dietary supplement for the management of diabetes through the inhibition of PTP1B. Full article

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Figure 1
Structures of compounds isolated from Hizikia fusiformis and 18α and 18β-glycyrrhetinic acids. Full article ">Figure 2
The key 2D NMR correlations for compound 13. Full article ">Figure 3
Enzyme kinetic analysis of compounds 6 (A), 13 (B), 22 (C), and 23 (D) using Lineweaver-Burk plots and its secondary plots (1/Vmax,app (Y-intercept) and Km,app/Vmax,app (slope) of the respective linear regression of Lineweaver-Burk plot). Full article ">Figure 4
Best docked models of compounds from H. fusiformis in the catalytic (A and C) and allosteric (A and B) pocket of PTP1B (1T49) along with positive ligands, compounds A (red line) and B (black line). Fucosterol (5), 24R,28R-epoxy-24-ethylcholesterol (6a), 24S,28R-epoxy-24-ethylcholesterol (6b), compound 13, and 18α and 18β-glycyrrhetinic acids (22 and 23) are shown as pink, yellow, green, blue, cyan, and purple stick, respectively. The residues forming inter H-bond with the ligands are shown as blue dotted lines. Hydrophobic interactions between Pro188 residue and compounds are shown as black lines. Full article ">Figure 5
Detailed binding interactions visualized by docking simulation for the compounds 5 (A), 6a (B), 6b (C), 13 (D), 22 (E), and 23 (F). Full article ">

15 pages, 2442 KiB

Open AccessArticle

Renieramycin T Induces Lung Cancer Cell Apoptosis by Targeting Mcl-1 Degradation: A New Insight in the Mechanism of Action

by Korrakod Petsri, Supakarn Chamni, Khanit Suwanborirux, Naoki Saito and Pithi Chanvorachote

Mar. Drugs 2019, 17(5), 301; https://doi.org/10.3390/md17050301 - 21 May 2019

Cited by 19 | Viewed by 4864

Abstract

Among malignancies, lung cancer is the major cause of cancer death. Despite the advance in lung cancer therapy, the five-year survival rate is extremely restricted due to therapeutic failure and disease relapse. Targeted therapies selectively inhibiting certain molecules in cancer cells have been [...] Read more.

Among malignancies, lung cancer is the major cause of cancer death. Despite the advance in lung cancer therapy, the five-year survival rate is extremely restricted due to therapeutic failure and disease relapse. Targeted therapies selectively inhibiting certain molecules in cancer cells have been accepted as promising ways to control cancer. In lung cancer, evidence has suggested that the myeloid cell leukemia 1 (Mcl-1) protein, an anti-apoptotic member of the Bcl-2 family, is a target for drug action. Herein, we report the Mcl-1 targeting activity of renieramycin T (RT), a marine-derived tetrahydroisoquinoline alkaloid that was isolated from the Thai blue sponge Xestospongia sp. RT was shown to be dominantly toxic to lung cancer cells compared to the normal cells in the lung. The cytotoxicity of this compound toward lung cancer cells was mainly exerted through apoptosis induction. For the mechanism of action, we found that RT mediated activation of p53 protein and caspase-9 and -3 activations. While others Bcl-2 family proteins (Bcl-2, Bak, and Bax) were minimally changed in response to RT, Mcl-1 protein was dramatically diminished. We further performed the cycloheximide experiment and found that the half-life of Mcl-1 was significantly shortened by RT treatment. When MG132, a potent selective proteasome inhibitor, was utilized, it could restore the Mcl-1 level. Furthermore, immunoprecipitation analysis revealed that RT significantly increased the formation of Mcl-1-ubiquitin complex compared to the non-treated control. In conclusion, we report the potential apoptosis induction of RT with a mechanism of action involving the targeting of Mcl-1 for ubiquitin-proteasomal degradation. As Mcl-1 is critical for cancer cell survival and chemotherapeutic failure, this novel information regarding the Mcl-1-targeted compound would be beneficial for the development of efficient anti-cancer strategies or targeted therapies. Full article

(This article belongs to the Special Issue Bioactive Compounds from Marine Sponges 2020)

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Figure 1
The structures of renieramycin T (RT) and ecteinascidin 743 (Et 743). Full article ">Figure 2
Renieramycin T (RT) reduced cell viability and induced apoptosis in NSCLC and human normal lung epithelial (BEAS-2B) cell lines. (A) NSCLC and BEAS-2B cell lines were treated with various concentrations of RT (0–25 µM) for 24 h. Percentages of cell viability were determined using the MTT assay. (B) The half maximal inhibitory concentrations (IC50) in NSCLC and BEAS-2B cell lines were calculated by comparison with the untreated control. (C–G) H460 and BEAS-2B cell lines were treated with RT (0–25 µM) for 24 h. Hoechst 33342 and propidium iodide (PI) were added. Then, Images were detected by using an inverted fluorescence microscope (a–c). A condensed blue fluorescence of Hoechst 33342 reflected fragmented chromatin in apoptotic cells (c) while a red fluorescence of PI reflected late apoptotic or necrotic cells (b) comparing with no staining condition (a). Percentages of nuclear fragmented and PI positive cells were calculated. (H) H460 was treated with RT (0–25 µM) for 24 h. Apoptotic and necrotic cells were determined using annexin V-FITC/PI staining with flow cytometry. (I) Percentages of cells at each stage were calculated. Data represented the mean ± SEM (n = 3) (* 0.01 ≤ p < 0.05, ** p < 0.01, compared with the untreated control). Full article ">Figure 3
Renieramycin T (RT) induced activation of PARP, caspase-3, and caspase-9 in the H460 cell line. Moreover, RT also significantly up-regulated p53 and down-regulated Mcl-1 in the H460 cell line. H460 cells were treated with RT (0–25 µM) for 24 h. (A) and (C) Apoptotis-related proteins were measured with Western blot analysis. The blots were reprobed with β-actin to confirm equal loading of each of the protein samples. (B) and (D) The relative protein levels were calculated by densitometry. Data represented the mean ± SEM (n = 3) (* 0.01 ≤ p < 0.05, ** p < 0.01, compared with the untreated control). Full article ">Figure 4
Renieramycin T (RT) induced ubiquitin-mediated Mcl-1 proteasomal degradation. (A) Cycloheximide (CHX) chasing assay was performed to measure Mcl-1 half-lives. H460 cells were treated with RT (0–5 µM) with or without 50 µg/mL CHX as indicated by the time in h. Western blot analysis was performed for determined Mcl-1 levels. The blots were reprobed with β-actin to confirm equal loading of each of the protein samples. (B) The relative protein levels were calculated by densitometry (** p < 0.01, compared with the untreated control at 0 h, # 0.01 ≤ p < 0.05, ## p < 0.01, compared with the untreated control at the same time). (C) Mcl-1 half-lives were calculated. (D) H460 cell line was treated with RT (0–5 µM) with or without MG132 (0–20 µM) for 4 h. Mcl-1 expression levels were measured using Western blot analysis. The blots were reprobed with β-actin to confirm equal loading of each of the protein samples. (E) The reversal of RT-mediated down-regulation of Mcl-1 levels by MG132 was calculated by densitometry compared to the non-MG132 treated group (* 0.01 ≤ p < 0.05, compared with the non-MG132 treated group). (F) H460 was treated with RT (5 µM) and MG132 (10 µM) for 4 h. Then, protein lysates were collected subsequent to Mcl-1 immunoprecipitation, and the ubiquitinated protein levels were measured by Western blotting. (G) Ub-Mcl-1 levels were quantified using densitometry (* p < 0.01, compared with the untreated control) All data represented the mean ± SEM (n = 3). Full article ">Figure 5
Renieramycin T (RT) enhances apoptosis induction through Mcl-1 proteasomal degradation. Normally, Mcl-1 forms complex with Bak to inhibit its apoptotic function, but when Mcl-1 is degraded through the ubiquitin-mediated proteasomal degradation by treatment of RT, Bak is relieved. Activated Bak forms oligomerization that can permeabilize the outer membrane of mitochondria and release cytochrome c to initiate the apoptosis mechanism. Full article ">

14 pages, 2826 KiB

Open AccessArticle

Activity Improvement and Vital Amino Acid Identification on the Marine-Derived Quorum Quenching Enzyme MomL by Protein Engineering

by Jiayi Wang, Jing Lin, Yunhui Zhang, Jingjing Zhang, Tao Feng, Hui Li, Xianghong Wang, Qingyang Sun, Xiaohua Zhang and Yan Wang

Mar. Drugs 2019, 17(5), 300; https://doi.org/10.3390/md17050300 - 21 May 2019

Cited by 16 | Viewed by 4636

Abstract

MomL is a marine-derived quorum-quenching (QQ) lactonase which can degrade various N-acyl homoserine lactones (AHLs). Intentional modification of MomL may lead to a highly efficient QQ enzyme with broad application potential. In this study, we used a rapid and efficient method combining [...] Read more.

MomL is a marine-derived quorum-quenching (QQ) lactonase which can degrade various N-acyl homoserine lactones (AHLs). Intentional modification of MomL may lead to a highly efficient QQ enzyme with broad application potential. In this study, we used a rapid and efficient method combining error-prone polymerase chain reaction (epPCR), high-throughput screening and site-directed mutagenesis to identify highly active MomL mutants. In this way, we obtained two candidate mutants, MomL_I144V and MomL_V149A. These two mutants exhibited enhanced activities and blocked the production of pathogenic factors of Pectobacterium carotovorum subsp. carotovorum (Pcc). Besides, seven amino acids which are vital for MomL enzyme activity were identified. Substitutions of these amino acids (E238G/K205E/L254R) in MomL led to almost complete loss of its QQ activity. We then tested the effect of MomL and its mutants on Pcc-infected Chinese cabbage. The results indicated that MomL and its mutants (MomL_L254R, MomL_I144V, MomL_V149A) significantly decreased the pathogenicity of Pcc. This study provides an efficient method for QQ enzyme modification and gives us new clues for further investigation on the catalytic mechanism of QQ lactonase. Full article

(This article belongs to the Special Issue Marine Enzymes: Sources, Biochemistry and Bioprocesses for Marine Biotechnology)

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Figure 1
The schematic diagram of high efficiency strategy of constructing and screening random mutagenesis library (A) and the process of error-prone polymerase chain reaction (epPCR) and seamless cloning (B). Full article ">Figure 2
Efficiency comparison between seamless cloning and traditional cloning (TA). All data are presented as mean ± standard deviation (SD, n = 3). Full article ">Figure 3
Screening target proteins by isopropyl-β-d-thiogalactoside (IPTG) in situ photocopying. M1–M8 are single colonies with highly activity; M9–M10 indicate inactive proteins. Full article ">Figure 4
Multiple sequence alignment of amino acid sequences of MomL, putative homologues, and other representative N-acyl homoserine lactone (AHL) lactonases. Sequence alignment was performed by the MUSCLE program in the MEGA software package and enhanced by ESPript 3.0. MomL homologue from Eudoraea adriatica (WP_019670967) showed the highest score when BLASTP searching nonredundant (NR) databases. Other sequences of AHL lactonase are AiiA from Bacillus sp. strain 240B1 (AAF62398), AidC from Chryseobacterium sp. strain StRB126 (BAM28988), QlcA from unculturable soil bacteria, and AttM (AAD43990), AiiB (NP 396590) from Agrobacterium fabrum C58 and YtnP from Bacillus. Filled triangles show amino acids which are essential for MomL activity. Filled rhombuses show amino acids, the mutation of which increased MomL activity. Full article ">Figure 5
(A) Enzyme kinetics experiments of MomL and mutant proteins on different substrates C6-HSL and 3OC10-HSL. (B) Protein activity test of mutant proteins. All data are presented as mean ± standard deviation (SD, n = 3). An unpaired t-test was performed for testing significant differences between groups (*** P < 0.001, ** P < 0.01, * P < 0.05). (C) Multiple-sequence alignment of the amino acid sequences of MomL, putative homologues, and other representative AHL lactonases. The multiple-sequence alignment procedure is the same as described in <a href="#marinedrugs-17-00300-f004" class="html-fig">Figure 4</a>. (D) The structure and active site of AiiA, the homologous protein of MomL. A114 and A119 in AiiA are located near the C-loop. Full article ">Figure 6
Transcriptional level of pectate lyase encoding gene in Pectobacterium carotovorum subsp. carotovorum (Pcc) (A) and the production of pectate lyase (OD492). (B). Effects of MomL and mutant proteins towards the Pcc survival rate (C). All data are presented as mean ± standard deviation (SD, n = 3). An unpaired t-test was performed for testing significant differences between groups (*** P < 0.001, ** P < 0.01, * P < 0.05). Full article ">Figure 7
Effects of MomL and mutant proteins on Pcc infection of Chinese cabbage. (A) Pcc; (B) Pcc with MomLE238G; (C) Pcc with MomLK205E; (D) Pcc with MomLL254R; (E) Pcc with MomL; (F) Pcc with MomLI144V; (G) Pcc with MomLV149A; (H) Pcc with boiled MomL. The results shown are representative of biological duplicates. Full article ">

12 pages, 734 KiB

Open AccessCommunication

Different Antifungal Activity of Anabaena sp., Ecklonia sp., and Jania sp. against Botrytis cinerea

by Hillary Righini, Elena Baraldi, Yolanda García Fernández, Antera Martel Quintana and Roberta Roberti

Mar. Drugs 2019, 17(5), 299; https://doi.org/10.3390/md17050299 - 20 May 2019

Cited by 34 | Viewed by 4730

Abstract

Water extracts and polysaccharides from Anabaena sp., Ecklonia sp., and Jania sp. were tested for their activity against the fungal plant pathogen Botrytis cinerea. Water extracts at 2.5, 5.0, and 10.0 mg/mL inhibited B. cinerea growth in vitro. Antifungal activity of polysaccharides [...] Read more.

Water extracts and polysaccharides from Anabaena sp., Ecklonia sp., and Jania sp. were tested for their activity against the fungal plant pathogen Botrytis cinerea. Water extracts at 2.5, 5.0, and 10.0 mg/mL inhibited B. cinerea growth in vitro. Antifungal activity of polysaccharides obtained by N-cetylpyridinium bromide precipitation in water extracts was evaluated in vitro and in vitro at 0.5, 2.0, and 3.5 mg/mL. These concentrations were tested against fungal colony growth, spore germination, colony forming units (CFUs), CFU growth, and on strawberry fruits against B. cinerea infection with pre- and post-harvest application. In in vitro experiments, polysaccharides from Anabaena sp. and from Ecklonia sp. inhibited B. cinerea colony growth, CFUs, and CFU growth, while those extracted from Jania sp. reduced only the pathogen spore germination. In in vitro experiments, all concentrations of polysaccharides from Anabaena sp., Ecklonia sp., and Jania sp. reduced both the strawberry fruits infected area and the pathogen sporulation in the pre-harvest treatment, suggesting that they might be good candidates as preventive products in crop protection. Full article

(This article belongs to the Collection Marine Polysaccharides)

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Effect of different POL concentrations on Botrytis cinerea colony growth rate. Treatment and dose factors and their interaction are significant, according to factorial ANOVA. F(2,36) = 18.2, p < 0.0001 (for treatment factor), F(3,36) = 27.8, p < 0.0001 (for dose factor), F(6,36) = 2.7, p < 0.05 (for interaction). Columns are mean values ± SD. The same uppercase letter within each POL treatment and the same lowercase letter among concentrations indicates no significant differences according to Student–Newman–Keuls test (p < 0.05). Full article ">Figure 2
Infected area of strawberry fruit caused by Botrytis cinerea (a) and its sporulation (b) after pre-harvest treatment with different concentrations of polysaccharides from Anabaena sp. (AN), Ecklonia sp. (ECK), and Jania sp. (JAN). Polysaccharides and concentration factors and their interaction are significant, according to factorial ANOVA. (a) F(2,240) = 270.0, p < 0.0001 (for treatment factor), F(3,240) = 266.3, p < 0.0001 (for dose factor), F(6,240) = 45.0, p < 0.05 (for interaction). (b) F(2,96) = 23.0, p < 0.0001 (for treatment factor), F(3,96) = 370.0, p < 0.0001 (for dose factor), F(6,96) = 18.5, p < 0.05 (for interaction). Columns are mean values ± SD. The same uppercase letter within each POL treatment and the same lowercase letter within each concentration indicates no significant differences according to Student–Newman–Keuls test (p < 0.05). Full article ">

11 pages, 1969 KiB

Open AccessCommunication

Profiling of Small Molecular Metabolites in Nostoc flagelliforme during Periodic Desiccation

by Xiang Gao, Bin Liu and Boyang Ji

Mar. Drugs 2019, 17(5), 298; https://doi.org/10.3390/md17050298 - 18 May 2019

Cited by 8 | Viewed by 2988

Abstract

The mass spectrometry-based metabolomics approach has become a powerful tool for the quantitative analysis of small-molecule metabolites in biological samples. Nostoc flagelliforme, an edible cyanobacterium with herbal value, serves as an unexploited bioresource for small molecules. In natural environments, N. flagelliforme undergoes [...] Read more.

The mass spectrometry-based metabolomics approach has become a powerful tool for the quantitative analysis of small-molecule metabolites in biological samples. Nostoc flagelliforme, an edible cyanobacterium with herbal value, serves as an unexploited bioresource for small molecules. In natural environments, N. flagelliforme undergoes repeated cycles of rehydration and dehydration, which are interrupted by either long- or short-term dormancy. In this study, we performed an untargeted metabolite profiling of N. flagelliforme samples at three physiological states: Dormant (S1), physiologically fully recovered after rehydration (S2), and physiologically partially inhibited following dehydration (S3). Significant metabolome differences were identified based on the OPLS-DA (orthogonal projections to latent structures discriminant analysis) model. In total, 183 differential metabolites (95 up-regulated; 88 down-regulated) were found during the rehydration process (S2 vs. S1), and 130 (seven up-regulated; 123 down-regulated) during the dehydration process (S3 vs. S2). Thus, it seemed that the metabolites’ biosynthesis mainly took place in the rehydration process while the degradation or possible conversion occurred in the dehydration process. In addition, lipid profile differences were particularly prominent, implying profound membrane phase changes during the rehydration–dehydration cycle. In general, this study expands our understanding of the metabolite dynamics in N. flagelliforme and provides biotechnological clues for achieving the efficient production of those metabolites with medical potential. Full article

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Figure 1
The overview of N. flagelliforme in response to the rewetting–drying cycle. (A) a descriptive model for native environmental adaptation. (B) the changes in PSII activity (in terms of Fv/Fm), and (C) the relative water contents of the samples, respectively, during the rewetting and drying processes. The data shown in (B) are means ± S.D. (n = 5). S1, S2, and S3—three sampling points. Full article ">Figure 2
The PCA analysis of the LS-MS metabolomic profiles in positive mode (A), negative mode (B), and the total ion chromatograms (C). The three groups of samples from the three time points (S1, S2, and S3) and pooled QC samples were shown. Full article ">Figure 3
A summary of the differentially regulated metabolites between the samples from the three time points. Full article ">Figure 4
The top 20 significantly differential metabolites relatively upregulated in the rewetting stage and then reduced in the drying stage. * significant difference (p-value < 0.05), as compared to the S1 stage. 1—Ethenodeoxyadenosine; 2—TG(12:0/12:0/20:2(11Z,14Z))[iso3]; 3—3-Hexadecanoyloleanolic acid; 4—Hericenone E; 5—PA(12:0/15:1(9Z)); 6—Bacteriohopane-32,33,34-triol-35-carbamate; 7—Norselic acid E; 8—PG(18:4(6Z,9Z,12Z,15Z)/15:1(9Z)); 9—PE(17:0/20:4(5Z,8Z,11Z,14Z)); 10—PG(13:0/20:3(8Z,11Z,14Z)); 11—PS(O-16:0/18:3(9Z,12Z,15Z)); 12—PE(22:6(4Z,7Z,10Z,13Z,16Z,19Z)/20:4(5Z,8Z,11Z,14Z))[U]; 13—PS(O-16:0/18:4(6Z,9Z,12Z,15Z)); 14—MIPC(t18:0/22:0(2OH)); 15—PE(18:0/20:4(5Z,8Z,10E,14Z)(12OH[S])); 16—SQDG(16:0/16:0); 17—PS(12:0/21:0); 18—Mucronine A; 19—PE(16:0/22:6(4Z,7Z,10Z,13Z,16Z,19Z)); 20—PI(20:2(11Z,14Z)/22:4(7Z,10Z,13Z,16Z)). Full article ">Figure 5
The significantly differential metabolites relatively upregulated in the drying stage or both the rewetting and drying stages. * significant difference (p-value < 0.05), as compared to the S1 stage. 1—2-Ethylacrylylcarnitine; 2—PC(O-12:0/O-1:0); 3—Dihydroskullcap flavone I; 4—Neuraminic acid; 5—(E)-Resveratrol 3-glucoside 4’-sulfate; 6—Echinenone/ (Myxoxanthin); 7—PE-Cer(d14:2(4E,6E)/24:1(15Z)(2OH)); 8—(S)-2,3-Dihydro-3,5-dihydroxy-2-oxo-3-indoleacetic acid 5-[glucosyl-(1->4)-b-D-glucoside]; 9—Fenothiocarb; 10—6-Methoxy-9H-carbazole-3-carboxaldehyde; 11—Levomethadyl acetate; 12—3-Indolebutyric acid; 13—CerP(d18:1/12:0); 14—PI(O-16:0/12:0); 15—PC(15:0/19:3(9Z,12Z,15Z))[U]; 16—Taxiphyllin; 17—PG(16:0/22:5(4Z,7Z,10Z,13Z,16Z)); 18—Phosphohydroxypyruvic acid. Full article ">Figure 6
The metabolic pathway analysis of N. flagelliforme in response to the rewetting (A) and drying (B) processes. The impacted pathways are shown as circles. The size of the circle corresponds to the pathway impact score, and their colors are based on p-value. Full article ">

12 pages, 2171 KiB

Open AccessArticle

Effect of Cyclophilin from Pyropia Yezoensis on the Proliferation of Intestinal Epithelial Cells by Epidermal Growth Factor Receptor/Ras Signaling Pathway

by Jae-Hun Jung, Jeong-Wook Choi, Min-Kyeong Lee, Youn-Hee Choi and Taek-Jeong Nam

Mar. Drugs 2019, 17(5), 297; https://doi.org/10.3390/md17050297 - 18 May 2019

Cited by 7 | Viewed by 2939

Abstract

Cyclophilin (Cyp) is peptidyl–prolyl isomerase (PPIase), and it has many biological functions, including immune response regulation, antioxidants, etc. Cyp from red algae is known for its antioxidant and antifungal activity. However, the other biological effects of Cyp from Pyropia yezoensis are unclear. In [...] Read more.

Cyclophilin (Cyp) is peptidyl–prolyl isomerase (PPIase), and it has many biological functions, including immune response regulation, antioxidants, etc. Cyp from red algae is known for its antioxidant and antifungal activity. However, the other biological effects of Cyp from Pyropia yezoensis are unclear. In this study, we synthesized Cyp from P. yezoensis (pyCyp) and examined its biological activity on IEC-6 cells. First, the MTS assay showed that pyCyp increased cell proliferation in a dose-dependent manner. pyCyp activated the EGFR signaling pathway that regulates cell growth, proliferation, and survival. It induced intracellular signaling pathways, including the Ras signaling pathway. In addition, we observed cell cycle-related proteins. pyCyp increased the expression of cyclin A, cyclin E, and Cdk2, and decreased the expression of p27 and p21 proteins. These results indicate that pyCyp stimulates cell proliferation via the EGFR signaling pathway and promotes cell cycle progression in intestinal epithelial cells. Therefore, we suggest pyCyp as a potential material to promote the proliferation of intestinal epithelial cells. Full article

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Figure 1
Expression and purification of Cyp from P. yezoensis (pyCyp) protein. pyCyp was separated by size exclusion chromatography. One visible band indicates that pyCyp is completely separated. Full article ">Figure 2
Proliferative effect of pyCyp on intestinal epithelial cell line (IEC-6). Full article ">Figure 3
Effect of treatment with pyCyp on epidermal growth factor receptor (EGFR), growth factor receptor-bound protein-2 (Grb2), and son of sevenless (SOS) protein expression levels in IEC-6 cells. (A) Proteins were subjected to Western blot analysis. Protein expression levels were increased upon incubation with pyCyp for 48 h. (B) Bands were normalized to anti-glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as an internal control. Protein expression or the phosphorylated vs. total protein ratio is graphed. * p < 0.05 vs. corresponding control group. Full article ">Figure 4
Effects of treatment with pyCyp on Ras, Raf-1, MEK, and ERK protein expression levels in IEC-6 cells. (A) Whole-cell extracts were prepared and analyzed by Western blot analysis using anti-Ras, anti-Raf-1, anti-phosphorylated-Raf-1, anti-MEK, anti-phosphorylated-MEK anti-phosphorylated-ERK, anti-ERK, and anti-glyceraldehyde 3-phosphate dehydrogenase (GAPDH) antibodies. (B) Bands were normalized to GAPDH as an internal control. Protein expression, or the phosphorylated vs total protein ratio, is graphed. * p < 0.05 vs. corresponding control group. Full article ">Figure 5
Representative DNA histograms on the cell cycle profile of IEC-6 cells. (A) In the dose-dependence experiments, pyCyp was added at each concentration (0 pg/mL, 5 pg/mL, 25 pg/mL, and 50 pg/mL) for 48 h. Cells were harvested and fixed by 70% ethanol for at least more than 3 h. The cell cycle was analyzed by using flow cytometry (Muse Cell Znalyzer). (B) Change of cell cycle phase ratio by the pyCyp concentration in IEC-6 cells. Full article ">Figure 6
Effect of pyCyp treatment on the levels of cell cycle related proteins in IEC-6 cells. (A) Cells were treated with pyCyp after preincubation with SFM for 4 h. Whole cell extracts were prepared and analyzed by Western blotting using anti-Cyclin E, anti-Cyclin A, anti-Cdk2, anti-Cdc25a, anti-pRb, anti-phosphorylated-pRb anti-p27, and anti-p21. (B) Bands were normalized to GAPDH as an internal control. Protein expression, or the phosphorylated vs total protein ratio, is graphed. * p < 0.05 vs. corresponding control group. Full article ">Figure 7
Model of pyCyp protein effects on EGFR signaling in IEC-6 cells. Full article ">

13 pages, 1735 KiB

Open AccessArticle

Polyketides from the Mangrove-Derived Endophytic Fungus Cladosporium cladosporioides

by Fan-Zhong Zhang, Xiao-Ming Li, Xin Li, Sui-Qun Yang, Ling-Hong Meng and Bin-Gui Wang

Mar. Drugs 2019, 17(5), 296; https://doi.org/10.3390/md17050296 - 17 May 2019

Cited by 27 | Viewed by 3951

Abstract

Five new polyketides, namely, 5R-hydroxyrecifeiolide (1), 5S-hydroxyrecifeiolide (2), ent-cladospolide F (3), cladospolide G (4), and cladospolide H (5), along with two known compounds (6 and 7), [...] Read more.

Five new polyketides, namely, 5R-hydroxyrecifeiolide (1), 5S-hydroxyrecifeiolide (2), ent-cladospolide F (3), cladospolide G (4), and cladospolide H (5), along with two known compounds (6 and 7), were isolated from the endophytic fungal strain Cladosporium cladosporioides MA-299 that was obtained from the leaves of the mangrove plant Bruguiera gymnorrhiza. The structures of these compounds were established by extensive analysis of 1D/2D NMR data, mass spectrometric data, ECDs and optical rotations, and modified Mosher’s method. The structures of 3 and 6 were confirmed by single-crystal X-ray diffraction analysis and this is the first time for reporting the crystal structures of these two compounds. All of the isolated compounds were examined for antimicrobial activities against human and aquatic bacteria and plant pathogenic fungi as well as enzymatic inhibitory activities against acetylcholinesterase. Compounds 1–4, 6, and 7 exhibited antimicrobial activity against some of the tested strains with MIC values ranging from 1.0 to 64 μg/mL, while 3 exhibited enzymatic inhibitory activity against acetylcholinesterase with the IC₅₀ value of 40.26 μM. Full article

(This article belongs to the Special Issue Bioactive Marine Heterocyclic Compounds)

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14 pages, 3269 KiB

Open AccessArticle

A New Tyrosinase Inhibitor from the Red Alga Symphyocladia latiuscula (Harvey) Yamada (Rhodomelaceae)

by Pradeep Paudel, Aditi Wagle, Su Hui Seong, Hye Jin Park, Hyun Ah Jung and Jae Sue Choi

Mar. Drugs 2019, 17(5), 295; https://doi.org/10.3390/md17050295 - 17 May 2019

Cited by 30 | Viewed by 4726

Abstract

A marine red alga, Symphyocladia latiuscula (Harvey) Yamada (Rhodomelaceae), is a rich source of bromophenols with a wide array of biological activities. This study investigates the anti-tyrosinase activity of the alga. Moderate activity was demonstrated by the methanol extract of S. latiuscula, [...] Read more.

A marine red alga, Symphyocladia latiuscula (Harvey) Yamada (Rhodomelaceae), is a rich source of bromophenols with a wide array of biological activities. This study investigates the anti-tyrosinase activity of the alga. Moderate activity was demonstrated by the methanol extract of S. latiuscula, and subsequent column chromatography identified three bromophenols: 2,3,6-tribromo-4,5-dihydroxybenzyl methyl alcohol (1), 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (2), and bis-(2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether) (3). Bromophenols 1 and 3 exhibited potent competitive tyrosinase inhibitory activity against l-tyrosine substrates, with IC₅₀ values of 10.78 ± 0.19 and 2.92 ± 0.04 μM, respectively. Against substrate l-3,4-dihydroxyphenylalanine (l-DOPA), compounds 1 and 3 demonstrated moderate activity, while 2 showed no observable effect. The experimental data were verified by a molecular docking study that found catalytic hydrogen and halogen interactions were responsible for the activity. In addition, compounds 1 and 3 exhibited dose-dependent inhibitory effects in melanin and intracellular tyrosinase levels in α-melanocyte-stimulating hormone (α-MSH)-induced B16F10 melanoma cells. Compounds 3 and 1 were the most effective tyrosinase inhibitors. In addition, increasing the bromine group number increased the mushroom tyrosinase inhibitory activity. Full article

(This article belongs to the Special Issue Seaweeds Secondary Metabolites: Successes in and/or Probable Therapeutic Applications)

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Structure of the compounds isolated from the ethyl acetate fraction of S. latiuscula. Full article ">Figure 2
Lineweaver–Burk plots and the secondary plots of Kmapp/Vmaxapp and 1/Vmaxapp for the inhibition of tyrosinase by compounds 1 (A,B) and 3 (C,D) in the presence of different concentrations of substrate (l-tyrosine). Full article ">Figure 3
Molecular docking results of bromophenol compounds from S. latiuscula in the active site of oxy-form Agaricus bisporus tyrosinase (2Y9X) along with reference ligands. The chemical structure of compounds 1, 2, 3, l-tyrosine, and luteolin are shown in green, purple, yellow, black, and cyan sticks, respectively. Bromine, oxygen, and nitrogen atoms are shown in brown, red, and blue, respectively. Copper and peroxide ions are shown in orange and red spheres, respectively. Full article ">Figure 4
Molecular docking results of bromo-compounds 1 (A), 2 (B), and 3 (C) in the catalytic site of oxy-form Agaricus bisporus tyrosinase (2Y9X). Full article ">Figure 5
Effect of bromophenols 1–3 on cell viability in B16F10 cells (A) and co-treatment with 5 μM α-MSH (B). Cell viability was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method. Cells were pretreated with the indicated concentrations (25, 50, and 100 μM) of test compounds for 48 h. Data shown represent mean ± SD of triplicate experiments. a p < 0.05 and b p < 0.01 indicates significant differences from the control group. Full article ">Figure 6
Effect of bromophenols 1–3 on extracellular melanin content (A) and cellular tyrosinase activity (B) in α-MSH-stimulated B16F10 cells. Cells were pretreated with the indicated concentrations (6.25, 12.5, and 25 μM) of bromophenols 1–3 for 1 h followed by exposure to α-MSH (5.0 μM) for 48 h in the presence or the absence of test bromophenols. Arbutin (500 μM) was used as a positive control. Values represent the mean ± SD of triplicate experiments. a p < 0.01 indicates significant differences from the control group; b p < 0.05, c p < 0.01 and d p < 0.001 indicate significant differences from the α-MSH treated group. Full article ">Figure 7
Effects of bromophenol 1 (A), 2 (B), and 3 (C) on cellular tyrosinase protein expression levels in α-MSH-stimulated B16F10 cells. Western blotting was performed, and protein band intensities were quantified by densitometric analysis. Upper panels display representative blots. Graphs under each bands represent the relative band density for tyrosinase (TYR) normalized to β-actin. Values represent the mean ± SD of three independent experiments; a p < 0.001 indicates significant differences from the control group; b p < 0.05, c p < 0.01 and d p < 0.001 indicate significant differences from the α-MSH treated group. Full article ">

12 pages, 2302 KiB

Open AccessArticle

Three New Isoflavonoid Glycosides from the Mangrove-Derived Actinomycete Micromonospora aurantiaca 110B

by Rui-Jun Wang, Shao-Yong Zhang, Yang-Hui Ye, Zhen Yu, Huan Qi, Hui Zhang, Zheng-Lian Xue, Ji-Dong Wang and Min Wu

Mar. Drugs 2019, 17(5), 294; https://doi.org/10.3390/md17050294 - 17 May 2019

Cited by 20 | Viewed by 3711

Abstract

The mangrove ecosystem is a rich resource for the discovery of actinomycetes with potential applications in pharmaceutical science. Besides the genus Streptomyces, Micromonospora is also a source of new bioactive agents. We screened Micromonospora from the rhizosphere soil of mangrove plants in [...] Read more.

The mangrove ecosystem is a rich resource for the discovery of actinomycetes with potential applications in pharmaceutical science. Besides the genus Streptomyces, Micromonospora is also a source of new bioactive agents. We screened Micromonospora from the rhizosphere soil of mangrove plants in Fujian province, China, and 51 strains were obtained. Among them, the extracts of 12 isolates inhibited the growth of human lung carcinoma A549 cells. Strain 110B exhibited better cytotoxic activity, and its bioactive constituents were investigated. Consequently, three new isoflavonoid glycosides, daidzein-4′-(2-deoxy-α-l-fucopyranoside) (1), daidzein-7-(2-deoxy-α-l-fucopyranoside) (2), and daidzein-4′,7-di-(2-deoxy-α-l-fucopyranoside) (3) were isolated from the fermentation broth of strain 110B. The structures of the new compounds were determined by spectroscopic methods, including 1D and 2D nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HR-ESIMS). The result of medium-changing experiments implicated that these new compounds were microbial biotransformation products of strain M. aurantiaca 110B. The three compounds displayed moderate cytotoxic activity to the human lung carcinoma cell line A549, hepatocellular liver carcinoma cell line HepG2, and the human colon tumor cell line HCT116, whereas none of them showed antifungal or antibacterial activities. Full article

(This article belongs to the Special Issue Natural Products from Marine Actinomycetes)

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Cytotoxic activity of extracts obtained from 12 isolates against the human lung tumor cell line A549 in vitro. Full article ">Figure 2
Neighbor-joining phylogenetic tree based on nearly complete 16S rRNA gene sequences showing relationships between the 12 active isolates and the type strains of the highest 16S rDNA sequence similarity. Bootstrap values were based on 1000 replicates; only values ≥50% are shown. Bar: 0.002 substitutions per nucleotide position. Full article ">Figure 3
The structures and key 1H–1H COSY and HMBC correlations for compounds 1–3. Full article ">Figure 4
The key NOESY correlations for compound 1. Full article ">Figure 5
HPLC analysis of the formation of compounds 1–3 in different media, with a mobile phase of CH3CN/H2O (25:75, v/v), flow rate of 1.5 mL/min−1, and detection wavelength at 254 nm. Full article ">Figure 6
Alignment of the deduced amino acid sequence of AXH94677.1 in strain 110B with different 2-deoxyfucosyltransferases: A0A1C4KH77 (SCD60843.1) from Streptomyces sp. DvalAA-19, AknK (AAF70102.1) from Streptomyces galilaeus, A0A1M5X8V1 (SHH96196.1) from Streptomyces sp. 3214.6, and A0A2G7A0A5 (PIG12760.1) from Streptomyces sp. 1121.2. Full article ">

20 pages, 3622 KiB

Open AccessFeature PaperArticle

A Glycosaminoglycan Extract from Portunus pelagicus Inhibits BACE1, the β Secretase Implicated in Alzheimer’s Disease

by Courtney J. Mycroft-West, Lynsay C. Cooper, Anthony J. Devlin, Patricia Procter, Scott E. Guimond, Marco Guerrini, David G. Fernig, Marcelo A. Lima, Edwin A. Yates and Mark A. Skidmore

Mar. Drugs 2019, 17(5), 293; https://doi.org/10.3390/md17050293 - 16 May 2019

Cited by 9 | Viewed by 4489

Abstract

Therapeutic options for Alzheimer’s disease, the most common form of dementia, are currently restricted to palliative treatments. The glycosaminoglycan heparin, widely used as a clinical anticoagulant, has previously been shown to inhibit the Alzheimer’s disease-relevant β-secretase 1 (BACE1). Despite this, the deployment of [...] Read more.

Therapeutic options for Alzheimer’s disease, the most common form of dementia, are currently restricted to palliative treatments. The glycosaminoglycan heparin, widely used as a clinical anticoagulant, has previously been shown to inhibit the Alzheimer’s disease-relevant β-secretase 1 (BACE1). Despite this, the deployment of pharmaceutical heparin for the treatment of Alzheimer’s disease is largely precluded by its potent anticoagulant activity. Furthermore, ongoing concerns regarding the use of mammalian-sourced heparins, primarily due to prion diseases and religious beliefs hinder the deployment of alternative heparin-based therapeutics. A marine-derived, heparan sulphate-containing glycosaminoglycan extract, isolated from the crab Portunus pelagicus, was identified to inhibit human BACE1 with comparable bioactivity to that of mammalian heparin (IC₅₀ = 1.85 μg mL⁻¹ (R² = 0.94) and 2.43 μg mL⁻¹ (R² = 0.93), respectively), while possessing highly attenuated anticoagulant activities. The results from several structural techniques suggest that the interactions between BACE1 and the extract from P. pelagicus are complex and distinct from those of heparin. Full article

(This article belongs to the Special Issue Marine Glycobiology, Glycomics and Lectins)

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13 pages, 3073 KiB

Open AccessArticle

Novel Bioactive Penicipyrroether A and Pyrrospirone J from the Marine-Derived Penicillium sp. ZZ380

by Tengfei Song, Mingmin Tang, Hengju Ge, Mengxuan Chen, Xiaoyuan Lian and Zhizhen Zhang

Mar. Drugs 2019, 17(5), 292; https://doi.org/10.3390/md17050292 - 15 May 2019

Cited by 39 | Viewed by 4133

Abstract

The marine-sourced fungus Penicillium sp. ZZ380 was previously reported to have the ability to produce a series of new pyrrospirone alkaloids. Further investigation on this strain resulted in the isolation and identification of novel penicipyrroether A and pyrrospirone J. Each of them represents [...] Read more.

The marine-sourced fungus Penicillium sp. ZZ380 was previously reported to have the ability to produce a series of new pyrrospirone alkaloids. Further investigation on this strain resulted in the isolation and identification of novel penicipyrroether A and pyrrospirone J. Each of them represents the first example of its structural type, with a unique 6/5/6/5 polycyclic fusion that is different from the 6/5/6/6 fused ring system for the reported pyrrospirones. Their structures were elucidated by extensive nuclear magnetic resonance (NMR) and high resolution electrospray ionization mass spectroscopy (HRESIMS) spectroscopic analyses, electronic circular dichroism (ECD) and ¹³C NMR calculations and X-ray single crystal diffraction. Penicipyrroether A showed potent antiproliferative activity against human glioma U87MG and U251 cells with half maximal inhibitory concentration (IC₅₀) values of 1.64–5.50 μM and antibacterial inhibitory activity with minimum inhibitory concentration (MIC) values of 1.7 μg/mL against methicillin-resistant Staphylococcus aureus and 3.0 μg/mL against Escherichia coli. Full article

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Graphical abstract

19 pages, 3918 KiB

Open AccessArticle

Anticoagulant Activity of Sulfated Ulvan Isolated from the Green Macroalga Ulva rigida

by Amandine Adrien, Antoine Bonnet, Delphine Dufour, Stanislas Baudouin, Thierry Maugard and Nicolas Bridiau

Mar. Drugs 2019, 17(5), 291; https://doi.org/10.3390/md17050291 - 14 May 2019

Cited by 79 | Viewed by 7023

Abstract

(1) Background: Brown and red algal sulfated polysaccharides have been widely described as anticoagulant agents. However, data on green algae, especially on the Ulva genus, are limited. This study aimed at isolating ulvan from the green macroalga Ulva rigida using an acid- and [...] Read more.

(1) Background: Brown and red algal sulfated polysaccharides have been widely described as anticoagulant agents. However, data on green algae, especially on the Ulva genus, are limited. This study aimed at isolating ulvan from the green macroalga Ulva rigida using an acid- and solvent-free procedure, and investigating the effect of sulfate content on the anticoagulant activity of this polysaccharide. (2) Methods: The obtained ulvan fraction was chemically sulfated, leading to a doubling of the polysaccharide sulfate content in a second ulvan fraction. The potential anticoagulant activity of both ulvan fractions was then assessed using different assays, targeting the intrinsic and/or common (activated partial thromboplastin time), extrinsic (prothrombin time), and common (thrombin time) pathways, and the specific antithrombin-dependent pathway (anti-Xa and anti-IIa), of the coagulation cascade. Furthermore, their anticoagulant properties were compared to those of commercial anticoagulants: heparin and Lovenox^®. (3) Results: The anticoagulant activity of the chemically-sulfated ulvan fraction was stronger than that of Lovenox^® against both the intrinsic and extrinsic coagulation pathways. (4) Conclusion: The chemically-sulfated ulvan fraction could be a very interesting alternative to heparins, with different targets and a high anticoagulant activity. Full article

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

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Graphical abstract

Graphical abstract
Full article ">Figure 1
Size exclusion chromatograms of the ULVAN-01 and ULVAN-02 fractions. Full article ">Figure 2
Negative-ion mode electrospray ionization-mass spectrometry targeted fragmentation spectra (ESI−-pseudo-MS3) of the ions (m/z) 401.0383 (A, sequence 5 in <a href="#marinedrugs-17-00291-t002" class="html-table">Table 2</a>), 502.9776 (B, sequence 6 in <a href="#marinedrugs-17-00291-t002" class="html-table">Table 2</a>), 604.9166 (C, sequence 7 in <a href="#marinedrugs-17-00291-t002" class="html-table">Table 2</a>), and 706.8558 (D, sequence 8 in <a href="#marinedrugs-17-00291-t002" class="html-table">Table 2</a>). Full article ">Figure 3
(A) Activated partial thromboplastin time (APTT), (B) prothrombin time (PT), and (C) thrombin time (TT) assays of ULVAN-01 (Δ), ULVAN-02 (▼), unfractionated heparin (UFH) (○), and Lovenox® (●). The clotting times of the plasma in the absence of fractions (negative control, 0.9% NaCl) were (A) 38.2 s, (B) 13.1 s, and (C) 12.9 s. The maximum clotting times measured by the coagulometer were (A) 120 s, (B) 70 s, and (C) 60 s (no coagulation within this time range). Data shown as the mean +/−SD, n = 6. Full article ">Figure 4
Dose-response curves of antithrombin-mediated (A) anti-Xa and (B) anti-IIa activities of ULVAN-02 (▼), unfractionated heparin (UFH) (○), and Lovenox® (●). Data shown as the mean, n = 6 (error bars are not indicated for better readability). Full article ">Figure 5
Viability of human fibroblasts treated for 72 h with ULVAN-01, ULVAN-02, unfractionated heparin (UFH), and Lovenox®. Results are expressed as the relative percentage of viability compared to the negative control. Data shown as the mean +/−SD, n = 5. Significant differences between samples and negative control are indicated by * (p < 0.05), ** (p < 0.01), and *** (p < 0.001). Full article ">Scheme 1
Dissociation mechanism resulting in Z2 ion formation (example of the ion (m/z) 401.0385: sequence 5 in <a href="#marinedrugs-17-00291-t002" class="html-table">Table 2</a> and <a href="#marinedrugs-17-00291-f002" class="html-fig">Figure 2</a>A) (adapted from [<a href="#B53-marinedrugs-17-00291" class="html-bibr">53</a>]). Full article ">

15 pages, 2564 KiB

Open AccessArticle

Zeaxanthin Isolated from Dunaliella salina Microalgae Ameliorates Age Associated Cardiac Dysfunction in Rats through Stimulation of Retinoid Receptors

by Farouk Kamel El-Baz, Rehab Ali Hussein, Dalia Osama Saleh and Gehad Abdel Raheem Abdel Jaleel

Mar. Drugs 2019, 17(5), 290; https://doi.org/10.3390/md17050290 - 14 May 2019

Cited by 36 | Viewed by 4248

Abstract

Retinoids are essential during early cardiovascular morphogenesis. However, recent studies showed their important role in cardiac remodeling in rats with hypertension and following myocardial infarction. The present study aimed to investigate the effect of zeaxanthin heneicosylate (ZH); a carotenoid ester isolated from Dunaliella [...] Read more.

Retinoids are essential during early cardiovascular morphogenesis. However, recent studies showed their important role in cardiac remodeling in rats with hypertension and following myocardial infarction. The present study aimed to investigate the effect of zeaxanthin heneicosylate (ZH); a carotenoid ester isolated from Dunaliella salina microalgae, on cardiac dysfunction ensuing d-galactose injection in rats. Rats injected with d-GAL (200 mg/kg; I.P) for 8 weeks were orally treated with ZH (250 μg/kg) for 28 consecutive days. Results showed that d-GAL injection caused dramatic electrocardiographic changes as well as marked elevation in serum levels of homocysteine, creatinine kinase isoenzyme and lactate dehydrogenase. A reduction in the cardiac contents of glucose transporter-4 and superoxide dismutase along with the elevation of inducible nitric oxide synthetase and interleukin-6 was also noticed. Oral administration of ZH significantly improved the above mentioned cardiac aging manifestations; this was further emphasized through histopathological examinations. The effect of ZH is mediated through the interaction with retinoid receptor alpha (RAR-α) as evidenced through a significant elevation of RAR-α expression in cardiac tissue following the lead of an in silico molecular docking study. In conclusion, zeaxanthin heneicosylate isolated from D. salina ameliorated age-associated cardiac dysfunction in rats through the activation of retinoid receptors. Full article

(This article belongs to the Special Issue Marine Natural Products and Cardiovascular Disease Prevention)

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Chemical structure of zeaxanthin heneicosylate (ZH). Full article ">Figure 2
Docking of zeaxanthin metabolic product on retinoic acid receptor (RAR)-α. Full article ">Figure 3
Effect of ZH on electrocardiographic (ECG) patterns in cardiac dysfunction induced in rats. ECG of normal rats showed a normal pattern (A). d-GAL treated rats showed an irregular rhythm of heartbeats and depressed ST height and negative T wave (B). d-GAL injected rats were orally treated with ZH for two weeks after d-GAL injection (C). The green lines represent the cumulative ECG pattern of a rat while the black line represents the average ECG pattern of a rat during 5 s. Full article ">Figure 4
Effect of ZH on cardiac levels of interleukin-6 (il-6) (a), inducible nitric oxide synthase (iNOS) (b), superoxide dismutase (SOD) (c) and NF-κB (d) in cardiac dysfunction induced in rats. Data are presented as mean ± SEM. Statistical analysis was performed by one-way analysis of variance (ANOVA) followed by Tukey-Kramer test for multiple comparisons (n = 6–8). * significantly different from the normal group at p ≤ 0.05. a significantly different from d-GAL-treated group at p ≤ 0.05. Full article ">Figure 5
Effect of ZH on RAR-α cardiac expression in d-GAL-induced cardiac dysfunction in rats. Data are presented as mean ± SEM. Statistical analysis was performed by one-way analysis of variance (ANOVA) followed by a Tukey-Kramer test for multiple comparisons (n = 6–8). * significantly different from normal group at p ≤ 0.05. a significantly different from d-GAL-treated group at p ≤ 0.05. Full article ">Figure 6
Effect of ZH on the histopathological alterations of the cardiac tissue of d-GAL-induced cardiac dysfunction in rats. (A) Control rat showing normal histological architecture (H and E × 300). (B) d-GAL treated rats (200 mg/kg; i.p.) showed an irregular rhythm of heartbeats. (C) Treatment of d-GAL-treated rats d-GAL injected rats were orally treated with ZH (250 µg/kg) for four weeks after d-GAL injection. Full article ">Figure 7
Metabolic products of zeaxanthin. Full article ">

8 pages, 605 KiB

Open AccessArticle

Two New Spiro-Heterocyclic γ-Lactams from A Marine-Derived Aspergillus fumigatus Strain CUGBMF170049

by Xiuli Xu, Jiahui Han, Yanan Wang, Rui Lin, Haijin Yang, Jiangpeng Li, Shangzhu Wei, Steven W. Polyak and Fuhang Song

Mar. Drugs 2019, 17(5), 289; https://doi.org/10.3390/md17050289 - 14 May 2019

Cited by 12 | Viewed by 3245

Abstract

Two new spiro-heterocyclic γ-lactam derivatives, cephalimysins M (1) and N (2), were isolated from the fermentation cultures of the marine-derived fungus Aspergillus fumigatus CUGBMF17018. Two known analogues, pseurotin A (3) and FD-838 (4), as [...] Read more.

Two new spiro-heterocyclic γ-lactam derivatives, cephalimysins M (1) and N (2), were isolated from the fermentation cultures of the marine-derived fungus Aspergillus fumigatus CUGBMF17018. Two known analogues, pseurotin A (3) and FD-838 (4), as well as four previously reported helvolic acid derivatives, 16-O-propionyl-16-O-deacetylhelvolic acid (5), 6-O-propionyl-6-O-deacetylhelvolic acid (6), helvolic acid (7), and 1,2-dihydrohelvolic acid (8) were also identified. One-dimensional (1D), two-dimensional (2D) NMR, HRMS, and circular dichroism spectral analysis characterized the structures of the isolated compounds. Full article

(This article belongs to the Special Issue Marine Microbial Diversity as a Source of Bioactive Natural Products)

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9 pages, 1080 KiB

Open AccessArticle

Antihypertensive Effect in Vivo of QAGLSPVR and Its Transepithelial Transport Through the Caco-2 Cell Monolayer

by Liping Sun, Beiyi Wu, Mingyan Yan, Hu Hou and Yongliang Zhuang

Mar. Drugs 2019, 17(5), 288; https://doi.org/10.3390/md17050288 - 13 May 2019

Cited by 10 | Viewed by 2916

Abstract

The peptide QAGLSPVR, which features high angiotensin-I-converting enzyme (ACE) inhibitory activity, was identified in our previous study. In this study, the in vivo antihypertensive effect of QAGLSPVR was evaluated. Results showed that QAGLSPVR exerts a clear antihypertensive effect on spontaneously hypertensive rats (SHRs), [...] Read more.

The peptide QAGLSPVR, which features high angiotensin-I-converting enzyme (ACE) inhibitory activity, was identified in our previous study. In this study, the in vivo antihypertensive effect of QAGLSPVR was evaluated. Results showed that QAGLSPVR exerts a clear antihypertensive effect on spontaneously hypertensive rats (SHRs), and the systolic and diastolic blood pressures of the rats remarkably decreased by 41.86 and 40.40 mm Hg, respectively, 3 h after peptide administration. The serum ACE activities of SHRs were determined at different times, and QAGLSPVR was found to decrease ACE activities in serum; specifically, minimal ACE activity was found 3 h after administration. QAGLSPVR could be completely absorbed by the Caco-2 cell monolayer, and its transport percentage was 3.5% after 2 h. The transport route results of QAGLSPVR showed that Gly-Sar and wortmannin exert minimal effects on the transport percentage of the peptide (p> 0.05), thus indicating that QAGLSPVR transport through the Caco-2 cell monolayer is not mediated by peptide transporter 1 or transcytosis. By contrast, cytochalasin D significantly increased QAGLSPVR transport (p< 0.05); thus, QAGLSPVR may be transported through the Caco-2 cell monolayer via the paracellular pathway. Full article

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

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14 pages, 4349 KiB

Open AccessArticle

Flaccidoxide-13-Acetate-Induced Apoptosis in Human Bladder Cancer Cells is through Activation of p38/JNK, Mitochondrial Dysfunction, and Endoplasmic Reticulum Stress Regulated Pathway

by Yu-Jen Wu, Tzu-Rong Su, Guo-Fong Dai, Jui-Hsin Su and Chih-I Liu

Mar. Drugs 2019, 17(5), 287; https://doi.org/10.3390/md17050287 - 13 May 2019

Cited by 25 | Viewed by 4334

Abstract

Flaccidoxide-13-acetate, an active compound isolated from cultured-type soft coral Sinularia gibberosa, has been shown to have inhibitory effects against invasion and cell migration of RT4 and T24 human bladder cancer cells. In our study, we used an 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), colony formation [...] Read more.

Flaccidoxide-13-acetate, an active compound isolated from cultured-type soft coral Sinularia gibberosa, has been shown to have inhibitory effects against invasion and cell migration of RT4 and T24 human bladder cancer cells. In our study, we used an 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), colony formation assay, and flow cytometry to determine the mechanisms of the anti-tumor effect of flaccidoxide-13-acetate. The MTT and colony formation assays showed that the cytotoxic effect of flaccidoxide-13-acetate on T24 and RT4 cells was dose-dependent, and the number of colonies formed in the culture was reduced with increasing flaccidoxide-13-acetate concentration. Flow cytometry analysis revealed that flaccidoxide-13-acetate induced late apoptotic events in both cell lines. Additionally, we found that flaccidoxide-13-acetate treatment upregulated the expressions of cleaved caspase 3, cleaved caspase 9, Bax, and Bad, and down-regulated the expressions of Bcl-2, p-Bad, Bcl-x1, and Mcl-1. The results indicated that apoptotic events were mediated by mitochondrial dysfunction via the caspase-dependent pathway. Flaccidoxide-13-acetate also provoked endoplasmic reticulum (ER) stress and led to activation of the PERK-eIF2α-ATF6-CHOP pathway. Moreover, we examined the PI3K/AKT signal pathway, and found that the expressions of phosphorylated PI3K (p-PI3K) and AKT (p-AKT) were decreased with flaccidoxide-13-acetate concentrations. On the other hand, our results showed that the phosphorylated JNK and p38 were obviously activated. The results support the idea that flaccidoxide-13-acetate-induced apoptosis is mediated by mitochondrial dysfunction, ER stress, and activation of both the p38 and JNK pathways, and also relies on inhibition of PI3K/AKT signaling. These findings imply that flaccidoxide-13-acetate has potential in the development of chemotherapeutic agents for human bladder cancer. Full article

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

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13 pages, 2310 KiB

Open AccessArticle

TAT-Modified ω-Conotoxin MVIIA for Crossing the Blood-Brain Barrier

by Shuo Yu, Yumeng Li, Jinqin Chen, Yue Zhang, Xinling Tao, Qiuyun Dai, Yutian Wang, Shupeng Li and Mingxin Dong

Mar. Drugs 2019, 17(5), 286; https://doi.org/10.3390/md17050286 - 12 May 2019

Cited by 20 | Viewed by 4277

Abstract

As the first in a new class of non-opioid drugs, ω-Conotoxin MVIIA was approved for the management of severe chronic pains in patients who are unresponsive to opioid therapy. Unfortunately, clinical application of MVIIA is severely limited due to its poor ability to [...] Read more.

As the first in a new class of non-opioid drugs, ω-Conotoxin MVIIA was approved for the management of severe chronic pains in patients who are unresponsive to opioid therapy. Unfortunately, clinical application of MVIIA is severely limited due to its poor ability to penetrate the blood-brain barrier (BBB), reaching the central nervous system (CNS). In the present study, we have attempted to increase MVIIA’s ability to cross the BBB via a fusion protein strategy. Our results showed that when the TAT-transducing domain was fused to the MVIIA C-terminal with a linker of varied numbers of glycine, the MVIIA-TAT fusion peptide exhibited remarkable ability to cross the bio-membranes. Most importantly, both intravenous and intranasal administrations of MVIIA-TAT in vivo showed therapeutic efficacy of analgesia. Compared to the analgesic effects of intracerebral administration of the nascent MVIIA, these systemic administrations of MVIIA-TAT require higher doses, but have much prolonged effects. Taken together, our results showed that TAT conjugation of MVIIA not only enables its peripheral administration, but also maintains its analgesic efficiency with a prolonged effective time window. Intranasal administration also rendered the MVIIA-TAT advantages of easy applications with potentially reduced side effects. Our results may present an alternative strategy to improve the CNS accessibility for neural active peptides. Full article

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Circular dichroism (CD) spectra of MVIIA and its variants. The final concentration of each peptide was 35 μmol/L in phosphate buffer (10 mM, pH = 7.2) solution. Full article ">Figure 2
Inhibitory effects on CaV2.2 channel currents induced by MVIIA and its variants. The dose-response curve for MVIIA (A) and its TAT variants (B–E), IC50 and Hill slope values of each peptide were shown above, data was presented in mean ± SEM, n = 5. (F) Superimposed traces of depolarization-activated whole-cell calcium channel currents, elicited by a voltage step from a holding potential of −80 to +10 mV in the absence of 10 μM l-MVIIA (blue) and 2 μM MVIIA (red). (G) A summary on the IC50 value of MVIIA and its variants. Full article ">Figure 3
Antinociceptive effect in mice after intracerebral vesicular, intravenous, and intranasal administration of MVIIA and MVIIA-c. The antinociceptive effect was evaluated by the hot-plate test after intravenous administration of MVIIA (A), intracerebral vesicular administration of MVIIA (B), intravenous administration of MVIIA-c (C), and intranasal administration of MVIIA-c (D). They were evaluated by the hot-plate test. The antinociceptive effect was expressed as reaction latency. Date are shown as mean ± SEM of 6–8 mice (A,B,C) and 10 mice (D). For A,B, and C: * p < 0.05, ** p < 0.01 and *** p < 0.001 vs Saline group. ForD: *,# p < 0.05, **, ## p < 0.01 and ***, ### p < 0.001 vs 0 hr. Full article ">Figure 4
Antinociceptive effect in acetic acid-induced writhing test. The number of writhing responses was counted from 5 min to 20 min after acetic acid injection. (A) 30 min after intracerebroventricular administration of MVIIA and MVIIA-c, mice were injected with 1% acetic acid intraperitoneally, no differences were found between MVIIA and MVIIA-c in various doses. (B) 30 min after intravenous administration of MVIIA and MVIIA-c, mice were injected with 1% acetic acid intraperitoneally. The total writhing number of MVIIA-c were significantly decreased compared to MVIIA at the dose of 1.00 and 3.00 μmol/kg, * p < 0.05 and *** p < 0.001. Full article ">Figure 5
Effects of MVIIA and MVIIA-c on coordinated locomotion in the rotarod test. MVIIA (0.9 nmol/kg), MVIIA-c (0.9 nmol/kg), or saline were administered (I.C.V.) to the mice prior to placement on the rotarod at 30 min (A) or 120 min (B) post-injection. The stay times were shown as mean ± SEM (n = 8–10). ** p < 0.05, *** p < 0.01 vs the saline group. Full article ">Figure 6
Effects of MVIIA and MVIIA-c on mouse tremor. The peptides (0.9 nmol/kg) and saline were administered I.C.V. to the mice in a volume of 6 μL. After 30 and 120 min, the accumulative tremor time (s) were recorded during a period of 5 min. The data were expressed as means ± SEM (n = 12). Full article ">Scheme 1
Primary amino acid sequences of peptides and their electrophysiology activity. Full article ">

14 pages, 3138 KiB

Open AccessArticle

Edaravone-Loaded Alginate-Based Nanocomposite Hydrogel Accelerated Chronic Wound Healing in Diabetic Mice

by Ying Fan, Wen Wu, Yu Lei, Caroline Gaucher, Shuchen Pei, Jinqiang Zhang and Xuefeng Xia

Mar. Drugs 2019, 17(5), 285; https://doi.org/10.3390/md17050285 - 11 May 2019

Cited by 60 | Viewed by 5983

Abstract

Refractory wound healing is one of the most common complications of diabetes. Excessive production of reactive oxygen species (ROS) can cause chronic inflammation and thus impair cutaneous wound healing. Scavenging these ROS in wound dressing may offer effective treatment for chronic wounds. Here, [...] Read more.

Refractory wound healing is one of the most common complications of diabetes. Excessive production of reactive oxygen species (ROS) can cause chronic inflammation and thus impair cutaneous wound healing. Scavenging these ROS in wound dressing may offer effective treatment for chronic wounds. Here, a nanocomposite hydrogel based on alginate and positively charged Eudragit nanoparticles containing edaravone, an efficient free radical scavenger, was developed for maximal ROS sequestration. Eudragit nanoparticles enhanced edaravone solubility and stability breaking the limitations in application. Furthermore, loading these Eudragit nanoparticles into an alginate hydrogel increased the protection and sustained the release of edaravone. The nanocomposite hydrogel is shown to promote wound healing in a dose-dependent way. A low dose of edaravone-loaded nanocomposite hydrogel accelerated wound healing in diabetic mice. On the contrary, a high dose of edaravone might hamper the healing. Those results indicated the dual role of ROS in chronic wounds. In addition, the discovery of this work pointed out that dose could be the key factor limiting the translational application of antioxidants in wound healing. Full article

(This article belongs to the Special Issue Marine Biopolymers and Drug Delivery)

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Representative scanning electron microscopy image of edaravone-loaded nanoparticles (A), edaravone-loaded nanocomposite hydrogel (B), and calcium alginate hydrogel (C). Full article ">Figure 2
In vitro release behavior of different edaravone loaded formulations using a dialysis bag method in phosphate buffer (pH 5) at 37 °C. The edaravone concentrations were measured by high performance liquid chromatography (mean ± SD, n = 3, *** p < 0.005: EDA-NP vs. EDA-NP-gel and free EDA **** p < 0.001: free EDA vs. EDA-NP-gel). Full article ">Figure 3
Solubility of free edaravone and edaravone nanoparticles in different conditions (mean ± SD, n = 3, **** p < 0.0001). Full article ">Figure 4
Effects of edaravone-loaded nanocomposite hydrogel (edaravone loading is 0.1 mg) on wound closure in diabetic mice model. (A) Representative images of wounds in four groups. (B) Healing progression during 13 days. (C) Percentage wound closure on day 5, 10, 13 post-wounding. (mean ± SD, n = 4, *p < 0.05, ** p < 0.01, *** p < 0.005; **** p < 0.001). Full article ">Figure 5
Effects of edaravone-loaded nanocomposite hydrogel (edaravone loading is 0.3 mg) on wound closure in diabetic mice model. (A) Representative images of wounds in four groups. (B) Healing progression during 13 days. (C) Percentage wound closure on day 5, 10, 13 post-wounding, (mean ± SD, n = 4, * p < 0.05). Full article ">Figure 6
Effects of edaravone with a different dosage on wound closure. (A) Representative images of wounds in four groups. (B) Healing progression for day 0–13. (C) Percentage wound closure on day 5, 10, 13 post-wounding. (Mean ± SD, n = 4, * p < 0.05, ** p < 0.01, *** p < 0.005). Full article ">Scheme 1
Schematic representation of alginate based nanocomposite hydrogel promoted wound healing. ERL: Eudragit RL PO polymer. Full article ">

21 pages, 4003 KiB

Open AccessFeature PaperArticle

Protective Effect of Pyropia yezoensis Peptide on Dexamethasone-Induced Myotube Atrophy in C2C12 Myotubes

by Min-Kyeong Lee, Jeong-Wook Choi, Youn Hee Choi and Taek-Jeong Nam

Mar. Drugs 2019, 17(5), 284; https://doi.org/10.3390/md17050284 - 11 May 2019

Cited by 18 | Viewed by 5434

Abstract

Dexamethasone (DEX), a synthetic glucocorticoid, causes skeletal muscle atrophy. This study examined the protective effects of Pyropia yezoensis peptide (PYP15) against DEX-induced myotube atrophy and its association with insulin-like growth factor-I (IGF-I) and the Akt/mammalian target of rapamycin (mTOR)-forkhead box O (FoxO) signaling [...] Read more.

Dexamethasone (DEX), a synthetic glucocorticoid, causes skeletal muscle atrophy. This study examined the protective effects of Pyropia yezoensis peptide (PYP15) against DEX-induced myotube atrophy and its association with insulin-like growth factor-I (IGF-I) and the Akt/mammalian target of rapamycin (mTOR)-forkhead box O (FoxO) signaling pathway. To elucidate the molecular mechanisms underlying the effects of PYP15 on DEX-induced myotube atrophy, C2C12 myotubes were treated for 24 h with 100 μM DEX in the presence or absence of 500 ng/mL PYP15. Cell viability assays revealed no PYP15 toxicity in C2C12 myotubes. PYP15 activated the insulin-like growth factor-I receptor (IGF-IR) and Akt-mTORC1 signaling pathway in DEX-induced myotube atrophy. In addition, PYP15 markedly downregulated the nuclear translocation of transcription factors FoxO1 and FoxO3a, and inhibited 20S proteasome activity. Furthermore, PYP15 inhibited the autophagy-lysosomal pathway in DEX-stimulated myotube atrophy. Our findings suggest that PYP15 treatment protected against myotube atrophy by regulating IGF-I and the Akt-mTORC1-FoxO signaling pathway in skeletal muscle. Therefore, PYP15 treatment appears to exert protective effects against skeletal muscle atrophy. Full article

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

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9 pages, 916 KiB

Open AccessCommunication

Isolation and Characterization of Two New Metabolites from the Sponge-Derived Fungus Aspergillus sp. LS34 by OSMAC Approach

by Wei Li, Lijian Ding, Ning Wang, Jianzhou Xu, Weiyan Zhang, Bin Zhang, Shan He, Bin Wu and Haixiao Jin

Mar. Drugs 2019, 17(5), 283; https://doi.org/10.3390/md17050283 - 11 May 2019

Cited by 18 | Viewed by 4015

Abstract

The application of an OSMAC (One Strain-Many Compounds) approach on the sponge-derived fungus Aspergillus sp. LS34, using two different media including solid rice medium and potato dextrose broth (PDB) resulted in the isolation and identification of two new compounds, named asperspin A ( [...] Read more.

The application of an OSMAC (One Strain-Many Compounds) approach on the sponge-derived fungus Aspergillus sp. LS34, using two different media including solid rice medium and potato dextrose broth (PDB) resulted in the isolation and identification of two new compounds, named asperspin A (1) and asperther A (2) along with seven known compounds 3–9. Compounds 1–5 were detected in fungal extracts from rice medium, while compounds 6–9 were isolated from PDB medium. Their structures were unambiguously characterized by HRESIMS and NMR spectroscopic data. The growth inhibitory activity of these compounds against four pathogenic bacteria (Vibrio parahaemolyticus, Vibrio harveyi, Escherichia coli, and Staphylococcus aureus) were evaluated. All the compounds were also tested for their cytotoxicity against seven cancer cell lines, including CCRF-CEM, K562, BGC823, AGS, HCT-116, MDA-MB-453, and COR-L23. Among them, compound 9 showed strong activity against CCRF-CEM and K562 cells with IC₅₀ values of 1.22 ± 0.05 µM and 10.58 ± 0.19 µM, respectively. Notably, compound 7 also showed pronounced activity against S. aureus with an MIC value of 3.54 µM. Full article

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37 pages, 1551 KiB

Open AccessReview

Oceans as a Source of Immunotherapy

by Bilal Ahmad, Masaud Shah and Sangdun Choi

Mar. Drugs 2019, 17(5), 282; https://doi.org/10.3390/md17050282 - 10 May 2019

Cited by 24 | Viewed by 5674

Abstract

Marine flora is taxonomically diverse, biologically active, and chemically unique. It is an excellent resource, which offers great opportunities for the discovery of new biopharmaceuticals such as immunomodulators and drugs targeting cancerous, inflammatory, microbial, and fungal diseases. The ability of some marine molecules [...] Read more.

Marine flora is taxonomically diverse, biologically active, and chemically unique. It is an excellent resource, which offers great opportunities for the discovery of new biopharmaceuticals such as immunomodulators and drugs targeting cancerous, inflammatory, microbial, and fungal diseases. The ability of some marine molecules to mediate specific inhibitory activities has been demonstrated in a range of cellular processes, including apoptosis, angiogenesis, and cell migration and adhesion. Immunomodulators have been shown to have significant therapeutic effects on immune-mediated diseases, but the search for safe and effective immunotherapies for other diseases such as sinusitis, atopic dermatitis, rheumatoid arthritis, asthma and allergies is ongoing. This review focuses on the marine-originated bioactive molecules with immunomodulatory potential, with a particular focus on the molecular mechanisms of specific agents with respect to their targets. It also addresses the commercial utilization of these compounds for possible drug improvement using metabolic engineering and genomics. Full article

(This article belongs to the Special Issue Marine Immunomodulators)

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Mar. Drugs, Volume 17, Issue 5 (May 2019) – 64 articles

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