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Mar. Drugs, Volume 19, Issue 9 (September 2021) – 55 articles

Cover Story (view full-size image): Seaweeds contain unique bioactive metabolites that are not found in terrestrial plants because of the harsh environment in which they survive, leading to in vitro and in vivo studies of their prevention and treatment effects. This review summarizes studies that focused on the beneficial effects of seaweeds and their natural products targeting markers involved in a cascade of mechanisms related to CVD pathogenesis. The purpose of this review is to describe the potential of seaweeds and their natural products for preventing and treating CVD based on in vivo and in vitro studies. View this paper.
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16 pages, 2568 KiB  
Article
Response to Static Magnetic Field-Induced Stress in Scenedesmus obliquus and Nannochloropsis gaditana
by Génesis Serrano, Carol Miranda-Ostojic, Pablo Ferrada, Cristian Wulff-Zotelle, Alejandro Maureira, Edward Fuentealba, Karem Gallardo, Manuel Zapata and Mariella Rivas
Mar. Drugs 2021, 19(9), 527; https://doi.org/10.3390/md19090527 - 21 Sep 2021
Cited by 11 | Viewed by 2775
Abstract
Magnetic fields in biological systems is a promising research field; however, their application for microalgae has not been fully exploited. This work aims to measure the enzymatic activity and non-enzymatic activity of two microalgae species in terms of superoxide dismutase (SOD), catalase (CAT), [...] Read more.
Magnetic fields in biological systems is a promising research field; however, their application for microalgae has not been fully exploited. This work aims to measure the enzymatic activity and non-enzymatic activity of two microalgae species in terms of superoxide dismutase (SOD), catalase (CAT), and carotenoids, respectively, in response to static magnetic fields-induced stress. Two magnet configurations (north and south) and two exposure modes (continuous and pulse) were applied. Two microalgae species were considered, the Scenedesmus obliquus and Nannochloropsis gaditana. The SOD activity increased by up to 60% in S. obliquus under continuous exposure. This trend was also found for CAT in the continuous mode. Conversely, under the pulse mode, its response was hampered as the SOD and CAT were reduced. For N. gaditana, SOD increased by up to 62% with the south configuration under continuous exposure. In terms of CAT, there was a higher activity of up to 19%. Under the pulsed exposure, SOD activity was up to 115%. The CAT in this microalga was increased by up to 29%. For N. gaditana, a significant increase of over 40% in violaxanthin production was obtained compared to the control, when the microalgae were exposed to SMF as a pulse. Depending on the exposure mode and species, this methodology can be used to produce oxidative stress and obtain an inhibitory or enhanced response in addition to the significant increase in the production of antioxidant pigments. Full article
(This article belongs to the Special Issue Biotechnology Applications of Microalgae)
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15 pages, 2972 KiB  
Article
Comparative Metabolomics Reveals Fungal Conversion of Co-Existing Bacterial Metabolites within a Synthetic Aspergillus-Streptomyces Community
by Yutong Shi, Yihan Ma, Jihua Wei, Yichao Ge, Wei Jiang, Shan He, Xiaodan Wu, Xiaoqin Zhang and Bin Wu
Mar. Drugs 2021, 19(9), 526; https://doi.org/10.3390/md19090526 - 19 Sep 2021
Cited by 9 | Viewed by 2394
Abstract
In nature, secondary metabolites have been proven to be the essential communication media between co-occurring microorganisms and to influence their relationship with each other. In this study, we conducted a metabolomics survey of the secondary metabolites of an artificial co-culture related to a [...] Read more.
In nature, secondary metabolites have been proven to be the essential communication media between co-occurring microorganisms and to influence their relationship with each other. In this study, we conducted a metabolomics survey of the secondary metabolites of an artificial co-culture related to a hydrothermal vent fungal–bacterial community comprising Aspergillus sclerotiorum and Streptomyces and their reciprocal relationship. The fungal strain was found to increase the secretion of notoamides and the compound cyclo(Pro-Trp) produced by the actinomycetes strain was discovered to be the responsible molecule. This led to the hypothesis that the fungi transformed cyclo(Pro-Trp) synthesized by the actinomycetes as the biosynthetic precursors of notoamides in the chemical communication. Further analysis showed Streptomyces sp. WU20 was efficient in transforming amino acids into cyclo(Pro-Trp) and adding tryptophan as well as proline into the chemical communication enhanced the induction of the notoamide accumulation. Thus, we propose that the microbial transformation during the synthetic metabolically-mediated chemical communication might be a promising means of speeding up the discovery of novel bioactive molecules. The objective of this research was to clarify the mechanism of microbial transformation for the chemical communication. Besides, this research also highlights the utility of mass spectrometry-based metabolomics as an effective tool in the direct biochemical analysis of community metabolites. Full article
(This article belongs to the Special Issue Marine Fungal Metabolites: Structures, Activities and Biosynthesis)
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18 pages, 2257 KiB  
Article
Astaxanthin Mitigates Thiacloprid-Induced Liver Injury and Immunotoxicity in Male Rats
by Shimaa M. Abou-Zeid, Samira H. Aljuaydi, Huda O. AbuBakr, Enas A. Tahoun, Alessandro Di Cerbo, Mahmoud Alagawany, Samah R. Khalil and Mayada R. Farag
Mar. Drugs 2021, 19(9), 525; https://doi.org/10.3390/md19090525 - 18 Sep 2021
Cited by 15 | Viewed by 2846
Abstract
Thiacloprid (TCP) is a widely used neonicotinoid insecticide with a probable toxic hazard to animals and human beings. This hazard has intensified the demand for natural compounds to alleviate the expected toxic insults. This study aimed at determining whether astaxanthin (ASX) could mitigate [...] Read more.
Thiacloprid (TCP) is a widely used neonicotinoid insecticide with a probable toxic hazard to animals and human beings. This hazard has intensified the demand for natural compounds to alleviate the expected toxic insults. This study aimed at determining whether astaxanthin (ASX) could mitigate the hepatotoxic effect of TCP and diminish its suppressive effect on immune responses in rats. Animals received TCP by gavage at 62.1 mg/kg (1/10th LD50) with or without ASX at 40 mg/kg for 60 days. Intoxicated rats showed modulation of serum transaminases and protein profiles. The hemagglutination antibody titer to sheep red blood cells (SRBC) and the number of plaque-forming cells in the spleen were reduced. The cell-mediated immunity and phagocytosis were suppressed, while serum interleukins IL-1β, IL-6, and IL-10 were elevated. Additionally, malondialdehyde, nitric oxide, and 8-hydroxy-2′-deoxyguanosine levels were increased in the liver, spleen, and thymus, with depletion of glutathione and suppression of superoxide dismutase and catalase activities. The expressions of inducible nitric oxide synthase and the high mobility group box protein 1 genes were upregulated with histomorphological alterations in the aforementioned organs. Cotreatment with ASX markedly ameliorated the toxic effects of TCP, and all markers showed a regression trend towards control values. Collectively, our data suggest that the protective effects of ASX on the liver and immune system of TCP-treated animals depend upon improving the antioxidant status and relieving the inflammatory response, and thus it may be used as a promising therapeutic agent to provide superior hepato- and immunoprotection. Full article
(This article belongs to the Special Issue Marine Natural Products Modulating the Immune System)
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18 pages, 3262 KiB  
Article
Extraction Procedure, Characteristics, and Feasibility of Caulerpa microphysa (Chlorophyta) Polysaccharide Extract as a Cosmetic Ingredient
by Meng-Chou Lee, Han-Yang Yeh and Wen-Ling Shih
Mar. Drugs 2021, 19(9), 524; https://doi.org/10.3390/md19090524 - 18 Sep 2021
Cited by 8 | Viewed by 3385
Abstract
The green alga Caulerpa microphysa, which is native to Taiwan, has a relatively high economic value and a well-developed culture technique, and is used mainly as a foodstuff. Its extract has been shown to exhibit antitumor properties, but the polysaccharide content of [...] Read more.
The green alga Caulerpa microphysa, which is native to Taiwan, has a relatively high economic value and a well-developed culture technique, and is used mainly as a foodstuff. Its extract has been shown to exhibit antitumor properties, but the polysaccharide content of the extract and its anti-inflammatory and wound-healing effects and moisture-absorption and -retention capacity remain unknown. Hence, the objective of this study was to evaluate the potential of the polysaccharides in C. microphysa extract (CME) for use in cosmetics. The overall polysaccharide yield from the CME was 73.93% w/w, with four molecular weight fractions. The polysaccharides comprised 59.36 mol% mannose, 27.16 mol% glucose, and 13.48 mol% galactose. In addition, the CME exhibited strong antiallergic, wound-healing, transdermal-delivery, and moisture-absorption and -retention effects. In conclusion, the results suggested that CME potentially has anti-inflammatory and wound-healing effects and a good moisture capacity, which can be used in cosmetic applications. Full article
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12 pages, 2100 KiB  
Article
Isolation of Sesquiterpenoids and Steroids from the Soft Coral Sinularia brassica and Determination of Their Absolute Configuration
by Giang Nam Pham, Da Yeun Kang, Min Ju Kim, Se Jong Han, Jun Hyuck Lee and MinKyun Na
Mar. Drugs 2021, 19(9), 523; https://doi.org/10.3390/md19090523 - 17 Sep 2021
Cited by 8 | Viewed by 2669
Abstract
Two undescribed rearranged cadinane-type sesquiterpenoids (12), named sinulaketol A-B, together with one new chlorinated steroid (3), one new gorgosterol (4), one known sesquiterpene (5), one known dibromoditerpene (6) and two known [...] Read more.
Two undescribed rearranged cadinane-type sesquiterpenoids (12), named sinulaketol A-B, together with one new chlorinated steroid (3), one new gorgosterol (4), one known sesquiterpene (5), one known dibromoditerpene (6) and two known polyhydroxylated steroids (78) were isolated from the soft coral Sinularia brassica. The structures of these compounds were established by extensive spectroscopic analysis, including HRESIMS, 1D, and 2D NMR spectroscopy. Their absolute configurations were also determined by the ECD calculations and DP4+ probability analysis. Antileishmanial activity of compounds 18 was evaluated in vitro against the amastigote forms of Leishmania donovani, in which compounds 3, 6, and 7 inhibited the growth of L. donovani by 58.7, 74.3, 54.7%, respectively, at a concentration of 50 μM. Antimicrobial effect of the isolated compounds were also evaluated against Candida albicans, Staphylococcus aureus, and Escherichia coli. Compound 6, a brominated diterpene, exhibited antimicrobial effect against S. aureus. Full article
(This article belongs to the Special Issue Marine Drug Research in Korea)
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15 pages, 4142 KiB  
Article
Characterization and Biotechnological Potential of Extracellular Polysaccharides Synthesized by Alteromonas Strains Isolated from French Polynesia Marine Environments
by Patrícia Concórdio-Reis, Vítor D. Alves, Xavier Moppert, Jean Guézennec, Filomena Freitas and Maria A. M. Reis
Mar. Drugs 2021, 19(9), 522; https://doi.org/10.3390/md19090522 - 17 Sep 2021
Cited by 21 | Viewed by 3148
Abstract
Marine environments comprise almost three quarters of Earth’s surface, representing the largest ecosystem of our planet. The vast ecological and metabolic diversity found in marine microorganisms suggest that these marine resources have a huge potential as sources of novel commercially appealing biomolecules, such [...] Read more.
Marine environments comprise almost three quarters of Earth’s surface, representing the largest ecosystem of our planet. The vast ecological and metabolic diversity found in marine microorganisms suggest that these marine resources have a huge potential as sources of novel commercially appealing biomolecules, such as exopolysaccharides (EPS). Six Alteromonas strains from different marine environments in French Polynesia atolls were selected for EPS extraction. All the EPS were heteropolysaccharides composed of different monomers, including neutral monosaccharides (glucose, galactose, and mannose, rhamnose and fucose), and uronic acids (glucuronic acid and galacturonic acid), which accounted for up to 45.5 mol% of the EPS compositions. Non-carbohydrate substituents, such as acetyl (0.5–2.1 wt%), pyruvyl (0.2–4.9 wt%), succinyl (1–1.8 wt%), and sulfate (1.98–3.43 wt%); and few peptides (1.72–6.77 wt%) were also detected. Thermal analysis demonstrated that the EPS had a degradation temperature above 260 °C, and high char yields (32–53%). Studies on EPS functional properties revealed that they produce viscous aqueous solutions with a shear thinning behavior and could form strong gels in two distinct ways: by the addition of Fe2+, or in the presence of Mg2+, Cu2+, or Ca2+ under alkaline conditions. Thus, these EPS could be versatile materials for different applications. Full article
(This article belongs to the Special Issue Marine Oligosaccharides and Polysaccharides 2.0)
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11 pages, 1211 KiB  
Article
Antibacterial Bicyclic Fatty Acids from a Korean Colonial Tunicate Didemnum sp.
by Hiyoung Kim, Tae Gu Lee, Inho Yang, Weihong Wang, Jungwook Chin, Jusung Lee, Boon Jo Rho, Hyukjae Choi, Sang-Jip Nam, Dongyup Hahn and Heonjoong Kang
Mar. Drugs 2021, 19(9), 521; https://doi.org/10.3390/md19090521 - 16 Sep 2021
Cited by 1 | Viewed by 2149
Abstract
Five new bicyclic carboxylic acids were obtained by antibacterial activity-guided isolation from a Korean colonial tunicate Didemnum sp. Their structures were elucidated by the interpretation of NMR, MS and CD spectroscopic data. They all belong to the class of aplidic acids. Three of [...] Read more.
Five new bicyclic carboxylic acids were obtained by antibacterial activity-guided isolation from a Korean colonial tunicate Didemnum sp. Their structures were elucidated by the interpretation of NMR, MS and CD spectroscopic data. They all belong to the class of aplidic acids. Three of them were amide derivatives (13), and the other two were dicarboxylic derivatives (4 and 5). The absolute configurations were determined by a bisignate pattern of CD spectroscopy, which revealed that the absolute configurations of amides were opposite to those of dicarboxylates at every stereogenic centers. Compound 2 exhibited the most potent antibacterial activity (MIC, 2 μg/mL). Full article
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14 pages, 6266 KiB  
Article
Guidance Level for Brevetoxins in French Shellfish
by Nathalie Arnich, Eric Abadie, Zouher Amzil, Marie-Yasmine Dechraoui Bottein, Katia Comte, Estelle Chaix, Nicolas Delcourt, Vincent Hort, César Mattei, Jordi Molgó and Raphaele Le Garrec
Mar. Drugs 2021, 19(9), 520; https://doi.org/10.3390/md19090520 - 15 Sep 2021
Cited by 13 | Viewed by 2901
Abstract
Brevetoxins (BTXs) are marine biotoxins responsible for neurotoxic shellfish poisoning (NSP) after ingestion of contaminated shellfish. NSP is characterized by neurological, gastrointestinal and/or cardiovascular symptoms. The main known producer of BTXs is the dinoflagellate Karenia brevis, but other microalgae are also suspected [...] Read more.
Brevetoxins (BTXs) are marine biotoxins responsible for neurotoxic shellfish poisoning (NSP) after ingestion of contaminated shellfish. NSP is characterized by neurological, gastrointestinal and/or cardiovascular symptoms. The main known producer of BTXs is the dinoflagellate Karenia brevis, but other microalgae are also suspected to synthesize BTX-like compounds. BTXs are currently not regulated in France and in Europe. In November 2018, they have been detected for the first time in France in mussels from a lagoon in the Corsica Island (Mediterranean Sea), as part of the network for monitoring the emergence of marine biotoxins in shellfish. To prevent health risks associated with the consumption of shellfish contaminated with BTXs in France, a working group was set up by the French Agency for Food, Environmental and Occupational Health & Safety (Anses). One of the aims of this working group was to propose a guidance level for the presence of BTXs in shellfish. Toxicological data were too limited to derive an acute oral reference dose (ARfD). Based on human case reports, we identified two lowest-observed-adverse-effect levels (LOAELs). A guidance level of 180 µg BTX-3 eq./kg shellfish meat is proposed, considering a protective default portion size of 400 g shellfish meat. Full article
(This article belongs to the Special Issue Marine Biotoxins)
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10 pages, 1380 KiB  
Article
Oxygenated Cembrene Diterpenes from Sarcophyton convolutum: Cytotoxic Sarcoconvolutum A–E
by Tarik A. Mohamed, Abdelsamed I. Elshamy, Asmaa M. Abdel-Tawab, Mona M. AbdelMohsen, Shinji Ohta, Paul W. Pare and Mohamed-Elamir F. Hegazy
Mar. Drugs 2021, 19(9), 519; https://doi.org/10.3390/md19090519 - 13 Sep 2021
Cited by 10 | Viewed by 2519
Abstract
The soft coral genus Sarcophyton contains the enzymatic machinery to synthesize a multitude of cembrene-type diterpenes. Herein, highly oxygenated cembrenoids, sarcoconvolutum A–E (15) were purified and characterized from an ethyl acetate extract of the red sea soft coral, Sarcophyton [...] Read more.
The soft coral genus Sarcophyton contains the enzymatic machinery to synthesize a multitude of cembrene-type diterpenes. Herein, highly oxygenated cembrenoids, sarcoconvolutum A–E (15) were purified and characterized from an ethyl acetate extract of the red sea soft coral, Sarcophyton convolutum. Compounds were assemblies according to spectroscopic methods including FTIR, 1D- and 2D-NMR as well as HRMS. Metabolite cytotoxicity was tested against lung adenocarcinoma, cervical cancer, and oral-cavity carcinoma (A549, HeLa and HSC-2, respectively). The most cytotoxic compound, (4) was observed to be active against cell lines A549 and HSC-2 with IC50 values of 49.70 and 53.17 μM, respectively. Full article
(This article belongs to the Special Issue Marine Natural Products as Anticancer Agents 2.0)
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3 pages, 180 KiB  
Editorial
Synthesis of Marine Natural Products and Molecules Inspired by Marine Substances II
by Emiliano Manzo
Mar. Drugs 2021, 19(9), 518; https://doi.org/10.3390/md19090518 - 13 Sep 2021
Cited by 1 | Viewed by 1554
Abstract
The sea occupies more than 70% of the Earth’s surface and includes more than 300,000 organisms with huge biodiversity [...] Full article
19 pages, 3188 KiB  
Article
Production of Fucoxanthin from Phaeodactylum tricornutum Using High Performance Countercurrent Chromatography Retaining Its FOXO3 Nuclear Translocation-Inducing Effect
by Daniela Bárcenas-Pérez, Antonín Střížek, Pavel Hrouzek, Jiří Kopecký, Marta Barradas, Arantzazu Sierra-Ramirez, Pablo J. Fernandez-Marcos and José Cheel
Mar. Drugs 2021, 19(9), 517; https://doi.org/10.3390/md19090517 - 11 Sep 2021
Cited by 6 | Viewed by 3255
Abstract
Phaeodactylum tricornutum is a rich source of fucoxanthin, a carotenoid with several health benefits. In the present study, high performance countercurrent chromatography (HPCCC) was used to isolate fucoxanthin from an extract of P. tricornutum. A multiple sequential injection HPCCC method was developed [...] Read more.
Phaeodactylum tricornutum is a rich source of fucoxanthin, a carotenoid with several health benefits. In the present study, high performance countercurrent chromatography (HPCCC) was used to isolate fucoxanthin from an extract of P. tricornutum. A multiple sequential injection HPCCC method was developed combining two elution modes (reverse phase and extrusion). The lower phase of a biphasic solvent system (n-heptane, ethyl acetate, ethanol and water, ratio 5/5/6/3, v/v/v/v) was used as the mobile phase, while the upper phase was the stationary phase. Ten consecutive sample injections (240 mg of extract each) were performed leading to the separation of 38 mg fucoxanthin with purity of 97% and a recovery of 98%. The process throughput was 0.189 g/h, while the efficiency per gram of fucoxanthin was 0.003 g/h. Environmental risk and general process evaluation factors were used for assessment of the developed separation method and compared with existing fucoxanthin liquid-liquid isolation methods. The isolated fucoxanthin retained its well-described ability to induce nuclear translocation of transcription factor FOXO3. Overall, the developed isolation method may represent a useful model to produce biologically active fucoxanthin from diatom biomass. Full article
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16 pages, 3915 KiB  
Article
A Thermotolerant Marine Bacillus amyloliquefaciens S185 Producing Iturin A5 for Antifungal Activity against Fusarium oxysporum f. sp. cubense
by Pratiksha Singh, Jin Xie, Yanhua Qi, Qijian Qin, Cheng Jin, Bin Wang and Wenxia Fang
Mar. Drugs 2021, 19(9), 516; https://doi.org/10.3390/md19090516 - 11 Sep 2021
Cited by 14 | Viewed by 2553
Abstract
Fusarium wilt of banana (also known as Panama disease), is a severe fungal disease caused by soil-borne Fusarium oxysporum f. sp. cubense (Foc). In recent years, biocontrol strategies using antifungal microorganisms from various niches and their related bioactive compounds have been [...] Read more.
Fusarium wilt of banana (also known as Panama disease), is a severe fungal disease caused by soil-borne Fusarium oxysporum f. sp. cubense (Foc). In recent years, biocontrol strategies using antifungal microorganisms from various niches and their related bioactive compounds have been used to prevent and control Panama disease. Here, a thermotolerant marine strain S185 was identified as Bacillus amyloliquefaciens, displaying strong antifungal activity against Foc. The strain S185 possesses multiple plant growth-promoting (PGP) and biocontrol utility properties, such as producing indole acetic acid (IAA) and ammonia, assimilating various carbon sources, tolerating pH of 4 to 9, temperature of 20 to 50 °C, and salt stress of 1 to 5%. Inoculation of S185 colonized the banana plants effectively and was mainly located in leaf and root tissues. To further investigate the antifungal components, compounds were extracted, fractionated, and purified. One compound, inhibiting Foc with minimum inhibitory concentrations (MICs) of 25 μg/disk, was identified as iturin A5 by high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) and nuclear magnetic resonance (NMR). The isolated iturin, A5, resulted in severe morphological changes during spore germination and hyphae growth of Foc. These results specify that B. amyloliquefaciens S185 plays a key role in preventing the Foc pathogen by producing the antifungal compound iturin A5, and possesses potential as a cost-effective and sustainable biocontrol strain for Panama disease in the future. This is the first report of isolation of the antifungal compound iturin A5 from thermotolerant marine B. amyloliquefaciens S185. Full article
(This article belongs to the Special Issue Bioactive Molecules from Extreme Environments II)
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19 pages, 1233 KiB  
Review
Method Development Progress in Genetic Engineering of Thraustochytrids
by E-Ming Rau and Helga Ertesvåg
Mar. Drugs 2021, 19(9), 515; https://doi.org/10.3390/md19090515 - 11 Sep 2021
Cited by 10 | Viewed by 3266
Abstract
Thraustochytrids are unicellular, heterotrophic marine eukaryotes. Some species are known to store surplus carbon as intracellular lipids, and these also contain the long-chain polyunsaturated fatty acid docosahexaenoic acid (DHA). Most vertebrates are unable to synthesize sufficient amounts of DHA, and this fatty acid [...] Read more.
Thraustochytrids are unicellular, heterotrophic marine eukaryotes. Some species are known to store surplus carbon as intracellular lipids, and these also contain the long-chain polyunsaturated fatty acid docosahexaenoic acid (DHA). Most vertebrates are unable to synthesize sufficient amounts of DHA, and this fatty acid is essential for, e.g., marine fish, domesticated animals, and humans. Thraustochytrids may also produce other commercially valuable fatty acids and isoprenoids. Due to the great potential of thraustochytrids as producers of DHA and other lipid-related molecules, a need for more knowledge on this group of organisms is needed. This necessitates the ability to do genetic manipulation of the different strains. Thus far, this has been obtained for a few strains, while it has failed for other strains. Here, we systematically review the genetic transformation methods used for different thraustochytrid strains, with the aim of aiding studies on strains not yet successfully transformed. The designs of transformation cassettes are also described and compared. Moreover, the potential problems when trying to establish transformation protocols in new thraustochytrid species/strains are discussed, along with suggestions utilized in other organisms to overcome similar challenges. The approaches discussed in this review could be a starting point when designing protocols for other non-model organisms. Full article
(This article belongs to the Special Issue Marine Thraustochytrids: Biology, Chemical Ecology and Biotechnology)
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79 pages, 20819 KiB  
Review
Marine Pyrrole Alkaloids
by Kevin Seipp, Leander Geske and Till Opatz
Mar. Drugs 2021, 19(9), 514; https://doi.org/10.3390/md19090514 - 10 Sep 2021
Cited by 35 | Viewed by 5355
Abstract
Nitrogen heterocycles are essential parts of the chemical machinery of life and often reveal intriguing structures. They are not only widespread in terrestrial habitats but can also frequently be found as natural products in the marine environment. This review highlights the important class [...] Read more.
Nitrogen heterocycles are essential parts of the chemical machinery of life and often reveal intriguing structures. They are not only widespread in terrestrial habitats but can also frequently be found as natural products in the marine environment. This review highlights the important class of marine pyrrole alkaloids, well-known for their diverse biological activities. A broad overview of the marine pyrrole alkaloids with a focus on their isolation, biological activities, chemical synthesis, and derivatization covering the decade from 2010 to 2020 is provided. With relevant structural subclasses categorized, this review shall provide a clear and timely synopsis of this area. Full article
(This article belongs to the Special Issue Heterocyclic Compounds from Marine Organisms)
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19 pages, 677 KiB  
Review
Antiaging Potential of Peptides from Underused Marine Bioresources
by Enqin Xia, Xuan Zhu, Xuebin Gao, Jindong Ni and Honghui Guo
Mar. Drugs 2021, 19(9), 513; https://doi.org/10.3390/md19090513 - 10 Sep 2021
Cited by 4 | Viewed by 3011
Abstract
Aging is a biological process that occurs under normal conditions and in several chronic degenerative diseases. Bioactive natural peptides have been shown to improve the effects of aging in cell and animal models and in clinical trials. However, few reports delve into the [...] Read more.
Aging is a biological process that occurs under normal conditions and in several chronic degenerative diseases. Bioactive natural peptides have been shown to improve the effects of aging in cell and animal models and in clinical trials. However, few reports delve into the enormous diversity of peptides from marine organisms. This review provides recent information on the antiaging potential of bioactive peptides from underused marine resources, including examples that scavenge free radicals in vitro, inhibit cell apoptosis, prolong the lifespan of fruit flies and Caenorhabditis elegans, suppress aging in mice, and exert protective roles in aging humans. The underlying molecular mechanisms involved, such as upregulation of oxidase activity, inhibition of cell apoptosis and MMP-1 expression, restoring mitochondrial function, and regulating intestinal homeostasis, are also summarized. This work will help highlight the antiaging potential of peptides from underused marine organisms which could be used as antiaging foods and cosmetic ingredients in the near future. Full article
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21 pages, 4877 KiB  
Article
Adsorption of Cationic Dyes on a Magnetic 3D Spongin Scaffold with Nano-Sized Fe3O4 Cores
by Maryam Akbari, Hessam Jafari, Mojtaba Rostami, Gholam Reza Mahdavinia, Ali Sobhani nasab, Dmitry Tsurkan, Iaroslav Petrenko, Mohammad Reza Ganjali, Mehdi Rahimi-Nasrabadi and Hermann Ehrlich
Mar. Drugs 2021, 19(9), 512; https://doi.org/10.3390/md19090512 - 09 Sep 2021
Cited by 19 | Viewed by 2513
Abstract
The renewable, proteinaceous, marine biopolymer spongin is yet the focus of modern research. The preparation of a magnetic three-dimensional (3D) spongin scaffold with nano-sized Fe3O4 cores is reported here for the first time. The formation of this magnetic spongin–Fe3 [...] Read more.
The renewable, proteinaceous, marine biopolymer spongin is yet the focus of modern research. The preparation of a magnetic three-dimensional (3D) spongin scaffold with nano-sized Fe3O4 cores is reported here for the first time. The formation of this magnetic spongin–Fe3O4 composite was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA) (TGA-DTA), vibrating sample magnetometer (VSM), Fourier-transform infrared spectroscopy (FTIR), and zeta potential analyses. Field emission scanning electron microscopy (FE-SEM) confirmed the formation of well-dispersed spherical nanoparticles tightly bound to the spongin scaffold. The magnetic spongin–Fe3O4 composite showed significant removal efficiency for two cationic dyes (i.e., crystal violet (CV) and methylene blue (MB)). Adsorption experiments revealed that the prepared material is a fast, high-capacity (77 mg/g), yet selective adsorbent for MB. This behavior was attributed to the creation of strong electrostatic interactions between the spongin–Fe3O4 and MB or CV, which was reflected by adsorption mechanism evaluations. The adsorption of MB and CV was found to be a function of pH, with maximum removal performance being observed over a wide pH range (pH = 5.5–11). In this work, we combined Fe3O4 nanoparticles and spongin scaffold properties into one unique composite, named magnetic spongin scaffold, in our attempt to create a sustainable absorbent for organic wastewater treatment. The appropriative mechanism of adsorption of the cationic dyes on a magnetic 3D spongin scaffold is proposed. Removal of organic dyes and other contaminants is essential to ensure healthy water and prevent various diseases. On the other hand, in many cases, dyes are used as models to demonstrate the adsorption properties of nanostructures. Due to the good absorption properties of magnetic spongin, it can be proposed as a green and uncomplicated adsorbent for the removal of different organic contaminants and, furthermore, as a carrier in drug delivery applications. Full article
(This article belongs to the Special Issue Marine Skeletal Biopolymers and Proteins 2)
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17 pages, 1084 KiB  
Review
Astaxanthin Delivery Systems for Skin Application: A Review
by Sarah Giovanna Montenegro Lima, Marjorie Caroline Liberato Cavalcanti Freire, Verônica da Silva Oliveira, Carlo Solisio, Attilio Converti and Ádley Antonini Neves de Lima
Mar. Drugs 2021, 19(9), 511; https://doi.org/10.3390/md19090511 - 09 Sep 2021
Cited by 16 | Viewed by 6145
Abstract
Astaxanthin (AST) is a biomolecule known for its powerful antioxidant effect, which is considered of great importance in biochemical research and has great potential for application in cosmetics, as well as food products that are beneficial to human health and medicines. Unfortunately, its [...] Read more.
Astaxanthin (AST) is a biomolecule known for its powerful antioxidant effect, which is considered of great importance in biochemical research and has great potential for application in cosmetics, as well as food products that are beneficial to human health and medicines. Unfortunately, its poor solubility in water, chemical instability, and low oral bioavailability make its applications in the cosmetic and pharmaceutical field a major challenge for the development of new products. To favor the search for alternatives to enhance and make possible the use of AST in formulations, this article aimed to review the scientific data on its application in delivery systems. The search was made in databases without time restriction, using keywords such as astaxanthin, delivery systems, skin, cosmetic, topical, and dermal. All delivery systems found, such as liposomes, particulate systems, inclusion complexes, emulsions, and films, presented peculiar advantages able to enhance AST properties, among which are stability, antioxidant potential, biological activities, and drug release. This survey showed that further studies are needed for the industrial development of new AST-containing cosmetics and topical formulations. Full article
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15 pages, 1971 KiB  
Article
Field Validation of the Southern Rock Lobster Paralytic Shellfish Toxin Monitoring Program in Tasmania, Australia
by Alison Turnbull, Juan José Dorantes-Aranda, Tom Madigan, Jessica Jolley, Hilary Revill, Tim Harwood and Gustaaf Hallegraeff
Mar. Drugs 2021, 19(9), 510; https://doi.org/10.3390/md19090510 - 08 Sep 2021
Cited by 2 | Viewed by 2395
Abstract
Paralytic shellfish toxins (PST) are found in the hepatopancreas of Southern Rock Lobster Jasus edwardsii from the east coast of Tasmania in association with blooms of the toxic dinoflagellate Alexandrium catenella. Tasmania’s rock lobster fishery is one of the state’s most important [...] Read more.
Paralytic shellfish toxins (PST) are found in the hepatopancreas of Southern Rock Lobster Jasus edwardsii from the east coast of Tasmania in association with blooms of the toxic dinoflagellate Alexandrium catenella. Tasmania’s rock lobster fishery is one of the state’s most important wild capture fisheries, supporting a significant commercial industry (AUD 97M) and recreational fishing sector. A comprehensive 8 years of field data collected across multiple sites has allowed continued improvements to the risk management program protecting public health and market access for the Tasmanian lobster fishery. High variability was seen in toxin levels between individuals, sites, months, and years. The highest risk sites were those on the central east coast, with July to January identified as the most at-risk months. Relatively high uptake rates were observed (exponential rate of 2% per day), similar to filter-feeding mussels, and meant that lobster accumulated toxins quickly. Similarly, lobsters were relatively fast detoxifiers, losing up to 3% PST per day, following bloom demise. Mussel sentinel lines were effective in indicating a risk of elevated PST in lobster hepatopancreas, with annual baseline monitoring costing approximately 0.06% of the industry value. In addition, it was determined that if the mean hepatopancreas PST levels in five individual lobsters from a site were <0.22 mg STX equiv. kg−1, there is a 97.5% probability that any lobster from that site would be below the bivalve maximum level of 0.8 mg STX equiv. kg−1. The combination of using a sentinel species to identify risk areas and sampling five individual lobsters at a particular site, provides a cost-effective strategy for managing PST risk in the Tasmanian commercial lobster fishery. Full article
(This article belongs to the Special Issue Marine Toxins in Non-traditional Vectors)
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13 pages, 3151 KiB  
Article
Influence of Cultivation Conditions on the Sioxanthin Content and Antioxidative Protection Effect of a Crude Extract from the Vegetative Mycelium of Salinispora tropica
by Zuzana Jezkova, Vera Schulzova, Ivana Krizova, Marcel Karabin and Tomas Branyik
Mar. Drugs 2021, 19(9), 509; https://doi.org/10.3390/md19090509 - 08 Sep 2021
Viewed by 2006
Abstract
Due to their bioavailability, glycosylated carotenoids may have interesting biological effects. Sioxanthin, as a representative of this type of carotenoid, has been identified in marine actinomycetes of the genus Salinispora. This study evaluates, for the first time, the effect of cultivation temperature [...] Read more.
Due to their bioavailability, glycosylated carotenoids may have interesting biological effects. Sioxanthin, as a representative of this type of carotenoid, has been identified in marine actinomycetes of the genus Salinispora. This study evaluates, for the first time, the effect of cultivation temperature (T) and light intensity (LI) on the total cellular carotenoid content (TC), antioxidant activity (AA) and sioxanthin content (SX) of a crude extract (CE) from Salinispora tropica biomass in its vegetative state. Treatment-related differences in TC and SX values were statistically significantly and positively affected by T and LI, while AA was most significantly affected by T. In the S. tropica CE, TC correlated well (R2 = 0.823) with SX and somewhat less with AA (R2 = 0.777). A correlation between AA and SX was found to be less significant (R2 = 0.731). The most significant protective effect against oxidative stress was identified in the CE extracted from S. tropica biomass grown at the highest T and LI (CE-C), as was demonstrated using LNCaP and KYSE-30 human cell lines. The CE showed no cytotoxicity against LNCaP and KYSE-30 cell lines. Full article
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12 pages, 1907 KiB  
Article
Structure of the 4-O-[1-Carboxyethyl]-d-Mannose-Containing O-Specific Polysaccharide of a Halophilic Bacterium Salinivibrio sp. EG9S8QL
by Elena N. Sigida, Ibrahim M. Ibrahim, Maxim S. Kokoulin, Hussein H. Abulreesh, Khaled Elbanna, Svetlana A. Konnova and Yulia P. Fedonenko
Mar. Drugs 2021, 19(9), 508; https://doi.org/10.3390/md19090508 - 07 Sep 2021
Cited by 2 | Viewed by 2243
Abstract
The moderately halophilic strain Salinivibrio sp. EG9S8QL was isolated among 11 halophilic strains from saline mud (Emisal Salt Company, Lake Qarun, Fayoum, Egypt). The lipopolysaccharide was extracted from dried cells of Salinivibrio sp. EG9S8QL by the phenol–water procedure. The OPS was obtained by [...] Read more.
The moderately halophilic strain Salinivibrio sp. EG9S8QL was isolated among 11 halophilic strains from saline mud (Emisal Salt Company, Lake Qarun, Fayoum, Egypt). The lipopolysaccharide was extracted from dried cells of Salinivibrio sp. EG9S8QL by the phenol–water procedure. The OPS was obtained by mild acid hydrolysis of the lipopolysaccharide and was studied by sugar analysis along with 1H and 13C NMR spectroscopy, including 1H,1H COSY, TOCSY, ROESY, 1H,13C HSQC, and HMBC experiments. The OPS was found to be composed of linear tetrasaccharide repeating units of the following structure: →2)-β-Manp4Lac-(1→3)-α-ManpNAc-(1→3)-β-Rhap-(1→4)-α-GlcpNAc-(1→, where Manp4Lac is 4-O-[1-carboxyethyl]mannose. Full article
(This article belongs to the Special Issue Carbohydrate-Containing Marine Compounds of Mixed Biogenesis)
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14 pages, 4925 KiB  
Review
Seaweeds and Their Natural Products for Preventing Cardiovascular Associated Dysfunction
by Bomi Ryu, Young-Sang Kim and You-Jin Jeon
Mar. Drugs 2021, 19(9), 507; https://doi.org/10.3390/md19090507 - 07 Sep 2021
Cited by 9 | Viewed by 3516
Abstract
Cardiovascular disease (CVD), which involves the onset and exacerbation of various conditions including dyslipidemia, activation of the renin–angiotensin system, vascular endothelial cell damage, and oxidative stress, is a leading cause of high mortality rates and accounts for one-third of deaths worldwide. Accordingly, as [...] Read more.
Cardiovascular disease (CVD), which involves the onset and exacerbation of various conditions including dyslipidemia, activation of the renin–angiotensin system, vascular endothelial cell damage, and oxidative stress, is a leading cause of high mortality rates and accounts for one-third of deaths worldwide. Accordingly, as dietary changes in daily life are thought to greatly reduce the prevalence of CVD, numerous studies have been conducted to examine the potential use of foods and their bioactive components for preventing and treating CVD. In particular, seaweeds contain unique bioactive metabolites that are not found in terrestrial plants because of the harsh environment in which they survive, leading to in vitro and in vivo studies of their prevention and treatment effects. This review summarizes studies that focused on the beneficial effects of seaweeds and their natural products targeting markers involved in a cascade of mechanisms related to CVD pathogenesis. The purpose of this review is to describe the potential of seaweeds and their natural products for preventing and treating CVD based on in vivo and in vitro studies. This review provides a basis for future research in the field of marine drugs. Full article
(This article belongs to the Special Issue Marine Natural Products That Target Metabolic Diseases)
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17 pages, 7636 KiB  
Article
RSK1 vs. RSK2 Inhibitory Activity of the Marine β-Carboline Alkaloid Manzamine A: A Biochemical, Cervical Cancer Protein Expression, and Computational Study
by Alejandro M. S. Mayer, Mary L. Hall, Joseph Lach, Jonathan Clifford, Kevin Chandrasena, Caitlin Canton, Maria Kontoyianni, Yeun-Mun Choo, Dev Karan and Mark T. Hamann
Mar. Drugs 2021, 19(9), 506; https://doi.org/10.3390/md19090506 - 07 Sep 2021
Cited by 7 | Viewed by 2647
Abstract
Manzamines are complex polycyclic marine-derived β-carboline alkaloids with reported anticancer, immunostimulatory, anti-inflammatory, antibacterial, antiviral, antimalarial, neuritogenic, hyperlipidemia, and atherosclerosis suppression bioactivities, putatively associated with inhibition of glycogen synthase kinase-3, cyclin-dependent kinase 5, SIX1, and vacuolar ATPases. We hypothesized that additional, yet undiscovered molecular [...] Read more.
Manzamines are complex polycyclic marine-derived β-carboline alkaloids with reported anticancer, immunostimulatory, anti-inflammatory, antibacterial, antiviral, antimalarial, neuritogenic, hyperlipidemia, and atherosclerosis suppression bioactivities, putatively associated with inhibition of glycogen synthase kinase-3, cyclin-dependent kinase 5, SIX1, and vacuolar ATPases. We hypothesized that additional, yet undiscovered molecular targets might be associated with Manzamine A’s (MZA) reported pharmacological properties. We report here, for the first time, that MZA selectively inhibited a 90 kDa ribosomal protein kinase S6 (RSK1) when screened against a panel of 30 protein kinases, while in vitro RSK kinase assays demonstrated a 10-fold selectivity in the potency of MZA against RSK1 versus RSK2. The effect of MZA on inhibiting cellular RSK1 and RSK2 protein expression was validated in SiHa and CaSki human cervical carcinoma cell lines. MZA’s differential binding and selectivity toward the two isoforms was also supported by computational docking experiments. Specifically, the RSK1-MZA (N- and C-termini) complexes appear to have stronger interactions and preferable energetics contrary to the RSK2–MZA ones. In addition, our computational strategy suggests that MZA binds to the N-terminal kinase domain of RSK1 rather than the C-terminal domain. RSK is a vertebrate family of cytosolic serine-threonine kinases that act downstream of the ras-ERK1/2 (extracellular-signal-regulated kinase 1/2) pathway, which phosphorylates substrates shown to regulate several cellular processes, including growth, survival, and proliferation. Consequently, our findings have led us to hypothesize that MZA and the currently known manzamine-type alkaloids isolated from several sponge genera may have novel pharmacological properties with unique molecular targets, and MZA provides a new tool for chemical-biology studies involving RSK1. Full article
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10 pages, 1639 KiB  
Article
Fusaripyridines A and B; Highly Oxygenated Antimicrobial Alkaloid Dimers Featuring an Unprecedented 1,4-Bis(2-hydroxy-1,2-dihydropyridin-2-yl)butane-2,3-dione Core from the Marine Fungus Fusarium sp. LY019
by Lamiaa A. Shaala, Torki Alzughaibi, Grégory Genta-Jouve and Diaa T. A. Youssef
Mar. Drugs 2021, 19(9), 505; https://doi.org/10.3390/md19090505 - 06 Sep 2021
Cited by 9 | Viewed by 2048
Abstract
The fungal strain, Fusarium sp. LY019, was obtained from the Red Sea sponge Suberea mollis. Bioassay-directed partition of the antimicrobial fraction of the extract of the culture of the fungus provided two dimeric alkaloids, fusaripyridines A and B (1 and 2 [...] Read more.
The fungal strain, Fusarium sp. LY019, was obtained from the Red Sea sponge Suberea mollis. Bioassay-directed partition of the antimicrobial fraction of the extract of the culture of the fungus provided two dimeric alkaloids, fusaripyridines A and B (1 and 2). The compounds possess a previously unreported moiety, 1,4-bis(2-hydroxy-1,2-dihydropyridin-2-yl)butane-2,3-dione. Further, the compounds display a highly oxygenated substitution pattern on the dihydropyridine moieties, representing an additional feature of the fusaripyridines. Fusaripyridines A and B are the first examples of natural products possessing 1,4-bis(2-hydroxy-1,2-dihydropyridin-2-yl)butane-2,3-dione backbone. Careful analyses of the one- and two-dimensional NMR and HRESIMS spectra of the compounds secured their structural mapping, while their absolute stereochemistry was established by analyses of their ECD spectra. The production of such dimeric alkaloids with an unprecedented moiety in the culture of Fusarium sp. LY019 supports further understanding of the biosynthetic competences of the cultured marine-derived fungi. Fusaripyridines A and B selectively inhibited the growth of Candida albicans with MIC values down to 8.0 µM, while they are moderately active against S. aureus, E. coli and HeLa cells. Full article
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20 pages, 3048 KiB  
Article
Phlorotannin and Pigment Content of Native Canopy-Forming Sargassaceae Species Living in Intertidal Rockpools in Brittany (France): Any Relationship with Their Vertical Distribution and Phenology?
by Camille Jégou, Solène Connan, Isabelle Bihannic, Stéphane Cérantola, Fabienne Guérard and Valérie Stiger-Pouvreau
Mar. Drugs 2021, 19(9), 504; https://doi.org/10.3390/md19090504 - 04 Sep 2021
Cited by 5 | Viewed by 1980
Abstract
Five native Sargassaceae species from Brittany (France) living in rockpools were surveyed over time to investigate photoprotective strategies according to their tidal position. We gave evidences for the existence of a species distribution between pools along the shore, with the most dense and [...] Read more.
Five native Sargassaceae species from Brittany (France) living in rockpools were surveyed over time to investigate photoprotective strategies according to their tidal position. We gave evidences for the existence of a species distribution between pools along the shore, with the most dense and smallest individuals in the highest pools. Pigment contents were higher in lower pools, suggesting a photo-adaptive process by which the decreasing light irradiance toward the low shore was compensated by a high production of pigments to ensure efficient photosynthesis. Conversely, no xanthophyll cycle-related photoprotective mechanism was highlighted because high levels of zeaxanthin rarely occurred in the upper shore. Phlorotannins were not involved in photoprotection either; only some lower-shore species exhibited a seasonal trend in phlorotannin levels. The structural complexity of phlorotannins appears more to be a taxonomic than an ecological feature: Ericaria produced simple phloroglucinol while Cystoseira and Gongolaria species exhibited polymers. Consequently, tide pools could be considered as light-protected areas on the intertidal zone, in comparison with the exposed emerged substrata where photoprotective mechanisms are essential. Full article
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25 pages, 7049 KiB  
Review
Methods in Microbial Biodiscovery
by Angela A. Salim, Zeinab G. Khalil, Ahmed H. Elbanna, Taizong Wu and Robert J. Capon
Mar. Drugs 2021, 19(9), 503; https://doi.org/10.3390/md19090503 - 03 Sep 2021
Cited by 13 | Viewed by 3944
Abstract
This review presents an account of the microbial biodiscovery methodology developed and applied in our laboratory at The University of Queensland, Institute for Molecular Bioscience, with examples drawn from our experiences studying natural products produced by Australian marine-derived (and terrestrial) fungi and bacteria. [...] Read more.
This review presents an account of the microbial biodiscovery methodology developed and applied in our laboratory at The University of Queensland, Institute for Molecular Bioscience, with examples drawn from our experiences studying natural products produced by Australian marine-derived (and terrestrial) fungi and bacteria. Full article
(This article belongs to the Special Issue Fungal Natural Products: An Ongoing Source for New Drug Leads)
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17 pages, 8445 KiB  
Article
Changes in the Molecular Characteristics of Bovine and Marine Collagen in the Presence of Proteolytic Enzymes as a Stage Used in Scaffold Formation
by Marfa N. Egorikhina, Ludmila L. Semenycheva, Victoria O. Chasova, Irina I. Bronnikova, Yulia P. Rubtsova, Evgeniy A. Zakharychev and Diana Ya. Aleynik
Mar. Drugs 2021, 19(9), 502; https://doi.org/10.3390/md19090502 - 02 Sep 2021
Cited by 6 | Viewed by 4062
Abstract
Biopolymers, in particular collagen and fibrinogen, are the leading materials for use in tissue engineering. When developing technology for scaffold formation, it is important to understand the properties of the source materials as well as the mechanisms that determine the formation of the [...] Read more.
Biopolymers, in particular collagen and fibrinogen, are the leading materials for use in tissue engineering. When developing technology for scaffold formation, it is important to understand the properties of the source materials as well as the mechanisms that determine the formation of the scaffold structures. Both factors influence the properties of scaffolds to a great extent. Our present work aimed to identify the features of the molecular characteristics of collagens of different species origin and the changes they undergo during the enzymatic hydrolysis used for the process of scaffold formation. For this study, we used the methods of gel-penetrating chromatography, dynamic light scattering, reading IR spectra, and scanning electron microscopy. It was found that cod collagen (CC) and bovine collagen (BC) have different initial molecular weight parameters, and that, during hydrolysis, the majority of either type of protein is hydrolyzed by the proteolytic enzymes within the first minute. The differently sourced collagen samples were also hydrolyzed with the formation of two low molecular fractions: Mw ~ 10 kDa and ~20 kDa. In the case of CC, the microstructure of the final scaffolds contained denser, closely spaced fibrillar areas, while the BC-sourced scaffolds had narrow, short fibrils composed of unbound fibers of hydrolyzed collagen in their structure. Full article
(This article belongs to the Special Issue Regenerative Potential of Marine Natural Compounds)
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12 pages, 819 KiB  
Review
The Role of Chitosan Oligosaccharide in Metabolic Syndrome: A Review of Possible Mechanisms
by Wenjing Tao, Geng Wang and Jintao Wei
Mar. Drugs 2021, 19(9), 501; https://doi.org/10.3390/md19090501 - 01 Sep 2021
Cited by 15 | Viewed by 3172
Abstract
Metabolic syndrome, a cluster of metabolic disorders including central obesity, insulin resistance, hyperglycemia, dyslipidemia, and hypertension, has become a major public health problem worldwide. It is of great significance to develop natural products to prevent and treat metabolic syndrome. Chitosan oligosaccharide (COS) is [...] Read more.
Metabolic syndrome, a cluster of metabolic disorders including central obesity, insulin resistance, hyperglycemia, dyslipidemia, and hypertension, has become a major public health problem worldwide. It is of great significance to develop natural products to prevent and treat metabolic syndrome. Chitosan oligosaccharide (COS) is an oligomer of chitosan prepared by the deacetylation of chitin, which is the second most abundant polymer in nature. In recent years, COS has received widespread attention due to its various biological activities. The present review will summarize the evidence from both in vitro and in vivo studies of the beneficial effects of COS on obesity, dyslipidemia, diabetes mellitus, hyperglycemia, and hypertension, and focus attention on possible mechanisms of the prevention and treatment of metabolic syndrome by COS. Full article
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22 pages, 1418 KiB  
Review
Seaweed Protein Hydrolysates and Bioactive Peptides: Extraction, Purification, and Applications
by Javier Echave, Maria Fraga-Corral, Pascual Garcia-Perez, Jelena Popović-Djordjević, Edina H. Avdović, Milanka Radulović, Jianbo Xiao, Miguel A. Prieto and Jesus Simal-Gandara
Mar. Drugs 2021, 19(9), 500; https://doi.org/10.3390/md19090500 - 31 Aug 2021
Cited by 42 | Viewed by 9043
Abstract
Seaweeds are industrially exploited for obtaining pigments, polysaccharides, or phenolic compounds with application in diverse fields. Nevertheless, their rich composition in fiber, minerals, and proteins, has pointed them as a useful source of these components. Seaweed proteins are nutritionally valuable and include several [...] Read more.
Seaweeds are industrially exploited for obtaining pigments, polysaccharides, or phenolic compounds with application in diverse fields. Nevertheless, their rich composition in fiber, minerals, and proteins, has pointed them as a useful source of these components. Seaweed proteins are nutritionally valuable and include several specific enzymes, glycoproteins, cell wall-attached proteins, phycobiliproteins, lectins, or peptides. Extraction of seaweed proteins requires the application of disruptive methods due to the heterogeneous cell wall composition of each macroalgae group. Hence, non-protein molecules like phenolics or polysaccharides may also be co-extracted, affecting the extraction yield. Therefore, depending on the macroalgae and target protein characteristics, the sample pretreatment, extraction and purification techniques must be carefully chosen. Traditional methods like solid–liquid or enzyme-assisted extraction (SLE or EAE) have proven successful. However, alternative techniques as ultrasound- or microwave-assisted extraction (UAE or MAE) can be more efficient. To obtain protein hydrolysates, these proteins are subjected to hydrolyzation reactions, whether with proteases or physical or chemical treatments that disrupt the proteins native folding. These hydrolysates and derived peptides are accounted for bioactive properties, like antioxidant, anti-inflammatory, antimicrobial, or antihypertensive activities, which can be applied to different sectors. In this work, current methods and challenges for protein extraction and purification from seaweeds are addressed, focusing on their potential industrial applications in the food, cosmetic, and pharmaceutical industries. Full article
(This article belongs to the Special Issue Nutra-Cosmeceuticals from Algae for Health and Wellness)
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15 pages, 4484 KiB  
Article
Docosahexaenoic Acid-Acylated Astaxanthin Esters Exhibit Superior Renal Protective Effect to Recombination of Astaxanthin with DHA via Alleviating Oxidative Stress Coupled with Apoptosis in Vancomycin-Treated Mice with Nephrotoxicity
by Hao-Hao Shi, Ying Guo, Li-Pin Chen, Cheng-Cheng Wang, Qing-Rong Huang, Chang-Hu Xue, Yu-Ming Wang and Tian-Tian Zhang
Mar. Drugs 2021, 19(9), 499; https://doi.org/10.3390/md19090499 - 31 Aug 2021
Cited by 1 | Viewed by 2121
Abstract
Prevention of acute kidney injury caused by drugs is still a clinical problem to be solved urgently. Astaxanthin (AST) and docosahexaenoic acid (DHA) are important marine-derived active ingredients, and they are reported to exhibit renal protective activity. It is noteworthy that the existing [...] Read more.
Prevention of acute kidney injury caused by drugs is still a clinical problem to be solved urgently. Astaxanthin (AST) and docosahexaenoic acid (DHA) are important marine-derived active ingredients, and they are reported to exhibit renal protective activity. It is noteworthy that the existing forms of AST in nature are mainly fatty acid-acylated AST monoesters and diesters, as well as unesterified AST, in which DHA is an esterified fatty acid. However, no reports focus on the different bioactivities of unesterified AST, monoesters and diesters, as well as the recombination of DHA and unesterified AST on nephrotoxicity. In the present study, vancomycin-treated mice were used to evaluate the effects of DHA-acylated AST monoesters, DHA-acylated AST diesters, unesterified AST, and the recombination of AST and DHA in alleviating nephrotoxicity by determining serum biochemical index, histopathological changes, and the enzyme activity related to oxidative stress. Results found that the intervention of DHA-acylated AST diesters significantly ameliorated kidney dysfunction by decreasing the levels of urea nitrogen and creatinine, alleviating pathological damage and oxidative stress compared to AST monoester, unesterified AST, and the recombination of AST and DHA. Further studies revealed that dietary DHA-acylated AST esters could inhibit the activation of the caspase cascade and MAPKs signaling pathway, and reduce the levels of pro-inflammatory cytokines. These findings indicated that the administration of DHA-acylated AST esters could alleviate vancomycin-induced nephrotoxicity, which represented a potentially novel candidate or therapeutic adjuvant for alleviating acute kidney injury. Full article
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25 pages, 3581 KiB  
Article
Biochemical Characterization of Cassiopea andromeda (Forsskål, 1775), Another Red Sea Jellyfish in the Western Mediterranean Sea
by Gianluca De Rinaldis, Antonella Leone, Stefania De Domenico, Mar Bosch-Belmar, Rasa Slizyte, Giacomo Milisenda, Annalisa Santucci, Clara Albano and Stefano Piraino
Mar. Drugs 2021, 19(9), 498; https://doi.org/10.3390/md19090498 - 31 Aug 2021
Cited by 13 | Viewed by 3265
Abstract
Increasing frequency of native jellyfish proliferations and massive appearance of non-indigenous jellyfish species recently concur to impact Mediterranean coastal ecosystems and human activities at sea. Nonetheless, jellyfish biomass may represent an exploitable novel resource to coastal communities, with reference to its potential use [...] Read more.
Increasing frequency of native jellyfish proliferations and massive appearance of non-indigenous jellyfish species recently concur to impact Mediterranean coastal ecosystems and human activities at sea. Nonetheless, jellyfish biomass may represent an exploitable novel resource to coastal communities, with reference to its potential use in the pharmaceutical, nutritional, and nutraceutical Blue Growth sectors. The zooxanthellate jellyfish Cassiopea andromeda, Forsskål, 1775 (Cnidaria, Rhizostomeae) entered the Levant Sea through the Suez Canal and spread towards the Western Mediterranean to reach Malta, Tunisia, and recently also the Italian coasts. Here we report on the biochemical characterization and antioxidant activity of C. andromeda specimens with a discussion on their relative biological activities. The biochemical characterization of the aqueous (PBS) and hydroalcoholic (80% ethanol) soluble components of C. andromeda were performed for whole jellyfish, as well as separately for umbrella and oral arms. The insoluble components were hydrolyzed by sequential enzymatic digestion with pepsin and collagenase. The composition and antioxidant activity of the insoluble and enzymatically digestible fractions were not affected by the pre-extraction types, resulting into collagen- and non-collagen-derived peptides with antioxidant activity. Both soluble compounds and hydrolyzed fractions were characterized for the content of proteins, phenolic compounds, and lipids. The presence of compounds coming from the endosymbiont zooxanthellae was also detected. The notable yield and the considerable antioxidant activity detected make this species worthy of further study for its potential biotechnological sustainable exploitation. Full article
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