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1.
Mar Drugs ; 20(2)2022 Feb 17.
Article in English | MEDLINE | ID: covidwho-1708635

ABSTRACT

Omicron is an emerging SARS-CoV-2 variant, evolved from the Indian delta variant B.1.617.2, which is currently infecting worldwide. The spike glycoprotein, an important molecule in the pathogenesis and transmissions of SARS-CoV-2 variants, especially omicron B.1.1.529, shows 37 mutations distributed over the trimeric protein domains. Notably, fifteen of these mutations reside in the receptor-binding domain of the spike glycoprotein, which may alter transmissibility and infectivity. Additionally, the omicron spike evades neutralization more efficiently than the delta spike. Most of the therapeutic antibodies are ineffective against the omicron variant, and double immunization with BioNTech-Pfizer (BNT162b2) might not adequately protect against severe disease induced by omicron B.1.1.529. So far, no efficient antiviral drugs are available against omicron. The present study identified the promising inhibitors from seaweed's bioactive compounds to inhibit the omicron variant B.1.1.529. We have also compared the seaweed's compounds with the standard drugs ceftriaxone and cefuroxime, which were suggested as beneficial antiviral drugs in COVID-19 treatment. Our molecular docking analysis revealed that caffeic acid hexoside (-6.4 kcal/mol; RMSD = 2.382 Å) and phloretin (-6.3 kcal/mol; RMSD = 0.061 Å) from Sargassum wightii (S. wightii) showed the inhibitory effect against the crucial residues ASN417, SER496, TYR501, and HIS505, which are supported for the inviolable omicron and angiotensin-converting enzyme II (ACE2) receptor interaction. Cholestan-3-ol, 2-methylene-, (3beta, 5 alpha) (CMBA) (-6.0 kcal/mol; RMSD = 3.074 Å) from Corallina officinalis (C. officinalis) manifested the strong inhibitory effect against the omicron RBD mutated residues LEU452 and ALA484, was magnificently observed as the essential residues in Indian delta variant B.1.617.2 previously. The standard drugs (ceftriaxone and cefuroxime) showed no or less inhibitory effect against RBD of omicron B.1.1.529. The present study also emphasized the pharmacological properties of the considered chemical compounds. The results could be used to develop potent seaweed-based antiviral drugs and/or dietary supplements to treat omicron B.1.1529-infected patients.


Subject(s)
Angiotensin-Converting Enzyme 2/chemistry , Gene Expression Regulation, Viral/drug effects , Molecular Docking Simulation , SARS-CoV-2/metabolism , Seaweed/chemistry , Spike Glycoprotein, Coronavirus/chemistry , Angiotensin-Converting Enzyme 2/metabolism , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , COVID-19/drug therapy , Humans , Mutation , Protein Binding , Protein Conformation , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics
2.
Carbohydr Polym ; 280: 119006, 2022 Mar 15.
Article in English | MEDLINE | ID: covidwho-1588175

ABSTRACT

Caulerpa lentillifera (Bryopsidophyceae, Chlorophyta) is an edible seaweed attracting great attention for its expansion of farming scale and increasing consumption in these years. In the present study, a sulfated polysaccharide (CLSP-2) was isolated and separated from C. lentillifera, and its chemical structure was elucidated by a series of chemical and spectroscopic methods. Among these methods, mild acid hydrolysis and photocatalytic degradation were applied to release mono- and oligo-saccharide fragments which were further identified by HPLC-MSn analysis, affording the information of the sugar sequences and the sulfate substitution in CLSP-2. Results indicated that the backbone of CLSP-2 was constructed of →6)-ß-Manp-(1→ with sulfated branches at C2, which were comprised of prevalent →3)-ß-Galp4S-(1→, →3)-ß-Galp2,4S-(1→, and minor Xyl. In addition, the virus neutralization assay revealed that CLSP-2 could effectively protect HeLa cells against SARS-CoV-2 infection with an IC50 of 48.48 µg/mL. Hence, the present study suggests CLSP-2 as a promising agent against SARS-CoV-2.


Subject(s)
COVID-19/virology , Caulerpa/chemistry , Polysaccharides/chemistry , Polysaccharides/pharmacology , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Chromatography, High Pressure Liquid/methods , HeLa Cells , Humans , Hydrolysis , Magnetic Resonance Spectroscopy/methods , Mass Spectrometry/methods , Molecular Weight , Polysaccharides/analysis , SARS-CoV-2 , Seaweed/chemistry , Spectroscopy, Fourier Transform Infrared/methods , Sulfates/chemistry
3.
Carbohydr Polym ; 275: 118779, 2022 Jan 01.
Article in English | MEDLINE | ID: covidwho-1466086

ABSTRACT

Previous researches suggested that polysaccharides from brown algae had anti-virus activity. We hypothesized that nature polysaccharide from marine plants might have the effect on anti-SARS-CoV-2 activity. By high throughput screening to target 3CLpro enzyme using polysaccharides library, we discover a crude polysaccharide 375 from seaweed Ecklonia kurome blocked 3CLpro enzymatic activity and shows good anti-SARS-CoV-2 infection activity in cell. Further, we show that homogeneous polysaccharide 37502 from the 375 may bind to 3CLpro well and disturb spike protein binding to ACE2 receptor. The structure characterization uncovers that 37502 is alginate. These results imply that the bioactivities of 375 on SARS-CoV-2 may target multiple key molecules implicated in the virus infection and replication. The above results suggest that 375 may be a potential drug candidate against SARS-CoV-2.


Subject(s)
COVID-19 , Polysaccharides , Humans , Molecular Docking Simulation , Seaweed/chemistry , Virus Internalization/drug effects
4.
Viruses ; 13(9)2021 09 13.
Article in English | MEDLINE | ID: covidwho-1411081

ABSTRACT

Over the decades, the world has witnessed diverse virus associated pandemics. The significant inhibitory effects of marine sulfated polysaccharides against SARS-CoV-2 shows its therapeutic potential in future biomedical applications and drug development. Algal polysaccharides exhibited significant role in antimicrobial, antitumor, antioxidative, antiviral, anticoagulant, antihepatotoxic and immunomodulating activities. Owing to their health benefits, the sulfated polysaccharides from marine algae are a great deal of interest globally. Algal polysaccharides such as agar, alginate, carrageenans, porphyran, fucoidan, laminaran and ulvans are investigated for their nutraceutical potential at different stages of infection processes, structural diversity, complexity and mechanism of action. In this review, we focus on the recent antiviral studies of the marine algae-based polysaccharides and their potential towards antiviral medicines.


Subject(s)
Antiviral Agents/pharmacology , Aquatic Organisms/chemistry , Polysaccharides/pharmacology , Seaweed/chemistry , Virus Diseases/epidemiology , Alginates/chemistry , Alginates/pharmacology , Antiviral Agents/chemistry , Glucans/chemistry , Glucans/pharmacology , Humans , Molecular Structure , Pandemics , Polysaccharides/chemistry , Virus Diseases/drug therapy , Virus Diseases/etiology , Virus Diseases/prevention & control
5.
Mar Drugs ; 19(8)2021 Jul 29.
Article in English | MEDLINE | ID: covidwho-1376892

ABSTRACT

Seaweed of Saccharina japonica is the most abundantly cultured brown seaweed in the world, and has been consumed in the food industry due to its nutrition and the unique properties of its polysaccharides. In this study, fucoidan (LJNF3), purified from S. japonica, was found to be a novel sulfated galactofucan, with the monosaccharide of only fucose and galactose in a ratio of 79.22:20.78, and with an 11.36% content of sulfate groups. NMR spectroscopy showed that LJNF3 consists of (1→3)-α-l-fucopyranosyl-4-SO3 residues and (1→6)-ß-d-galactopyranose units. The molecular mechanism of the anti-inflammatory effect in RAW264.7 demonstrated that LJNF3 reduced the production of nitric oxide (NO), and down-regulated the expression of MAPK (including p38, ENK and JNK) and NF-κB (including p65 and IKKα/IKKß) signaling pathways. In a zebrafish experiment assay, LJNF3 showed a significantly protective effect, by reducing the cell death rate, inhibiting NO to 59.43%, and decreasing about 40% of reactive oxygen species. This study indicated that LJNF3, which only consisted of fucose and galactose, had the potential to be developed in the biomedical, food and cosmetic industries.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Aquatic Organisms/chemistry , Fucose/pharmacology , Galactose/pharmacology , Seaweed/chemistry , Animals , Inhibitory Concentration 50 , Mice , RAW 264.7 Cells/drug effects , Zebrafish
6.
Molecules ; 26(9)2021 Apr 29.
Article in English | MEDLINE | ID: covidwho-1217102

ABSTRACT

Hemostasis disorders play an important role in the pathogenesis, clinical manifestations, and outcome of COVID-19. First of all, the hemostasis system suffers due to a complicated and severe course of COVID-19. A significant number of COVID-19 patients develop signs of hypercoagulability, thrombocytopenia, and hyperfibrinolysis. Patients with severe COVID-19 have a tendency toward thrombotic complications in the venous and arterial systems, which is the leading cause of death in this disease. Despite the success achieved in the treatment of SARS-CoV-2, the search for new effective anticoagulants, thrombolytics, and fibrinolytics, as well as their optimal dose strategies, continues to be relevant. The wide therapeutic potential of seaweed sulfated polysaccharides (PSs), including anticoagulant, thrombolytic, and fibrinolytic activities, opens up new possibilities for their study in experimental and clinical trials. These natural compounds can be important complementary drugs for the recovery from hemostasis disorders due to their natural origin, safety, and low cost compared to synthetic drugs. In this review, the authors analyze possible pathophysiological mechanisms involved in the hemostasis disorders observed in the pathological progression of COVID-19, and also focus the attention of researchers on seaweed PSs as potential drugs aimed to correction these disorders in COVID-19 patients. Modern literature data on the anticoagulant, antithrombotic, and fibrinolytic activities of seaweed PSs are presented, depending on their structural features (content and position of sulfate groups on the main chain of PSs, molecular weight, monosaccharide composition and type of glycosidic bonds, the degree of PS chain branching, etc.). The mechanisms of PS action on the hemostasis system and the issues of oral bioavailability of PSs, important for their clinical use as oral anticoagulant and antithrombotic agents, are considered. The combination of the anticoagulant, thrombolytic, and fibrinolytic properties, along with low toxicity and relative cheapness of production, open up prospects for the clinical use of PSs as alternative sources of new anticoagulant and antithrombotic compounds. However, further investigation and clinical trials are needed to confirm their efficacy.


Subject(s)
Anticoagulants/pharmacology , COVID-19/complications , Hemostasis/drug effects , Polysaccharides/pharmacology , Seaweed , Sulfates/pharmacology , Thrombosis/complications , Animals , Anticoagulants/chemistry , Anticoagulants/pharmacokinetics , Anticoagulants/therapeutic use , COVID-19/blood , COVID-19/drug therapy , Drug Discovery , Humans , Polysaccharides/chemistry , Polysaccharides/pharmacokinetics , Polysaccharides/therapeutic use , Seaweed/chemistry , Sulfates/chemistry , Sulfates/pharmacokinetics , Sulfates/therapeutic use , Thrombosis/blood , Thrombosis/drug therapy
7.
Mar Drugs ; 19(4)2021 Apr 15.
Article in English | MEDLINE | ID: covidwho-1187000

ABSTRACT

Much attention is being devoted to the potential of marine sulfated polysaccharides as antiviral agents in preventing COVID-19. In this study, sulfated fucoidan and crude polysaccharides, extracted from six seaweed species (Undaria pinnatifida sporophyll, Laminaria japonica, Hizikia fusiforme, Sargassum horneri, Codium fragile, Porphyra tenera) and Haliotis discus hannai (abalone viscera), were screened for their inhibitory activity against SARS-CoV-2 virus entry. Most of them showed significant antiviral activities at an IC50 of 12~289 µg/mL against SARS-CoV-2 pseudovirus in HEK293/ACE2, except for P. tenera (IC50 > 1000 µg/mL). The crude polysaccharide of S. horneri showed the strongest antiviral activity, with an IC50 of 12 µg/mL, to prevent COVID-19 entry, and abalone viscera and H. fusiforme could also inhibit SARS-CoV-2 infection with an IC50 of 33 µg/mL and 47 µg/mL, respectively. The common properties of these crude polysaccharides, which have strong antiviral activity, are high molecular weight (>800 kDa), high total carbohydrate (62.7~99.1%), high fucose content (37.3~66.2%), and highly branched polysaccharides. These results indicated that the crude polysaccharides from seaweeds and abalone viscera can effectively inhibit SARS-CoV-2 entry.


Subject(s)
COVID-19/virology , Gastropoda/chemistry , Polysaccharides/pharmacology , SARS-CoV-2/physiology , Seaweed/chemistry , Virus Internalization/drug effects , Animals , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , HEK293 Cells , Humans , Inhibitory Concentration 50 , Polysaccharides/chemistry , Viscera
8.
Mar Drugs ; 18(11)2020 Oct 29.
Article in English | MEDLINE | ID: covidwho-902592

ABSTRACT

Seaweed lectins, especially high-mannose-specific lectins from red algae, have been identified as potential antiviral agents that are capable of blocking the replication of various enveloped viruses like influenza virus, herpes virus, and HIV-1 in vitro. Their antiviral activity depends on the recognition of glycoprotein receptors on the surface of sensitive host cells-in particular, hemagglutinin for influenza virus or gp120 for HIV-1, which in turn triggers fusion events, allowing the entry of the viral genome into the cells and its subsequent replication. The diversity of glycans present on the S-glycoproteins forming the spikes covering the SARS-CoV-2 envelope, essentially complex type N-glycans and high-mannose type N-glycans, suggests that high-mannose-specific seaweed lectins are particularly well adapted as glycan probes for coronaviruses. This review presents a detailed study of the carbohydrate-binding specificity of high-mannose-specific seaweed lectins, demonstrating their potential to be used as specific glycan probes for coronaviruses, as well as the biomedical interest for both the detection and immobilization of SARS-CoV-2 to avoid shedding of the virus into the environment. The use of these seaweed lectins as replication blockers for SARS-CoV-2 is also discussed.


Subject(s)
Betacoronavirus/isolation & purification , Coronavirus Infections/virology , Lectins/chemistry , Mannose/chemistry , Pneumonia, Viral/virology , Polysaccharides/chemistry , Seaweed/chemistry , COVID-19 , Coronavirus Infections/diagnosis , Pandemics , Pneumonia, Viral/diagnosis , SARS-CoV-2
9.
Carbohydr Polym ; 247: 116740, 2020 Nov 01.
Article in English | MEDLINE | ID: covidwho-635683

ABSTRACT

Pulmonary fibrosis (PF) is a lung disease with highly heterogeneous and mortality rate, but its therapeutic options are now still limited. Corona virus disease 2019 (COVID-19) has been characterized by WHO as a pandemic, and the global number of confirmed COVID-19 cases has been more than 8.0 million. It is strongly supported for that PF should be one of the major complications in COVID-19 patients by the evidences of epidemiology, viral immunology and current clinical researches. The anti-PF properties of naturally occurring polysaccharides have attracted increasing attention in last two decades, but is still lack of a comprehensively understanding. In present review, the resources, structural features, anti-PF activities, and underlying mechanisms of these polysaccharides are summarized and analyzed, which was expected to provide a scientific evidence supporting the application of polysaccharides for preventing or treating PF in COVID-19 patients.


Subject(s)
Betacoronavirus , Biological Products/therapeutic use , Coronavirus Infections/complications , Pandemics , Pneumonia, Viral/complications , Polysaccharides/therapeutic use , Pulmonary Fibrosis/drug therapy , Animals , Antioxidants/pharmacology , Antioxidants/therapeutic use , Bleomycin/toxicity , COVID-19 , Disease Models, Animal , Drug Evaluation, Preclinical , Forkhead Box Protein O3/physiology , Fungi/chemistry , Heterogeneous Nuclear Ribonucleoprotein D0/physiology , Humans , Macrophages/drug effects , Medicine, Chinese Traditional , Mice , Neutrophils/drug effects , Phytotherapy , Plants, Medicinal/chemistry , Polysaccharides/pharmacology , Pulmonary Fibrosis/chemically induced , Pulmonary Fibrosis/etiology , Pulmonary Fibrosis/prevention & control , RNA, Long Noncoding/antagonists & inhibitors , Rats , SARS-CoV-2 , Seaweed/chemistry , Signal Transduction/drug effects , Smad2 Protein/physiology , Smad3 Protein/physiology , Transforming Growth Factor beta1/antagonists & inhibitors
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