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Mar Drugs ; 19(1)2021 Jan 10.
Article in English | MEDLINE | ID: covidwho-1033055


Microalgae are at the start of the food chain, and many are known producers of a significant amount of lipids with essential fatty acids. However, the bioactivity of microalgal lipids for anti-inflammatory and antithrombotic activities have rarely been investigated. Therefore, for a sustainable source of the above bioactive lipids, the present study was undertaken. The total lipids of microalga Chlorococcum sp., isolated from the Irish coast, were fractionated into neutral-, glyco-, and phospho-lipids, and were tested in vitro for their anti-inflammatory and antithrombotic activities. All tested lipid fractions showed strong anti-platelet-activating factor (PAF) and antithrombin activities in human platelets (half maximal inhibitory concentration (IC50) values ranging ~25-200 µg of lipid) with the highest activities in glyco- and phospho-lipid fractions. The structural analysis of the bioactive lipid fraction-2 revealed the presence of specific sulfoquinovosyl diacylglycerols (SQDG) bioactive molecules and the HexCer-t36:2 (t18:1/18:1 and 18:2/18:0) cerebrosides with a phytosphingosine (4-hydrosphinganine) base, while fraction-3 contained bioactive phosphatidylcholine (PC) and phosphatidylethanolamine (PE) molecules. These novel bioactive lipids of Chlorococcum sp. with putative health benefits may indicate that marine microalgae can be a sustainable alternative source for bioactive lipids production for food supplements and nutraceutical applications. However, further studies are required towards the commercial technology pathways development and biosafety analysis for the use of the microalga.

Anti-Inflammatory Agents, Non-Steroidal/chemistry , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Fibrinolytic Agents/chemistry , Fibrinolytic Agents/pharmacology , Lipids/chemistry , Lipids/pharmacology , Microalgae/chemistry , Antithrombins/pharmacology , Blood Platelets/drug effects , Fatty Acids/chemistry , Fatty Acids/pharmacology , Humans , Platelet Activating Factor/antagonists & inhibitors , Platelet Aggregation/drug effects , Water Microbiology
Biofactors ; 46(6): 927-933, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-966303


Recent articles report elevated markers of coagulation, endothelial injury, and microthromboses in lungs from deceased COVID-19 patients. However, there has been no discussion of what may induce intravascular coagulation. Platelets are critical in the formation of thrombi and their most potent trigger is platelet activating factor (PAF), first characterized by Demopoulos and colleagues in 1979. PAF is produced by cells involved in host defense and its biological actions bear similarities with COVID-19 disease manifestations. PAF can also stimulate perivascular mast cell activation, leading to inflammation implicated in severe acute respiratory syndrome (SARS). Mast cells are plentiful in the lungs and are a rich source of PAF and of inflammatory cytokines, such as IL-1ß and IL-6, which may contribute to COVID-19 and especially SARS. The histamine-1 receptor antagonist rupatadine was developed to have anti-PAF activity, and also inhibits activation of human mast cells in response to PAF. Rupatadine could be repurposed for COVID-19 prophylaxis alone or together with other PAF-inhibitors of natural origin such as the flavonoids quercetin and luteolin, which have antiviral, anti-inflammatory, and anti-PAF actions.

COVID-19/prevention & control , Cyproheptadine/analogs & derivatives , Disseminated Intravascular Coagulation/prevention & control , Platelet Activating Factor/antagonists & inhibitors , Pulmonary Embolism/prevention & control , SARS-CoV-2/pathogenicity , Severe Acute Respiratory Syndrome/prevention & control , Antiviral Agents/therapeutic use , Blood Platelets/drug effects , Blood Platelets/pathology , Blood Platelets/virology , COVID-19/blood , COVID-19/pathology , COVID-19/virology , Cyproheptadine/therapeutic use , Disseminated Intravascular Coagulation/blood , Disseminated Intravascular Coagulation/pathology , Disseminated Intravascular Coagulation/virology , Gene Expression Regulation , Humans , Inflammation , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Interleukin-6/genetics , Interleukin-6/metabolism , Lung/drug effects , Lung/pathology , Lung/virology , Luteolin/therapeutic use , Mast Cells/drug effects , Mast Cells/pathology , Mast Cells/virology , Platelet Activating Factor/genetics , Platelet Activating Factor/metabolism , Pulmonary Embolism/blood , Pulmonary Embolism/pathology , Pulmonary Embolism/virology , Quercetin/therapeutic use , SARS-CoV-2/drug effects , Severe Acute Respiratory Syndrome/blood , Severe Acute Respiratory Syndrome/pathology , Severe Acute Respiratory Syndrome/virology