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Arch Toxicol ; 95(4): 1179-1226, 2021 04.
Article in English | MEDLINE | ID: covidwho-1384375


Here, we addressed the pharmacology and toxicology of synthetic organoselenium compounds and some naturally occurring organoselenium amino acids. The use of selenium as a tool in organic synthesis and as a pharmacological agent goes back to the middle of the nineteenth and the beginning of the twentieth centuries. The rediscovery of ebselen and its investigation in clinical trials have motivated the search for new organoselenium molecules with pharmacological properties. Although ebselen and diselenides have some overlapping pharmacological properties, their molecular targets are not identical. However, they have similar anti-inflammatory and antioxidant activities, possibly, via activation of transcription factors, regulating the expression of antioxidant genes. In short, our knowledge about the pharmacological properties of simple organoselenium compounds is still elusive. However, contrary to our early expectations that they could imitate selenoproteins, organoselenium compounds seem to have non-specific modulatory activation of antioxidant pathways and specific inhibitory effects in some thiol-containing proteins. The thiol-oxidizing properties of organoselenium compounds are considered the molecular basis of their chronic toxicity; however, the acute use of organoselenium compounds as inhibitors of specific thiol-containing enzymes can be of therapeutic significance. In summary, the outcomes of the clinical trials of ebselen as a mimetic of lithium or as an inhibitor of SARS-CoV-2 proteases will be important to the field of organoselenium synthesis. The development of computational techniques that could predict rational modifications in the structure of organoselenium compounds to increase their specificity is required to construct a library of thiol-modifying agents with selectivity toward specific target proteins.

Organoselenium Compounds/pharmacology , Organoselenium Compounds/toxicity , Amino Acids/chemistry , Animals , Azoles , Humans , Isoindoles , Molecular Structure , Selenium/chemistry , Selenium/physiology , Selenoproteins/chemistry , Sulfhydryl Compounds/chemistry
J Chin Med Assoc ; 84(9): 821-826, 2021 09 01.
Article in English | MEDLINE | ID: covidwho-1317943


Different dietary nutrients have distinct effects, including enhancing immune response activity and supporting mucous membrane integrity. These effects are critical in fighting against pathogenic agents, which cover coronavirus disease 2019 (COVID-19), the coronavirus disease that shuts down globally. Recent researches have shown that micronutrient deficiency is commonly associated with compromised immune responses, respiratory tract infections, or even susceptibility to COVID-19. The relationship between Vit A and infection is its role in mucosal epithelium integrity (skin and mucous membrane), the supplementation could be an option for assisted-treating the SARS-CoV-2 virus and a possible prevention of lung infection. Vit C/ascorbic acid stimulates oxygen radical scavenging activity of the skin and enhances epithelial barrier function. Ascorbic acid alone or with other natural compounds (baicalin and theaflavin) may inhibit the expression of angiotensin-converting enzyme II in human small alveolar epithelial cells and limited the entry of SARS-CoV-2. Vitamin D receptors can be expressed by immune cells, and different immune cells (macrophages, monocytes, dendritic cells, T cells, and B cells) can convert Vit D into its active form 1,25-(OH)2 D. Oral vitamin D intake can be a readily way to restrict the viral infection through downregulation of ACE2 receptor and to attenuate the disease severity by decreasing the frequency of cytokine storm and pulmonary pro-inflammatory response. Vit E supports T-cell mediated functions, optimization of Th1 response, and suppression of Th2 response. Vitamin E supplementation can lower the production of superoxides and may favors the antioxidants and benefit the progress of COVID-19 treatment. Zinc plays an essential role in both innate and adaptive immune systems and cytokine production, and Zinc-dependent viral enzymes to initiate the infectious process have proved the Zinc levels are directly associated with symptoms relieved of COVID-19. Iron is an essential component of enzymes involved in the activation of immune cells, lower iron levels predispose to severe symptoms of SARS-CoV-2, and monitoring the status can predict the disease severity and mortality. Selenium participates in the adaptive immune response by supporting antibody production and development. Deficiency can reduce antibody concentration, decreased cytotoxicity of NK cells, compromised cellular immunity, and an attenuated response to vaccination. The COVID-19 vaccines including three broad categories, protein-based vaccines, gene-based vaccines (mRNA vaccines and DNA vaccines), combination of gene and protein-based vaccines. Micronutrients are involved in immunity from the virus entering the human to innate immune response and adaptive immune response. Micronutrients are indispensable in immune response of vaccination.

COVID-19 Vaccines/immunology , COVID-19/therapy , Immunomodulation , Micronutrients/physiology , SARS-CoV-2 , COVID-19/immunology , Dietary Supplements , Humans , Iron/physiology , Micronutrients/administration & dosage , Selenium/physiology , Vitamins/physiology , Zinc/physiology