The Relevance of Plant-Derived Se Compounds to Human Health in the SARS-CoV-2 (COVID-19) Pandemic Era

Abstract

Dietary selenium (Se)-compounds accumulated in plants are essential for human metabolism and normal physiological processes. Inorganic and organic Se species can be readily absorbed by the human body, but are metabolized differently and thus exhibit distinct mechanisms of action. They can act as antioxidants or serve as a source of Se for the synthesis of selenoproteins. Selenocysteine, in particular, is incorporated at the catalytic center of these proteins through a specific insertion mechanism and, due to its electronic features, enhances their catalytic activity against biological oxidants. Selenite and other Se-organic compounds may also act as direct antioxidants in cells due to their strong nucleophilic properties. In addition, Se-amino acids are more easily subjected to oxidation than the corresponding thiols/thioethers and can bind redox-active metal ions. Adequate Se intake aids in preventing several metabolic disorders and affords protection against viral infections. At present, an epidemic caused by a novel coronavirus (SARS-CoV-2) threatens human health across several countries and impacts the global economy. Therefore, Se-supplementation could be a complementary treatment to vaccines and pharmacological drugs to reduce the viral load, mutation frequency, and enhance the immune system of populations with low Se intake in the diet.

Selenium compounds as promising antiviral agents

“…It is well tolerated at a dose of 50 mg/kg administered twice a day for three days. 90 Another series of amide derivatives, 1,2,3-selenadazole thioacetanilides (15), have been designed as non-nucleoside reverse transcriptase inhibitors which display anti-HIV-1 activity with the EC 50 value varying between 2.45 and 6.65 mM. 78 Anti-HIV-1 activities of the selenium analogue of ritonavir (an anti-HIV drug) (16) have been evaluated in acutely infected MT-4 cells.…”

Immunomodulatory and Anti-Inflammatory Properties of Selenium-Containing Agents: Their Role in the Regulation of Defense Mechanisms against COVID-19

“…For example, SLM and MSC can be metabolized to methylselenol (CH 3 SeH), Sec, and selenide. Moreover, the formation of methylselenol from SLM requires several enzymatic reactions, while MSC is converted in one step [71,72]. Methylselenol is a key metabolite with an anticancer activity.…”

Thyroid Dysfunction and COVID-19: The Emerging Role of Selenium in This Intermingled Relationship

“…Therefore, Se-enriched food and supplementation (e.g., sodium selenite) could be considered in populations with suboptimal Se in their diet/environment to prevent SARS-Cov-2 infection, as well as measurement and monitoring of Se in hospitalized and symptomatic outpatients, taking care to avoid adverse effects related to excessive Se (supplementation may potentially increase the risk of certain diseases and toxicity in individuals with a pre-existing adequate or high status) or in other specific conditions (e.g., patients with type 2 diabetes) [ 16 , 109 , 121 , 125 , 126 ]. For these reasons, a combined assessment of Se, SELENOP, and zinc (Zn) could serve as a reliable biomarker of survival in COVID-19 patients, contributing to a better stratification of patients affected by COVID-19 (or other similar infectious diseases) and suggesting that a personalized adjuvant supplementation of microelements may help clinical care [ 123 , 127 ].…”

“…Moreover, COVID-19 patients had low blood Se levels associated with increased levels of oxidative stress and inflammatory biomarkers and lower circulating antioxidants [ 14 , 15 ]. Selenium supplementation (e.g., sodium selenite) may therefore represent an opportunity as it could serve as an adjunctive tool for the treatment of coronavirus infection for its anti-inflammatory, immunostimulatory, and antiviral actions, possibly preventing SARS-CoV-2-triggered thyroid aggravation in patients during and after COVID-19 [ 16 , 17 ].…”