Can Selenium Reduce the Susceptibility and Severity of SARS-CoV-2?-A Comprehensive Review

Abstract

The SARS-CoV-2 infection is a highly contagious viral infection, which has claimed millions of lives in the last two years. The infection can cause acute respiratory distress, myocarditis, and systemic inflammatory response in severe cases. The interaction of the viral spike protein with the angiotensin-converting enzyme in various tissues causes damage to vital organs and tissues, leading to complications in the post-infection period. Vaccines and antiviral drugs have improved patient response to the infection, but the long-term effect on vital organs is still unknown. Investigations are now focused on supportive nutrient therapies, which can mitigate the susceptibility as well as the long-term complications of COVID-19. Selenium is one such micronutrient that plays a vital role in preventing oxidative stress induced by the virus. Further, selenium is important for effective immune response, controlling systemic inflammation, and maintain overall health of humans. We examine the role of selenium in various aspects of SARS-CoV-2 infection and address the importance of selenium supplementation in reducing the susceptibility and severity of infection in this review.

Keywords: SARS-CoV-2; immunity; inflammation; micronutrient; oxidative stress; selenium.

Figure 1

Multiple risk factors of severe coronavirus disease 2019 (COVID-19) illness.

Figure 2

Mechanism of SARS-CoV-2 infection via the interaction with angiotensin-converting enzyme 2 (ACE2) receptors. TMPRSS2: Transmembrane protease, serine 2. The arrows represent the sequence of events following SARS-CoV-2 infection.

Figure 3

Selenoproteins in viral infection: Dietary selenium is incorporated in selenoproteins that play regulatory roles in immune function and redox homeostasis. These include the Selenoproteins glutathione peroxidases (GPX), 15 kDa selenoprotein F (SELENOF), selenoproteins K and S and thioredoxin reductases (TXNRD). Viral infection alters the expression of selenoproteins and induces oxidative stress, increasing virus virulence. The resultant inflammation and excess cytokine production eventually lead to poor clinical outcomes. The blue arrows represent the sequence of events of selenoprotein synthesis from dietary selenium. The red arrows represent the consequence of viral infection. Adequate selenium levels can reduce the impact of viral infection and help in an optimum antiviral response.

Figure 4

Effects of selenium supplementation on COVID-19. Adequate selenium levels reduce oxidative stress by restoring antioxidant enzymes, reduce cell death and coagulation pathways, and protect endothelial cells, thus having an overall protective effect on lungs and other organs.