Immune-Boosting, Antioxidant and Anti-inflammatory Food Supplements Targeting Pathogenesis of COVID-19

Abstract

The COVID-19 is an acute and contagious disease characterized by pneumonia and ARDS. The disease is caused by SARS-CoV-2, which belongs to the family of Coronaviridae along with MERS-CoV and SARS-CoV-1. The virus has the positive-sense RNA as its genome encoding for ∼26 proteins that work together for the virus survival, replication, and spread in the host. The virus gets transmitted through the contact of aerosol droplets from infected persons. The pathogenesis of COVID-19 is highly complex and involves suppression of host antiviral and innate immune response, induction of oxidative stress followed by hyper inflammation described as the "cytokine storm," causing the acute lung injury, tissue fibrosis, and pneumonia. Currently, several vaccines and drugs are being evaluated for their efficacy, safety, and for determination of doses for COVID-19 and this requires considerable time for their validation. Therefore, exploring the repurposing of natural compounds may provide alternatives against COVID-19. Several nutraceuticals have a proven ability of immune-boosting, antiviral, antioxidant, anti-inflammatory effects. These include Zn, vitamin D, vitamin C, curcumin, cinnamaldehyde, probiotics, selenium, lactoferrin, quercetin, etc. Grouping some of these phytonutrients in the right combination in the form of a food supplement may help to boost the immune system, prevent virus spread, preclude the disease progression to severe stage, and further suppress the hyper inflammation providing both prophylactic and therapeutic support against COVID-19.

Dietary Supplements during COVID-19 Outbreak. Results of Google Trends Analysis Supported by PLifeCOVID-19 Online Studies

“…In our study, immunity improvement and improving the overall health and wellness were the main reasons for DSs use, declared by nearly 60% of respondents. In addition, other studies report that use of some DSs is often justified by the desire to improve immunity, overall health, to prevent illness, or to treat viral infections, even before the COVID-19 outbreak [ 3 , 5 , 6 , 7 , 13 , 31 , 33 , 34 ].…”

“…Indeed, there is some scientific evidence on immune-boosting, anti-inflammatory, antioxidant, and antiviral properties of several bioactive compounds and foods, including vitamins D and C, zinc, selenium, garlic, ginger, turmeric, lactoferrin, elderberry, or Nigella sativa , however they cannot be freely extrapolated to the effects on the SARS-CoV-2 virus [ 9 , 11 , 14 , 22 , 23 , 34 ]. Recently, the compounds like vitamin D, vitamin C, zinc, probiotics, curcumin, quercetin have been extensively studied in the context of coronavirus [ 34 , 35 , 36 ]. Initial surveys have found them to possess an anti-SARS-CoV-2 effect, and suggest they might provide both prophylactic and adjuvant therapy against COVID-19 effects, therefore, they are being fast-tracked into clinical trials [ 34 , 35 ].…”

“…Recently, the compounds like vitamin D, vitamin C, zinc, probiotics, curcumin, quercetin have been extensively studied in the context of coronavirus [ 34 , 35 , 36 ]. Initial surveys have found them to possess an anti-SARS-CoV-2 effect, and suggest they might provide both prophylactic and adjuvant therapy against COVID-19 effects, therefore, they are being fast-tracked into clinical trials [ 34 , 35 ]. Recent studies have linked deficiency of zinc [ 35 ], selenium [ 37 ], or vitamin C [ 36 , 38 ] to poorer COVID-19 outcomes.…”

“…Above mentioned pieces of evidence suggest that the use of DSs may be necessary to obtain and/or maintain the optimal levels of those nutrients, specifically in individuals with higher risk of their deficiencies, including the elderly, obese, or with co-morbidities, like diabetes [ 45 ]. On the other hand, results concerning the role of supplementation in the prevention of COVID-19 in healthy and well-nourished individuals are still not fully investigated [ 34 ]. Analysis of 13 guidelines regarding nutrition during the pandemic revealed that in eleven documents, the use of DSs in COVID-19 prevention was not mentioned at all, while in the remaining two, the authors remarked that DSs use was acceptable but to meet the nutrients’ recommendations [ 10 ].…”

A rational approach to COVID-19

“…Zinc from poultry, red meat, nuts, pumpkin seeds, sesame seeds, beans, and lentils will enhance immunity and inhibit virus proliferation. Food supplements to boost the immune system and reduce inflammation include curcumin, cinnamon, garlic, black pepper, selenium, lactoferrin, and quercetin [ 27 ]. Lactoferrin is a protein that is present in the milk exhibits antiviral activity, including against coronaviruses [ 28 ].…”