Can Natural Polyphenols Help in Reducing Cytokine Storm in COVID-19 Patients?

Abstract

SARS-CoV-2 first emerged in China during late 2019 and rapidly spread all over the world. Alterations in the inflammatory cytokines pathway represent a strong signature during SARS-COV-2 infection and correlate with poor prognosis and severity of the illness. The hyper-activation of the immune system results in an acute severe systemic inflammatory response named cytokine release syndrome (CRS). No effective prophylactic or post-exposure treatments are available, although some anti-inflammatory compounds are currently in clinical trials. Studies of plant extracts and natural compounds show that polyphenols can play a beneficial role in the prevention and the progress of chronic diseases related to inflammation. The aim of this manuscript is to review the published background on the possible effectiveness of polyphenols to fight SARS-COV-2 infection, contributing to the reduction of inflammation. Here, some of the anti-inflammatory therapies are discussed and although great progress has been made though this year, there is no proven cytokine blocking agents for COVID currently used in clinical practice. In this regard, bioactive phytochemicals such as polyphenols may become promising tools to be used as adjuvants in the treatment of SARS-CoV-2 infection. Such nutrients, with anti-inflammatory and antioxidant properties, associated to classical anti-inflammatory drugs, could help in reducing the inflammation in patients with COVID-19.

A Review of the Role of Micronutrients and Bioactive Compounds on Immune System Supporting to Fight against the COVID-19 Disease

“…Bioactive phytochemicals and immunomodulatory agents, such as polyphenols, with interesting properties, like reducing inflammation and preventing oxidation process [ 52 ], may also be interesting adjuvants in the treatment of SARS-CoV-2 infection helping to reduce the inflammation [ 53 ]. Different polyphenols have shown promising activity, such as glycyrrhizin or polyphenols (e.g., caffeic acid, kaempferol, resveratrol, curcumin, quercetin, catechin, or hesperidin) [ 54 , 55 ].…”

Consumption of Phenolic-Rich Food and Dietary Supplements as a Key Tool in SARS-CoV-19 Infection

“…Consequently, severe attacks can occur in many organs, including lungs and kidneys, leading to eventual cell death, sepsis, organs failure, and sometimes, patient death [ 52 ]. In this context, some phenolic compounds have been shown to have a determining effect on the modulation of interleukin synthesis induction routes, allowing them to be promising tools in the management of this response [ 53 ]. These can act at different levels, modulating gene expression and inhibiting the activity of certain receptors related to the initiation of chronic inflammatory response cascades, such as nuclear factor kappa-B, or mitogen-activated protein kinase and cyclooxygenase-2 [ 54 ].…”

“…The administration of 140 mg of nano-curcumin showed having a modulating effect in COVID-19 patients ( Table 2 ) by suppressing the expression of genes involved in the pro-inflammatory cytokines IL-1 β and IL-6, IL-18, and TNF-α production [ 99 ]. That way, the cytokine storm, which is a determining factor in the severity of this disease and can lead to the most critical cases, is avoided [ 51 , 53 ]. Another study also observed that the percentage of deceased patients in the control group was lower (40%, 8 out of 20) compared to the group treated with nano-curcumin (20%, 4 out of 20).…”

Comparison of Antibacterial and Antioxidant Properties of Red (cv. Negramaro) and White (cv. Fiano) Skin Pomace Extracts

“…The health-promoting activities of plant polyphenols have been widely ascertained by hundreds scientific publications. Studies on plant extracts and phytochemicals showed that polyphenols could play an anti-inflammatory and antibacterial action [ 1 , 2 , 3 , 4 ]. Grape by-products are one of the main sources of bioactive polyphenols [ 5 , 6 ].…”

“…However, the bioactivities of grape pomace extracts are the result of their polyphenolic profile that is affected by the grape variety, the geographical origin and the winemaking process [ 1 , 8 , 9 ]. The phenolic compounds of grape pomace can be classified in phenolic acids, flavonoids (flavonols, flavanols, anthocyanins), stilbenes, and tannins [ 5 ].…”