Molecular Mechanisms of Possible Action of Phenolic Compounds in COVID-19 Protection and Prevention

Abstract

The worldwide outbreak of COVID-19 was caused by a pathogenic virus called Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). Therapies against SARS-CoV-2 target the virus or human cells or the immune system. However, therapies based on specific antibodies, such as vaccines and monoclonal antibodies, may become inefficient enough when the virus changes its antigenicity due to mutations. Polyphenols are the major class of bioactive compounds in nature, exerting diverse health effects based on their direct antioxidant activity and their effects in the modulation of intracellular signaling. There are currently numerous clinical trials investigating the effects of polyphenols in prophylaxis and the treatment of COVID-19, from symptomatic, via moderate and severe COVID-19 treatment, to anti-fibrotic treatment in discharged COVID-19 patients. Antiviral activities of polyphenols and their impact on immune system modulation could serve as a solid basis for developing polyphenol-based natural approaches for preventing and treating COVID-19.

Phenolic compounds versus SARS-CoV-2: An update on the main findings against COVID-19

“…During the writing of the manuscript, the snowballing technique was used to include other studies relevant to the topic (from any period) from the references of the selected articles. Since the targets of SARS-CoV 1 and 2 are very similar, results on activity against SARS-CoV were also shown, as suggested by Gligorijevic et al (2021) . To complement the anti-COVID-19 potential of PCs, a brief explanation was made on their immunomodulatory/anti-inflammatory/antioxidant effect, which strengthens the body's defenses to prevent COVID-19 or resist its impact in case of infection.…”

“…During the writing of the manuscript, the snowballing technique was used to include other studies relevant to the topic (from any period) from the references of the selected articles. Since the targets of SARS-CoV 1 and 2 are very similar, results on activity against SARS-CoV were also shown, as suggested by Gligorijevic et al (2021) .…”

“…Fortunately, many isolated PCs such as baicalein, hesperidin, quercetin, luteolin, gallocatechin, epigallocatechin gallate, kaempferol, and isoliquiritigenin have shown efficiency in its inhibition ( Paraiso et al, 2020 ; de la Lastra et al, 2021 ). For example, xanthoangelol E from Angelica keiskei , PCs from Psoralea corylifolia seeds and PCs from Broussonetia papyrifera showed an IC50 value of de 1,2, 15 g/L y 3,7 μM, respectively against SARS-CoV PLpro ( Gligorijevic et al, 2021 ). When evaluating the potential of myricetin from Scutellaria baicalensis against nsP13 helicase of SARS-CoV, the IC50 value was 2.71 μM.…”

Screening and evaluation of cytotoxicity and antiviral effects of secondary metabolites from water extracts of Bersama abyssinica against SARS-CoV-2 Delta

“…Generally, water extract exhibited varied types of active metabolites with two phenolics, coumari and flavonoid which could have synergetic activity against SARS-CoV-2. The increased activity of water extract could be attributed to a high concentration of polar molecules, particularly phenolic compounds with high antioxidant and antiviral properties [ 42 ]. Again, the presence of coumarin and flavonoids contributed to antiviral activity which havebeen reported by other studies to have high antiviral activity against SARS-CoV-2 [ 43 , 44 ].…”

Tucaresol: A Unique Oral Candidate Drug Ideally Accessible for Treatment of COVID-19 Disease

“…Multiple examples of compound screens in various cell-based or virtual assays have been published since last year. A mention of one compound class, polyphenolic plant compounds, merits note since multiple members of this class have been or are under clinical evaluation as treatments for COVID-19 disease 16 .…”