Efficacy of a Polyphenolic, Standardized Green Tea Extract for the Treatment of COVID-19 Syndrome: A Proof-of-Principle Study

Abstract

The lack of therapies for moderate COVID-19 syndrome prompted us to use a standardized polyphenolic green tea extract rich in catechins during the lockdown due to the pandemic in Italy (Autumn 2020). Catechins are powerful antioxidant, anti-inflammatory and antiviral agents that are safe for human use. While awaiting hospitalization, 10 swab-positive patients, symptomatic for SARS-COV-2, were treated for 15 days at home with two sessions of inhalation plus three capsules per day (total catechins: 840 mg; total EGCG: 595 mg). All patients recovered fully and had no symptoms at a median of 9 days, with a range of 7–15 days. Seven switched to a negative SARS-COV-2 nasopharyngeal swab test at a median of 9 days, with a range of 6–13 days. Among the 3 patients still swab-positive, one had a strong decrease of infection down to a “very low” SARS-COV-2 nucleic acid load at 5 days. All patients exited quarantine at the end of therapy because they were free of symptoms. Inflammation markers α-1 anti-trypsin, C-reactive protein and eosinophils had significantly decreased. The IL-6 and erythrocyte sedimentation rate decreased in 7 out of 10 patients. To the best of our knowledge, this is the first report of the efficacy of green tea catechin against COVID-19 syndrome. These results may open new perspectives in the fight against the disease.

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

“…Manusco et al [123] reported that at day 10, 0.7% of the patients had a first negative swab test, with the percentage increasing to 19.0% on day 20. It seems that green tea polyphenol treatment might have helped clear the virus from the patients, as 20% of patients from the Bettuzzi et al study [117] had the first negative swab at 10 days, increasing to 70% at day 20 from the first swab. As the authors declared, the effect of green tea polyphenols was noticeable, as the probability of this happening by chance was p < 0.0023 at day 10 or p < 0.005 at day 20 (one-tailed Fisher-Yates test performed by the authors of the study), but the mechanism was unknown.…”

“…The lack of therapies for COVID-19 patients with mild and moderate symptoms compelled a group of researchers from the Istituto Nazionale Biostrutture e Biosistemi, Italy, to use standardized polyphenolic green tea extract during the lockdown in Italy in Autumn 2020 [117] to treat ten symptomatic COVID-19 patients with positive nasopharyngeal swab tests for the SARS-CoV-2 virus. The group already had experience in green tea extract application and dosage in animal [118] and clinical studies [119] related to vascular and cancer disease.…”

“…Before testing the efficacy of ThE on COVID-19 patients, Bettuzzi et al [117] tested the proposed therapy in two healthy volunteers with no side effects. All COVID-19 patients started the ThE therapy at a median of 5 days within a range of 3-6 days.…”

“…Complications accompanying COVID-19 can lead to organ dysfunction, metabolic acidosis, sepsis, blood coagulation dysfunction, cardiac arrest, and death [25]. Polyphenols and polyphenol-rich plants have been widely tested and used for the general treatment of COVID-19 [23,117,131,132]. An update on completed or recruiting clinical trials based on plants, their isolated products, and functional foods against COVID-19 is summarized in an article by Alam et al (2021) [133].…”

A Comprehensive Review about the Molecular Structure of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2): Insights into Natural Products against COVID-19

“…The therapeutic blocking of p38 could consequently impair COVID-19 infection. Thus, they revealed a common pattern that virus-induced p38 MAPK activation facilitates viral infection, and targeting p38 MAPK is a promising antiviral strategy [252]. It is a successful example to use the knowledge of animal toxic peptide for probing and addressing some of the major health challenges of our time such as viral infection.…”