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1.
Viruses ; 13(12)2021 12 17.
Article in English | MEDLINE | ID: covidwho-1580427

ABSTRACT

The COVID-19 pandemic has resulted in a huge number of deaths from 2020 to 2021; however, effective antiviral drugs against SARS-CoV-2 are currently under development. Recent studies have demonstrated that green tea polyphenols, particularly EGCG, inhibit coronavirus enzymes as well as coronavirus replication in vitro. Herein, we examined the inhibitory effect of green tea polyphenols on coronavirus replication in a mouse model. We used epigallocatechin gallate (EGCG) and green tea polyphenols containing more than 60% catechin (GTP60) and human coronavirus OC43 (HCoV-OC43) as a surrogate for SARS-CoV-2. Scanning electron microscopy analysis results showed that HCoV-OC43 infection resulted in virion particle production in infected cells. EGCG and GTP60 treatment reduced coronavirus protein and virus production in the cells. Finally, EGCG- and GTP60-fed mice exhibited reduced levels of coronavirus RNA in mouse lungs. These results demonstrate that green tea polyphenol treatment is effective in decreasing the level of coronavirus in vivo.


Subject(s)
Antiviral Agents/pharmacology , Catechin/analogs & derivatives , Coronavirus Infections/drug therapy , Polyphenols/pharmacology , Tea/chemistry , Virus Replication/drug effects , Animals , Antiviral Agents/chemistry , Antiviral Agents/therapeutic use , Catechin/pharmacology , Catechin/therapeutic use , Cell Line , Coronavirus Infections/virology , Coronavirus OC43, Human/drug effects , Coronavirus OC43, Human/physiology , Disease Models, Animal , Humans , Mice , Polyphenols/chemistry , Polyphenols/therapeutic use
2.
Molecules ; 26(21)2021 Nov 08.
Article in English | MEDLINE | ID: covidwho-1512511

ABSTRACT

This work describes an untargeted analytical approach for the screening, identification, and characterization of the trans-epithelial transport of green tea (Camellia sinensis) catechin extracts with in vitro inhibitory effect against the SARS-CoV-2 papain-like protease (PLpro) activity. After specific catechin extraction, a chromatographic separation obtained six fractions were carried out. The fractions were assessed in vitro against the PLpro target. Fraction 5 showed the highest inhibitory activity against the SARS-CoV-2 PLpro (IC50 of 0.125 µg mL-1). The untargeted characterization revealed that (-)-epicatechin-3-gallate (ECG) was the most abundant compound in the fraction and the primary molecule absorbed by differentiated Caco-2 cells. Results indicated that fraction 5 was approximately 10 times more active than ECG (IC50 value equal to 11.62 ± 0.47 µg mL-1) to inhibit the PLpro target. Overall, our findings highlight the synergistic effects of the various components of the crude extract compared to isolated ECG.


Subject(s)
Catechin/pharmacology , Coronavirus Papain-Like Proteases/metabolism , Tea/metabolism , Antiviral Agents/chemistry , COVID-19/drug therapy , COVID-19/metabolism , Caco-2 Cells , Camellia sinensis/metabolism , Catechin/analogs & derivatives , Catechin/chemistry , Catechin/metabolism , Coronavirus Papain-Like Proteases/drug effects , Epithelium/drug effects , Epithelium/metabolism , Humans , Mass Spectrometry/methods , Plant Extracts/chemistry , Plant Extracts/pharmacology , SARS-CoV-2/drug effects , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Tea/chemistry , Tea/physiology
3.
Drug Des Devel Ther ; 15: 4447-4454, 2021.
Article in English | MEDLINE | ID: covidwho-1502185

ABSTRACT

Coronavirus disease-19 (COVID-19) pandemic is currently ongoing worldwide and causes a lot of deaths in many countries. Although different vaccines for the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection have been developed and are now available, there are no effective antiviral drugs to treat the disease, except for Remdesivir authorized by the US FDA to counteract the emergency. Thus, it can be useful to find alternative therapies based on the employment of natural compounds, with antiviral features, to circumvent SARS-CoV-2 infection. Pre-clinical studies highlighted the antiviral activities of epigallocatechin-3-gallate (EGCG), a catechin primarily found in green tea, against various viruses, including SARS-CoV-2. In this review, we summarize this experimental evidence and highlight the potential use of EGCG as an alternative therapeutic choice for the treatment of SARS-CoV-2 infection.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Catechin/analogs & derivatives , Antiviral Agents/administration & dosage , COVID-19/virology , Catechin/administration & dosage , Catechin/pharmacology , Humans , Tea/chemistry
4.
Jpn J Infect Dis ; 74(5): 421-423, 2021 Sep 22.
Article in English | MEDLINE | ID: covidwho-1436359

ABSTRACT

Green tea extracts effectively inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro in a dose-dependent manner. Ten-fold serially diluted solutions of catechin mixture reagent from green tea were mixed with the viral culture fluid at a volume ratio of 9:1, respectively, and incubated at room temperature for 5 min. The solution of 10 mg/mL catechin reagent reduced the viral titer by 4.2 log and 1.0 mg/mL solution by one log. Pre-infection treatment of cells with the reagent alone did not affect viral growth. In addition, cells treated with only the reagent were assayed for host cell viability using the WST-8 system, and almost no host cell damage by the treatment was observed. These findings suggested that the direct treatment of virus with the reagent before inoculation decreased the viral activity and that catechins might have the potential to suppress SARSCoV-2 infection.


Subject(s)
Antiviral Agents/pharmacology , Catechin/pharmacology , SARS-CoV-2/drug effects , Tea/chemistry , Animals , COVID-19/virology , Cell Survival/drug effects , Chlorocebus aethiops , Dose-Response Relationship, Drug , Humans , Vero Cells , Viral Load/drug effects
5.
Molecules ; 26(16)2021 Aug 08.
Article in English | MEDLINE | ID: covidwho-1348676

ABSTRACT

Since severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is producing a large number of infections and deaths globally, the development of supportive and auxiliary treatments is attracting increasing attention. Here, we evaluated SARS-CoV-2-inactivation activity of the polyphenol-rich tea leaf extract TY-1 containing concentrated theaflavins and other virucidal catechins. The TY-1 was mixed with SARS-CoV-2 solution, and its virucidal activity was evaluated. To evaluate the inhibition activity of TY-1 in SARS-CoV-2 infection, TY-1 was co-added with SARS-CoV-2 into cell culture media. After 1 h of incubation, the cell culture medium was replaced, and the cells were further incubated in the absence of TY-1. The viral titers were then evaluated. To evaluate the impacts of TY-1 on viral proteins and genome, TY-1-treated SARS-CoV-2 structural proteins and viral RNA were analyzed using western blotting and real-time RT-PCR, respectively. TY-1 showed time- and concentration-dependent virucidal activity. TY-1 inhibited SARS-CoV-2 infection of cells. The results of western blotting and real-time RT-PCR suggested that TY-1 induced structural change in the S2 subunit of the S protein and viral genome destruction, respectively. Our findings provided basic insights in vitro into the possible value of TY-1 as a virucidal agent, which could enhance the current SARS-CoV-2 control measures.


Subject(s)
COVID-19/virology , Polyphenols/pharmacology , SARS-CoV-2/drug effects , Tea/chemistry , Animals , Antiviral Agents/metabolism , Antiviral Agents/pharmacology , Biflavonoids/chemistry , Biflavonoids/pharmacology , COVID-19/drug therapy , COVID-19/metabolism , Camellia sinensis/metabolism , Catechin/chemistry , Catechin/pharmacology , Cell Line , Chlorocebus aethiops , Genome, Viral/drug effects , Humans , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Polyphenols/isolation & purification , SARS-CoV-2/metabolism , Vero Cells , Viral Load/drug effects
6.
Molecules ; 26(13)2021 Jun 30.
Article in English | MEDLINE | ID: covidwho-1304690

ABSTRACT

Influenza is one of the most serious respiratory viral infections worldwide. Although several studies have reported that green tea catechins (GTCs) might prevent influenza virus infection, this remains controversial. We performed a systematic review and meta-analysis of eight studies with 5,048 participants that examined the effect of GTC administration on influenza prevention. In a random-effects meta-analysis of five RCTs, 884 participants treated with GTCs showed statistically significant effects on the prevention of influenza infection compared to the control group (risk ratio (RR) 0.67, 95%CIs 0.51-0.89, P = 0.005) without evidence of heterogeneity (I2= 0%, P = 0.629). Similarly, in three cohort studies with 2,223 participants treated with GTCs, there were also statistically significant effects (RR 0.52, 95%CIs 0.35-0.77, P = 0.001) with very low evidence of heterogeneity (I2 = 3%, P = 0.358). Additionally, the overall effect in the subgroup analysis of gargling and orally ingested items (taking capsules and drinking) showed a pooled RR of 0.62 (95% CIs 0.49-0.77, P = 0.003) without heterogeneity (I2= 0%, P = 0.554). There were no obvious publication biases (Egger's test (P = 0.138) and Begg's test (P = 0.103)). Our analysis suggests that green tea consumption is effective in the prophylaxis of influenza infections. To confirm the findings before implementation, longitudinal clinical trials with specific doses of green tea consumption are warranted.


Subject(s)
Antiviral Agents/therapeutic use , Catechin/therapeutic use , Plant Extracts/chemistry , Tea/chemistry , Antiviral Agents/chemistry , Catechin/chemistry , Clinical Trials as Topic , Humans , Influenza, Human
7.
Molecules ; 26(13)2021 Jun 29.
Article in English | MEDLINE | ID: covidwho-1288963

ABSTRACT

(-)-Epigallocatechin-3-O-gallate (EGCG), the most abundant component of catechins in tea (Camellia sinensis (L.) O. Kuntze), plays a role against viruses through inhibiting virus invasiveness, restraining gene expression and replication. In this paper, the antiviral effects of EGCG on various viruses, including DNA virus, RNA virus, coronavirus, enterovirus and arbovirus, were reviewed. Meanwhile, the antiviral effects of the EGCG epi-isomer counterpart (+)-gallocatechin-3-O-gallate (GCG) were also discussed.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Catechin/analogs & derivatives , Tea/chemistry , Animals , Antiviral Agents/therapeutic use , Catechin/pharmacology , Catechin/therapeutic use , Humans , Virus Internalization/drug effects , Viruses/drug effects
8.
Molecules ; 26(12)2021 Jun 11.
Article in English | MEDLINE | ID: covidwho-1270089

ABSTRACT

Potential effects of tea and its constituents on SARS-CoV-2 infection were assessed in vitro. Infectivity of SARS-CoV-2 was decreased to 1/100 to undetectable levels after a treatment with black tea, green tea, roasted green tea, or oolong tea for 1 min. An addition of (-) epigallocatechin gallate (EGCG) significantly inactivated SARS-CoV-2, while the same concentration of theasinensin A (TSA) and galloylated theaflavins including theaflavin 3,3'-di-O-gallate (TFDG) had more remarkable anti-viral activities. EGCG, TSA, and TFDG at 1 mM, 40 µM, and 60 µM, respectively, which are comparable to the concentrations of these compounds in tea beverages, significantly reduced infectivity of the virus, viral RNA replication in cells, and secondary virus production from the cells. EGCG, TSA, and TFDG significantly inhibited interaction between recombinant ACE2 and RBD of S protein. These results suggest potential usefulness of tea in prevention of person-to-person transmission of the novel coronavirus.


Subject(s)
Antiviral Agents/pharmacology , Biflavonoids/chemistry , Catechin/chemistry , Gallic Acid/analogs & derivatives , SARS-CoV-2/physiology , Tea/chemistry , Virus Replication/drug effects , Angiotensin-Converting Enzyme 2/chemistry , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antiviral Agents/chemistry , Biflavonoids/pharmacology , COVID-19/pathology , COVID-19/virology , Catechin/analogs & derivatives , Catechin/pharmacology , Cell Survival/drug effects , Chlorocebus aethiops , Gallic Acid/chemistry , Gallic Acid/pharmacology , Humans , Protein Interaction Maps/drug effects , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Tea/metabolism , Vero Cells
9.
J Gen Virol ; 102(4)2021 04.
Article in English | MEDLINE | ID: covidwho-1172672

ABSTRACT

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection has caused a pandemic with tens of millions of cases and more than a million deaths. The infection causes COVID-19, a disease of the respiratory system of divergent severity. No treatment exists. Epigallocatechin-3-gallate (EGCG), the major component of green tea, has several beneficial properties, including antiviral activities. Therefore, we examined whether EGCG has antiviral activity against SARS-CoV-2. EGCG blocked not only the entry of SARS-CoV-2, but also MERS- and SARS-CoV pseudotyped lentiviral vectors and inhibited virus infections in vitro. Mechanistically, inhibition of the SARS-CoV-2 spike-receptor interaction was observed. Thus, EGCG might be suitable for use as a lead structure to develop more effective anti-COVID-19 drugs.


Subject(s)
Antiviral Agents/pharmacology , Catechin/analogs & derivatives , SARS-CoV-2/drug effects , Tea/chemistry , Animals , Betacoronavirus/drug effects , Betacoronavirus/physiology , COVID-19/prevention & control , COVID-19/virology , Catechin/pharmacology , Cell Survival/drug effects , Chlorocebus aethiops , HEK293 Cells , Humans , Lentivirus/drug effects , Lentivirus/genetics , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/genetics , Vero Cells , Virus Attachment/drug effects , Virus Replication/drug effects
10.
Molecules ; 26(5)2021 Feb 24.
Article in English | MEDLINE | ID: covidwho-1100140

ABSTRACT

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has emerged to be the greatest threat to humanity in the modern world and has claimed nearly 2.2 million lives worldwide. The United States alone accounts for more than one fourth of 100 million COVID-19 cases across the globe. Although vaccination against SARS-CoV-2 has begun, its efficacy in preventing a new or repeat COVID-19 infection in immunized individuals is yet to be determined. Calls for repurposing of existing, approved, drugs that target the inflammatory condition in COVID-19 are growing. Our initial gene ontology analysis predicts a similarity between SARS-CoV-2 induced inflammatory and immune dysregulation and the pathophysiology of rheumatoid arthritis. Interestingly, many of the drugs related to rheumatoid arthritis have been found to be lifesaving and contribute to lower COVID-19 morbidity. We also performed in silico investigation of binding of epigallocatechin gallate (EGCG), a well-known catechin, and other catechins on viral proteins and identified papain-like protease protein (PLPro) as a binding partner. Catechins bind to the S1 ubiquitin-binding site of PLPro, which might inhibit its protease function and abrogate SARS-CoV-2 inhibitory function on ubiquitin proteasome system and interferon stimulated gene system. In the realms of addressing inflammation and how to effectively target SARS-CoV-2 mediated respiratory distress syndrome, we review in this article the available knowledge on the strategic placement of EGCG in curbing inflammatory signals and how it may serve as a broad spectrum therapeutic in asymptomatic and symptomatic COVID-19 patients.


Subject(s)
Antiviral Agents , COVID-19/drug therapy , Catechin/analogs & derivatives , Coronavirus 3C Proteases , Cysteine Proteinase Inhibitors , SARS-CoV-2/enzymology , Tea/chemistry , Antiviral Agents/chemistry , Antiviral Agents/therapeutic use , Binding Sites , COVID-19/enzymology , COVID-19/epidemiology , Catechin/chemistry , Catechin/therapeutic use , Coronavirus 3C Proteases/antagonists & inhibitors , Coronavirus 3C Proteases/chemistry , Cysteine Proteinase Inhibitors/chemistry , Cysteine Proteinase Inhibitors/therapeutic use , Humans
11.
Food Chem ; 346: 128933, 2021 Jun 01.
Article in English | MEDLINE | ID: covidwho-1082161

ABSTRACT

Immensely aggravated situation of COVID-19 has pushed the scientific community towards developing novel therapeutics to fight the pandemic. Small molecules can possibly prevent the spreading infection by targeting specific vital components of the viral genome. Non-structural protein 15 (Nsp15) has emerged as a promising target for such inhibitor molecules. In this investigation, we docked bioactive molecules of tea onto the active site of Nsp15. Based on their docking scores, top three molecules (Barrigenol, Kaempferol, and Myricetin) were selected and their conformational behavior was analyzed via molecular dynamics simulations and MMPBSA calculations. The results indicated that the protein had well adapted the ligands in the binding pocket thereby forming stable complexes. These molecules displayed low binding energy during MMPBSA calculations, substantiating their strong association with Nsp15. The inhibitory potential of these molecules could further be examined by in-vivo and in-vitro investigations to validate their use as inhibitors against Nsp15 of SARS-CoV2.


Subject(s)
Antiviral Agents/pharmacology , Computer Simulation , Endoribonucleases/antagonists & inhibitors , Plant Extracts/pharmacology , Tea/chemistry , Viral Nonstructural Proteins/antagonists & inhibitors , Catalytic Domain , Endoribonucleases/chemistry , Endoribonucleases/metabolism , Humans , Ligands , Molecular Dynamics Simulation , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/metabolism
12.
Biochem Biophys Res Commun ; 547: 23-28, 2021 04 02.
Article in English | MEDLINE | ID: covidwho-1077785

ABSTRACT

COVID-19 pandemic results in record high deaths in many countries. Although a vaccine for SARS-CoV-2 is now available, effective antiviral drugs to treat coronavirus diseases are not available yet. Recently, EGCG, a green tea polyphenol, was reported to inhibit SARS-CoV-2 3CL-protease, however the effect of EGCG on coronavirus replication is unknown. In this report, human coronavirus HCoV-OC43 (beta coronavirus) and HCoV-229E (alpha coronavirus) were used to examine the effect of EGCG on coronavirus. EGCG treatment decreases 3CL-protease activity of HCoV-OC43 and HCoV-229E. Moreover, EGCG treatment decreased HCoV-OC43-induced cytotoxicity. Finally, we found that EGCG treatment decreased the levels of coronavirus RNA and protein in infected cell media. These results indicate that EGCG inhibits coronavirus replication.


Subject(s)
Coronavirus 229E, Human/drug effects , Coronavirus OC43, Human/drug effects , Polyphenols/pharmacology , Tea/chemistry , Virus Replication/drug effects , Amino Acid Sequence , Cell Line, Tumor , Coronavirus 229E, Human/physiology , Coronavirus 3C Proteases/antagonists & inhibitors , Coronavirus OC43, Human/physiology , Humans , SARS-CoV-2/drug effects , SARS-CoV-2/physiology
13.
Phytomedicine ; 85: 153286, 2021 May.
Article in English | MEDLINE | ID: covidwho-701846

ABSTRACT

BACKGROUND: The rapid spread of novel coronavirus called SARS-CoV-2 or nCoV has caused countries all over the world to impose lockdowns and undertake stringent preventive measures. This new positive-sense single-stranded RNA strain of coronavirus spreads through droplets of saliva and nasal discharge. PURPOSE: US FDA has authorized the emergency use of Remdesivir looking at the increasing number of cases of COVID-19, however there is still no drug approved to treat COVID-19. An alternative way of treatment could be the use of naturally derived molecules with known antiviral properties. METHOD: We reviewed the antiviral activities of two polyphenols derived from tea, epigallocatechin-3-gallate (EGCG) from green tea and theaflavins from black tea. Both green tea and black tea polyphenols have been reported to exhibit antiviral activities against various viruses, especially positive-sense single-stranded RNA viruses. RESULTS: Recent studies have revealed the possible binding sites present on SARS-CoV-2 and studied their interactions with tea polyphenols. EGCG and theaflavins, especially theaflavin-3,3'-digallate (TF3) have shown a significant interaction with the receptors under consideration in this review. Some docking studies further emphasize on the activity of these polyphenols against COVID-19. CONCLUSION: This review summarizes the available reports and evidences which support the use of tea polyphenols as potential candidates in prophylaxis and treatment of COVID-19.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Polyphenols/pharmacology , SARS-CoV-2/drug effects , Tea/chemistry , Antioxidants/pharmacology , Biflavonoids/pharmacology , Binding Sites , Camellia sinensis/chemistry , Catechin/analogs & derivatives , Catechin/pharmacology , Humans
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