scholarly journals Rapid Inactivation In Vitro of SARS-CoV-2 in Saliva by Black Tea and Green Tea

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 721
Author(s):  
Eriko Ohgitani ◽  
Masaharu Shin-Ya ◽  
Masaki Ichitani ◽  
Makoto Kobayashi ◽  
Takanobu Takihara ◽  
...  
Keyword(s):  
Virus Infection ◽  
Green Tea ◽  
Virus Titer ◽  
Epigallocatechin Gallate ◽  
Black Tea ◽  
Human Saliva ◽  
Detectable Level ◽  
Healthy Human ◽  
Rapid Inactivation

Saliva plays major roles in the human-to-human transmission of SARS-CoV-2. If the virus in saliva in SARS-CoV-2-infected individuals can be rapidly and efficiently inactivated by a beverage, the ingestion of the beverage may attenuate the spread of virus infection within a population. Recently, we reported that SARS-CoV-2 was significantly inactivated by treatment with black tea, green tea, roasted green tea and oolong tea, as well as their constituents, (-) epigallocatechin gallate (EGCG), theasinensin A (TSA), and galloylated theaflavins. However, it remains unclear to what extent tea inactivates the virus present in saliva, because saliva contains various proteins, nitrogenous products, electrolytes, and so on, which could influence the antivirus effect of tea. Here, we assessed whether tea inactivated the SARS-CoV-2 which was added in human saliva. A virus was added in healthy human saliva in vitro, and after treatment with black tea or green tea, the infectivity of the virus was evaluated by TCID50 assays. The virus titer fell below the detectable level or less than 1/100 after treatment with black tea or green tea for 10 s. The black tea-treated virus less remarkably replicated in cells compared with the untreated virus. These findings suggest the possibility that the ingestion of tea may inactivate SARS-CoV-2 in saliva in infected individuals, although clinical studies are required to determine the intensity and duration of the anti-viral effect of tea in saliva in humans.

scholarly journals Rapid inactivation in vitro of SARS-CoV-2 in saliva by black tea and green tea

2020 ◽  
Author(s):  
Eriko Ohgitani ◽  
Masaharu Shin-Ya ◽  
Masaki Ichitani ◽  
Makoto Kobayashi ◽  
Takanobu Takihara ◽  
...  
Keyword(s):  
Green Tea ◽  
Clinical Studies ◽  
Virus Titer ◽  
Epigallocatechin Gallate ◽  
Black Tea ◽  
Human Saliva ◽  
Long Period ◽  
Oolong Tea ◽  
Rapid Inactivation

AbstractSaliva plays major roles in human-to-human transmission of the SARS-CoV-2. Recently we reported that black, green and oolong tea significantly inactivated SARS-CoV-2 within 1 min. Theaflavin-3,3’-di-gallate (TFDG), theasinensin A (TSA) and (-) epigallocatechin gallate (EGCG) were involved in the anti-viral activities. Here we examined how long period is required for the compounds to inactivate the virus. We also assessed whether tea inactivates SARS-CoV-2 diluted in human saliva. Treatment of SARS-CoV-2 with 500 μM TFDG or TSA for 10 sec reduced the virus titer to undetectable levels (less than 1/1,000). Black and green tea decreased virus titer to less than 1/100 within 10 sec even in saliva. These findings suggest a possibility that intake of, or gargling with, tea may inactivate SARS-CoV-2 in saliva in infected individuals, which may eventually attenuate spread of COVID-19 within a population, although clinical studies are required to test this hypothesis by determining the intensity and duration of the anti-viral effect of tea in saliva in humans.

scholarly journals Significant inactivation of SARS-CoV-2 by a green tea catechin, a catechin-derivative and galloylated theaflavins in vitro

2020 ◽  
Author(s):  
Eriko Ohgitani ◽  
Masaharu Shin-Ya ◽  
Masaki Ichitani ◽  
Makoto Kobayashi ◽  
Takanobu Takihara ◽  
...  
Keyword(s):  
Green Tea ◽  
Untreated Control ◽  
Virus Titer ◽  
Epigallocatechin Gallate ◽  
Black Tea ◽  
The Novel ◽  
Undetectable Level ◽  
Green Tea Catechin ◽  
Novel Coronavirus

AbstractPotential effects of teas and their constituents on SARS-CoV-2 infection were studied in vitro. Infectivity of SARS-CoV-2 was significantly reduced by a treatment with green tea, roasted green tea or oolong tea. Most remarkably, exposure to black tea for 1 min decreased virus titer to an undetectable level (less than 1/1,000 of untreated control). An addition of (-) epigallocatechin gallate (EGCG) significantly inactivated SARS-CoV-2, while theasinensin A (TSA) and galloylated theaflavins including theaflavin 3, 3’-di-gallate (TFDG) had more remarkable anti-viral activities. Virus treated with TSA at 500 μM or TFDG at 100 μM showed less than 1/10,000 infectivity compared with untreated virus. TSA and TFDG significantly inhibited interaction between recombinant ACE2 and RGD of S protein. These results strongly suggest that EGCG, and more remarkably TSA and galloylated theaflavins, inactivate the novel coronavirus.

scholarly journals Milk casein prevents inactivation effect of black tea galloylated theaflavins on SARS-CoV-2 in vitro

2021 ◽  
Author(s):  
Eriko Ohgitani ◽  
Masaharu Shin-Ya ◽  
Masaki Ichitani ◽  
Makoto Kobayashi ◽  
Takanobu Takihara ◽  
...  
Keyword(s):  
Virus Infection ◽  
Green Tea ◽  
Black Tea ◽  
Suppressive Effect ◽  
Lemon Juice ◽  
Viral Transmission ◽  
Gamma Delta ◽  
Milk Casein ◽  
Inactivation Effect

Repeated emergence of highly contagious and potentially immune-evading variant SARS-CoV-2 is posing global health and socioeconomical threats. For suppression of the spread of the virus infection among people, a procedure to inactivate virus in saliva may be useful, because saliva of infected persons is the major origin of droplets and aerosols that mediate viral transmission to nearby persons. We previously reported that SARS-CoV-2 is rapidly and remarkably inactivated by treatment in vitro with tea including green tea, roasted green tea, oolong tea and black tea. Tea catechin-derived compounds including theaflavins (TFs) with (a) galloyl moiety(ies) showed this activity. Although black tea is popularly consumed worldwide, a lot of people consume it with sugar, milk, lemon juice, and so on. But it has not been determined whether these ingredients may influence the inactivation effect of black tea against SARS-CoV-2. Moreover, it has not been revealed whether black tea is capable of inactivating variant viruses such as delta variant. Here we examined the effect of black tea on some variants in the presence or absence of sugar, milk, and lemon juice in vitro. Black tea and galloylated TFs remarkably inactivated alpha, gamma, delta and kappa variants. Intriguingly, an addition of milk but not sugar and lemon juice totally prevented black tea from inactivating alpha and delta variant viruses. The suppressive effect was also exerted by milk casein. These results suggest the possibility that intake of black tea without milk by infected persons may result in inactivation of the virus in saliva and attenuation of spread of SARS-CoV-2 to nearby persons through droplets. Clinical studies are required to investigate this possibility.

scholarly journals Significant Inactivation of SARS-CoV-2 In Vitro by a Green Tea Catechin, a Catechin-Derivative, and Black Tea Galloylated Theaflavins

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3572
Author(s):  
Eriko Ohgitani ◽  
Masaharu Shin-Ya ◽  
Masaki Ichitani ◽  
Makoto Kobayashi ◽  
Takanobu Takihara ◽  
...  
Keyword(s):  
Green Tea ◽  
Epigallocatechin Gallate ◽  
Virus Production ◽  
Black Tea ◽  
Rna Replication ◽  
Viral Rna ◽  
The Novel ◽  
Green Tea Catechin ◽  
Novel Coronavirus

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.

Green tea extract and its major component epigallocatechin gallate inhibits hepatitis B virus in vitro

2008 ◽  
Vol 78 (3) ◽  
pp. 242-249 ◽  
Author(s):  
Jun Xu ◽  
Jue Wang ◽  
Fei Deng ◽  
Zhihong Hu ◽  
Hualin Wang
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Green Tea ◽  
Epigallocatechin Gallate ◽  
Green Tea Extract ◽  
B Virus ◽  
Tea Extract

scholarly journals Green tea phytocompounds targets Lansterol 14-α demethylase against ergosterol biosynthesis in Candida glabrata

2021 ◽  
Vol 12 (3) ◽  
pp. 1793-1797
Author(s):  
Priyanka Sirari ◽  
Jigisha Anand ◽  
Devvret ◽  
Ashish Thapliyal ◽  
Nishant Rai
Keyword(s):  
Green Tea ◽  
Candida Glabrata ◽  
Scientific Evidence ◽  
Epigallocatechin Gallate ◽  
Ergosterol Biosynthesis ◽  
Epicatechin Gallate ◽  
P450 Monooxygenase ◽  
Antifungal Potential ◽  
Inhibitory Potential

Green tea is credited as one of the world’s healthiest drinks with enriched antioxidants. It is known for its multi-beneficial health benefits against diabetes, blood pressure, hypertension, gastro-intestinal upset and is bestowed with significant antimicrobial potential. There are previous scientific evidence highlighting the antifungal potential of green tea and has identified it as a potential inhibitor of non-albicans Candida species. Lansterol 14-α demethylase (Erg 11) or CYP51 protein belongs to the cytochrome P450 monooxygenase (CYP) superfamily. Erg 11 is involved in ergosterol biosynthesis and has a significant role in azole drug resistance in Candida glabrata. The present study attempted to identify the inhibitory potential of green tea phytocompounds against inhibition of Erg 11 in Candida glabrata using bioinformatics tool viz., autodock vina software. Out of 15 green tea phytocompounds investigated, the study identified, Rutin (-10.5 kcal) Kaempferitrin (-9.4kcal), Epigallocatechin gallate (-10kcal), Epicatechin gallate (-8.7kcal), and Coumaroylquinic acid (-8.6kcal) acid as the potent phytocompounds which showed significant molecular interaction with Erg 11 in Candida glabrata. In attribution to the constant emergence of azole-resistant isolates, this preliminary analysis therefore, indicated the potential of green tea phytocompounds against inhibition of non-albicans Candida specific candidiasis. However, further, in vitro antimicrobial efficacy of these phytocompounds, the dose regime, drug likeliness, and cytotoxic analysis are required to be investigated and validated.

scholarly journals In Vitro Growth- and Encystation-Inhibitory Efficacies of Matcha Green Tea and Epigallocatechin Gallate Against Acanthameoba Castellanii

Pathogens ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 763
Author(s):  
Ameliya Dickson ◽  
Elise Cooper ◽  
Lenu B. Fakae ◽  
Bo Wang ◽  
Ka Lung Andrew Chan ◽  
...  
Keyword(s):  
Green Tea ◽  
Colorimetric Assay ◽  
Epigallocatechin Gallate ◽  
Acanthamoeba Castellanii ◽  
Inhibitory Effect ◽  
Response To Treatment ◽  
Ftir Microscopy ◽  
Sulforhodamine B ◽  
Chemical Fingerprinting

We examined the inhibitory effect of matcha green tea (Camellia sinensis) and epigallocatechin gallate (EGCg; the most abundant catechin in tea) on the vegetative growth and encystation of Acanthamoeba castellanii T4 genotype. The sulforhodamine B (SRB) stain-based colorimetric assay and hemocytometer counting were used to determine the reduction in A. castellanii trophozoite proliferation and encystation, in response to treatment with C. sinensis or EGCg. Fourier transform infrared (FTIR) microscopy was used to analyze chemical changes in the trophozoites and cysts due to C. sinensis treatment. Hot brewed and cold brewed matcha inhibited the growth of trophozoites by >40% at a 100 % concentration. EGCg at concentrations of 50 to 500 µM significantly inhibited the trophozoite growth compared to control. Hot brewed matcha (100% concentration) also showed an 87% reduction in the rate of encystation compared to untreated control. Although 500 µM of EGCg increased the rate of encystation by 36.3%, 1000 µM reduced it by 27.7%. Both percentages were not significant compared to control. C. sinensis induced more cytotoxicity to Madin Darby canine kidney cells compared to EGCg. FTIR chemical fingerprinting analysis showed that treatment with brewed matcha significantly increased the levels of glycogen and carbohydrate in trophozoites and cysts.

scholarly journals High-Quality Draft Genome Sequence of Low-pH-ActiveVeillonella parvulaStrain SHI-1, Isolated from Human Saliva within anIn VitroOral Biofilm Model

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Anna Edlund ◽  
Quanhui Liu ◽  
Michael Watling ◽  
Thao T. To ◽  
Roger E. Bumgarner ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Draft Genome ◽  
Human Saliva ◽  
Low Ph ◽  
Draft Genome Sequence ◽  
Oral Biofilm ◽  
High Quality ◽  
Healthy Human ◽  
Biofilm Model

We announce here a draft genome sequence ofVeillonella parvulastrain SHI-1, obtained from healthy human saliva, discovered to be active at low pH using metatranscriptomics within anin vitrooral biofilm model. The genome is composed of 7 contigs, for a total of 2,200,064 bp.

scholarly journals Aβ42 fibril formation from predominantly oligomeric samples suggests a link between oligomer heterogeneity and fibril polymorphism

2019 ◽  
Vol 6 (7) ◽  
pp. 190179 ◽  
Author(s):  
Christine Xue ◽  
Joyce Tran ◽  
Hongsu Wang ◽  
Giovanna Park ◽  
Frederick Hsu ◽  
...  
Keyword(s):  
Growth Rate ◽  
Green Tea ◽  
Epigallocatechin Gallate ◽  
Amyloid Β ◽  
Lag Time ◽  
Aβ Oligomers ◽  
Wide Range ◽  
Aβ Aggregation

Amyloid-β (Aβ) oligomers play a central role in the pathogenesis of Alzheimer's disease. Oligomers of different sizes, morphology and structures have been reported in both in vivo and in vitro studies, but there is a general lack of understanding about where to place these oligomers in the overall process of Aβ aggregation and fibrillization. Here, we show that Aβ42 spontaneously forms oligomers with a wide range of sizes in the same sample. These Aβ42 samples contain predominantly oligomers, and they quickly form fibrils upon incubation at 37°C. When fractionated using ultrafiltration filters, the samples enriched with smaller oligomers form fibrils at a faster rate than the samples enriched with larger oligomers, with both a shorter lag time and faster fibril growth rate. This observation is independent of Aβ42 batches and hexafluoroisopropanol treatment. Furthermore, the fibrils formed by the samples enriched with larger oligomers are more readily solubilized by epigallocatechin gallate, a main catechin component of green tea. These results suggest that the fibrils formed by larger oligomers may adopt a different structure from fibrils formed by smaller oligomers, pointing to a link between oligomer heterogeneity and fibril polymorphism.

Effect of the green tea polyphenol epigallocatechin gallate (EGCG) on growth and IL-6 signalling pathways in malignant plasma cells

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 8114-8114
Author(s):  
R. Burger ◽  
H. Czekalla ◽  
K. Richter ◽  
T. Ahrens ◽  
A. Guenther ◽  
...  
Keyword(s):  
Cell Lines ◽  
Green Tea ◽  
Epigallocatechin Gallate ◽  
Myeloma Cell ◽  
Signalling Pathways ◽  
Dependent Manner ◽  
Green Tea Polyphenol ◽  
Dose Dependent ◽  
Human Myeloma Cell

8114 Background: Epigallocatechin gallate (EGCG) is the predominant polyphenolic constituent of green tea leaves that possesses antitumor, antiinflammatory, and antioxidant activity. EGCG exerts its effects through potentially multiple mechanisms including inhibition of growth factor receptor signalling. The compound is currently under investigation in a phase I/II clinical trial for treatment of patients with early stage chronic lymphocytic leukemia at Mayo Clinic. The goal of our study was to examine the in vitro effects of EGCG in multiple myeloma (MM). Methods: A panel of human myeloma cell lines (n=6) including the IL-6 dependent INA-6 cell line was used to evaluate the sensitivity to EGCG. Cells were cultured for three days in the absence or presence of EGCG at concentrations between 6.25 μM and 100 μM. Cell viability was determined in a colorimetric tetrazolium (MTS) based assay and by trypanblue exclusion. For signalling experiments, INA-6 cells were IL-6 and serum starved and then treated with EGCG for two hours before IL-6 was added. Whole cell lysates were prepared and subjected to SDS-PAGE and Western blot analysis. Results: EGCG inhibited the in vitro growth of human myeloma cell lines by inducing cell death in a time and dose-dependent manner. IC50 concentrations were between 12,5 μM and 50 μM. IL-6 mediated growth of INA-6 cells was inhibited at similar doses. The addition of excess amounts of IL-6 could not protect from EGCG induced cytotoxicity. Pretreatment of INA-6 cells with EGCG resulted in a dose-dependent inhibition of IL-6 induced STAT3 tyrosine phosphorylation. In these cells, stimulation with IL-6 leads to upregulation of Mcl-1 expression. In contrast, phosphorylation of p44/p42 MAPK, which is constitutively activated in INA-6 cells, was not affected. Conclusion: EGCG has growth inhibitory activity on myeloma cells. Specific inhibition of signalling pathways that regulate expression of anti-apoptotic proteins could be one mechanism how EGCG exerts its activity. Our work provides the rationale for further studies to evaluate the effect of EGCG not only in B-CLL, but also in plasma cell tumors. No significant financial relationships to disclose.

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