scholarly journals Green Tea Polyphenols Function as Prooxidants To Activate Oxidative-Stress-Responsive Transcription Factors in Yeasts

2006 ◽  
Vol 73 (2) ◽  
pp. 572-580 ◽  
Author(s):  
Kazuhiro Maeta ◽  
Wataru Nomura ◽  
Yoshifumi Takatsume ◽  
Shingo Izawa ◽  
Yoshiharu Inoue
Keyword(s):  
Oxidative Stress ◽  
Transcription Factors ◽  
Green Tea ◽  
Nuclear Localization ◽  
Disulfide Bonds ◽  
Epigallocatechin Gallate ◽  
Tea Polyphenols ◽  
Green Tea Polyphenols ◽  
Alkaline Conditions ◽  
Tea Extract

ABSTRACT Epigallocatechin gallate (EGCG) is the most abundant polyphenolic flavonoid in green tea. Catechin and its derivatives, including EGCG, are widely believed to function as antioxidants. Here we demonstrate that both EGCG and green tea extract (GTE) cause oxidative stress-related responses in the budding yeast Saccharomyces cerevisiae and the fission yeast Schizosaccharomyces pombe under weak alkaline conditions in terms of the activation of oxidative-stress-responsive transcription factors. GTE as well as EGCG induced the nuclear localization of Yap1 in S. cerevisiae, which was repressed by the addition of catalase but not by the addition of superoxide dismutase. The same phenomena were observed for the nucleocytoplasmic localization of Msn2 in S. cerevisiae and Pap1, a Yap1 homologue, in S. pombe. The formation of intramolecular disulfide bonds has been proposed to be crucial for the H2O2-induced nuclear localization of Yap1, and we verified the importance of cysteine residues of Yap1 in response to EGCG and GTE. Additionally, we show that EGCG and GTE produce H2O2 in a weak alkaline medium. Finally, we conclude that tea polyphenols are able to act as prooxidants to cause a response to oxidative stress in yeasts under certain conditions.

Separation of epigallocatechin gallate and epicatechin gallate from tea polyphenols by macroporous resin and crystallization

2021 ◽  
Author(s):  
Li Wang ◽  
Xin Huang ◽  
Huijuan Jing ◽  
Xin Ye ◽  
Chao Jiang ◽  
...  
Keyword(s):  
Green Tea ◽  
Epigallocatechin Gallate ◽  
Tea Polyphenols ◽  
Green Tea Polyphenols ◽  
Macroporous Resin ◽  
Epicatechin Gallate

Epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) are the most abundant ester catechins of green tea polyphenols (GTPs) with numerous potential bioactivities, which have a wide application prospect in the...

scholarly journals Evaluation of the Antioxidant Interactions Between Green Tea Polyphenols and Nonsteroidal Anti-inflammatory Drugs

2019 ◽  
Vol 6 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Aleksandra Sentkowska ◽  
Krystyna Pyrzynska
Keyword(s):  
Green Tea ◽  
Antioxidant Properties ◽  
Antagonistic Effect ◽  
Tea Polyphenols ◽  
Green Tea Polyphenols ◽  
High Concentration ◽  
Tea Infusion ◽  
Scavenging Effect ◽  
Interaction Factors ◽  
Tea Extract

Introduction: The antioxidant interactions between the commonly used pharmaceuticals (diclofenac, ibuprofen and naproxen) and green tea polyphenols were evaluated. Methods: The antioxidant properties of the mixtures were evaluated by a scavenging effect on the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical. Results: The mixtures contained green tea extract and each drug exhibited lower antioxidant activity than the mathematical sum of the results obtained for individual components showing antagonistic effect. The results were obtained using isobolographic analysis and interaction factors also suggested the antagonistic type of interaction. Only when the concentration of the green tea infusion was relatively high (in comparison to the drug), an additive effect could be concluded. Conclusion: The high concentration of green tea infusion in comparison to the drug should be used in developing the new formulations as it can help in the therapy due to their antioxidant properties.

scholarly journals Epigallocatechin Gallate (EGCG), a Green Tea Polyphenol, Reduces Coronavirus Replication in a Mouse Model

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2533
Author(s):  
Rackhyun Park ◽  
Minsu Jang ◽  
Yea-In Park ◽  
Yeonjeong Park ◽  
Woochul Jung ◽  
...  
Keyword(s):  
Mouse Model ◽  
Green Tea ◽  
Particle Production ◽  
Epigallocatechin Gallate ◽  
Tea Polyphenols ◽  
Green Tea Polyphenols ◽  
Tea Polyphenol ◽  
Green Tea Polyphenol

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.

Sign in / Sign up

Export Citation Format

Share Document