Comparative Safety Evaluation of Chinese Pu-erh Green Tea Extract and Pu-erh Black Tea Extract in Wistar Rats

2010 ◽  
Vol 58 (2) ◽  
pp. 1350-1358 ◽  
Author(s):  
Di Wang ◽  
Rong Xiao ◽  
Xueting Hu ◽  
Kunlong Xu ◽  
Yan Hou ◽  
...  
2010 ◽  
Vol 30 (8) ◽  
pp. 884-896 ◽  
Author(s):  
Amar K Chandra ◽  
Neela De ◽  
Shyamosree Roy Choudhury

Tea is a rich source of polyphenolic flavonoids including catechins, which are thought to contribute to the health benefits of it. Flavonoids have been reported to have antithyroid and goitrogenic effect. The purpose of this study was to evaluate whether high doses of green and black tea have a harmful effect on thyroid physiology. Un-fractionated green and black tea extracts were administered orally to male rats for 30 days at doses of 1.25 g%, 2.5 g% and 5.0 g%. The results showed that green tea extract at 2.5 g% and 5.0 g% doses and black tea extract only at 5.0 g% dose have the potential to alter the thyroid gland physiology and architecture, that is, enlargement of thyroid gland as well as hypertrophy and/or hyperplasia of the thyroid follicles and inhibition of the activity of thyroid peroxidase and 5′-deiodinase I with elevated thyroidal Na+, K+-ATPase activity along with significant decrease in serum T3 and T4, and a parallel increase in serum thyroid stimulating hormone (TSH). This study concludes that goitrogenic/antithyroidal potential of un-fractionated green tea extract is much more than black tea extract because of the differences in catechin contents in the tea extracts.


2018 ◽  
Vol 9 (7) ◽  
pp. 3798-3806 ◽  
Author(s):  
Pei Yuan ◽  
Lian-yun Pan ◽  
Li-gui Xiong ◽  
Jie-wen Tong ◽  
Juan Li ◽  
...  

Black tea extract is more effective than green tea extract in protecting C. elegans against hypertonic stress, within the studied concentration range.


Author(s):  
Andi Arjuna ◽  
Winda Setya Pratama ◽  
Sartini Sartini ◽  
Mufidah Mufidah

Tea (Camellia sinensis L.) has an activity as an antibacterial, widely studied to plankton cells, without further researching into biofilm cell. Therefore, this research had been conducted to initially evaluate the activity of green- and black-tea extracts in inhibiting Streptococcus mutans biofilm. Green and black tea leaves were extracted using 70% methanol. Determination of MIC was subsequently performed by microdilution method. Next, the biofilm formation and inhibition were run through microtiter plate method using flexible U-bottom PVC 96 wells, which then observed using microplate reader on λ = 515 nm. As The results, MIC for green and black tea extract stood at 4 mg/mL, 6 mg/mL respectively. The biofilm inhibitory activity of black tea extract was at 8 and 10 mg/mL inhibiting 6 % and 12.5 % S. mutans. Green tea extract showed that concentration of 4 to 10 mg/mL was able to inhibit biofilm growth by 24%; 45%; 48% and 53%. Thus, through microtiter plate assay, it could be concluded that tea extract has potent antibiofilm to S. mutans, where green tea extract has better activity than black tea extract.


2020 ◽  
Vol 17 (2) ◽  
Author(s):  
Joane Isis Travassos Vieira ◽  
Taylane Alves da Silva ◽  
Williane Maria Pereira Barbosa ◽  
Gabriela Lima de Azevêdo ◽  
Lúcia Cristina Pereira Arruda ◽  
...  

2004 ◽  
Vol 80 (6) ◽  
pp. 1558-1564 ◽  
Author(s):  
Susanne M Henning ◽  
Yantao Niu ◽  
Nicolas H Lee ◽  
Gail D Thames ◽  
Rosario R Minutti ◽  
...  

2017 ◽  
pp. 137-152
Author(s):  
K. A. Treasa Nimy ◽  
Vincent Terrence Rebello ◽  
T. K. Mukundan

2017 ◽  
Vol 8 (3) ◽  
pp. 289-295 ◽  
Author(s):  
Hymavathi Reddyvari ◽  
Suresh Govatati ◽  
Sumanth Kumar Matha ◽  
Swapna Vahini Korla ◽  
Sravanthi Malempati ◽  
...  

2021 ◽  
Vol 16 (Supp. 1) ◽  
pp. 25-32
Author(s):  
Indra Bramanti ◽  
Annisa Hidaratri Uningojati ◽  
Dilla Asriyani ◽  
Urfa Tabtila ◽  
Fathul Muin ◽  
...  

Green tea (Camellia sinensis) has high level of flavonoids which are proven to have anti-inflammatory activity. Effect of flavonoids can be enhanced by nano-chitosan capsulation as drug carrier. Chitosan is polysaccharide derived from crustacean shells that mostly used as matrix of various drugs and plant extracts. The aim of this study was to determine the effectivity of flavonoids in green tea extract in nanochitosan capsulation towards the number of fibroblasts on proliferative phase of gingival wound healing process. Green tea was extracted, encapsulated with nano-chitosan and then made into gel. Gingiva labial of 24 male white 3-month-old Wistar rats were wounded by punch biopsy (2 mm diameter), then were treated two times a day, and were divided randomly into four groups of topical gel applications: green tea extract gel encapsulated nano-chitosan, green tea extract gel, base gel as negative control, and NSAIDs gel as positive control, starting at 0 day until 7th day. At 5th and 7th day, three rats from each group were decapitated and the mandibular gingiva was taken in order to make histology slides with hematoxylin eosin staining. Under microscope, the number of fibroblasts were examined. The data were analysed using ANOVA test with 95% confidence level. The results showed that the number of fibroblasts on proliferative phase was significantly higher than control negative (p < 0.05) and has no significant differences (p > 0.05) with control positive. In conclusion, topical application of green tea extract gel encapsulated nano-chitosan was effective to accelerate rats gingival wound healing process by increasing the fibroblasts.


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