Composition of Polyphenols in Fresh Tea Leaves and Associations of Their Oxygen-Radical-Absorbing Capacity with Antiproliferative Actions in Fibroblast Cells

Autor:	Ying-Ling Chen, Jen-Kun Lin, Yu-Chih Liang, I-Ming Juan, Yu Li Lin
Rok vydání:	1996
Předmět:	Antioxidant Chemistry Radical medicine.medical_treatment Apical dominance food and beverages General Chemistry complex mixtures Epidermoid carcinoma Fermented tea Polyphenol Botany medicine Composition (visual arts) Fermentation Food science General Agricultural and Biological Sciences
Zdroj:	Journal of Agricultural and Food Chemistry. 44:1387-1394
ISSN:	1520-5118 0021-8561
DOI:	10.1021/jf950652k
Popis:	The polyphenols in various parts of the tea plant used in manufacture of tea products (young leaves, old leaves, and stem) were analyzed by HPLC. The young leaves (apical bud and the two youngest leaves) were found to be richer (2.7-fold) in polyphenols than old leaves (from the tenth to the fifth leaf). Also, the tea polyphenols were found to be higher (1.4-fold) in summer than in spring. Ten different types of commercial tea (manufactured tea), including unfermented, semifermented, and fermented tea, were analyzed for their polyphenol compounds, and it was found that both yields of solids in tea water extracts (TWEs) and the amount of (−)-epigallocatechin 3-gallate (EGCG) in these products varied with different tea leaves and processing methods. Longjing tea (unfermented green tea) contained the highest concentration of EGCG and polyphenols, whereas Assam black tea (most fermented) contained the least. Longjing TWEs showed strong inhibitory effect on DNA synthesis in A-431 tumor cells. We also found tha...
Databáze:	OpenAIRE
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