Comparative chemopreventive mechanisms of green tea, black tea and selected polyphenol extracts measured by in vitro bioassays

Black tea extracts (hot aqueous, polyphenols and theaflavins) and green tea extracts (hot aqueous, polyphenols, epicatechin, epicatechin gallate, epigallocatechin and epigallocatechin gallate) were tested in nine standardized cell culture assays for comparative cancer chemopreventive properties. Mos...

Full description

Saved in:
Bibliographic Details
Published in:Carcinogenesis (New York) 2000-01, Vol.21 (1), p.63-67
Main Authors: Steele, Vernon E., Kelloff, Gary J., Balentine, Douglas, Boone, Charles W., Mehta, Rajendra, Bagheri, Donya, Sigman, Caroline C., Zhu, Songyun, Sharma, Sheela
Format: Article
Language:English
Subjects:
12-dimethylbenz[a]anthracene
12-O-tetradecanoylphorbol-13-acetate
Animals
Anticarcinogenic Agents - pharmacology
B[a]P
benzo[a]pyrene
Biological and medical sciences
black tea extract
black tea polyphenols
BTE
BTP
Carcinogenesis, carcinogens and anticarcinogens
difluoromethylornithine
dimethyl sulfoxide
DMBA
DMFO
DMSO
ECG
EGC
EGCG
epicatechin
epicatechin gallate
epigallocatechin
epigallocatechin gallate
ethyl acetate
ETOAc
Flavonoids
Foods and miscellaneous
Free Radicals
glutathione
Glutathione Transferase - biosynthesis
glutathione-S-transferase
green tea extract
green tea polyphenols
GSH
GST
GTE
GTP
Humans
Male
Medical sciences
Mice
MMOC
mouse mammary organ culture
NAD(P)H Dehydrogenase (Quinone) - metabolism
NADPH:QR
ODC
ornithine decarboxylase
Ornithine Decarboxylase Inhibitors
Phenols - pharmacology
Plant Extracts - pharmacology
Polymers - pharmacology
Polyphenols
quinone reductase
rat tracheal epithelial
Rats
Rats, Inbred F344
RTE
Tea
TPA
Tumor Cells, Cultured
Tumors
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Black tea extracts (hot aqueous, polyphenols and theaflavins) and green tea extracts (hot aqueous, polyphenols, epicatechin, epicatechin gallate, epigallocatechin and epigallocatechin gallate) were tested in nine standardized cell culture assays for comparative cancer chemopreventive properties. Most black and green tea extracts strongly inhibited neoplastic transformation in mouse mammary organ cultures, rat tracheal epithelial cells and human lung tumor epithelial cells. Nearly all tea fractions strongly inhibited benzo[a]pyrene adduct formation with human DNA. Induction of phase II enzymes, glutathione-S-transferase and quinone reductase, were enhanced by nearly all tea fractions, while glutathione was induced by only a few fractions. Ornithine decarboxylase activity was inhibited by nearly all the green tea fractions, but none of the black tea fractions. 12-O-tetradecanoylphorbol-13-acetate-induced free radicals were inhibited by most tea fractions. These results provide strong evidence of both anti-mutagenic, anti-proliferative and anti-neoplastic activities for both black and green tea extracts. Such anticancer mechanisms may well be responsible for the cancer preventive efficacies seen in both experimental and human studies.
ISSN:0143-3334
1460-2180
1460-2180
DOI:10.1093/carcin/21.1.63