Abstract |
One newly bred variety of tea cultivar, purple-shoot tea, was selected to evaluate its antiproliferative effects on colorectal carcinoma cells, as well as normal colon cells. The phytochemicals and identified catechins of purple-shoot tea extract (PTE) were significantly higher than that of ordinary tea, especially the anthocyanins (surpassed by 135-fold) and anthocyanidins (surpassed by 3.5-fold). PTE inhibited the proliferation of COLO 320DM (IC(50) = 64.9 μg/mL) and HT-29 (IC(50) = 55.2 μg/mL) by blocking cell cycle progression during the G(0)/G(1) phase and inducing apoptotic death. Western blotting indicated that PTE induced cell cycle arrest by reducing the expression of cyclin E and cyclin D1 in COLO 320DM and the upregulation of p21 and p27 cyclin-dependent kinase inhibitors in HT-29. Two cells treated with PTE also indicated the cleavage of PARP, activation of caspase 3, and an increased Bax/Bcl-2 ratio. Our results showed that PTE is a potential novel dietary agent for colorectal cancer chemoprevention.
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Authors | Chih-Ping Hsu, Yi-Ting Shih, Bor-Ru Lin, Chui-Feng Chiu, Chih-Cheng Lin |
Journal | Journal of agricultural and food chemistry
(J Agric Food Chem)
Vol. 60
Issue 14
Pg. 3686-92
(Apr 11 2012)
ISSN: 1520-5118 [Electronic] United States |
PMID | 22404116
(Publication Type: Journal Article)
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Chemical References |
- Anthocyanins
- Flavonoids
- Plant Extracts
- Tea
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Topics |
- Animals
- Anthocyanins
(administration & dosage)
- Apoptosis
(drug effects)
- Cell Cycle
(drug effects)
- Cell Line
- Cell Line, Tumor
- Cell Proliferation
(drug effects)
- Colonic Neoplasms
- Colorectal Neoplasms
(pathology)
- Epithelial Cells
- Flavonoids
(analysis)
- HT29 Cells
- Humans
- Plant Extracts
(administration & dosage, chemistry)
- Rats
- Tea
(chemistry)
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