Breast Cancer Prevention by Green Tea Catechins and Black Tea Theaflavins in the C3(1) SV40 T,t Antigen Transgenic Mouse Model Is Accompanied by Increased Apoptosis and a Decrease in Oxidative DNA Adducts

• Published in: Journal of agricultural and food chemistry 2007-05, Vol.55 (9), p.3378-3385
• Main Authors: Kaur, Siminder, Greaves, Peter, Cooke, Darren N, Edwards, Richard, Steward, William P, Gescher, Andreas J, Marczylo, Timothy H
• Format: Article
• Language: English
• Subjects: adenocarcinoma; Animals; anticarcinogenic activity; Antigens, Polyomavirus Transforming - genetics; apoptosis; Apoptosis - drug effects; Biflavonoids - administration & dosage; Biological and medical sciences; black tea; breast neoplasms; Caspase 3 - analysis; Catechin - administration & dosage; Cell Line, Tumor; chemoprevention; Coffee, tea and other stimulative beverage industries; DNA Adducts - analysis; DNA damage; DNA-binding proteins; flavanols; Food industries; food intake; Fundamental and applied biological sciences. Psychology; green tea; Humans; Mammary Neoplasms, Animal - prevention & control; Mice; Mice, Transgenic; oral administration; oxidation; protective effect; Simian virus 40; T,T antigen; Tea - chemistry; theaflavins; transgenic animals
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf0633342

Tea consumption is associated with a reduced risk of mammary cancer as reflected by epidemiological studies and experiments in carcinogen-induced rodent models of mammary carcinogenesis. We tested the hypothesis that green tea catechins (GTC) or theaflavins from black tea (BTT) interfere with mammary carcinogenesis in C3(1) SV40 T,t antigen transgenic multiple mammary adenocarcinoma (TAg) mice and that GTC/BTT affect tumor survival or oxidation status. TAg mice received GTC/BTT (0.05%) in drinking water for their lifetime. As compared to control mice, they survived longer and had smaller tumors. On microscopic inspection, the size of the largest tumor per mouse was decreased by 40−42% (p < 0.01). GTC (0.01%) and BTT (0.05%) increased levels of cleaved caspase 3 in tumor tissue by 67 and 38%, respectively (p < 0.05), intimating increased apoptosis. Tumor levels of the malondialdehyde−DNA adduct M1dG in mice receiving GTC or BTT (0.05%) were reduced by 78 (p < 0.001) or 63% (p < 0.05), respectively, as compared to controls. The results render the exploration of the breast cancer chemopreventive properties of tea preparations in humans worthwhile. Keywords: Chemoprevention; catechins; theaflavins; breast cancer; malondialdehyde