title: Black tea polyphenols protect against 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis.
abstract: Dietary chemoprevention has emerged as a cost-effective approach for cancer control. We evaluated the chemopreventive effects of black tea polyphenols (Polyphenon-B) administration during the preinitiation phase of 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. The expression of proliferating cell nuclear antigen (PCNA) in the buccal pouch and the concentration of lipid peroxides, protein carbonyl, and the antioxidant status in the buccal pouch, liver and erythrocytes were used as biomarkers of chemoprevention. All the hamsters painted with DMBA alone for 14 weeks developed buccal pouch carcinomas associated with increased expression of PCNA, diminished lipid and protein oxidation, and enhanced antioxidant status. In the liver and erythrocytes of tumor-bearing animals, enhanced oxidation of lipids and proteins was accompanied by compromised antioxidant defenses. Dietary administration of Polyphenon-B effectively suppressed DMBA-induced HBP carcinogenesis as revealed by decreased incidence of tumours and PCNA expression. In addition, Polyphenon-B modulated lipid and protein oxidation and enhanced the antioxidant status in the pouch, liver, and erythrocytes. We suggest that Polyphenon-B exerts its chemopreventive effects by inhibiting cell proliferation in the target tissue and modulating the oxidant-antioxidant status in the target as well as in host tissues.
authors.affiliation: Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar-608 002, Tamil Nadu, India.
authors.forename: P Vidjaya
authors.initials: PV
authors.lastname: Letchoumy
authors.forename: K V P
authors.initials: KV
authors.lastname: Chandra Mohan
authors.forename: R
authors.initials: R
authors.lastname: Kumaraguruparan
authors.forename: Y
authors.initials: Y
authors.lastname: Hara
authors.forename: S
authors.initials: S
authors.lastname: Nagini
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000378:metabolism; D001551:Benz(a)Anthracenes; D001835:Body Weight / Q000187:drug effects; D002610:Cheek; D006224:Cricetinae; D004435:Eating / Q000187:drug effects; D007150:Immunohistochemistry; D008297:Male; D008647:Mesocricetus; D009062:Mouth Neoplasms / Q000139:chemically induced / Q000378:metabolism / Q000517:prevention & control*; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology*; D018809:Proliferating Cell Nuclear Antigen / Q000096:biosynthesis; D011897:Random Allocation
chemical_list: D016588:Anticarcinogenic Agents; D000975:Antioxidants; D001551:Benz(a)Anthracenes; D010636:Phenols; D018809:Proliferating Cell Nuclear Antigen; C506663:polyphenon B; C046810:7,12-dihydroxymethylbenz(a)anthracene