title: Chemopreventive effects of green and black tea on pulmonary and hepatic carcinogenesis.
abstract: The chemopreventive effects of decaffeinated green and black tea treatment on liver and lung tumorigenesis were examined in carcinogen-treated mice. Male C3H mice were given decaffeinated green or decaffeinated black tea in their drinking water prior to, during, and after treatment with diethylnitrosamine (50 micrograms/kg bw, i.p., once per week for 8 weeks). After 40 weeks of tea treatment, mice were sampled and examined for pulmonary and hepatic tumors. Mice treated with both DENA and tea displayed a significant decrease in the mean number of lung and liver tumors compared to DENA-only treated animals. Mice that received 0.63 or 1.25% green tea or 1.25% black tea exhibited a reduction in liver tumor numbers of 54, 50, and 63%, respectively from that seen in the DENA-only treated mice. Tea treatment also significantly decreased the multiplicity of lung adenomas. Mice receiving DENA and either 0.63 or 1.25% green tea or 1.25% black tea showed a decrease in the mean number of lung tumors of 40, 46, and 34%, respectively, from DENA-only treated mice. While a possible association between the chemopreventive activity of tea on lung tumor response and the concentration of (-) epigallocatechin gallate (EGCG) in the tea was suggested, no apparent relationship between EGCG concentration and liver tumor response was seen, however. These results show a dose-dependent chemoprevention of both lung and liver tumors by both black and green tea in diethylnitrosamine-treated C3H mice.
authors: Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis 46202-5196, USA.
authors: J
authors: J
authors: Cao
authors: Y
authors: Y
authors: Xu
authors: J
authors: J
authors: Chen
authors: J E
authors: JE
authors: Klaunig
mesh_terms: D000236:Adenoma / Q000139:chemically induced / Q000517:prevention & control*; D000284:Administration, Oral; D000704:Analysis of Variance; D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D004052:Diethylnitrosamine / Q000008:administration & dosage / Q000633:toxicity*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000517:prevention & control*; D008168:Lung / Q000187:drug effects / Q000473:pathology; D008175:Lung Neoplasms / Q000139:chemically induced / Q000517:prevention & control*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use; D013662:Tea
chemical_list: D002273:Carcinogens; D010936:Plant Extracts; D013662:Tea; D004052:Diethylnitrosamine