Journal Article

Prevention of dual promoting effects of pentachlorophenol, an environmental pollutant, on diethylnitrosamine-induced hepato- and cholangiocarcinogenesis in mice by green tea infusion

Takashi Umemura, Sachie Kai, Ryuichi Hasegawa, Keita Kanki, Yasuki Kitamura, Akiyoshi Nishikawa and Masao Hirose

in Carcinogenesis

Volume 24, issue 6, pages 1105-1109
Published in print June 2003 | ISSN: 0143-3334
Published online June 2003 | e-ISSN: 1460-2180 | DOI: http://dx.doi.org/10.1093/carcin/bgg053
Prevention of dual promoting effects of pentachlorophenol, an environmental pollutant, on diethylnitrosamine-induced hepato- and cholangiocarcinogenesis in mice by green tea infusion

More Like This

Show all results sharing this subject:

  • Clinical Cytogenetics and Molecular Genetics

GO

Show Summary Details

Preview

In order to explore a possibility that the custom of drinking green tea infusion is efficacious for reducing the carcinogenic risk of environmental exposure to pentachlorophenol (PCP), we examined the effects in a hepato- and cholangiocarcinogenesis model in mice exposed to diethylnitrosamine (DEN). In the first experiment, groups of 15 male mice were initially treated with DEN at a dose of 20 p.p.m. in the drinking water for the first 8 weeks followed by a 4 week recovery interval by PCP at concentrations of 0 (basal diet), 300 or 600 p.p.m. in the diet for 23 weeks. Further groups of animals were treated with DEN and PCP in the same manner and received 2% green tea infusion (GT) instead of the drinking water from week 10 until death. PCP exposure at the high dose promoted DEN-induced hepatocarcinogenesis, and also caused progression of cystic hyperplasias of the intrahepatic bile ducts to cholangiocellular tumors. Co-administration of GT was able to prevent the increases of incidences and multiplicities of DEN-induced hepatocellular tumors and also arrest the progression of cholangiocellular tumors. In the second experiment, co-treatment with GT in the drinking water from 1 week before 300 or 600 p.p.m. PCP treatment in the diet to the end of the experiment at week 3 in B6C3F1 male mice suppressed increases of serum ALT activities, 8-oxodeoxyguanosine levels in liver DNA and bromodeoxyuridine labeling indices of hepatocytes and intrahepatic biliary epithelial cells induced by PCP. These findings suggest that regular intake of green tea may reduce the carcinogenic risk posed by an environmental pollutant, PCP, presumably due to effects on oxidative stress.

Keywords: ALT, serum alanine aminotransferase; BrdU, bromodeoxyuridine; DEN, diethylnitrosamine; EC, epicatechin; ECG, epicatechin gallate; EGC, epigallocatechin; EGCG, epigallocatechin gallate; GT, green tea infusion; LI, labeling index; 8-oxodG, 8-oxodeoxyguanosine; PCP, pentachlorophenol

Journal Article.  3895 words.  Illustrated.

Subjects: Clinical Cytogenetics and Molecular Genetics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.