Effect of polyphenon-60 on the development of renal cell tumors in rats treated with N-ethyl-N hydroxyethylnitrosamine.
Green tea consumed as a beverage in Asia contains polyphenols, which contain about a 15% mixture of catechins. The present paper reports the effect of polyphenon-60 (60% pure catechin) on the development of renal cell neoplasms in Wistar rats pretreated with N-ethyl-N-hydroxyethylnitrosamine (EHEN): 0.1% polyphenon-60 in block diet was given over a period of 30 weeks while EHEN was given in drinking water for 2 weeks. The results appears to show a tendency for green tea catechins (GTC) to decrease the incidence of renal cell tumors greater than 3 mm in diameter in Wistar rats but not tumors that are less than 3 mm in diameter. Polyphenon-60 did not affect EHEN initiation in the kidneys of rats. It is postulated that free radicals induced by EHEN may be suppressed by GTC, resulting in a lowering of the tendency for tumor growth.
Yoshioka
N
N
Department of Pathology, Nara Medical University, Kashihara, Japan.
Hiasa
Y
Y
Cho
M
M
Kitahori
Y
Y
Hirao
K
K
Konishi
N
N
Kuwashima
S
S
D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D002273:Carcinogens / Q000037:antagonists & inhibitors*; D002292:Carcinoma, Renal Cell / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D002392:Catechin / Q000494:pharmacology*; D004052:Diethylnitrosamine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors; D007680:Kidney Neoplasms / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013662:Tea
D016588:Anticarcinogenic Agents; D002273:Carcinogens; D013662:Tea; C023845:N-ethyl-N-hydroxyethylnitrosamine; D004052:Diethylnitrosamine; D002392:Catechin