Inhibition of azoxymethane-induced colon carcinogenesis in rat by green tea polyphenol fraction.
The effect of green tea polyphenol fraction (GTP) on azoxymethane(AOM)-induced colon carcinogenesis was investigated in male Fischer rats. The rats were given AOM (7.4 mg/kg body weight) s.c. once a week for 10 weeks. A week after the treatment, they were divided into three groups: AOM-control (26 rats), AOM-GTP1 (26 rats) and AOM-GTP2 (25 rats). AOM-GTP1 and AOM-GTP2 groups respectively received 0.01 and 0.1% GTP in drinking water from week 11 to 26. AOM-control group received tap water throughout this experiment. Autopsy on week 26 showed that tumor incidence and average numbers of tumors per rat in the AOM-GTP1 and AOM-GTP2 groups were significantly lower than those of the AOM-control group: 38.1% and 47.6% versus 77.3%; 0.6 and 0.7 versus 1.5. Thus, it was concluded that GTP inhibited the development of AOM-induced colon carcinogenesis. The inhibition by GTP did not show significant dose dependence.
Yamane
T
T
First Department of Surgery, Kyoto Prefectural University of Medicine.
Hagiwara
N
N
Tateishi
M
M
Akachi
S
S
Kim
M
M
Okuzumi
J
J
Kitao
Y
Y
Inagake
M
M
Kuwata
K
K
Takahashi
T
T
D000818:Animals; D001397:Azoxymethane; D001835:Body Weight / Q000187:drug effects; D002392:Catechin / Q000031:analogs & derivatives / Q000627:therapeutic use; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000517:prevention & control*; D005419:Flavonoids; D008297:Male; D010636:Phenols / Q000627:therapeutic use*; D010936:Plant Extracts / Q000627:therapeutic use; D011108:Polymers / Q000627:therapeutic use*; D051381:Rats; D011916:Rats, Inbred F344; D013662:Tea; D013997:Time Factors
D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D011108:Polymers; D013662:Tea; D002392:Catechin; C045651:epigallocatechin gallate; D001397:Azoxymethane