Promotion effects of hot water on N-nitrosomethylbenzylamine-induced esophageal tumorigenesis in F344 rats.
This study is to determine the effects of hot water on N-nitrosomethylbenzylamine (NMBA)-induced rat esophageal tumorigenesis model. F344 rats received one treatment of hot water 1 ml/kg and NMBA 1 mg/kg, or a combination treatment of NMBA 1 mg/kg pus hot water 1 ml/kg, or/and EGCG (epigallocatechin-3-gallate) 10 mg/kg. The experiment was concluded at the 20th week. Our results showed that the number of tumors and incidence of carcinomas were significantly increased by hot water (65 degrees C) (p<0.05, p<0.03, respectively), as compared with the group which received NMBA injections only. EGCG treatment did not significantly reduce the number or the size of tumours as the temperature of added hot water increased. In addition, PGE2 production was induced by NMBA, and further significantly increased by added hot water (p<0.05). On the other hand, EGCG slightly decreased the elevated PGE2 production, however, this effect of EGCG was offset by hot water. Our study further confirmed that the drinking of hot beverages increased the risk of esophageal carcinogenesis, and the drinking hot tea will abolish the inhibitory effects of EGCG on this disease.
Li
Zhi Gang
ZG
Department of Surgery and Surgical Basic Science, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan.
Shimada
Yutaka
Y
Sato
Fumiaki
F
Maeda
Masato
M
Itami
Atsushi
A
Kaganoi
Junichi
J
Komoto
Izumi
I
Kawabe
Atsushi
A
Imamura
Masayuki
M
D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D019938:Cyclin D1 / Q000235:genetics / Q000378:metabolism; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D017931:DNA Primers / Q000737:chemistry; D004128:Dimethylnitrosamine / Q000031:analogs & derivatives* / Q000633:toxicity*; D015232:Dinoprostone / Q000378:metabolism; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D004938:Esophageal Neoplasms / Q000139:chemically induced* / Q000378:metabolism / Q000517:prevention & control; D006358:Hot Temperature; D015994:Incidence; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014867:Water / Q000009:adverse effects*
D002273:Carcinogens; D017931:DNA Primers; D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; D014867:Water; D019938:Cyclin D1; D002392:Catechin; C014707:nitrosobenzylmethylamine; C045651:epigallocatechin gallate; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; C496513:Ptgs1 protein, rat; D015232:Dinoprostone; D004128:Dimethylnitrosamine