Analysis of the potential carcinogenicity of coffee and its related compounds in a medium-term liver bioassay of rats

摘要: The potential carcinogenicity of coffee and related compounds was examined using a medium-term liver bioassay based on the induction glutathione S-transferase placental form (GST-P)-positive foci in F344 rats. A total 230 males were initially injected with diethylnitrosamine (200 mg/kg body weight, ip) or saline as controls 2 wk later fed diet drinking water supplemented follows for 6 wk: 5% regular instant coffee; decaffeinated freshly brewed coffee, 8 g 140 ml water; 0.1% caffeine, 0.2% methylglyoxal, glyoxal; 0.3% theophylline (w/v); 0.4% theobromine (w/w). All rats subjected to two-thirds partial hepatectomy at 3 killed 8. resultant values GST-P-positive hepatic focus slightly increased methylglyoxal decreased glyoxal compared corresponding controls. Although increase number statistically significant P < 0.05, value within historical control levels. Regular well fresh-brewed caffeine exerted no effects development. Thus, coffee-related demonstrated obvious enhancing potential, it is therefore concluded that its main constituents are not carcinogenic rat liver.