Abstract A47: Drinking water with red beetroot food dye antagonizes esophageal carcinogenesis in NMBA-treated rats

A47

This study was undertaken to determine if the oral consumption of red beetroot dye would result in an inhibition of N-nitrosomethylbenzylamine (NMBA)-induced tumors in the rat esophagus. Rats were treated with NMBA and given either regular water ad libitum or water containing 78 µg/ml of commercial red beetroot dye, E162. The number of NMBA-induced esophageal papillomas was reduced by 45% (p<0.001) in animals that received the dye when compared to controls. Dye treatment also resulted in reduced rates of cell proliferation in both precancerous esophageal lesions and in papillomas of NMBA-treated rats, as measured by immunohistochemical staining of Ki-67 in esophageal tissue specimens. The effects of beetroot dye on angiogenesis (microvessel density by CD34 immunostaining), inflammation (by CD45 immunostaining), and apoptosis (by TUNEL staining) in esophageal tissue specimens were also determined. When compared to rats treated with NMBA only, the levels of angiogenesis and inflammation in the beetroot dye-consuming animals was reduced and the apoptotic rate was increased. Thus, the mechanism(s) of chemoprevention by the active constituents of red beetroot dye include reducing cell proliferation, angiogenesis and inflammation, and stimulating apoptosis. Importantly, consumption of the dye in the drinking water for a period of 35 weeks did not appear to induce any overt toxicity. Based on the fact that red beetroot dye contains betacyanins, which have strong anti-oxidant activity, it is postulated that these effects are mediated through inhibition of oxygen radical-induced signal transduction.

Citation Information: Cancer Prev Res 2008;1(7 Suppl):A47.