Endogenously formed N-nitroso compounds: A new group of colon carcinogens relevant to man?

Pablo Steinberg, Hannover

For a number of years it has been postulated that the consumption of red meat leads to an enhanced risk of developing colon cancer. Sheila Bingham and her group in Cambridge, United Kingdom, showed for the first time that high concentrations of N-nitroso compounds are excreted in the faeces of humans consuming large amounts of red meat.

In the meantime, it has been demonstrated that haem is responsible for the enhanced formation of N-nitroso compounds in the gastrointestinal tract and that the main N-nitroso compounds formed after consuming red meat are S-nitrosothiols and nitrosyl haem. The endogenously formed N-nitroso compounds may contribute to the development of colon cancer in two ways. On the one hand, S-nitrosothiols and nitrosyl haem may act as NO donors and NO stimulates the proliferation and metastasis of tumour cells. On the other hand, N-nitroso compounds may lead to the formation of nitrosoglycine, which in turn can give rise to the highly reactive alkylating agent diazoacetate. Diazoacetate can lead to the modification of DNA bases and thus to the induction of mutations in DNA.

Keywords: N-nitroso compounds, colon cancer, prevention, meat consumption, colorectal tumours.

Sie finden den Artikel in deutscher Sprache in Ernährungs Umschau 06/09 ab Seite 332.