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Inhibition of nitrosation
H Bartsch1, B Pignatelli, S Calmels
1Unit of Environmental Carcinogens and Host Factors, International Agency for Research on Cancer, Lyon, France.
Basic Life Sciences
|January 1, 1993
Summary
N-nitroso compounds (NOC) can form in the body and environment. Inhibitors like vitamins C and E, found in fruits and vegetables, can block NOC formation, potentially preventing cancer.
Area of Science:
- Biochemistry
- Toxicology
- Cancer Prevention
Background:
- Humans encounter N-nitroso compounds (NOC) environmentally and through endogenous nitrosation.
- Activated immune cells and bacteria can produce nitrosating agents and NOC at neutral pH.
- Endogenous nitrosation occurs in various body sites, including the oral cavity, stomach, and urinary bladder.
Purpose of the Study:
- To review the chemistry of NOC formation and inhibition.
- To summarize animal studies on the effects of inhibiting endogenous NOC synthesis.
- To discuss recent human studies quantifying NOC synthesis inhibition and its role in cancer prevention.
Main Methods:
- Review of chemical mechanisms of NOC formation and inhibition.
- Analysis of experimental animal studies on NOC synthesis inhibition.
- Examination of human studies measuring endogenous NOC synthesis inhibition.
Main Results:
- Numerous inhibitors, including vitamins C and E and plant extracts, are identified.
- Inhibitors act by destroying nitrosating agents or competing for amino substrates.
- Epidemiological data link fruit and vegetable consumption (rich in inhibitors) to reduced cancer risk, especially gastric cancer.
Conclusions:
- Inhibition of endogenous NOC synthesis reduces toxic, mutagenic, and carcinogenic effects.
- Nitrosation inhibitors may contribute to cancer prevention in humans.
- Further research is warranted on the role of dietary inhibitors in human cancer prevention.