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Bacterial mutagenicity of some tobacco aromatic nitrogen bases and their mixtures

S H Yim1, S S Hee

  • 1Department of Environmental Health Sciences and Center for Occupational and Environmental Health, School of Public Health, University of California, 10833 Le Conte Avenue, Los Angeles 90095-1772, USA.

Mutation Research
|May 30, 2001
PubMed

Insights

This study compared the genotoxicity of tobacco-specific nitrosamines (TSNA) NNK and NNN using bacterial assays. Other tobacco chemicals modulated TSNA mutagenicity, indicating complex interactions in genotoxicity testing.

Area of Science:

  • Toxicology
  • Genetics
  • Biochemistry

Background:

  • Tobacco-specific nitrosamines (TSNA) are potent carcinogens found in tobacco products.
  • Understanding the genotoxicity of TSNA and their interactions with other tobacco constituents is crucial for risk assessment.

Purpose of the Study:

  • To compare the genotoxicities of NNK and NNN using Salmonella reverse mutation and Mutatox assays.
  • To evaluate the effects of other tobacco chemicals and metabolites on TSNA mutagenicity.

Main Methods:

  • Utilized Salmonella strains (TA100, TA7004, TA7005, TA7006) and Vibrio fischeri (Mutatox test).
  • Assessed genotoxicity of NNK, NNN, nicotine (NIC), cotinine (COT), 3-hydroxycotinine (3HC), cotinine-N-oxide (CNO), and nicotine-N-oxide (NNO).
  • Investigated interactions between TSNA and other tobacco chemicals with and without metabolic activation (S9).

Main Results:

  • NNN was a direct mutagen in Salmonella TA100 and Mutatox tests.
  • NNK was mutagenic in Salmonella TA7004 with S9 and directly mutagenic in the Mutatox test.
  • COT, 3HC, and NNO showed direct mutagenicity in the Mutatox test.
  • Other tobacco chemicals modulated TSNA genotoxicity, exhibiting complex interactions in both assays.

Conclusions:

  • NNK and NNN exhibit distinct genotoxic profiles.
  • Non-mutagenic tobacco compounds can influence the genotoxicity of potent TSNA.
  • These findings highlight the importance of considering chemical interactions in tobacco genotoxicity assessment.

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