Detection of carcinogens as mutagens in the Salmonella/microsome test: assay of 300 chemicals.
Level 5 - mechanism / opinion, no new human data
Bench research / in vitro bacterial assay (no human data)
PubMed 1061098 · doi:10.1073/pnas.72.12.5135
What was done
About 300 chemicals comprising carcinogens and non-carcinogens of varied chemical types were tested for mutagenicity using the Salmonella/microsome assay. The assay utilizes bacteria as indicators for DNA damage and mammalian liver extracts for metabolic activation.
What was found
Mutagenic potency varied over a 10(6)-fold range across linear dose-response curves. Ninety percent (156/174) of carcinogens were mutagenic in the assay. The authors reported that few non-carcinogens showed mutagenicity, demonstrating a high correlation between carcinogenicity and mutagenicity.
Why it matters
This paper demonstrated that bacterial mutagenesis with metabolic activation can rapidly and accurately identify chemical carcinogens.
Limits
The study is an in vitro bacterial assay that cannot fully replicate in vivo human or animal pharmacokinetics and physiology. Ten percent (18/174) of carcinogens were not detected (false negatives), and exact counts or false-positive rates for non-carcinogens were not quantified in the abstract.
Cited by
- supports Bruce Ames developed the Ames test to identify chemical carcinogens.