The EFSA Scientific Committee has provided draft guidance on the most appropriate in vivo tests to use in following up on positive in vitro results for aneugenicity (the induction of abnormal numbers of chromosomes). The in vivo bone marrow micronucleus (MN) test (with a relevant route of administration) is the preferred approach. Liver MN assays (although not fully validated) are suitable supporting tests for substances that are only aneugenic after metabolic activation. MN assays in the gastrointestinal tract have yet to be validated for the assessment of chemicals that are aneugenic at the initial site of contact (without metabolic activation). EFSA also concluded that, in principle, health-based guidance values (HBGVs) can be drafted for substances that are aneugenic but do not induce gene mutations or clastogenicity, provided that a comprehensive toxicological database is available. When data are lacking, and an HBGV cannot be derived, alternative approaches for risk assessment are proposed.

European Food Safety Authority (2020). Draft guidance on aneugenicity assessment. http://www.efsa.europa.eu/sites/default/files/consultation/consultation/Draft_guidance_on_aneugenicity_assessment.pdf

 

The above items were taken from the May 2020 issue of Toxicology and Regulatory News which is sent automatically to members of bibra.

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