Statistical Evaluation of In Vivo and In Vitro Micronucleus Assays in Toxicology

Abstract

Several alternative statistical procedures have been suggested and published to statistically analyze the incidence of micronucleated polychromatic erythrocytes (MNPCs) among treatment groups, but no standard procedure has been singled out and exclusively recommended. In this project, Hothorn and Gerhard (2008, 2009) recommendations for the statistical evaluation of in vivo and in vitro micronucleus (MN) assays were implemented. The genotoxic activity of two candidate chemicals, T01 and T02, were assessed in the rodent bone marrow micronucleus test using male mice. Results show that oral administration of T01 for a day was found not to increase significantly the frequency of micronucleated polychromatic erythrocytes (MNPCEs) in any of the test compound dose groups when compared to their concurrent vehicle control group (demineralised water). An increase in MN frequencies was noted only in the positive control group indicating the validity of the assay. On the other hand, MN frequenci