Genotoxicity of quercetin in the micronucleus assay in mouse bone marrow erythrocytes, human lymphocytes, V79 cell line and identification of kinetochore-containing (CREST staining) micronuclei in human lymphocytes.

Quercetin, a mutagenic flavonoid widely distributed in edible plants, was studied for the induction of micronuclei (MN). We have carried out the MN assay in bone marrow polychromatic erythrocytes in mice, in cytokinesis-blocked human lymphocytes and in cytokinesis-blocked V79 cells. MN assay in vitro was performed in the presence and in the absence of S9. To further extend the study, an antikinetochore antibody (CREST staining) was used to distinguish MN containing whole chromosomes (kinetochore positive) from those containing acentric fragments (kinetochore negative). When tested in vivo quercetin failed to induce micronuclei, a result which is in agreement with other published reports. When tested in vitro in V79 cells quercetin clearly induces micronuclei in the absence of S9 and also in the presence of S9 for the highest dose used. When tested in vitro in human lymphocytes quercetin shows a significant induction of micronuclei in the absence and in the presence of S9. The presence of S9 compared to its absence is not significant for any of the systems used. Both in the presence and absence of S9, quercetin appears to behave as a clastogenic agent in human lymphocytes inducing a significant majority of kinetochore-negative MN.