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 cy tokinesis-blocked human lymphocytes and in cytokinesis-blocked V79 cel ls. MN assay in vitro was performed in the presence and in the absence of S9. To further extend the study, an antikinetochore antibody (CRES T staining) was used to distinguish MN containing whole chromosomes (k inetochore positive) from those containing acentric fragments (kinetoc hore negative). When tested in vivo quercetin failed to induce micronu clei, a result which is in agreement with other published reports. Whe n tested in vitro in V79 cells quercetin clearly induces micronuclei i n the absence of S9 and also in the presence of S9 for the highest dos e used. When tested in vitro in human lymphocytes quercetin shows a si gnificant induction of micronuclei in the absence and in the presence of S9. The presence of S9 compared to its absence is not significant f or any of the systems used. Both in the presence and absence of S9, qu ercetin appears to behave as a clastogenic agent in human lymphocytes inducing a significant majority of kinetochore-negative MN.