Inhibitory effect of 7,8-benzoflavone on DMBA- and BaP-induced bone marrow micronuclei in mouse

Frequencies of micronucleated polychromatic erythrocytes (PCE) were analyzed in bone-marrow cells of mice injected with 7,12-dimethylbenza]anthracene (DMBA), benzoa]pyrene (BaP), 7,8-benzoflavone (-naphthoflavone) and the combination of either 7,8-benzoflavone and DMBA or 7,8-benzoflavone and BaP. 7,8-Benzoflavone was injected 48 and 24 h before injecting mice either with DMBA or BaP. Bone-marrow samples were collected at 24, 48, 72 and 96 h. The observed maximum mean number of micronucleated PCE per 500 PCE was 8.6 at 48 h with DMBA and 11.6 at 72 h with BaP. 7,8-Benzoflavone reduced the number of micronucleated PCE in the above treatments with DMBA by 90% and in the case of BaP by 75%. In other words, 7,8-benzoflavone acted as a potent inhibitor in preventing chromosomal breaks caused by DMBA or BaP.