In the present study, we screened newly synthesized antiviral aminopyrazoloquinoline derivatives for their cytotoxic and genotoxic potential in human normal and breast cancer cell lines using apoptosis and DNA adducts biomarkers. The compounds, along with the well-known antiviral drug acyclovir, were incubated with the normal (MCF-10A, MCF-12A) and cancer (MCF-7, MDA-MB-231) cell lines at 10, 50, and 100 lM for 72 h at 37-C. The most potent antiviral methoxy derivative (compound 3) was found to be more cytotoxic in the normal breast epithelial cell lines (MCF-10A and MCF-12A) and MDA-MB-231 cell lines at 50 lM. MCF-7 cells were found to be almost completely resistant to all these compounds while MDA-MB-231 cell lines were significantly killed by apoptosis. Acyclovir was ineffective in all these cell lines. We further tested these compounds using modulation of benzo[a]pyrene (BP)-DNA adduct formation in these cell lines. An inverse correlation was found between the degree of apoptosis and BP-DNA adduct levels for most of these compounds, although this seems to be the case only with the cancer cell lines. Our results suggest that the newly synthesized antiviral compounds have an associated risk of cytotoxicity and/or genotoxicity compared to acyclovir.