Silver nanoparticles (Ag-NPs) with antimicrobial activity are by far the most commercialized
nano-compound. However, there is limited information about antitumor potential. Therefore,
the present study was aimed to observe the effect of small-dimensional Ag-NPs (20 Nm) on
human epithelial colorectal adeno-carcinoma (Caco-2) cells. Caco-2 cells were exposed to Ag-
NPs with different concentrations (1–15 μg/mL) for 24 and 48 hrs. and cytotoxicity was
analyzed by MTT assay and IC50 was calculated. In addition, flow cytometry was used to
determine the effect of Ag-NPs on the cell cycle progression and on apoptosis. An MTT assay
revealed that following exposure to Ag-NPs the viability of Caco-2 cells decreased, and the
viability decreased further with increasing exposure time. The IC50 was 7.85 μg/ml and
4.92 μg/ml at 24 and 48 hrs. respectively after exposure. The flow cytometry technique revealed
that Ag-NPs induced a significant increase in the percentage of cells in G1 phase of the cell
cycle and of apoptotic cells. In conclusion, Ag-NPs exhibited dose- and time-dependent
cytotoxicity, and these results have signposted that Ag-NPs were promising nanoparticles which
could be a potential candidate in treating colorectal cancer.