Figure 4
Cytotoxic effect and induction of apoptosis by CuNPs towards U937 and Hela cells. (a) U937 and (b) Hela cells were treated with 100, 250 and 500 μM of CuNPs, and CuSO4 for 24 hours. Cell viability based on MTT assay is shown where viability for control untreated cells was considered as 100%. Data are presented as Mean ± SE. Phase contrast microscopic pictures of (c) U937 and (e) Hela cells untreated (top) or treated with 500 μM CuNPs (bottom). Fluorescence microscopic pictures of DAPI stained (d) U937 and (f) Hela cells untreated (top) and treated with 500 μM CuNPs (bottom). Arrows indicate fragmented nuclei. (g) U937 cells were treated for 24 hours with 250 μM CuNPs (lane 3) or a mixture of sodium borohydride and sodium citrate (lane 2) and inter nucleosomal DNA fragmentation was analyzed by electrophoresis on a 1.6% Tris-Borate-EDTA agarose gel. Lane 1 represents untreated U937 cells.