Design, synthesis, and cytotoxicity screening of 5-aryl-3-(2-(pyrrolyl) thiophenyl)-1, 2, 4-oxadiazoles as potential antitumor molecules on breast cancer MCF-7 cells.

The work representing the design and the cytotoxic screening of synthetic small molecules (SSMs) such as carbonitriles 3a-c, carboximidamides 4a-c, and oxadiazoles 5-19 as antitumor molecules. Molecules 4c, 9, 12, and 14 show promising cytotoxicity profiles against two cell lines higher than prodigiosin (PG). The results of topoisomerase enzyme inhibition assay show that compounds 4c and 14 display potent inhibitory activity in nano-molar concentration. In addition, DNA-flow cytometry and annexin V analysis also display that compounds 4c, 9, 12, and 14 exhibit antiproliferative activities over MCF-7 cells by cell cycle arrest at G phase and apoptosis-inducing activity by increasing cell percentages at pre G phase. Moreover, Elisa measurement of p53 and apoptosis mediators, show that carboximidamide 4c and oxadiazoles 9, 12, and 14 significantly up-regulate p53 and cell death mediators as puma and Bax/Bcl-2 ratio levels. Subsequently, pro-apoptotic activities are confirmed by active caspase 3/7 percentages green fluorescence assay.