Design synthesis and cytotoxicity studies of some novel indomethacin-based heterocycles as anticancer and apoptosis inducing agents

•Novel indomethacin-based heterocycles were synthesized and evaluated for their anticancer activity against a panel of five cancer cell lines.•All the designed and synthesized analogues showed significant cytotoxic activity against all the tested cell lines, compared with the reference drugs indomethacin and 5-fluorouracil.•Moreover, they showed high selectivity toward cancer cells over normal human fibroblast cells WI-38, indicating their safety profile.•The effect of the most potent compound on normal cell cycle profile and apoptotic potential confirmation were performed to explore and emphasize the possible mechanism underlying their anticancer effect. Indomethacin is a well-known nonsteroidal anti-inflammatory drug that has cytotoxic activity. In this study, a new series of structurally related indomethacin analogues was synthesized using simple chemical approaches, and their cytotoxic effects against five different human cancer cell lines (colon cancer cell lines HCT-116, HT-29 and Caco-2, hepatic cell line HepG-2 and breast cell line MCF-7) were evaluated. Most of the tested compounds displayed potent anti-cancer activity, especially against the three colon cancer cell lines. Among all tested derivatives, compound 12 demonstrated the most potent cytotoxic activity compared to the parent drug indomethacin and the reference compound 5-fluorouracil, with IC50 values ranging 0.83–1.54 µM. A mechanistic study of the most active compound against the HCT-116, HT-29 and Caco-2 cell lines revealed cell cycle arrest during the G2/M phase. Compound 12 was found to induce apoptosis through the up-regulation of Bax and p53 by 7.4 and 8.5-fold, respectively, and also the downregulation of Bcl-2 by 3.2-fold compared to the control. Western blot assay was performed on HCT-116 cells and demonstrated marked inhibition of CDK1 and Bcl-2 expression together with an increase in the expression of caspase-3, Bax and p53 in a concentration-dependent manner. Finally, a prediction of the chemo-informatic properties of compounds 11 and 12 indicated that they are orally bioavailable with no permeation of the blood-brain barrier.