Synthesis and cytotoxicity evaluation of DNA-interactive β-carboline indolyl-3-glyoxamide derivatives: Topo-II inhibition and in silico modelling studies

Abstract

In a quest for effective cancer targeted drug therapy, a series of new β-carboline tethered indole-3-glyoxylamide derivatives, conjoining salient pharmacophoric properties with prominent cytotoxicity, were synthesized. The in vitro cytotoxic ability of the compounds was established, and many of the compounds exhibited remarkable cytotoxicity (IC50 < 10 μM) on human cancer cell lines like HCT116, A549, SK-MEL-28, and MCF7. Precisely, compound 12x expressed the best cytotoxic potential against melanoma cancer cell line (SK-MEL-28) with an IC50 value of 4.37 μM. In addition, cytotoxicity evaluation against normal kidney cell line (NRK52E) entrenched the cytospecificity and selectivity index of 12x. The traditional apoptosis assays advised morphological and nuclear alterations such as apoptotic body formation, condensed/horseshoe-shaped/fragmented nuclei, and generation of ROS. The flow cytometric analysis revealed significant early and slight late-stage induction of apoptosis. The target-based physiochemical assays indicated the ability of compound 12x to bind with DNA and inhibition of Topoisomerase II. Moreover, molecular modeling studies affirm the excellent DNA intercalation potential and stabilized interactions of 12x with DNA base pairs. In silico prediction of physicochemical parameters revealed the promising drug-like properties of the synthesized derivatives.