Discovery of new VEGFR-2 inhibitors based on bis([1, 2, 4]triazolo)[4,3- a :3',4'- c ]quinoxaline derivatives as anticancer agents and apoptosis inducers.

Herein, a new wave of bis([1, 2, 4]triazolo)[4,3- a :3',4'- c ]quinoxaline derivatives have been successfully designed and synthesised. The synthesised derivatives were biologically investigated for their cytotoxic activities against HepG2 and MCF-7. Also, the tested compounds were further examined in vitro for their VEGFR-2 inhibitory activity. The most promising derivative 23j was further investigated for its apoptotic behaviour in HepG2 cell lines using flow cytometric and western-plot analyses. Additional in-silico studies were performed to predict how the synthesised compounds can bind to VEGFR-2 and to determine the drug-likeness profiling of these derivatives. The results revealed that compounds 23a , 23i , 23j , 23l , and 23n displayed the highest antiproliferative activities against the two cell lines with IC ₅₀ values ranging from 6.4 to 19.4 µM. Furthermore, compounds 23a , 23d , 23h , 23i , 23j , 23l , 23 m , and 23n showed the highest VEGFR-2 inhibitory activities with IC ₅₀ values ranging from 3.7 to 11.8 nM, comparing to sorafenib (IC ₅₀ = 3.12 nM). Moreover, compound 23j arrested the HepG2 cell growth at the G2/M phase and induced apoptosis by 40.12% compared to the control cells (7.07%). As well, such compound showed a significant increase in the level of caspase-3 (1.36-fold), caspase-9 (2.80-fold), and BAX (1.65-fold), and exhibited a significant decrease in Bcl-2 level (2.63-fold).