Identification of new theobromine-based derivatives as potent VEGFR-2 inhibitors: design, semi-synthesis, biological evaluation, and in silico studies

This study aimed to design anticancer theobromine derivatives inhibiting VEGFR-2. The new compounds were tested in vitro to evaluate their effectiveness against MCF-7 and HepG2 cancer cell lines. Among these compounds, 15a showed the highest cytotoxicity against HepG2, with an IC(50) value of 0.76 μM, and significant anti-proliferative effects on MCF-7, with an IC(50) value of 1.08 μM. Notably, the selectivity index of 15a against the two cancer cells was 98.97 and 69.64, respectively. Moreover, 15a demonstrated potent VEGFR-2 inhibitory activity (IC(50) = 0.239 μM). Further investigations revealed that 15a induced apoptosis in HepG2 cells, significantly increasing early-stage and late-stage apoptosis percentages from 3.06% and 0.71% to 29.49% and 9.63%, respectively. It also upregulated caspase-3 and caspase-9 levels by 3.45-fold and 2.37-fold, respectively compared to control HepG2 cells. Additionally, 15a inhibited the migration and wound healing ability of HepG2 cells. Molecular docking confirmed the binding affinities of the semi-synthesized compounds to VEGFR-2, consistent with in vitro results. Several computational analyses (DFT, MD simulations, MM-GBSA, PLIP, and essential dynamics) supported the stability of the 15a-VEGFR-2 complex. Overall, the biological and computational findings suggest that compound 15a could be a promising lead compound for the development of a novel apoptotic anticancer agent.