Topoisomerase II inhibitor 18 (Compound IV), a Quinoxaline derivative, exhibits an IC 50 of 7.5 μM in inhibiting topoisomerase II. It impedes PC-3 cell proliferation, arrests the cell cycle at the S phase, and induces apoptosis. Moreover, this compound demonstrates substantial antitumor activity against cancer [1].

Topoisomerase II:8.49 μM

Topoisomerase II inhibitor 18 (0-100 μM) inhibits the proliferation of cancer cells PC-3 and HepG2 with IC50 values of 2.11 μM and 11.03 μM, respectively, and exhibits low cytotoxicity towards normal Vero cells (IC50 = 23.12 μM) [1]. Western Blot analysis [1] conducted on the PC-3 cell line over a 48-hour incubation period at concentrations of 0-100 μM indicates an increase in p53, cleaved caspase-3, and cleaved caspase-8 levels, and a decrease in Bcl-2 levels. Similarly, proliferation assays [1] demonstrate inhibition of cell proliferation in both HepG2 and PC-3 cell lines, under the same concentration and incubation conditions.

Topoisomerase II inhibitor 18, administered at 5 mg/kg via intramuscular injection for 21 days, demonstrates antitumor activity and renal protective effects in an albino mice model with Ehrlich solid tumors [1].