CS1 is a potent DNA Topo II α inhibitor. CS1 exhibits broad-spectrum in vitro antitumor effects, low toxicity in vivo and potential anti-multidrug resistance capabilities. CS1 causes DNA damage, cell cycle arrest at G2/M phase, and apoptosis [1].

CS1 has cytotoxicity with IC 50 values of 16.92 and 18.88 μM for MCF-7 and MCF7/ADR cells, respectively [1]. CS1 (10, 50, 100 μM) inhibits the topoisomerase II α (Topo IIα) activity [1]. CS1 (0-20 μM) shows antiproliferation activity in cancer cells [1]. CS1 (2.5, 5, 10 μM) induces cell cycle arrest at the G2/M phase [1]. CS1 (2.5, 5, 10 μM) induces cell apoptosis [1]. CS1 (5, 10, 15 μM; 24 h) induces DNA breaks in MDA-MB-231 cells [1]. Cell Cycle Analysis [1] Cell Line: MDA-MB-231 cells Concentration: 2.5, 5, 10 μM Incubation Time: Result: Cells were arrest at the G2/M phase. Apoptosis Analysis [1] Cell Line: MDA-MB-231 cells Concentration: 2.5, 5, 10 μM Incubation Time: Result: Induced apoptosis

CS1, administered intravenously at a dosage of 20 mg/kg every other day for two weeks, demonstrated antitumor activity [1]. This was observed in an animal model using five-week-old female athymic nude mice (BALB/c-nu) [1].