Figure 1. The chemical structure and cytotoxicity of isocryptotanshinone (ICTS). (A) The chemical structure of ICTS. (B) MCF-7, MDA-MB-231, HepG2, and A549 cells were treated with indicated concentrations (0-40 µM) of ICTS for 24 hours. Cell viabilities were measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. (C) After treatment with ICTS (0-20 µM) for 24 hours, morphological changes of MCF-7 cells were photographed. (D) MCF-7 cells were treated with indicated concentrations of ICTS for 24 hours. At a concentration of 20 µM, ICTS almost completely inhibited colony formation by MCF-7 cells.
