Figure 1.

Chemical structures and the 50% cytotoxic concentration (CC₅₀) values of bis-benzylisoquinoline alkaloids tetrandrine (TET), fangchinoline (FAN), and cepharanthine (CEP). (A) Chemical structures of TET, FAN, and CEP. (B) MRC-5 cells were cultured from 20 μM for four days. Cell viability was assessed using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay, and the cytotoxic concentration (CC₅₀) values of the compounds were calculated. Data are presented as mean ± SEM of three independent experiments.