Fig. 7

Normalized dose–response curve for in vitro cytotoxicity of 17A and 21A. Human cell lines were cultured in the presence of 17A and 21A. Cytotoxicity of the compounds was evaluated using the CCK-8 kit. Per cent cell death was measured by measuring absorbance at OD 450 nm. a HepG2 cells treated with 17A, b HepG2 cells treated with 21A, c HeLa cells treated with 17A, and d HeLa cells treated with 21A. The mean OD 450 nm and the standard error of the mean (SEM) of triplicate wells and is shown. Each graph is representative of three independent experiments