Fig. 1

The structure of butein and its effect on melanoma cells viability and cytotoxicity. The structure of butein is shown in a. B16F10 cells were seeded onto plates for 24 hr and starved for another 24 hr with serum-free DMEM. b Quiescent cells were cultivated with DMEM containing 10 % FBS in the absence or presence of various concentrations of butein. After 48 h, cell viability was detected by the MTT assay. c Cytotoxicity was detected by manufacture’s protocol and finally recorded absorbance at 490 nm. Control was taken as basal condition of LDH release. The results are presented as percentages of inhibition (mean ± SEM, n = 4). All P values were obtained from comparisons between control and indicated concentration-treated cells. **, P < 0.01; ***, P < 0.001