Fig. 3

The effect of WSPM on A549 cell viability. The abscissa represents the exposure time of WSPM to A549 cells, while the ordinate represents the cell viability inhibition rate (%). A549 cells were treated by different concentrations (0, 12.5, 25, 100 and 200 µg/ml) of WSPM10 (A) and WSPM2.5 (B) for 6, 24, 48 and 72 h, and cell viability was determined by MTT. The optical density value (OD) of samples were measured at 550 nm. The cell viability inhibition rate = (1 - [OD of infected cells - background value] / [OD of control - background value]) × 100 %. The values shown on top of the bars represent the average of three individual experiments, and the standard errors are shown

* WSPM with different concentrations was compared with the control group (0 µg/ml) at the same exposure time, P < 0.01