Fig. 5

Solamargine inhibited p65 protein expression; exogenous expressed p65 reversed the solamargine-inhibited EP4 expression. a A549 and H1975 cells were treated with increased concentration of solamargine for 24 h. Afterwards, the expression of p65 protein was detected by Western blot. b A549 and H1975 cells were transfected with the control or expression constructs of SP1 for 24 h before exposing the cells to solamargine for an additional 24 h. Afterwards, SP1 and p65 protein expression were determined by Western blot. c-d A549 and H1975 cells were transfected with the control and p65 expression vectors for 24 h before exposing the cells to solamargine for an additional 24 h. Afterwards, the p65, SP1 and EP4 protein were determined using Western blot. GAPDH was used as internal control. Values in bar graphs were given as the mean ± SD from three independent experiments performed in triplicate. *Indicates significant difference as compared to the untreated control group (P < 0.05). **Indicates significant difference from the solamargine treated alone group (P < 0.01)