Inhibitory effects of luteolin on MKN45 and SGC7901 cell migration and invasion. (a) Representative images showing MKN45 and SGC7901 cell migration and invasion. Cells were seeded in transwell plates, incubated with 0–20 μM luteolin for 24 h, and then fixed and stained with 0.1% crystal violet. (b) Cells (blue in color) on the lower surface were counted in triplicate, in three independent experiments, using a light microscope. (c) MMP9 expression evaluated by Western blotting. Data are presented as the mean ± SD. Original magnification, ×200.