Fig. 1. Luteolin elicits cytotoxic effects on human colon cancer cells by inducing apoptosis.

a HT-29, SNU-407, and FHC cells were treated with various concentrations of luteolin for 48 h, and their viability was assessed using the MTT assay. IC₅₀, defined as the concentration that inhibited cell growth by 50%, was determined. b Apoptotic body formation was observed using a fluorescence microscope after cells were stained with Hoechst 33342. Arrows indicate apoptotic bodies; *p < 0.05 compared with control cells. Cells were treated with c various concentrations of luteolin for 48 h or d 30 µM luteolin for various durations. Cell lysates were electrophoresed, and Bax, Bcl-2, active caspase-9, and active caspase-3 proteins were detected using specific antibodies