Many natural compounds have been shown to prevent cancer cell growth through the redox regulation of transcription factors. $NF-{kappa}B$, a redox transcription factor, has been implicated in the apoptotic cell death of several cancer cells. This study examined whether or nor 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyranone (DDMP) isolated from onions can modulate the activity of $NF-{kappa}B$, thereby induce the apoptotic cell death of colon cancer cells. Treatment with different DDMP concentrations (0.5-1.5 mg/mL) for various periods (0-48 h) inhibited the growth of colon cancer cells (SW620 and HCT116) followed by the induction of apoptosis in a dose dependent manner. It was also found that DDMP modulated tumor necrosis $factor-{alpha}(TNF-{alpha})$ and tetradeanoyl phorbol acetate (TPA)-induced $NF-{kappa}B$ transcriptional and DNA binding activity. Moreover, DDMP suppressed the $NF-{kappa}B$ target anti-apoptotic genes (Bcl-2), whereas it induced the expression of the apoptotic genes (Bax, cleaved caspase-3 and cleaved PARP). These results suggest that DDMP from onions inhibit colon cancer cell growth by inducing apoptotic cell death through the inhibition of $NF-{kappa}B$.