Differential inhibition of human colon cancer cells by structurally similar flavonoids of citrus

► Structurally distinct flavonoids commonly found in citrus are subjected for proliferation inhibition. ► Inhibition of human colon cancer cell proliferation by different citrus flavonoids. ► Key structural requirement for induction of cytotoxicity to colon cancer cells. ► First report on influence of apigenin and quercetagetin on transcription and protein expression