In vitro study of molecular structure and cytotoxicity effect of luteolin in the human colon carcinoma cells

Luteolin is an important flavonoid with a potential antitumor effect. This study investigates the structural properties of luteolin by using the Becke three-parameter hybrid exchange functional and Lee-Yang-Parr correction functional methods. The structure-activity relationship is used to describe the antioxidant pharmacophore of luteolin by employing quantum chemical calculations and density functional theory method. The free radical scavenging activities of luteolin are evaluated in vitro with the use of 2,2-diphenyl-1-picrylhydrazyl assay. Luteolin decreases the cell proliferation rate in HCT-15 cells in terms of concentration and time-dependent response. Luteolin significantly promotes cell cycle arrest at the G2/M phase in HCT-15 cells and induces apoptosis in HCT-15 cells, as confirmed by flow cytometric analysis.