Combination of quercetin and kaempferol enhances in vitro cytotoxicity on human colon cancer (HCT-116) cells
Sara Jaramillo, Sergio López, Rocı́o Abia, Rocío Rodríguez‐Arcos, Ana Jiménez‐Araujo, Rafael Guillén, Francisco J.G. Muriana · 2014
Colon cancer is one of the most common types of c ancer malignancy. Although flavonoids naturally occur as mixtures, little information is available regarding the additive or synergistic biochemical i nteractions between flavonoids. The objectives of this study we re to examine the feasibility of combining two majo r structurally related flavonoids, quercetin and kaem pferol, to affect the cell viability, cell cycle, a nd proliferation of the human colon cancer HCT-116 cell line. The co mbination of quercetin and kaempferol exhibited a g reater cytotoxic efficacy than did either quercetin or kae mpferol alone. This effect was highest and acted in a synergistic fashion in a 2-fold quercetin and 1-fol d kaempferol IC50 combination, which also arrested cell growth in the G2/M phase and suppressed proliferati on. Our observations support a structure-activity relationship based on the presence of 3'-OH moiety and/or 4'-OH moiety on the B-ring of flavonoids.