Anthocyanins are potent
antioxidants and may be chemoprotective. However, the structure-function relationships are not well understood. The objectives of this study were to compare the chemoprotective properties of
anthocyanin-rich extracts (AREs) with variable
anthocyanin profiles to understand the relationship between
anthocyanin chemical structure and chemoprotective activity, measured as inhibition of
colon cancer cell proliferation. Additionally, the chemoprotective interaction of
anthocyanins and other phenolics was investigated. AREs with different
anthocyanin profiles from purple corn, chokeberry, bilberry, purple carrot, grape, radish, and elderberry were tested for growth inhibition (GI 50) using a human colorectal
adenocarcinoma (HT29) cell line. All AREs suppressed HT29 cell growth to various degrees as follows: purple corn (GI 50 approximately 14 microg of cy-3-glu equiv/mL) > chokeberry and bilberry > purple carrot and grape > radish and elderberry (GI 50 > 100 microg of cy-3-glu equiv/mL).
Anthocyanins played a major role in AREs' chemoprotection and exerted an additive interaction with the other phenolics present. Statistical analyses suggested that
anthocyanin chemical structure affected chemoprotection, with nonacylated monoglycosylated
anthocyanins having greater inhibitory effect on HT-29 cell proliferation, whereas
anthocyanins with
pelargonidin, triglycoside, and/or acylation with
cinnamic acid exerted the least effect. These findings should be considered for crop selection and the development of
anthocyanin-rich functional foods.