Comparison of the effect of chemical composition of anthocyanin-rich plant extracts on colon cancer cell proliferation and their potential mechanism of action using in vitro, in silico, and biochemical assays

•Plant extracts induced apoptosis and arrested colon cancer cells in G1 phase.•Black lentil, sorghum, red grape had the highest inhibition on colon cancer cells.•Phenolic concentration strongly correlated with HT-29 and HCT 116 inhibition.•Delphinidin-3-O-glucoside concentration strongly correlated with HT-29 inhibition.•Cyanidin-3-O-glucoside was the most potent on tyrosine kinase inhibition.

The objective was to compare the anti-proliferative effect of anthocyanin-rich plant extracts on human colon cancer cells and determine their mechanism of action. Eleven extracts were tested: red (RG) and purple grape, purple sweet potato, purple carrot, black and purple bean, black lentil (BL), black peanut, sorghum (SH), black rice, and blue wheat. HCT-116 and HT-29 inhibition correlated with total phenolics (r = 0.87 and 0.77, respectively), delphinidin-3-O-glucoside concentration with HT-29 inhibition (r = 0.69). The concentration inhibition fifty (IC50) for BL, SH, RG on HT-29 and HCT-116 cell proliferation ranged 0.9-2.0 mg/mL. Extracts decreased expression of anti-apoptotic proteins (survivin, cIAP-2, XIAP), induced apoptosis, and arrested cells in G1. Anthocyanins exhibited tyrosine kinase inhibitory potential in silico and biochemically; cyanidin-3-O-glucoside had one of the highest binding affinities with all kinases, especially ABL1 (−8.5 kcal/mol). Cyanidin-3-O-glucoside and delphinidin-3-O-glucoside inhibited EGFR (IC50 = 0.10 and 2.37 µM, respectively). Cyanidin-3-O-glucoside was the most potent anthocyanin on kinase inhibition.