Poster Topical Area: Dietary Bioactive Components
Location: Hall D
Poster Board Number: 327
Objective: The objective was to evaluate the ability of anthocyanins in colored corn to interact and activate the free fatty acid receptor-1 (FFAR1) and glucokinase (GK) in pancreatic cells and hepatocytes, respectively. Our hypothesis was that pure anthocyanins, and anthocyanin-rich extracts from colored corn would interact with FFAR1 and GK to increase insulin secretion in INS-1E pancreatic cells, and glucose uptake in HepG2 hepatic cells.
Methods: Using a dual-layer cell culture with Caco-2 cells plus INS-1E or Caco-2 cells plus HepG2, cells were treated with an anthocyanin-rich extract from the pericarp of purple corn (PCW) and red corn (RCW), as well as pure anthocyanins cyanidin-3-O-glucoside (C3G), peonidin-3-O-glucoside, pelargonidin-3-O-glucoside. Also, the semipurified C3G (C3Gp) and condensed forms (CFp) isolated from purple corn were used in the study. An indirect biochemical assay quantified the intermediate second messenger inositol monophosphate, and through ELISA. Glucose uptake was determined by remnant glucose quantification. Through a biochemical assay, the formation of NADPH determined activation of GK.
Results: At a concentration of 100 µM, the pure and semipurified anthocyanins enhanced the glucose-stimulated insulin secretion (GSIS) in INS-1E cells ranging from 18% to 40% higher than untreated cells (p < 0.05). PCW and RCW increased the GSIS by 51% and 40%, respectively. When the anthocyanins and extracts were combined with the FFAR1 specific inhibitor GW-1100, their efficacy was reduced by up to 20%, suggesting that FFAR1 activation is playing a role in the enhanced GSIS. It was determined that C3G was the most effective anthocyanin activating FFAR1 (EC50: 245.4 µM). Both, PCW and RCW had a comparable activating potential on FFAR1 (EC50: 77 µg/mL). Regarding hepatic HepG2 cells, the treatment with 100 µM of P3G, C3Gp and CFp increased (p < 0.05) the glucose uptake by 19%, 31% and 18%, respectively. PCW and RCW increased the glucose uptake in HepG2 cells by 48% and 37%, respectively. It was determined that CF-P was the most effective anthocyanin activating GK activity (EC50: 39.9 µM) and the extracts had similar efficacy (EC50: 44 µg/mL).
Conclusion: Results suggest that anthocyanins from purple corn interact with novel biomarkers FFAR1 and GK to ameliorate type-2 diabetes comorbidities.
Funding Source: USDA National Institute of Food and Agriculture Hatch 1014457.
University of Illinois at Urbana-Champaign