Activating Effects of Phenolics from Apache Red Zea mays L. on Free Fatty Acid Receptor 1 and Glucokinase Evaluated with a Dual Culture System with Epithelial, Pancreatic, and Liver Cells

Abstract

The aim was to characterize a phenolic-rich water extract from the pericarp of an improved genotype of Apache red maize (RPE) and evaluate its ability to activate the type 2 diabetes markers free fatty acid receptor 1 (GPR40) and glucokinase (GK) in vitro. The extract contained mainly phenolic acids, anthocyanins, and other flavonoids. RPE inhibited αamylase (IC 50 = 88.3 μg/mL), α-glucosidase (IC 50 = 169.3 μg/mL), and reduced glucose transport in a Caco-2 cell monolayer (up to 25%). Furthermore, RPE activated GPR40 (EC 50 = 77.7 μg/mL) in pancreatic INS-1E cells and GK (EC 50 = 43.4 μg/ mL) in liver HepG2 cells, potentially through allosteric modulation. RPE activated GPR40-related insulin secretory pathway and activated the glucose metabolism regulator AMPK (up to 78%). Our results support the hypothesis that foods with a high concentration of anthocyanins and phenolic acids, such as in the selected variety of maize used, could ameliorate obesity and type 2 diabetes comorbidities.

Lysophosphatidylcholine Containing Anisic Acid Is Able to Stimulate Insulin Secretion Targeting G Protein Coupled Receptors

“…The extract contained phenolic acids (caffeic acid, hydroxycinnamic acid, vanillic acid, gallic acid, and protocatechuic acid), anthocyanins (cyanidin, peonidin-3-glucosides, and pelargonidin), and other flavonoids (luteolin and kaempferol). According to molecular docking, all of the phenolic acids identified as constituents of the extract showed potential interaction with GPR40 [17].…”

review on upregulation of glucokinase expression by selected plants and their phytoconstituents

“…The major components of this extract are phenolic acids, anthocyanins, and some flavonoids. GCK, which has an EC50 of 43.4 g/mL and is activated by RPE in pancreatic INS-1E cells and liver HepG2 cells, which may be because of allosteric changes [De Mejia, E. G. et al,2019 ].…”

Spatial Distribution of Polyphenolic Compounds in Corn Grains (Zea mays L. var. Pioneer) Studied by Laser Confocal Microscopy and High-Resolution Mass Spectrometry

“…Confocal laser scanning microscopy was previously used to localize the phenolic compounds in different plants [ 22 ]. Morphological and biochemical changes in roots of corn Zea mays L. were previously studied by confocal microscopy [ 23 , 24 ]. To the best of the authors’ knowledge, no published studies report an application of confocal microscopy for the identification of phytochemicals in the grains of corn Zea mays L.…”