Selective detoxification of digesta revealed how cold-pressed apple fractions modulate transepithelial glucose
Ivan M Lopez-Rodulfo1, Martin K Rasmussen1, Bruce Hamaker2
1Centre for Innovative Food (CiFOOD), Department of Food Science, Aarhus University, Agro Food Park 48, Aarhus N 8200, Denmark.
Abstract:
This study examined whether whole apple and apple pomace modulate transepithelial glucose transport and GLP-1 secretion under physiologically relevant in vitro conditions, achieved via a laboratory-implementable solubilization and purification method that doubled polyphenol concentrations without inducing cytotoxicity. Samples collected at the end of the gastric and intestinal phases represented pre- and post-intestinal chyme. Purified digesta were incubated with Caco-2 monolayers, and UHPLC-ESI-QTOF-MS/MS analysis of 48 polyphenols across apical, intracellular, and basolateral compartments showed predominant apical retention. Apple and pomace inhibited glucose transport, primarily driven by dihydrochalcones and hydroxybenzoic acids (Spearman ρ > 0.70). Notably, although phloridzin alone inhibited GLP-1 secretion in mouse STC-1 L-cells, gastric digesta of both apple and pomace enhanced secretion by 50%. However, pomace digesta retained this effect after intestinal digestion, increasing GLP-1 by 179% and 62% compared to the glucose and intestinal blank controls, respectively. These findings suggest that pomace intake may attenuate postprandial glycemia and regulate appetite.
Related Concept Videos
Transcellular Transport of Solutes
Glucose Transporters
Facilitated diffusion-glucose transporters (GLUTs) are encoded by the solute-linked carrier (SLC) family 2, subfamily A gene family, or SLC2A. The 14 GLUT protein members are distributed into three classes:
Glucose Absorption Into the Small Intestine
Carbohydrate Absorption
After being swallowed, the partially digested carbohydrates mix with gastric secretions in the stomach. However, the acidic environment...
Oral Hypoglycemic Agents: α-Glucosidase Inhibitors
Acarbose and miglitol are...
Glucagon-like Receptor Agonists
GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by...


