title: Grape-seed procyanidins modulate cellular membrane potential and nutrient-induced GLP-1 secretion in STC-1 cells.
abstract: Grape-seed procyanidin extracts (GSPE) modulate glucose homeostasis, and it was suggested that GSPE may achieve this by enhancing the secretion of incretin hormones such as glucagon-like peptide-1 (GLP-1). Therefore, the aim of the present study is to examine in detail the effects of GSPE on intestinal endocrine cells (STC-1). GSPE was found to modulate plasma membrane potential in enteroendocrine cells, inducing depolarization at low concentrations (0.05 mg/l) and hyperpolarization at high concentrations (50 mg/l), and surprisingly this was also accompanied by suppressed GLP-1 secretion. Furthermore, how GSPE affects STC-1 cells under nutrient-stimulated conditions (i.e., glucose, linoleic acid, and l-proline) was also explored, and we found that the higher GSPE concentration was effective in limiting membrane depolarization and reducing GLP-1 secretion. Next, it was also examined whether GSPE affected mitochondrial membrane potential, and it was found that this too is altered by GSPE; however, this does not appear to explain the observed effects on plasma membrane potential and GLP-1 secretion. In conclusion, our results show that grape-seed procyanidins modulate cellular membrane potential and nutrient-induced enteroendocrine hormone secretion in STC-1 cells.
authors.affiliation: Departament de Bioquímica i Biotecnologia, Universitat Rovira i Virgili, Tarragona, Spain; and.
authors.forename: Noemi
authors.initials: N
authors.lastname: González-Abuín
authors.forename: Neus
authors.initials: N
authors.lastname: Martínez-Micaelo
authors.forename: Mayte
authors.initials: M
authors.lastname: Blay
authors.forename: Brian D
authors.initials: BD
authors.lastname: Green
authors.forename: Montserrat
authors.initials: M
authors.lastname: Pinent
authors.forename: Anna
authors.initials: A
authors.lastname: Ardévol
mesh_terms: D000818:Animals; D002460:Cell Line; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D019858:Enteroendocrine Cells / Q000187:drug effects* / Q000378:metabolism; D018565:Food-Drug Interactions; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D056604:Grape Seed Extract / Q000494:pharmacology*; D019787:Linoleic Acid / Q000378:metabolism*; D053078:Membrane Potential, Mitochondrial; D008564:Membrane Potentials; D051379:Mice; D044945:Proanthocyanidins / Q000494:pharmacology*; D011392:Proline / Q000378:metabolism*; D013997:Time Factors
chemical_list: D056604:Grape Seed Extract; C511402:Grape Seed Proanthocyanidins; D044945:Proanthocyanidins; D052216:Glucagon-Like Peptide 1; D011392:Proline; D019787:Linoleic Acid; D005947:Glucose
keywords: GLP-1; cellular membrane potential; enteroendocrine cell; grape-seed procyanidins