Black bean peptides inhibit glucose uptake in Caco-2 adenocarcinoma cells by blocking the expression and translocation pathway of glucose transporters

摘要

class="kwd-title">Chemical compounds studied in this article: Phloretin: PubChem CID: 4788, Glucose: PubChem CID: 10954115, 2-NBDG PubChem CID: 6711157 class="kwd-title">Abbreviations: A, alanine; AMPK, 5′ adenosine monophosphate-activated protein kinase; AU, arbitrary units; BPI, bean protein isolate; E, glutamic acid; F, phenylalanine; GLUT2, glucose transporter 2; L, leucine; I:K, lysine; N, asparagine; 2-NBDG, 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose; P, proline; P FRA, protein fractions; PHL, phloretin; PKC, protein kinase C II; SD, standard deviation; SGLT1, sodium-dependent glucose cotransporter 1; S, serine; T, threonine; V, valine; WZB117, 3-fluoro-1,2-phenylene bis (3-hydroxybenzoate) class="kwd-title">Keywords: Black bean protein fraction, Colorectal cancer, Glucose uptake, GLUT2, SGLT1 class="head no_bottom_margin" id="abs0015title">AbstractThe objective was to evaluate the effect of black bean protein fraction (PFRA), and its derived peptides on glucose uptake, SGLT1 and GLUT2 expression and translocation on Caco-2 cells. The effect of treatments was evaluated on glucose uptake, protein expression and localization and gene expression on Caco-2 cells. PFRA (10 mg/mL) lowered glucose uptake from 27.4% after 30 min to 33.9% after 180 min of treatment compared to untreated control (p < 0.05). All treatments lowered GLUT2 expression after 30 min of treatment compared to untreated control (31.4 to 48.6%, p < 0.05). Similarly, after 24 h of treatment, GLUT2 was decreased in all treatments (23.5% to 48.9%) (p < 0.05). SGLT1 protein expression decreased 18.3% for LSVSVL (100 μM) to 45.1% for PFRA (10 mg/mL) after 24 h. Immunofluorescence microscopy showed a decrease in expression and membrane translocation of GLUT2 and SGLT1 for all treatments compared to untreated control (p < 0.05). Relative gene expression of SLC2A2 (GLUT2) and SLC5A1 (SGLT1) was downregulated significantly up to two-fold change compared to the untreated control after 24 h treatment. Black bean protein fractions are an inexpensive, functional ingredient with significant biological potential to reduce glucose uptake and could be used as an adjuvant in the treatment of colorectal cancer.